1
|
ALRabeeah D, Almomen A, Alzoman N, Arafah M. Evaluating the bioequivalence of levetiracetam brand and generic oral tablets available in the Saudi market in vivo. Saudi Pharm J 2023; 31:101758. [PMID: 37753207 PMCID: PMC10518482 DOI: 10.1016/j.jsps.2023.101758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/20/2023] [Indexed: 09/28/2023] Open
Abstract
Background Epilepsy is a common global neurological disorder. About 30% of epileptic patients are managed with anti-epileptic Drugs (AEDs). Since 2000, Levetiracetam (LEV) has been marketed around the world as an AED under the brand name Keppra, and recently more generics are found in the Saudi market as cheaper alternatives. The objective of this study is to evaluate the bioequivalence of LEV brand and generics available in the Saudi market in mice. Methods Pharmacokinetics (PK), liver function test, and behavioral studies were conducted for LEV brand and generic in different groups of Blab/c mice. Results PK results show a significance difference in PK parameters mostly evidenced with generic 3, then generic 2. The only significant different between Keppra and generic 1 was in T1/2. In addition, Keppra did not significantly increase liver enzymes in comparison to other generics. On the other hand, other generics showed less favorable results in increasing liver enzymes. Keppra reduced the number and intensity of epileptic attacks, had no mortality rate due to epilepsy, and was associated with less sever seizures attacks. Conclusion Keppra, the brand form of LEV, has better safety and efficacy profiles in mice compared to 3 generics found in the Saudi market. Therefore, we recommend evaluating the same parameters tested in this study in patients utilizing similar generics and brand to establish the existence of bioequivalence between LEV brand and generics.
Collapse
Affiliation(s)
- Danah ALRabeeah
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11495, Saudi Arabia
| | - Aliyah Almomen
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11495, Saudi Arabia
| | - Nourah Alzoman
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11495, Saudi Arabia
| | - Maria Arafah
- Department of Pathology, College of Medicine, King Saud University, Riyadh 11495, Saudi Arabia
| |
Collapse
|
2
|
Meijboom RW, Gardarsdottir H, Becker ML, Movig KLL, Kuijvenhoven J, Egberts TCG, Giezen TJ. Discontinuation of infliximab treatment in patients with inflammatory bowel disease who retransitioned to originator and those who remained on biosimilar. Therap Adv Gastroenterol 2023; 16:17562848231197923. [PMID: 37706094 PMCID: PMC10496466 DOI: 10.1177/17562848231197923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 08/12/2023] [Indexed: 09/15/2023] Open
Abstract
Background Many patients with inflammatory bowel disease (IBD) have transitioned from an infliximab originator to a biosimilar. However, some patients retransition to the originator (i.e. stop biosimilar and reinitiate the originator). Whether this sign of potential unsatisfactory treatment response is specifically related to the infliximab biosimilar or the patient and/or the disease including patients' beliefs on the biosimilar is unclear. Objectives We aimed to compare the risk of and reasons for infliximab discontinuation between retransitioned patients and those remaining on biosimilar. Design Non-interventional, multicentre cohort study. Methods IBD patients who transitioned from infliximab originator to biosimilar between January 2015 and September 2019 in two Dutch hospitals were eligible for this study. Retransitioned patients (retransitioning cohort) were matched with patients remaining on biosimilar (biosimilar remainder cohort). Reasons for discontinuation were categorised as the unwanted response (i.e. loss of effect or adverse events) or remission. Risk of unwanted discontinuation was compared using Cox proportional hazards models. Results Patients in the retransitioning cohort (n = 44) were younger (median age 39.9 versus 44.0 years), more often female (65.9% versus 48.9%) and had shorter dosing intervals (median 48.5 versus 56.0 days) than in the biosimilar remainder cohort (n = 127). Infliximab discontinuation due to unwanted response was 22.7% in the retransitioning and 13.4% in the biosimilar remainder cohort, and due to remission was 2.3% and 9.4%, respectively. Retransitioned patients are at increased risk of discontinuing due to unwanted response compared with biosimilar remainder patients (adjusted HR 3.7, 95% CI: 1.0-13.9). Patients who retransitioned due to an increase in objective disease markers had higher discontinuation rates than patients who retransitioned due to symptoms only (66.7% versus 23.7%). Conclusion Retransitioned patients are at increased risk of infliximab discontinuation due to unwanted response. Retransitioning appeared related to the patient and/or disease and not the product. Clinicians might switch patients opting for retransitioning to other treatment regimens.
Collapse
Affiliation(s)
- Rosanne W. Meijboom
- Pharmacy Foundation of Haarlem Hospitals, Haarlem, the Netherlands
- Division of Pharmacoepidemiology & Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
| | - Helga Gardarsdottir
- Division of Pharmacoepidemiology & Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
- Department of Clinical Pharmacy, University Medical Center Utrecht, Utrecht, the Netherlands
- Department of Pharmaceutical Sciences, University of Iceland, Reykjavik, Iceland
| | - Matthijs L. Becker
- Pharmacy Foundation of Haarlem Hospitals, Haarlem, the Netherlands
- Department of Clinical Pharmacy, Spaarne Gasthuis, Haarlem, the Netherlands
| | - Kris L. L. Movig
- Department of Clinical Pharmacy, Medisch Spectrum Twente, Enschede, the Netherlands
| | - Johan Kuijvenhoven
- Department of Gastroenterology and Hepatology, Spaarne Gasthuis, Haarlem, the Netherlands
| | - Toine C. G. Egberts
- Division of Pharmacoepidemiology & Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
- Department of Clinical Pharmacy, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Thijs J. Giezen
- Pharmacy Foundation of Haarlem Hospitals, Boerhaavelaan 24, Haarlem 2035 RC, the Netherlands
- Division of Pharmacoepidemiology & Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
- Department of Clinical Pharmacy, Spaarne Gasthuis, Haarlem, the Netherlands
| |
Collapse
|
3
|
Fang L, Li Z, Kinjo M, Lomonaco S, Zheng N, Jiang W, Zhao L. Generic lamotrigine extended-release tablets are bioequivalent to innovator drug in fully replicated crossover bioequivalence study. Epilepsia 2023; 64:152-161. [PMID: 36259141 DOI: 10.1111/epi.17438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 01/25/2023]
Abstract
OBJECTIVE Lamotrigine is a commonly prescribed antiepileptic drug. U.S. Food and Drug Administration (FDA)-funded clinical studies have demonstrated bioequivalence (BE) for generic lamotrigine immediate-release (IR) products in epilepsy patients with generic substitution. To address the potential concerns about the risk of generic-brand substitution of lamotrigine extended-release (ER) products, considering the complexity of controlled release systems and pharmacokinetic variations associated with possible within-subject variability (WSV), this prospective study assessed (1) BE of generic and brand lamotrigine ER products in a fully replicated BE study design in healthy subjects and (2) whether such fully replicated study design and WSV data can better support the approval of generic lamotrigine ER products. METHODS This open-label, single-dose, two-treatment, four-period, two-sequence, fully replicated crossover BE study compared generic lamotrigine ER tablet to brand Lamictal XR (200 mg) in 30 healthy subjects under fed conditions. Pharmacokinetics (PK) profiles were generated based on intensive blood sampling up to 144 h. RESULTS The two products showed comparable peak plasma concentration (Cmax ), area under the concentration-time curve (AUC) from time zero to the last measurable time point (AUC0-t ) and AUC extrapolated to infinity (AUC0-inf ), whereas median time to Cmax (Tmax ) values differed, that is, 10 h for generic and 22 h for brand products, respectively. WSVs for PK metrics were small (~8% of Cmax and ~6% of AUC) and similar between these two products. PK simulation predicted equivalent PK measurements of both products at steady state and after brand-to-generic switch, except the first day upon switching. No serious adverse events were reported. SIGNIFICANCE The generic lamotrigine ER tablet product demonstrates BE to the brand product in a fully replicated BE study design with healthy subjects, supporting the adequacy of the two-way crossover study design to demonstrate BE and generic-brand substitution of lamotrigine ER products.
Collapse
Affiliation(s)
- Lanyan Fang
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Zhichuan Li
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Minori Kinjo
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Sara Lomonaco
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Nan Zheng
- Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Wenlei Jiang
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Liang Zhao
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| |
Collapse
|
4
|
Weitzel J, Langer K, Rose O. Effects of Generic Exchange of Levodopa Medication in Patients With Parkinson Disease. J Patient Saf 2022; 18:704-710. [PMID: 35532994 DOI: 10.1097/pts.0000000000001015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Generic exchange is common practice in most healthcare systems. This study investigated how patients with Parkinson disease (PD) perceived a switch of their levodopa medication and the resulting effects on their PD symptoms. METHODS A questionnaire was developed, piloted, and finally distributed to 13,857 members of the national PD patient support group. It was designed to be completed by patients and their pharmacies. χ 2 tests for independence statistics with or without Monte Carlo simulation were performed. Cramér φ and Cramér V were calculated. McNemar test was used to investigate whether a generic switch of a levodopa-containing medication had an impact on PD symptoms. RESULTS Analyses were done with 410 finalized respondents of 13,857 distributed questionnaires. More than half of the responders were 75 years or older and rated themselves Hoehn and Yahr stages 3 to 5. Most patients were confused by a change of their medication. A total of 54.7% of the switchers (n = 148) reported swallowing difficulties with medication, which was significantly more frequent than with nonswitchers (37.3% of 204, P = 0.001). Adverse effects related to the switch were reported by 26.6% of all switchers (switchback rate, 20.5%). The patients at higher Hoehn and Yahr stages were affected to a greater extend. CONCLUSIONS Patients, who experienced any brand switch of their levodopa medication, frequently expressed distrust and confusion. Swallowing difficulties and negative effects on their symptoms were problems, which were more pronounced in advanced disease stages. It remains unclear whether the detrimental impact on therapy was caused by the brand switch or by a nocebo effect.
Collapse
Affiliation(s)
- Johanna Weitzel
- From the Department of Pharmaceutical Technology and Biopharmacy, Westfälische Wilhelms-University Muenster
| | - Klaus Langer
- From the Department of Pharmaceutical Technology and Biopharmacy, Westfälische Wilhelms-University Muenster
| | | |
Collapse
|
5
|
Niyongere J, Welty TE, Bell MW, Consalvo D, Hammond C, Leung H, Patsalos PN, Ryan M, Suansanae T, Zhou D, Zuellig H. Barriers to Generic Antiseizure Medication Use: Results of a Global Survey by the International League Against Epilepsy Generic Substitution Task Force. Epilepsia Open 2022; 7:260-270. [PMID: 35124903 PMCID: PMC9159248 DOI: 10.1002/epi4.12583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/02/2022] [Accepted: 02/03/2022] [Indexed: 11/20/2022] Open
Abstract
The objective of this study was to identify and quantify barriers to generic substitution of antiseizure medications (ASM). A questionnaire on generic ASM substitution was developed by the International League Against Epilepsy (ILAE) Task Force on Generic Substitution. Questions addressed understanding of bioequivalence, standards for generic products, experiences with substitution, and demographic data. The survey was web‐based and distributed to ILAE chapters, their membership, and professional colleagues of task force members. Comparisons in responses were between ILAE regions and country income classification. A total of 800 individuals responded, with 44.2% being from the Asia‐Oceania ILAE Region and 38.6% from European Region. The majority of respondents had little or no education in generic substitution or bioequivalence. Many respondents indicated lack of understanding aspects of generic substitution. Common barriers to generic substitution included limited access, poor or inconsistent quality, too expensive, or lack of regulatory control. Increase in seizures was the most common reported adverse outcome of substitution. Of medications on the World Health Organization Essential Medication list, problems with generic products were most frequent with carbamazepine, lamotrigine, and valproic acid. Several barriers with generic substitution of ASM revolved around mistrust of regulatory control and quality of generic ASM. Lack of education on generic substitution is also a concern. Generic ASM products may be the only option in some parts of the world and efforts should address these issues. Efforts to address these barriers should improve access to medications in all parts of the world.
Collapse
Affiliation(s)
- Jenna Niyongere
- MercyOne Des Moines, Doctor of Pharmacy student, College of Pharmacy and Health Sciences at Drake University, Iowa, USA
| | - Timothy E Welty
- College of Pharmacy and Health Sciences, Drake University Des Moines, Iowa, USA
| | - Michelle W Bell
- Columbia University Irving Medical Center, Columbia University, New York City, New York, USA
| | - Damian Consalvo
- Epilepsy Section, Ramos Mejía Hospital, University of Buenos Aires, Institute of Neurology and Neurosurgery, Sanatorio de Los Arcos, Buenos Aires, Argentina
| | - Charles Hammond
- Komfo Anokye Teaching Hospital, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Howan Leung
- The Chinese University of Hong Kong, Hong Kong, China
| | - Philip N Patsalos
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, England
| | - Melody Ryan
- College of Pharmacy, University of Kentucky, Lexington, Kentucky, USA
| | - Thanarat Suansanae
- Department of Pharmacy, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand
| | - Dong Zhou
- Sichuan University, Chengdu, Sichuan, China, Department of Neurosciences, College of Medicine, San Beda University, College of Public Health, University of the Philippines Manila, Manila, Philippines
| | - Hazel Zuellig
- Sichuan University, Chengdu, Sichuan, China, Department of Neurosciences, College of Medicine, San Beda University, College of Public Health, University of the Philippines Manila, Manila, Philippines
| |
Collapse
|
6
|
Olsson P, Freij J, Compagno Strandberg M, Adelöw C, Östlund H, Lindberger M, Källén K. Physicians' attitudes toward generic substitutions of antiseizure drugs in epilepsy. Acta Neurol Scand 2021; 144:600-607. [PMID: 34273105 DOI: 10.1111/ane.13504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/29/2021] [Accepted: 07/06/2021] [Indexed: 01/19/2023]
Abstract
OBJECTIVES The safety of generic substitution of antiseizure drugs (ASDs) has been questioned for many years. This study aimed to identify physicians' attitudes to the generic substitution of ASDs in epilepsy and which factors were of significance when deciding on compound substitutions. MATERIAL AND METHODS A cross-sectional web-based survey was sent to neurologists and neurology residents in public health care and at private practices in two Swedish regions between February and March 2020. The 30-item survey covered drug- and patient-related factors, as well as considerations relating to practical, cost-related, and pharmacokinetic issues. RESULTS The total response rate was 55.8%. Respondents were generally positive to cutting costs through generic ASD utilization (74%) and prescribing generic compounds when starting a new ASD treatment (84.9%). The most substantial concern was a deterioration in seizure control (17.1%). Physicians refrained from switching if the patient wished to remain on the original compound (76.1%), had a cognitive impairment (52.5%), was on a drug with a narrow therapeutic index (47%), or had shown prior susceptibility to adverse effects (45.6%). Opinions on substitution decisions differed significantly between the Stockholm and Skåne regions. Less than one-third of the respondents were aware of supporting guidelines. CONCLUSIONS Neurologists generally accept the use of generic antiseizure compounds. Patient preference to remain on brand-name drug treatment was the most important factor that led to avoiding a switch. Our results may constitute material for consensus discussions to decide on quality indicators of interest for future research on substitution outcomes.
Collapse
Affiliation(s)
- Patrik Olsson
- Department of Emergency Medicine Helsingborg General Hospital Helsingborg Sweden
- Division of Clinical Sciences Helsingborg Department of Clinical Sciences Lund Faculty of Medicine Lund University Lund Sweden
| | - Julia Freij
- Department of Specialized Medicine – Neurology Helsingborg General Hospital Helsingborg Sweden
| | - Maria Compagno Strandberg
- Department of Neurology, Rehabilitation Medicine, Memory Disorders and Geriatrics Skåne University Hospital Lund Sweden
- Division of Neurology Department of Clinical Neurosciences Faculty of Medicine Lund University Lund Sweden
| | - Cecilia Adelöw
- Vällingby Neuro Vällingby Medical Centre Stockholm Sweden
| | - Hampus Östlund
- Department of Neurology Danderyd Hospital Stockholm Sweden
| | | | - Kristina Källén
- Division of Clinical Sciences Helsingborg Department of Clinical Sciences Lund Faculty of Medicine Lund University Lund Sweden
- Department of Specialized Medicine – Neurology Helsingborg General Hospital Helsingborg Sweden
- Department of Neurology, Rehabilitation Medicine, Memory Disorders and Geriatrics Skåne University Hospital Lund Sweden
- Division of Neurology Department of Clinical Neurosciences Faculty of Medicine Lund University Lund Sweden
| |
Collapse
|
7
|
Network Theory and Switching Behaviors: A User Guide for Analyzing Electronic Records Databases. FUTURE INTERNET 2021. [DOI: 10.3390/fi13090228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
As part of studies that employ health electronic records databases, this paper advocates the employment of graph theory for investigating drug-switching behaviors. Unlike the shared approach in this field (comparing groups that have switched with control groups), network theory can provide information about actual switching behavior patterns. After a brief and simple introduction to fundamental concepts of network theory, here we present (i) a Python script to obtain an adjacency matrix from a records database and (ii) an illustrative example of the application of network theory basic concepts to investigate drug-switching behaviors. Further potentialities of network theory (weighted matrices and the use of clustering algorithms), along with the generalization of these methods to other kinds of switching behaviors beyond drug switching, are discussed.
Collapse
|
8
|
Why Were More Than 200 Subjects Required to Demonstrate the Bioequivalence of a New Formulation of Levothyroxine with an Old One? Clin Pharmacokinet 2021; 59:1-5. [PMID: 31432471 PMCID: PMC6994420 DOI: 10.1007/s40262-019-00812-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
At the request of French Regulatory Authorities, a new formulation of Levothyrox® was licensed in France in 2017, with the objective of avoiding the stability deficiencies of an existing licensed formulation. Before launching the new formulation, an average bioequivalence (ABE) trial was conducted, having enrolled 204 subjects and selected for interpretation a narrow a priori bioequivalence range of 0.90-1.11. Bioequivalence was concluded. In a previous publication, we questioned the ability of an ABE trial to guarantee the switchability within patients of the new and old levothyroxine formulations. It was suggested that the two formulations should be compared using the conceptual framework of individual bioequivalence. The present paper is a response to those claiming that, despite the fact that ABE analysis does not formally address the switchability of the two formulations, future patients will nevertheless be fully protected. The basis for this claim is that the ABE study was established in a large trial and analyzed using a stringent a priori acceptance interval of equivalence. These claims are questionable, because the use of a very large number of subjects nullifies the implicit precautionary intention of the European guideline when, for a Narrow Therapeutic Index drug, it recommends shortening the a priori acceptance interval from 0.80-1.25 to 0.90-1.11.
Collapse
|
9
|
Giometto S, Baglietto L, Conte M, Vannacci A, Tuccori M, Mugelli A, Gini R, Lucenteforte E. Use of antiseizure medications and safety of branded versus generic formulations: A comparative study on Tuscan administrative databases. Epilepsy Behav 2021; 117:107876. [PMID: 33714929 DOI: 10.1016/j.yebeh.2021.107876] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/14/2021] [Accepted: 02/18/2021] [Indexed: 11/19/2022]
Abstract
PURPOSE To assess patterns of use of antiseizure medications (ASMs) and to compare the safety of generic versus branded formulations in terms of admission to hospital or to emergency department (ED). METHODS We conducted a drug utilization study with a propensity score-matched design using the administrative databases of the Italian Tuscany region. New users of ASMs during 2015 with no history of neoplasia were considered and their first prescription was classified as: available only as branded (only-B-ASM); branded with generic available (B-ASM); and generic (G-ASM). Patients with G-ASM first prescription were matched with four patients with B-ASM prescription. Participants were followed up for one year or until the date of death or diagnosis of neoplasia. Cox regression models were fitted to estimate the risk of admission to hospital or ED. RESULTS We identified 36,601 ASM new-users, including 2094 (6.4%) with only-B-ASM as first prescription, 24,588 (74.9%) with B-ASM, and 5788 (17.6%) with G-ASM. We found no differences in the risk of admission to hospital or ED (Hazard Ratio (HR), 0.92; 95% Confidence Interval (CI), 0.85-1.02) among users of generic ASMs compared to those using branded ASMs. CONCLUSIONS In our study population, generic ASMs were used less than branded ones. The similarity in the safety of branded and generic formulations suggests that generic ASMs could be the preferred formulation in current clinical practice resulting in a substantial decrease in the cost of treatment.
Collapse
Affiliation(s)
- Sabrina Giometto
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy.
| | - Laura Baglietto
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy.
| | - Marco Conte
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy
| | - Alfredo Vannacci
- Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy.
| | - Marco Tuccori
- Unit of Pharmacology and Pharmacovigilance, Department of Clinical and Experimental Medicine, University Hospital of Pisa, Pisa, Italy
| | - Alessandro Mugelli
- Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy.
| | - Rosa Gini
- Agenzia regionale di sanità della Toscana, Florence, Italy.
| | - Ersilia Lucenteforte
- Department of Clinical and Experimental Medicine, University of Pisa, 56126 Pisa, Italy.
| |
Collapse
|
10
|
Lang JD, Kostev K, Reindl C, Mueller TM, Stritzelberger J, Gollwitzer S, Westermayer V, Trollmann R, Hamer HM. Manufacturer switch of anti-seizure drugs may not increase the risk of seizure recurrence in Children: A nationwide study of prescription data in Germany. Epilepsy Behav 2021; 115:107705. [PMID: 33444987 DOI: 10.1016/j.yebeh.2020.107705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/09/2020] [Accepted: 12/12/2020] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Several publications on the exchangeability of antiepileptic drugs in clinical settings revealed an increased risk for seizure recurrence after changing the manufacturer of anti-seizure drugs (ASD) in adults, possibly due to a decline of adherence. It is unclear whether this holds true in children and adolescents. METHODS Patient data of children and adolescents (<18 years) were collected anonymously from 236 German pediatricians and pediatric neurologists between January 2011 and December 2018 using the IMS® Disease Analyzer database (IQVIA, Frankfurt, Germany). Patients with epilepsy were included if at least 2 prescriptions within 360 days and 1 within 180 days prior to the index date were available. The cohort was separated into a seizure group and seizure-free controls. Both groups were matched 1:1 according to age, gender, insurance status, and treating pediatrician. The risk for seizure recurrence after a manufacturer switch of the same ASD at the last prescription before the index date was analyzed using a multivariate regression model. RESULTS A total of 678 children and adolescents with epilepsy were included (each group: n = 339; age: 9.6 ± 4.4 years). Comparing both groups, the risk for seizures recurrence was not increased after a manufacturer switch had occurred. Albeit changes during the last prescription before the index date had occurred more often in the seizure-free group, neither change of branded and generic products nor substances reached significance. Only change of ASD strength showed a significantly reduced odds ratio for seizures (OR 0.40, 95% CI 0.24-0.65, p < 0.001). SIGNIFICANCE In contrast to the available evidence in adults, changing the manufacturer did not appear to increase the risk for seizure recurrence in previously seizure-free children and adolescents with epilepsy.
Collapse
Affiliation(s)
- Johannes D Lang
- Department of Neurology, Epilepsy Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Karel Kostev
- IQVIA, Epidemiology, Frankfurt am Main, Main Airport Center, Unterschweinstiege 2-14, 60549 Frankfurt am Main, Germany
| | - Caroline Reindl
- Department of Neurology, Epilepsy Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Germany
| | - Tamara M Mueller
- Department of Neurology, Epilepsy Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Germany
| | - Jenny Stritzelberger
- Department of Neurology, Epilepsy Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Germany
| | - Stephanie Gollwitzer
- Department of Neurology, Epilepsy Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Germany
| | - Vivien Westermayer
- Department of Neurology, Epilepsy Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Germany
| | - Regina Trollmann
- Department of Pediatrics, Division of Pediatric Neurology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Loschgestraße 15, 91054 Erlangen, Germany
| | - Hajo M Hamer
- Department of Neurology, Epilepsy Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Germany
| |
Collapse
|
11
|
Odi R, Franco V, Perucca E, Bialer M. Bioequivalence and switchability of generic antiseizure medications (ASMs): A re-appraisal based on analysis of generic ASM products approved in Europe. Epilepsia 2021; 62:285-302. [PMID: 33426641 DOI: 10.1111/epi.16802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/07/2020] [Accepted: 12/10/2020] [Indexed: 10/22/2022]
Abstract
The safety of switching between generic products of antiseizure medications (ASMs) continues to be a hot topic in epilepsy management. The main reason for concern relates to the uncertainty on whether, and when, two generics found to be bioequivalent to the same brand (reference) product are bioequivalent to each other, and the risk of a switch between generics resulting in clinically significant changes in plasma ASM concentrations. This article addresses these concerns by discussing the distinction between bioequivalence and statistical testing for significant difference, the importance of intra-subject variability in interpreting bioequivalence studies, the stricter regulatory bioequivalence requirements applicable to narrow-therapeutic-index (NTI) drugs, and the extent by which currently available generic products of ASMs comply with such criteria. Data for 117 oral generic products of second-generation ASMs approved in Europe by the centralized, mutual recognition or decentralized procedure were analyzed based on a review of publicly accessible regulatory assessment reports. The analysis showed that for 99% of generic products assessed (after exclusion of gabapentin products), the 90% confidence intervals (90% CIs) of geometric mean ratios (test/reference) for AUC (area under the drug concentration vs time curve) were narrow and wholly contained within the acceptance interval (90%-111%) applied to NTI drugs. Intra-subject variability for AUC was <10% for 53 (88%) of the 60 products for which this measure was reported. Many gabapentin generics showed broader, 90% CIs for bioequivalence estimates, and greater intra-subject variability, compared with generics of other ASMs. When interpreted within the context of other available data, these results suggest that any risk of non-bioequivalence between these individual generic products is small, and that switches across these products are not likely to result in clinically relevant changes in plasma drug exposure. The potential for variability in exposure when switching across generics is likely to be greatest for gabapentin.
Collapse
Affiliation(s)
- Reem Odi
- Faculty of Medicine, Institute of Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Valentina Franco
- Division of Clinical and Experimental Pharmacology, Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy.,IRCCS Mondino Foundation (member of the ERN EpiCARE), Pavia, Italy
| | - Emilio Perucca
- Division of Clinical and Experimental Pharmacology, Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy.,IRCCS Mondino Foundation (member of the ERN EpiCARE), Pavia, Italy
| | - Meir Bialer
- Faculty of Medicine, Institute of Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel.,Affiliated with the David R. Bloom Center for Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
12
|
Olsson P, Pearson K, Reimers A, Källén K. Widespread skeptic attitudes among people with epilepsy toward generic antiseizure drugs - A Swedish survey study. Epilepsy Behav 2021; 114:107554. [PMID: 33303376 DOI: 10.1016/j.yebeh.2020.107554] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 11/18/2022]
Abstract
PURPOSE To explore associations between the characteristics of people with epilepsy (PWE) and their attitudes toward generic substitution of antiseizure drugs (ASDs) in epilepsy. METHODS This was a cross-sectional survey study directed at adults with epilepsy using selected brand drugs: Keppra®, Lamictal®, Lyrica® or Topimax®. Symptoms of anxiety and depression, sense of self-efficacy, and beliefs about medicines were assessed. Caregivers were asked to answer for persons with intellectual or communicative difficulties. RESULTS The total response rate was 41% (n = 178). Almost half (46%) of subjects stated that they would oppose generic substitution (Gen-NEG) if suggested by their neurologist, while 71% would worry about adverse effects and/or increased seizure frequency after a putative switch. Age ≥50 increased the odds of being Gen-NEG (adjusted OR: 2.20, 95% CI: 1.18-4.11). Negative associations with both Gen-NEG and worriers were found for education level of high-school diploma or above, employment/studies, and prior experience of generic ASD switch. The proportion of worriers was much higher among caregivers (21/22) compared to subjects with epilepsy (106/156). CONCLUSION High proportions of PWE express concerns regarding generic substitution of ASDs. The elderly and caregivers seem to express particular concerns. Identifying ways to diminish negative outcomes and worries in connection with a switch is an important future field of research in order to ensure high quality, cost-effective health care for the most vulnerable people in our societies.
Collapse
Affiliation(s)
- Patrik Olsson
- Dept. of Emergency Medicine, Helsingborg General Hospital, Helsingborg, Sweden; Dept. of Clinical Sciences Lund, Clinical Sciences Helsingborg, Lund University, Lund, Sweden.
| | - Kevin Pearson
- Dept. of Clinical Sciences Lund, Clinical Sciences Helsingborg, Lund University, Lund, Sweden.
| | - Arne Reimers
- Dept. of Clinical Chemistry and Pharmacology, Division of Laboratory Medicine, Lund, Sweden.
| | - Kristina Källén
- Dept. of Clinical Sciences Lund, Clinical Sciences Helsingborg, Lund University, Lund, Sweden; Dept. of Specialized Medicine, Helsingborg General Hospital, Helsingborg, Sweden; Dept. of Neurology, Rehabilitation Medicine, Memory Disorders and Geriatrics, Skåne University Hospital, Lund, Sweden.
| |
Collapse
|
13
|
Hamada Y, Uchida M, Arai S, Yamazaki K, Takeda M, Arai K, Nakamura T, Suzuki T, Ishii I. Analysis of patients’ request to switch from a generic drug to the original drug in external prescriptions. J Pharm Health Care Sci 2020; 6:27. [PMID: 33292744 PMCID: PMC7716439 DOI: 10.1186/s40780-020-00180-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 10/26/2020] [Indexed: 12/04/2022] Open
Abstract
Background Generic drugs are heavily promoted in Japan. The aim of this retrospective single-center study was to clarify whether the frequency and reason that patients request a switch from a generic drug to the original drug differ according to therapeutic category and dosage form. Methods This study was performed at Chiba University Hospital. Prescription inquiries about 121 generic drugs from community pharmacies over a 3-year period (from July 2014 to June 2017) were analyzed. Results Approximately 30% of the requests were related to the efficacy, safety, and comfort of the generic drug. The most cited motive was “patient’s desire with no reason given” at 44.5%. According to multiple logistic regression analysis, therapeutic categories and dosage forms were associated with the requests. The median request frequency differed according to therapeutic category and dosage form. The frequency was highest for “agents affecting the central nervous system” and “tablets and capsules”, respectively. Among the therapeutic categories, “agents affecting the central nervous system” had the highest median number of requests related to “decreased effectiveness”; “cardiovascular agents” had the highest median number of requests related to “physician’s instruction”; and “agents for the epidermis” had the highest median number of requests related to “uncomfortable to use”. Among dosage forms, the odds ratio for patients’ original drug request for “liniment and patch” was about 1.5 times that for “tablets and capsules”. “Liniment and patch” had the highest median frequency of requests related to “decreased effectiveness”, “uncomfortable to use”, and “patient’s desire with no reason given”. Conclusions The request frequency and reason differed according to therapeutic category and dosage form. Pharmacists should advise each patient properly about the choice and switching of drug brands, taking into account the therapeutic category and dosage form, especially liniments and patches.
Collapse
|
14
|
Effects of generic exchange of solid oral dosage forms in neurological disorders: a systematic review. Int J Clin Pharm 2020; 42:393-417. [PMID: 32274633 DOI: 10.1007/s11096-020-01023-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 03/30/2020] [Indexed: 10/24/2022]
Abstract
Background Generic drug exchange is common practice in most healthcare systems. While generics certainly contribute to economic savings, the altered drug formulation might be associated with potential therapeutic problems. Given the narrow therapeutic windows in neurologic indications, any detrimental effect on the therapy can lead to significant consequences. Aim of the review This review aims to investigate potential problems related to a switch from brand-name to generic or from generic to generic drug products in patients with neurologic diseases. Method The review was conducted following the PICO framework and the PRISMA guidelines. MEDLINE and Scopus databases were searched for articles published in English and German language between January 1, 1995 and October 17, 2018. Studies included in this review were randomized controlled studies, reviews, systematic reviews, overviews, cohort studies and case-control studies. Studies excluded were letters, comments, authors view, congress or seminar papers and studies with a focus on economic impact or costs. Results were synthesized qualitatively. The primary outcomes were pharmacokinetic parameters such as the area under the curve (AUC), the peak serum concentration (cmax) or the time at which cmax is observed (tmax). Results The search identified 67 studies with a great variety of endpoints and study designs. The leading indication was epilepsy. Two small RCTs were found on lamotrigine switch. Analysis of the other studies found no significant differences in pharmacokinetic parameters when switching to generic drugs. A more heterogeneous picture was revealed regarding hospitalizations, breakthrough seizures, failure of therapy, adherence and patient concerns. Conclusion While most reports were of poor quality, lamotrigine was the drug with the best available data. Summarizing the results of the available studies, pharmacokinetic parameters of antiepileptic drugs show low deviation. In contrast, data on clinical parameters are less consistent. Some studies found increased seizure frequencies and adverse-drug events, while others showed no complications. Adherence and patient satisfaction seemed to be impaired. In daily practice, generic exchange in epilepsy should be a carefully balanced decision, conducted with great caution. Further research is needed, especially regarding neurologic indications other than epilepsy.
Collapse
|
15
|
Das S, Jiang X, Jiang W, Ting TY, Polli JE. Relationship of antiepileptic drugs to generic brittleness in patients with epilepsy. Epilepsy Behav 2020; 105:106936. [PMID: 32092462 DOI: 10.1016/j.yebeh.2020.106936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 01/08/2020] [Accepted: 01/17/2020] [Indexed: 10/25/2022]
Abstract
PURPOSE The purpose of the study was to assess if any antiepileptic drug (AED) was associated with patients being generic brittle (GB) and if any specific AED caused - and was not merely associated with - more frequent switch problems. METHODS Chi square and binary logistical regression analysis were performed, using a previously described study in patients with epilepsy who were routinely followed at the University of Maryland epilepsy outpatient clinic in Baltimore, Maryland. Determination of generic brittleness mirrored clinical practice and included patient opinion about generic formulations, usually based on a history of worsened seizures or side effects with prior AED formulation switching. The dataset included a total of 148 patients, who took 30 different AED formulations. Patients collectively took 530 AED formulation products. RESULTS Taking lamotrigine immediate release (IR) tablets was associated with a greater probability of being GB and tended to cause more frequent switch problems. Interestingly, six AEDs - Vimpat tablet, carbamazepine IR tablet, phenobarbital (any formulation), gabapentin capsule, Lyrica capsules, and phenytoin (any formulation) - were associated with a reduced probability of being GB, although perhaps not through greater efficacy and tolerability, or better formulation quality. Since tablet and capsule appearance may influence patient perceptions and clinical outcomes, it was observed that the six AEDs less associated with being GB also tended to have fewer generics, and hence possibly lessen treatment uncertainties from the patient perspective. A patient taking more AEDs had significantly increased odds of having a switch problem. An additional observation was that, when a generic was available for their most problematic AED, GB patients took a generic AED only 50% of the time, while not GB patients took a generic AED all the time. CONCLUSIONS Taking lamotrigine IR tablets was associated with a greater probability of being GB and tended to cause more frequent switch problems than other AEDs in this cohort of patients. Six AEDs were associated with a reduced probability of being GB. The lower number of different generics for these six drugs may result in greater patient certainty in medication identity, due to greater consistency in medication color, shape, and size, and hence less generic skepticism or generic brittleness. Also, patients taking more AEDs showed increased odds of a switch problem.
Collapse
Affiliation(s)
- Sharmila Das
- University of Maryland, Department of Pharmaceutical Sciences, 20 Penn Street, Baltimore, MD 21201, USA
| | - Xiaohui Jiang
- Food and Drug Administration, Center for Drug Evaluation, Office of Generic Drugs, Office of Research and Standards, 10903 New Hampshire Avenue, White Oak, MD 20993, USA
| | - Wenlei Jiang
- Food and Drug Administration, Center for Drug Evaluation, Office of Generic Drugs, Office of Research and Standards, 10903 New Hampshire Avenue, White Oak, MD 20993, USA
| | - Tricia Y Ting
- University of Maryland, Department of Neurology, 22 South Greene Street, Baltimore, MD 21201, USA; Georgetown University, 3800 Reservoir Road NW, Washington, D.C. 20007, USA
| | - James E Polli
- University of Maryland, Department of Pharmaceutical Sciences, 20 Penn Street, Baltimore, MD 21201, USA.
| |
Collapse
|
16
|
Xu ZY, Guo HL, Li L, Zhang M, Jing X, Xu ZJ, Qiu JC, Lu XP, Ding XS, Chen F, Xu J. Genetic and Non-genetic Factors Contributing to the Significant Variation in the Plasma Trough Concentration-to-Dose Ratio of Valproic Acid in Children With Epilepsy. Front Pediatr 2020; 8:599044. [PMID: 33553069 PMCID: PMC7855978 DOI: 10.3389/fped.2020.599044] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/07/2020] [Indexed: 12/12/2022] Open
Abstract
Objective: This study was conducted to evaluate the potential genetic and non-genetic factors contributing to plasma trough concentration-to-dose (C 0/D) ratio of valproic acid (VPA) in pediatric patients with epilepsy. Study Design: A single-center, retrospective cohort study was performed by collecting data from 194 children aged 1-14 years between May 2018 and November 2018. The oral solution (n = 135) group and the sustained-release (SR) tablet group (n = 59) were defined, and the plasma VPA C 0 was measured. Twenty-six single-nucleotide polymorphisms (SNPs) were chosen for genotyping with the MassARRAY system. A multiple logistic regression model was used for data analysis. Results: Body weight (BW) and age were positively correlated with the C 0/D ratio in 194 patients, but the positive correlation disappeared after the patients were divided into oral solution and SR tablet subgroups. The average C 0/D ratio was significantly increased by 2.11-fold (P = 0.000) in children who took VPA SR tablets compared with children who were administered VPA oral solutions. No significant association between genetic variants and the C 0/D ratio was found, even for the five well-studied SNPs, namely UGT2B7 G211T, C802T, C161T, T125C, and CYP2C9 * 3 A1075C. However, a significant association between the C 0/D ratio and UGT1A6/9 Del>A (rs144486213) was observed in the VPA oral solution group, but not in the VPA SR tablet group. Conclusions: The dosage forms of sodium valproate, rather than BW, age, or genetic polymorphisms, significantly affected the VPA C 0/D ratios in pediatric patients with epilepsy. Based on our findings, switching the dosage form between solution and SR tablet should be performed cautiously. Total daily dose adjustment should be considered, and the plasma concentration, seizure-control effect, and adverse drug reaction should also be monitored very closely.
Collapse
Affiliation(s)
- Ze-Yue Xu
- Department of Pharmacy, Children's Hospital of Nanjing Medical University, Nanjing, China.,School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Hong-Li Guo
- Department of Pharmacy, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Ling Li
- Department of Pharmacy, Children's Hospital of Nanjing Medical University, Nanjing, China.,School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Min Zhang
- Department of Pharmacy, Boston Medical Center, Boston, MA, United States
| | - Xia Jing
- Department of Pharmacy, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Ze-Jun Xu
- Department of Pharmacy, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Jin-Chun Qiu
- Department of Pharmacy, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Xiao-Peng Lu
- Department of Neurology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Xuan-Sheng Ding
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Feng Chen
- Department of Pharmacy, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Jing Xu
- Department of Pharmacy, Children's Hospital of Nanjing Medical University, Nanjing, China
| |
Collapse
|
17
|
Abstract
PURPOSE OF REVIEW This article reviews the management of patients with medically responsive epilepsy, including discussion of factors that may lead to transient breakthrough seizures and patient and physician strategies to maintain freedom from seizures. RECENT FINDINGS Imperfect adherence, unanticipated changes in ongoing medical therapy, inadvertent use of proconvulsants or concurrent medications that alter epilepsy medication kinetics, and a variety of seizure precipitants such as stress or sleep deprivation may alter long-term seizure control. SUMMARY The majority of patients with epilepsy are medically responsive. Many potential factors may lead to breakthrough seizures in these patients. Identification of these factors, patient education, and use of self-management techniques including mindfulness therapy and cognitive-behavioral therapy may play a role in protecting patients with epilepsy against breakthrough seizures.
Collapse
|
18
|
Olsson P, Reimers A, Källén K. Quality of life after switching to generic levetiracetam - A prospective comparative study. Epilepsy Behav 2019; 96:169-174. [PMID: 31150996 DOI: 10.1016/j.yebeh.2019.04.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 04/15/2019] [Accepted: 04/15/2019] [Indexed: 11/29/2022]
Abstract
BACKGROUND Improved quality of life (QoL) is one of the most important objectives in the treatment of epilepsy. Recent prospective, clinical studies proved no significant differences between brand antiepileptic drugs (AEDs) and their generic equivalents in terms of seizure control, pharmacokinetics, or safety. In this study, we focused on possible changes in QoL and adverse events in connection with generic substitution of levetiracetam (LEV). METHODS This was a prospective, naturalistic, two-cohort, twin-center study. After a baseline period of 10 weeks, outpatients with epilepsy on stable treatment with Keppra® either continued on this brand (reference group, n = 16) or switched to generic LEV (1A Pharma®) (study group, n = 16) for an eight-week study period. The Quality of Life in Epilepsy Inventory-31 (QOLIE-31) and an adverse events' questionnaire were administered at inclusion, after baseline, and at the end of the study period. The study protocol included a close clinical follow-up with repeated LEV serum concentration measurements and nurse-led outpatient visits. RESULTS Clinically relevant improvements in overall QOLIE-31 scores according to minimally important change (MIC) estimates were seen in both groups. QOLIE-31 subscales in both groups showed significantly less worry about seizures at the end of the study compared to scores at inclusion (study group: p = 0.01; reference group: p = 0.02). No significant deterioration in QoL or adverse events were observed following generic substitution. No switchbacks occurred. CONCLUSIONS We found reduced seizure worries over time among people with epilepsy allocated to either generic switch or continued treatment with brand LEV. We hypothesize that the nurse-led structured follow-up had an impact on seizure worries and switchback rates because of reduced nocebo effects. Further studies on generic AED substitution, focusing on psychological outcome measures, are warranted to test this supposition.
Collapse
Affiliation(s)
- Patrik Olsson
- Helsingborg General Hospital, Dept. of Emergency Medicine and Prehospital Care, Helsingborg, Sweden; Lund University, Dept. of Clinical Sciences Lund, Clinical Sciences Helsingborg, Lund, Sweden.
| | - Arne Reimers
- Dept. of Clinical Chemistry and Pharmacology, Division of Laboratory Medicine, Lund, Sweden
| | - Kristina Källén
- Lund University, Dept. of Clinical Sciences Lund, Clinical Sciences Helsingborg, Lund, Sweden; Helsingborg General Hospital, Dept. of Specialized Medicine, Helsingborg, Sweden; Skåne University Hospital, Dept. of Neurology and Rehabilitation Medicine, Lund, Sweden
| |
Collapse
|
19
|
Abstract
BACKGROUND Antiepileptic drugs (AEDs) are the mainstay of epilepsy treatment. Since 1989, 18 new AEDs have been licensed for clinical use and there are now 27 licensed AEDs in total for the treatment of patients with epilepsy. Furthermore, several AEDs are also used for the management of other medical conditions, for example, pain and bipolar disorder. This has led to an increasingly widespread application of therapeutic drug monitoring (TDM) of AEDs, making AEDs among the most common medications for which TDM is performed. The aim of this review is to provide an overview of the indications for AED TDM, to provide key information for each individual AED in terms of the drug's prescribing indications, key pharmacokinetic characteristics, associated drug-drug pharmacokinetic interactions, and the value and the intricacies of TDM for each AED. The concept of the reference range is discussed as well as practical issues such as choice of sample types (total versus free concentrations in blood versus saliva) and sample collection and processing. METHODS The present review is based on published articles and searches in PubMed and Google Scholar, last searched in March 2018, in addition to references from relevant articles. RESULTS In total, 171 relevant references were identified and used to prepare this review. CONCLUSIONS TDM provides a pragmatic approach to epilepsy care, in that bespoke dose adjustments are undertaken based on drug concentrations so as to optimize clinical outcome. For the older first-generation AEDs (carbamazepine, ethosuximide, phenobarbital, phenytoin, primidone, and valproic acid), much data have accumulated in this regard. However, this is occurring increasingly for the new AEDs (brivaracetam, eslicarbazepine acetate, felbamate, gabapentin, lacosamide, lamotrigine, levetiracetam, oxcarbazepine, perampanel, piracetam, pregabalin, rufinamide, stiripentol, sulthiame, tiagabine, topiramate, vigabatrin, and zonisamide).
Collapse
|
20
|
Gagne JJ, Popovic JR, Nguyen M, Sandhu SK, Greene P, Izem R, Jiang W, Wang Z, Zhao Y, Petrone AB, Wagner AK, Dutcher SK. Evaluation of Switching Patterns in FDA's Sentinel System: A New Tool to Assess Generic Drugs. Drug Saf 2019; 41:1313-1323. [PMID: 30120741 DOI: 10.1007/s40264-018-0709-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Nearly 90% of drugs dispensed in the US are generic products. OBJECTIVE The aim of this study was to develop and implement a tool for analyzing manufacturer-level drug utilization and switching patterns within the US Food and Drug Administration's Sentinel system. METHODS A descriptive tool was designed to analyze data in the Sentinel common data model and was tested with two case studies-metoprolol extended release (ER) and lamotrigine ER-using claims data from four Sentinel data partners. We plotted initiators of each brand and generic product over time. For metoprolol ER, we evaluated rates of switching from generics around the time of manufacturing issues. For lamotrigine ER, we examined rates of switching back to the brand among those who switched from brand to generic. RESULTS We identified 1,651,285 initiators of metoprolol ER products between July 2008 and September 2015. We observed a large decrease in monthly metoprolol ER initiators (from 25,465 in December 2008 to 13,128 in February 2009), corresponding to recalls by generic manufacturers. We observed simultaneous increases in utilization of the authorized generic and brand products. We identified 4266 initiators of lamotrigine ER with an epilepsy diagnosis between January 2012 and September 2015. Among those who switched from brand to generic, the cumulative incidence of switching back was close to 20% at 2 years. Switchback rates were higher for the first available generic products. CONCLUSIONS This developed tool was able to elucidate novel utilization and switching patterns in two case studies. Such information can be used to support surveillance of generic drugs and biosimilars.
Collapse
Affiliation(s)
- Joshua J Gagne
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Jennifer R Popovic
- Department of Population Medicine, Harvard Medical School, Harvard Pilgrim Health Care Institute, Boston, MA, USA.,RTI International, Waltham, MA, USA
| | - Michael Nguyen
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Sukhminder K Sandhu
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Patty Greene
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Rima Izem
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Wenlei Jiang
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Zhong Wang
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Yueqin Zhao
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Andrew B Petrone
- Department of Population Medicine, Harvard Medical School, Harvard Pilgrim Health Care Institute, Boston, MA, USA
| | - Anita K Wagner
- Department of Population Medicine, Harvard Medical School, Harvard Pilgrim Health Care Institute, Boston, MA, USA
| | - Sarah K Dutcher
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| |
Collapse
|
21
|
Bosak M, Słowik A, Dziedzic T. Brand-to-generic oxcarbazepine switch – A prospective observational study. Epilepsy Res 2019; 151:75-77. [DOI: 10.1016/j.eplepsyres.2019.02.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 02/11/2019] [Accepted: 02/26/2019] [Indexed: 10/27/2022]
|
22
|
Itabashi S, Bito R, Nishina M, Fukumoto M, Soda M, Doi M, Usui S, Kitaichi K. Determination of lamotrigine in human plasma using liquid chromatography-tandem mass spectrometry. Neuropsychopharmacol Rep 2019; 39:48-55. [PMID: 30604456 PMCID: PMC7292279 DOI: 10.1002/npr2.12045] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 11/20/2018] [Accepted: 11/22/2018] [Indexed: 12/26/2022] Open
Abstract
Aim Lamotrigine (LTG) is a widely used anti‐epileptic drug that is administered to avoid seizures and to maintain seizure‐free status. However, several factors reportedly cause individual differences of plasma LTG levels, and the therapeutic target range of LTG varies between individuals. Thus, to optimize effective doses of LTG, we developed a rapid and simple method for determining plasma LTG concentrations. Methods Lamotrigine and the internal standard papaverine were extracted from human plasma using solid‐phase extraction. After filtration, 5‐μL aliquots of final samples were injected into the liquid chromatography‐tandem mass spectrometry instrument and LTG and internal standard were separated using a Cadenza CD‐C18 column (100 × 2 mm, 3 μm) with 0.1% formic acid in water/acetonitrile (2/1, v/v). Results The calibration curve was linear from 0.2 to 5.0 μg/mL, and assessments of recovery, intra‐ and inter‐day precision and accuracy, matrix effects, freeze and thaw stability, and long‐term stability demonstrated good reproducibility. Retention times of LTG and internal standard were 1.6 and 2.0 minutes, respectively, and the total run time was 3.5 minutes for each sample. Conclusion We developed a rapid and simple method for determining plasma LTG concentrations. The present novel system could be used to inform LTG dose adjustments for individual patients. We developed a rapid and simple method for determining plasma concentrations of LTG showing good validation for a relatively wide range (0.2‐5.0 μg/mL). The present method can inform estimates of plasma concentrations of LTG to clinicians within 1 hour of sample collection.![]()
Collapse
Affiliation(s)
- Shogo Itabashi
- Laboratory of Pharmaceutics, Department of Biomedical Pharmaceutics, Gifu Pharmaceutical University, Gifu, Japan
| | - Rina Bito
- Laboratory of Pharmaceutics, Department of Biomedical Pharmaceutics, Gifu Pharmaceutical University, Gifu, Japan
| | - Maika Nishina
- Laboratory of Pharmaceutics, Department of Biomedical Pharmaceutics, Gifu Pharmaceutical University, Gifu, Japan
| | - Maki Fukumoto
- Laboratory of Pharmaceutics, Department of Biomedical Pharmaceutics, Gifu Pharmaceutical University, Gifu, Japan
| | - Midori Soda
- Laboratory of Pharmaceutics, Department of Biomedical Pharmaceutics, Gifu Pharmaceutical University, Gifu, Japan
| | - Mitsunori Doi
- Laboratory of Pharmaceutics, Department of Biomedical Pharmaceutics, Gifu Pharmaceutical University, Gifu, Japan.,Department of Pharmacy, Wakayama Medical University Hospital, Wakayama, Japan
| | - Shigeyuki Usui
- Laboratory of Pharmaceutics, Department of Biomedical Pharmaceutics, Gifu Pharmaceutical University, Gifu, Japan
| | - Kiyoyuki Kitaichi
- Laboratory of Pharmaceutics, Department of Biomedical Pharmaceutics, Gifu Pharmaceutical University, Gifu, Japan
| |
Collapse
|
23
|
Das S, Pu X, Jiang X, Jiang W, Tung R, Ting TY, Polli JE. Exploring generic brittleness and the demographic factors for its susceptibility in patients with epilepsy. Epilepsy Behav 2019; 90:197-203. [PMID: 30579779 DOI: 10.1016/j.yebeh.2018.11.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/29/2018] [Accepted: 11/30/2018] [Indexed: 11/27/2022]
Abstract
PURPOSE The purpose of this study was to provide an algorithm for generic brittleness and to elucidate the demographic factors that anticipate generic brittleness for patients with epilepsy. METHODS This exploratory, observational, and nontherapeutic study was conducted in patients with epilepsy who were routinely followed at the University of Maryland epilepsy outpatient clinic in Baltimore, Maryland. Patients were taking at least one antiepileptic drug (AED) for treatment of epilepsy. Based on patient interview and medical history, 12 demographic factors were collected. Each patient was assessed to be either generic brittle (GB) or not GB. Demographic factors were subjected to binary logistical regression and other statistical tests, to elucidate determinants of GB status. RESULTS N = 148 patients completed the study. An algorithm to define whether a patient was GB or not GB was devised. The two elements that defined GB status are as follows: patient opinion about generics and (if needed) whether patients were currently taking brand or generic of their most problematic AED. About 40% of patients were GB. From binary logistical regression, two demographic factors that contributed to patients being GB were whether a patient was currently taking a problem AED and total number of current medications for a patient, with odds ratios of 4.06 (95% confidence interval [CI] from 1.53 to 10.81) and 1.10 (95% CI from 1.003 to 1.21), respectively. Of the patients on a problem AED, 46.9% were GB, while only 18.2% of patients not currently on a problem AED were GB. The total number of current medications ranged from 1 to 22, with mode of four medications. From regression, for each additional medication that a patient took, the odds of being GB increased 1.10-fold. Although patient seizure and adverse event history was not employed to define GB status, being GB was associated with less seizure control and greater adverse events. CONCLUSIONS An algorithm for generic brittleness was derived, and about 40% of patients were GB, usually due to prior history of a switch problem. Two demographic factors favored patients being GB: whether the patient was currently taking a problem AED and the total number of current medications.
Collapse
Affiliation(s)
- Sharmila Das
- University of Maryland, Department of Pharmaceutical Sciences, 20 Penn Street, Baltimore, MD 21201, USA
| | - Xia Pu
- Food and Drug Administration, Center for Drug Evaluation, 10903 New Hampshire Avenue, White Oak, MD 20993, USA
| | - Xiaohui Jiang
- Food and Drug Administration, Center for Drug Evaluation, 10903 New Hampshire Avenue, White Oak, MD 20993, USA
| | - Wenlei Jiang
- Food and Drug Administration, Center for Drug Evaluation, 10903 New Hampshire Avenue, White Oak, MD 20993, USA
| | - Renee Tung
- University of Maryland, Department of Pharmaceutical Sciences, 20 Penn Street, Baltimore, MD 21201, USA; University of Maryland, Department of Neurology, 22 South Greene Street, Baltimore, MD 21201, USA
| | - Tricia Y Ting
- University of Maryland, Department of Neurology, 22 South Greene Street, Baltimore, MD 21201, USA; Georgetown University, 3900 Reservoir Road NW, Washington, D.C. 20007, USA
| | - James E Polli
- University of Maryland, Department of Pharmaceutical Sciences, 20 Penn Street, Baltimore, MD 21201, USA.
| |
Collapse
|
24
|
Affiliation(s)
- Martin Holtkamp
- Epilepsy-Center Berlin-Brandenburg, Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
| |
Collapse
|
25
|
Beauvais V, Marque A, Ferté G, Chrusciel J, Souille J, Nazeyrollas P, Sanchez S. Factors influencing the use of the "not for generic substitution" mention for prescriptions in primary care: a survey with general practitioners. BMC Health Serv Res 2018; 18:850. [PMID: 30419890 PMCID: PMC6233580 DOI: 10.1186/s12913-018-3652-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 10/26/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Generic drug substitution is a public health policy challenge with high economic potential. Generic drugs are generally cheaper than brand-name drugs. Drugs are a significant part of the total health expenditure, especially in ambulatory care. We conducted a cross-sectional study with general practitioners in the Champagne-Ardenne region to determine physician-related factors and beliefs causing doctors to use the Not for Generic Substitution (NGS) mention. METHODS Questionnaires were sent to General Practitioners (GPs) practicing in Champagne-Ardenne via 3 shipments, from January 2015 to May 2015. Prescriber characteristics and beliefs influencing the use of the NGS mention were assessed for frequent (≥ 5%) and less frequent (< 5%) users of the NGS mention. RESULTS Factors associated with above average NGS mention use in bivariate analysis included patient comorbidity, polypharmacy, a concern that generic and brand-name drugs are not bioequivalent and belief in higher efficacy of the brand name drug. The use of an e-prescribing system (EPS) and medical practice in rural areas appeared to be associated with lower use of NGS mention in bivariate analysis but not in multivariable analysis. In multivariable analysis, patient request was associated with a higher use of the NGS mention (NGS ≥ 5%, adjusted Odds Ratio (aOR) = 2.52; 95% CI = [1.46-4.35]; p = 0.001), which was also linked to patient age over 65 (NGS ≥ 5%, aOR = 2.33; 95% CI = [1.03-5.30]; p = 0.04). The NGS mention was often used for drugs where substitution is debated in the literature (thyroid hormones, antiepileptic drugs). CONCLUSION This work highlights the involvement of the doctor-patient pair for the use of the NGS mention. Patient request was the major reason for using the NGS mention, even though it was not always endorsed by prescribers. Further studies are needed to assess patient views on generic drugs and drug substitution, accounting for their health status and socio-economic condition, to help improve the relevance of the information available to them.
Collapse
Affiliation(s)
| | - Annabelle Marque
- Emergency Department, Centre Hospitalier de Troyes, 10000, Troyes, France
| | | | - Jan Chrusciel
- Medical Information Department, Centre Hospitalier de Troyes, 10000, Troyes, France
| | - Julie Souille
- Emergency Department, Centre Hospitalier Universitaire de Reims, 51092, Reims, France
| | - Pierre Nazeyrollas
- Cardiology Department, Centre Hospitalier Universitaire de Reims, 51092, Reims, France
| | - Stéphane Sanchez
- Medical Information Department, Centre Hospitalier de Troyes, 10000, Troyes, France. .,, Troyes, France.
| |
Collapse
|
26
|
Lang JD, Kostev K, Onugoren MD, Gollwitzer S, Graf W, Müller T, Olmes DG, Hamer HM. Switching the manufacturer of antiepileptic drugs is associated with higher risk of seizures: A nationwide study of prescription data in Germany. Ann Neurol 2018; 84:918-925. [DOI: 10.1002/ana.25353] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 09/20/2018] [Accepted: 09/23/2018] [Indexed: 12/26/2022]
Affiliation(s)
- Johannes D. Lang
- Department of Neurology, Epilepsy Center; Friedrich-Alexander-Universität; Erlangen-Nürnberg Erlangen Germany
| | - Karel Kostev
- IQVIA, Epidemiology, Frankfurt am Main, Main Airport Center; Unterschweinstiege 2-14, 60549 Frankfurt am Main Germany
| | - Müjgan Dogan Onugoren
- Department of Neurology, Epilepsy Center; Friedrich-Alexander-Universität; Erlangen-Nürnberg Erlangen Germany
| | - Stephanie Gollwitzer
- Department of Neurology, Epilepsy Center; Friedrich-Alexander-Universität; Erlangen-Nürnberg Erlangen Germany
| | - Wolfgang Graf
- Department of Neurology, Epilepsy Center; Friedrich-Alexander-Universität; Erlangen-Nürnberg Erlangen Germany
| | - Tamara Müller
- Department of Neurology, Epilepsy Center; Friedrich-Alexander-Universität; Erlangen-Nürnberg Erlangen Germany
| | - David G. Olmes
- Department of Neurology, Epilepsy Center; Friedrich-Alexander-Universität; Erlangen-Nürnberg Erlangen Germany
| | - Hajo M. Hamer
- Department of Neurology, Epilepsy Center; Friedrich-Alexander-Universität; Erlangen-Nürnberg Erlangen Germany
| |
Collapse
|
27
|
Gha-Hyun L, Dae SJ. Brand name to generic substitution of levetiracetam in patients with epilepsy. Seizure 2018; 60:127-131. [DOI: 10.1016/j.seizure.2018.06.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 06/18/2018] [Accepted: 06/24/2018] [Indexed: 11/24/2022] Open
|
28
|
Gronchi G. The Use of Network Theory for Analyzing Switching Behaviors: Assessing Cognitive and Educational-Based Intervention for Promoting Health. Front Psychol 2018; 9:1095. [PMID: 29997559 PMCID: PMC6028824 DOI: 10.3389/fpsyg.2018.01095] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/08/2018] [Indexed: 11/16/2022] Open
Affiliation(s)
- Giorgio Gronchi
- Psychology Section, Department of Neuroscience, Psychology, Drug Research and Child's Health, University of Florence, Florence, Italy
| |
Collapse
|
29
|
Holtkamp M, Theodore WH. Generic antiepileptic drugs-Safe or harmful in patients with epilepsy? Epilepsia 2018; 59:1273-1281. [PMID: 29894004 DOI: 10.1111/epi.14439] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/09/2018] [Indexed: 11/28/2022]
Abstract
Generic antiepileptic drugs (AED) are significantly cheaper than brand name drugs, and may reduce overall health care expenditures. Regulatory bodies in Europe and North America require bioequivalence between generic and innovator drugs with regard to area under the plasma concentration-time curve (AUC) and peak plasma concentration (Cmax ); strict cutoff values have been defined. The main issue is if bioequivalence ensures therapeutic equivalence. Are switches from brand to generic, or between generic AEDs entirely safe or potentially harmful in patients with epilepsy? We summarized and evaluated the available evidence from bioequivalence, health care utilization, and clinical studies on safety of generic AEDs. In most cases, variations in AUC and Cmax were negligible when comparing innovator and generic AEDs. Due to interindividual pharmacokinetic and pharmacodynamic variability, measured differences between innovator and generic drugs may be the same as differences between different lots of the same brand. Studies from several countries based on insurance data have reported an increase in health care usage after switch from brand to generic AEDs; switchback rates are significantly higher for AEDs compared to other compounds. Patients may be confused, and nonadherence may increase, when AEDs are switched between manufacturers, perhaps due to changes in medication shape and color. But clinical studies do not report changes in seizure frequency and tolerability attributable to generics. Sufficient evidence indicates that most generics are bioequivalent to innovator AEDs; they do not pose a relevant risk for patients with epilepsy. However, some patients are reluctant towards variations in color and shape of their AEDs which may result in nonadherence. We recommend administering generics when a new AED is initiated. Switches from brand to generic AEDs for cost reduction and between generics, which is rarely required, generally seem to be safe, but should be accompanied by thorough counseling of patients on low risks.
Collapse
Affiliation(s)
- Martin Holtkamp
- Epilepsy-Center Berlin-Brandenburg, Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - William H Theodore
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| |
Collapse
|
30
|
Grabowski DC, Fishman J, Wild I, Lavin B. Changing the neurology policy landscape in the United States: Misconceptions and facts about epilepsy. Health Policy 2018; 122:797-802. [PMID: 29908672 DOI: 10.1016/j.healthpol.2018.05.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 05/09/2018] [Accepted: 05/21/2018] [Indexed: 12/15/2022]
Abstract
Epilepsy has a relatively high prevalence, and diagnosis and treatment are often challenging. Seizure freedom without significant side effects is the ultimate goal for both physicians and patients, but not always achievable. In those cases, the treatment goals of patients and providers may differ. In the United States, many clinicians continue to prescribe older AEDs, even though newer AEDs have a more desirable safety and tolerability profile, fewer drug-drug interactions, and are associated with lower epilepsy-related hospital visits. Newer AEDs are more commonly prescribed by neurologists and epilepsy center physicians, highlighting the importance of access to specialty care. We report that antiepileptic drugs are not the dominant cost driver for patients with epilepsy and costs are considerably higher in patients with uncontrolled epilepsy. Poor drug adherence is considered a main cause of unsuccessful epilepsy treatment and is associated with increases in inpatient and emergency department admissions and related costs. Interventions and educational programs are needed to address the reasons for nonadherence. Coverage policies placing a higher cost burden on patients with epilepsy lead to lower treatment adherence, which can result in higher future health care spending. Epilepsy is lagging behind other neurological conditions in terms of funding and treatment innovation. Increased investment in epilepsy research may be particularly beneficial given current funding levels and the high prevalence of epilepsy.
Collapse
Affiliation(s)
- David C Grabowski
- Department of Health Care Policy, Harvard Medical School, 180 Longwood Avenue, Boston, MA, 02115-5899, USA.
| | - Jesse Fishman
- UCB Pharma, 1950 Lake Park Drive SE, Smyrna, GA 30080, USA.
| | - Imane Wild
- UCB Pharma, 1950 Lake Park Drive SE, Smyrna, GA 30080, USA.
| | - Bruce Lavin
- UCB Pharma, 1950 Lake Park Drive SE, Smyrna, GA 30080, USA.
| |
Collapse
|
31
|
Desai RJ, Sarpatwari A, Dejene S, Khan NF, Lii J, Rogers JR, Dutcher SK, Raofi S, Bohn J, Connolly J, Fischer MA, Kesselheim AS, Gagne JJ. Differences in rates of switchbacks after switching from branded to authorized generic and branded to generic drug products: cohort study. BMJ 2018; 361:k1180. [PMID: 29615391 PMCID: PMC5881140 DOI: 10.1136/bmj.k1180] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVES To compare rates of switchbacks to branded drug products for patients switched from branded to authorized generic drug products, which have the same active ingredients, appearance, and excipients as the branded product, with patients switched from branded to generic drug products, which have the same active ingredients as the branded product but may differ in appearance and excipients. DESIGN Observational cohort study. SETTING Private (a large commercial health plan) and public (Medicaid) insurance programs in the US. PARTICIPANTS Beneficiaries of a large US commercial health insurer between 2004 and 2013 (primary cohort) and Medicaid beneficiaries between 2000 and 2010 (replication cohort). MAIN OUTCOME MEASURES Patients taking branded products for one of the study drugs (alendronate tablets, amlodipine tablets, amlodipine-benazepril capsules, calcitonin salmon nasal spray, escitalopram tablets, glipizide extended release tablets, quinapril tablets, and sertraline tablets) were identified when they switched to an authorized generic or a generic drug product after the date of market entry of generic drug products. These patients were followed for switchbacks to the branded drug product in the year after their switch to an authorized generic or a generic drug product. Cox proportional hazard models were used to estimate hazard ratios and 95% confidence intervals after adjusting for demographics, including age, sex, and calendar year. Inverse variance meta-analysis was used to pool adjusted hazard ratios across all drug products. RESULTS A total of 94 909 patients switched from branded to authorized generic drug products and 116 017 patients switched from branded to generic drug products and contributed to the switchback analysis. Unadjusted incidence rates of switchback varied across drug products, ranging from a low of 3.8 per 100 person years (for alendronate tablets) to a high of 17.8 per 100 person years (for amlodipine-benazepril capsules), with an overall rate of 8.2 per 100 person years across all drug products. Adjusted switchback rates were consistently lower for patients who switched from branded to authorized generic drug products compared with branded to generic drug products in the primary cohort (pooled hazard ratio 0.72, 95% confidence interval 0.64 to 0.81). Similar results (0.75, 0.62 to 0.91) were observed in the replication cohort. CONCLUSION Switching from branded to authorized generic drug products was associated with lower switchback rates compared with switching from branded to generic drug products.
Collapse
Affiliation(s)
- Rishi J Desai
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA
| | - Ameet Sarpatwari
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA
| | - Sara Dejene
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA
| | - Nazleen F Khan
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA
| | - Joyce Lii
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA
| | - James R Rogers
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA
| | - Sarah K Dutcher
- Office of Generic Drugs, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA
| | - Saeid Raofi
- Office of Generic Drugs, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA
| | - Justin Bohn
- Harvard School of Public Health, Boston, MA, USA
| | | | - Michael A Fischer
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA
| | - Aaron S Kesselheim
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA
| | - Joshua J Gagne
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02120, USA
| |
Collapse
|
32
|
Abstract
Switching branded to generic medications has become a common cost-containment measure. Although this is an important objective for health care systems worldwide, the impact of this practice on patient outcomes needs to be carefully considered. We reviewed the literature summarizing the potential clinical and economic consequences of switching from branded to generic medications on patient outcomes. A literature search of peer-reviewed articles published 2003-2013 using key words of "generic switching" or "substitution" was conducted using PubMed, OvidSP, and ScienceDirect. Of 30 articles identified and reviewed, most were related to the diseases of the central nervous system, especially epilepsy. Based on our review, potential impacts of switching fell into 3 broad categories: patient attitudes and adherence, clinical and safety outcomes, and cost and resource utilization. Although in many cases generics may represent an appropriate alternative to branded products, this may not always be the case. Specifically, several studies suggested that switching may negatively impact medication adherence, whereas other studies found that generic switching was associated with poorer clinical outcomes and more adverse events. In some instances, switching accomplished cost savings but did so at increased total cost of care because of increased physician visits or hospitalizations. Although in many cases generics may represent an appropriate alternative, mandatory generic switching may lead to unintended consequences, especially in certain therapeutic areas. Although further study is warranted, based on our review, it may be medically justifiable for physicians and patients to retain the right to request the branded product in certain cases.
Collapse
|
33
|
Fife D, Cepeda MS, Baseman A, Richards H, Hu P, Starr HL, Sena AG. Medication changes after switching from CONCERTA® brand methylphenidate HCl to a generic long-acting formulation: A retrospective database study. PLoS One 2018; 13:e0193453. [PMID: 29489906 PMCID: PMC5831385 DOI: 10.1371/journal.pone.0193453] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 01/28/2018] [Indexed: 12/04/2022] Open
Abstract
Background Observational studies of switching from branded to generic formulations of the same drug substance often lack appropriate comparators for the subjects who switched. Three generic formulations were deemed equivalent to Concerta: an authorized generic (AG) identical except for external packaging, and two other generics (EG). Objective Compare the incidence of a combined endpoint (switching back to Concerta, changing the use of immediate release methylphenidate (MPH), stopping all long-acting methylphenidate, or starting a new medication) among people switched from Concerta to the AG versus the EG. Methods Cohort study from the Truven CCAE database of people aged 6 to 65 diagnosed with ADHD, treated with Concerta, and switched to the EG or to the AG formulation. Results In the EG arm 24.6% and in the AG arm 19.7% of subjects switched back to Concerta. The proportion of subjects meeting the combined endpoint was 39.5% in the EG arm, 32.9% in the AG arm, a crude risk ratio of 1.20 (95% CI 0.94, 1.54). After adjustment by propensity score stratification, the adjusted odds ratio (OR) was 1.23 (95% CI 0.90, 1.70). In an unplanned analysis using a different method of adjustment, the adjusted OR was 1.00 (95% CI 0.69, 1.44). Discussion This study did not detect a difference between the proportion of people who met the study endpoint in the two study arms, i.e. between those who switched to a generic formulation that was identical to Concerta except for external packaging and those who switched to the comparison generics. The high incidence of the combined endpoint in the AG arm demonstrates the need for an appropriate comparator in studies of this type. Trial registration ClinicalTrials.gov NCT02730572
Collapse
Affiliation(s)
- Daniel Fife
- Epidemiology, Janssen Research & Development, LLC, Titusville, NJ, United States of America
- * E-mail:
| | - M. Soledad Cepeda
- Epidemiology, Janssen Research & Development, LLC, Titusville, NJ, United States of America
| | - Alan Baseman
- Global Medical Safety, Janssen Research & Development, LLC, Horsham, PA, United States of America
| | - Henry Richards
- Established Products, Janssen Research & Development, LLC, Titusville, NJ, United States of America
| | - Peter Hu
- Clinical Biostatistics, Janssen Research & Development, LLC, Raritan, NJ, United States of America
| | - H. Lynn Starr
- Janssen Scientific Affairs, LLC, Titusville, NJ, United States of America
| | - Anthony G. Sena
- Epidemiology, Janssen Research & Development, LLC, Titusville, NJ, United States of America
| |
Collapse
|
34
|
Alhawassi TM, Abuelizz HA, Almetwazi M, Mahmoud MA, Alghamdi A, Alruthia YS, BinDhim N, Alburikan KA, Asiri YA, Pitts PJ. Advancing pharmaceuticals and patient safety in Saudi Arabia: A 2030 vision initiative. Saudi Pharm J 2018; 26:71-74. [PMID: 29379335 PMCID: PMC5783811 DOI: 10.1016/j.jsps.2017.10.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Accepted: 10/18/2017] [Indexed: 11/30/2022] Open
Abstract
Low-quality medicines deliver sub-optimal clinical outcomes and waste precious health resources. It is important to ensure that public funds are spent on healthcare technologies that meet national regulatory bodies such as the Saudi Food and Drug Authority (SFDA), quality standards for safety, efficacy, and quality. Medicines quality is a complicated combination of pre-market regulatory specifications, appropriate sourcing of ingredients (active pharmaceutical ingredient (API), excipients, etc.), manufacturing processes, healthcare ecosystem communications, and regular and robust pharmacovigilance practices. A recent conference in Riyadh, sponsored by King Saud University, sought to discuss these issues and develop specific policy recommendations for the Saudi 2030 Vision plan. This and other efforts will require more and more creative educational programs for physicians, pharmacists, hospitals, and patients, and, most importantly evolving regulations on quality standards and oversight by Saudi health authorities.
Collapse
Affiliation(s)
- Tariq M. Alhawassi
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
- Medication Safety Research Chair, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
- Pharmacy Care Services, King Saud University Medical City, Riyadh, Saudi Arabia
- Corresponding author at: Department of Clinical Pharmacy and Medication Safety Research Chair, College of Pharmacy, King Saud University, P.O Box 2457, Riyadh 11451, Saudi Arabia.Department of Clinical Pharmacy and Medication Safety Research ChairCollege of PharmacyKing Saud UniversityP.O Box 2457Riyadh11451Saudi Arabia
| | - Hatem A. Abuelizz
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mansour Almetwazi
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
- Medication Safety Research Chair, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mansour A. Mahmoud
- Medication Safety Research Chair, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Ahmed Alghamdi
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Yazed S. Alruthia
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | | | - Khalid A. Alburikan
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
- Medication Safety Research Chair, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
- Pharmacy Care Services, King Saud University Medical City, Riyadh, Saudi Arabia
| | - Yousif A. Asiri
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Peter J. Pitts
- Center for Medicine in the Public Interest, NY, USA
- École Supérieure des Sciences Économiques et Commerciales, Paris, France
- École Supérieure des Sciences Économiques et Commerciales, Singapore
| |
Collapse
|
35
|
A simple, rapid and stability indicating validated method for quantification of lamotrigine in human plasma and dry plasma spot using LC-ESI–MS/MS: Application in clinical study. J Chromatogr B Analyt Technol Biomed Life Sci 2018; 1072:362-369. [DOI: 10.1016/j.jchromb.2017.11.040] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/19/2017] [Accepted: 11/30/2017] [Indexed: 11/21/2022]
|
36
|
Cheng N, Rahman MM, Alatawi Y, Qian J, Peissig PL, Berg RL, Page CD, Hansen RA. Mixed Approach Retrospective Analyses of Suicide and Suicidal Ideation for Brand Compared with Generic Central Nervous System Drugs. Drug Saf 2017; 41:363-376. [PMID: 29196989 DOI: 10.1007/s40264-017-0624-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Several different types of drugs acting on the central nervous system (CNS) have previously been associated with an increased risk of suicide and suicidal ideation (broadly referred to as suicide). However, a differential association between brand and generic CNS drugs and suicide has not been reported. OBJECTIVES This study compares suicide adverse event rates for brand versus generic CNS drugs using multiple sources of data. METHODS Selected examples of CNS drugs (sertraline, gabapentin, zolpidem, and methylphenidate) were evaluated via the US FDA Adverse Event Reporting System (FAERS) for a hypothesis-generating study, and then via administrative claims and electronic health record (EHR) data for a more rigorous retrospective cohort study. Disproportionality analyses with reporting odds ratios and 95% confidence intervals (CIs) were used in the FAERS analyses to quantify the association between each drug and reported suicide. For the cohort studies, Cox proportional hazards models were used, controlling for demographic and clinical characteristics as well as the background risk of suicide in the insured population. RESULTS The FAERS analyses found significantly lower suicide reporting rates for brands compared with generics for all four studied products (Breslow-Day P < 0.05). In the claims- and EHR-based cohort study, the adjusted hazard ratio (HR) was statistically significant only for sertraline (HR 0.58; 95% CI 0.38-0.88). CONCLUSION Suicide reporting rates were disproportionately larger for generic than for brand CNS drugs in FAERS and adjusted retrospective cohort analyses remained significant only for sertraline. However, even for sertraline, temporal confounding related to the close proximity of black box warnings and generic availability is possible. Additional analyses in larger data sources with additional drugs are needed.
Collapse
Affiliation(s)
- Ning Cheng
- Department of Health Outcomes Research and Policy, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Md Motiur Rahman
- Department of Health Outcomes Research and Policy, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Yasser Alatawi
- Department of Health Outcomes Research and Policy, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Jingjing Qian
- Department of Health Outcomes Research and Policy, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA
| | - Peggy L Peissig
- Biomedical Informatics Research Center, Marshfield Clinic Research Institute, Marshfield, WI, USA
| | - Richard L Berg
- Biomedical Informatics Research Center, Marshfield Clinic Research Institute, Marshfield, WI, USA
| | - C David Page
- Department of Biostatistics and Medical Informatics, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA.,Department of Computer Science, University of Wisconsin, Madison, WI, USA
| | - Richard A Hansen
- Department of Health Outcomes Research and Policy, Harrison School of Pharmacy, Auburn University, Auburn, AL, USA.
| |
Collapse
|
37
|
|
38
|
Bosak M, Słowik A, Turaj W. Safety of switching from brand-name to generic levetiracetam in patients with epilepsy. DRUG DESIGN DEVELOPMENT AND THERAPY 2017; 11:2287-2291. [PMID: 28814836 PMCID: PMC5546726 DOI: 10.2147/dddt.s138270] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Purpose The approach to the use of generic antiepileptic drugs has recently evolved from major concern to general acceptance, but the evidence related specifically to the safety of switching from brand-name to generic levetiracetam (LEV) is scarce. The aim of the study was to assess the risk of increased frequency of seizures or other adverse events after replacement of a brand-name LEV with a generic one. Patients and methods This retrospective analysis included 159 patients treated with LEV in a tertiary outpatient epilepsy clinic. We included all patients diagnosed with epilepsy who were treated with LEV as at March 1, 2013. Most patients were forced to switch to the generic LEV because of the sudden rise in cost of the branded LEV. We recorded data on age, sex, age at onset of epilepsy, type of epilepsy, and its treatment. We analyzed data from one visit before potential switching and from two visits after the potential switching. The interval between visits was typically 3 months. We registered an increase in the frequency of seizures and in the occurrence of adverse events. Results Among 151 subjects who switched to generic LEV after March 1, 2013, increased frequency of seizures was noted in 9 patients (6%) during the first follow-up visit. Patients with increased frequency of seizures did not differ from other patients regarding sex, age, age at the onset of epilepsy, and the median dose of LEV before switching or the median duration of treatment with LEV before switching. Two patients returned to brand-name LEV. Adverse events were noted in six other patients (4%) and included somnolence, irritability, or dizziness. Conclusion Switching from brand-name to generic LEV is generally safe.
Collapse
Affiliation(s)
- Magdalena Bosak
- Department of Neurology, Jagiellonian University Medical College, Kraków, Poland
| | - Agnieszka Słowik
- Department of Neurology, Jagiellonian University Medical College, Kraków, Poland
| | - Wojciech Turaj
- Department of Neurology, Jagiellonian University Medical College, Kraków, Poland
| |
Collapse
|
39
|
Reimers A, Olsson P, Nilsson J, Hoff E, Reis M, Strandberg M, Lundgren A, Källén K. Impact of generic substitution on levetiracetam serum concentration—A prospective study in an outpatient setting. Epilepsy Res 2017; 134:54-61. [DOI: 10.1016/j.eplepsyres.2017.04.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 03/22/2017] [Accepted: 04/22/2017] [Indexed: 10/19/2022]
|
40
|
Markoula S, Chatzistefanidis D, Gatzonis S, Siatouni A, Siarava E, Verentzioti A, Kyritsis AP, Patsalos PN. Brand-to-generic levetiracetam switch in patients with epilepsy in a routine clinical setting. Seizure 2017; 48:1-6. [DOI: 10.1016/j.seizure.2017.03.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 03/18/2017] [Indexed: 10/19/2022] Open
|
41
|
Molinier A, Palmaro A, Rousseau V, Sommet A, Bourrel R, Montastruc JL, Bagheri H. Does substitution of brand name medications by generics differ between pharmacotherapeutic classes? A population-based cohort study in France. Eur J Clin Pharmacol 2016; 73:471-477. [PMID: 28035437 DOI: 10.1007/s00228-016-2185-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 12/19/2016] [Indexed: 10/20/2022]
Abstract
PURPOSE The purpose of this study was to measure the rate of substitution failure to generic antiepileptic drugs (AEDs) compared to two other pharmacotherapeutic classes (neuroleptics, beta-blockers). METHODS We conducted a cohort study involving beneficiaries of the French health insurance system from January 2009 to November 2012. Substitution failure to generic drugs was estimated by the rate of switchback (i.e. from generic drug back to its branded drug). We selected the patients who had a dispensation of a branded AED for 60 days or more during the 90 days preceding the generic substitution. Cox proportional hazard regression was used to model time to switchback for antiepileptics vs. other therapeutic classes in the 90 days after generic substitution, adjusting for age, gender and polytherapy. RESULTS The cohort included 6727 patients of whom 1947 were exposed to AEDs, 2398 to neuroleptics and 2382 to beta-blockers. The switchback rate was 62% for AEDs. AED users were more likely to switch back as compared to beta-blocker (crude hazard ratio 1.87; 95% CI 1.68-2.07 for patients under 75) or neuroleptic users. The same observation was made in patients above 75 years (crude hazard ratio 1.36; 95% CI 1.16-1.60). CONCLUSIONS Compared to beta-blocker users, AED users were more likely to switch back to the branded drug, whereas this difference was not observed with neuroleptics. These results could reflect a poor acceptance of switching AEDs to generic compounds in France.
Collapse
Affiliation(s)
- Alicia Molinier
- Laboratoire de Pharmacologie Médicale et Clinique de la Faculté de Médecine et du Centre Hospitalier, Universitaire de Toulouse, Toulouse, France.,INSERM UMR 1027, Faculté de Médecine, Université de Toulouse, Toulouse, France
| | - Aurore Palmaro
- Laboratoire de Pharmacologie Médicale et Clinique de la Faculté de Médecine et du Centre Hospitalier, Universitaire de Toulouse, Toulouse, France. .,INSERM UMR 1027, Faculté de Médecine, Université de Toulouse, Toulouse, France. .,CIC INSERM 1436 Université et Centre Hospitalier Universitaire de Toulouse, Toulouse , France.
| | - Vanessa Rousseau
- Laboratoire de Pharmacologie Médicale et Clinique de la Faculté de Médecine et du Centre Hospitalier, Universitaire de Toulouse, Toulouse, France.,INSERM UMR 1027, Faculté de Médecine, Université de Toulouse, Toulouse, France.,CIC INSERM 1436 Université et Centre Hospitalier Universitaire de Toulouse, Toulouse , France.,Centre Midi-Pyrénées de PharmacoVigilance, de Pharmacoépidémiologie et d'Informations sur le Médicament, Pharmacopôle Midi-Pyrénées, Centre Hospitalier Universitaire de Toulouse, Toulouse, France
| | - Agnès Sommet
- Laboratoire de Pharmacologie Médicale et Clinique de la Faculté de Médecine et du Centre Hospitalier, Universitaire de Toulouse, Toulouse, France.,INSERM UMR 1027, Faculté de Médecine, Université de Toulouse, Toulouse, France.,CIC INSERM 1436 Université et Centre Hospitalier Universitaire de Toulouse, Toulouse , France
| | - Robert Bourrel
- Direction Régionale du Service du contrôle Médical de Midi-Pyrénées, Toulouse, France
| | - Jean-Louis Montastruc
- Laboratoire de Pharmacologie Médicale et Clinique de la Faculté de Médecine et du Centre Hospitalier, Universitaire de Toulouse, Toulouse, France.,INSERM UMR 1027, Faculté de Médecine, Université de Toulouse, Toulouse, France.,Centre Midi-Pyrénées de PharmacoVigilance, de Pharmacoépidémiologie et d'Informations sur le Médicament, Pharmacopôle Midi-Pyrénées, Centre Hospitalier Universitaire de Toulouse, Toulouse, France
| | - Haleh Bagheri
- Laboratoire de Pharmacologie Médicale et Clinique de la Faculté de Médecine et du Centre Hospitalier, Universitaire de Toulouse, Toulouse, France.,INSERM UMR 1027, Faculté de Médecine, Université de Toulouse, Toulouse, France.,Centre Midi-Pyrénées de PharmacoVigilance, de Pharmacoépidémiologie et d'Informations sur le Médicament, Pharmacopôle Midi-Pyrénées, Centre Hospitalier Universitaire de Toulouse, Toulouse, France
| |
Collapse
|
42
|
Ku LC, Wu H, Greenberg RG, Hill KD, Gonzalez D, Hornik CP, Berezny A, Guptill JT, Jiang W, Zheng N, Cohen-Wolkowiez M, Melloni C. Use of Therapeutic Drug Monitoring, Electronic Health Record Data, and Pharmacokinetic Modeling to Determine the Therapeutic Index of Phenytoin and Lamotrigine. Ther Drug Monit 2016; 38:728-737. [PMID: 27764025 PMCID: PMC5113813 DOI: 10.1097/ftd.0000000000000354] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Defining a drug's therapeutic index (TI) is important for patient safety and regulating the development of generic drugs. For many drugs, the TI is unknown. A systematic approach was developed to characterize the TI of a drug using therapeutic drug monitoring and electronic health record (EHR) data with pharmacokinetic (PK) modeling. This approach was first tested on phenytoin, which has a known TI, and then applied to lamotrigine, which lacks a defined TI. METHODS Retrospective EHR data from patients in a tertiary hospital were used to develop phenytoin and lamotrigine population PK models and to identify adverse events (anemia, thrombocytopenia, and leukopenia) and efficacy outcomes (seizure-free). Phenytoin and lamotrigine concentrations were simulated for each day with an adverse event or seizure. Relationships between simulated concentrations and adverse events and efficacy outcomes were used to calculate the TI for phenytoin and lamotrigine. RESULTS For phenytoin, 93 patients with 270 total and 174 free concentrations were identified. A de novo 1-compartment PK model with Michaelis-Menten kinetics described the data well. Simulated average total and free concentrations of 10-15 and 1.0-1.5 mcg/mL were associated with both adverse events and efficacy in 50% of patients, resulting in a TI of 0.7-1.5. For lamotrigine, 45 patients with 53 concentrations were identified. A published 1-compartment model was adapted to characterize the PK data. No relationships between simulated lamotrigine concentrations and safety or efficacy endpoints were seen; therefore, the TI could not be calculated. CONCLUSIONS This approach correctly determined the TI of phenytoin but was unable to determine the TI of lamotrigine due to a limited sample size. The use of therapeutic drug monitoring and EHR data to aid in narrow TI drug classification is promising, but it requires an adequate sample size and accurate characterization of concentration-response relationships.
Collapse
Affiliation(s)
- Lawrence C. Ku
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Huali Wu
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina, USA
| | - Rachel G. Greenberg
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Kevin D. Hill
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Daniel Gonzalez
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Christoph P. Hornik
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Alysha Berezny
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina, USA
| | - Jeffrey T. Guptill
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Neurology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Wenlei Jiang
- Office of Generic Drugs, US Food and Drug Administration, Silver Spring, MD, USA
| | - Nan Zheng
- Office of Generic Drugs, US Food and Drug Administration, Silver Spring, MD, USA
| | - Michael Cohen-Wolkowiez
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Chiara Melloni
- Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina, USA
| |
Collapse
|
43
|
Kesselheim AS, Bykov K, Gagne JJ, Wang SV, Choudhry NK. Switching generic antiepileptic drug manufacturer not linked to seizures: A case-crossover study. Neurology 2016; 87:1796-1801. [PMID: 27683844 DOI: 10.1212/wnl.0000000000003259] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 07/11/2016] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE With more antiepileptic drugs (AED) becoming available in generic form, we estimated the risk of seizure-related events associated with refilling generic AEDs and the effect of switching between different manufacturers of the same generic drug. METHODS We designed a population-based case-crossover study using the Medicaid Analytic eXtract and a US commercial health insurance database. We identified 83,001 generic AED users who experienced a seizure-related hospital admission or emergency room visit between 2000 and 2013 and assessed whether they received a refill of the same AED from the same manufacturer or a different manufacturer. Patients served as their own controls and conditional logistic regression was used to compare exposure to a refill during the hazard period, defined as days 2-36 preceding the seizure-related event, to exposure during the control period, defined as days 51-85 preceding the seizure-related event. RESULTS Generic AED refilling was associated with an 8% increase in the odds of seizure-related events (odds ratio [OR] 1.08; 95% confidence interval [CI] 1.06-1.11). The OR following a switch to a different manufacturer of the same AED was 1.09 (95% CI 1.03-1.15); however, after adjusting for the process of refilling, there was no association between switching and seizure-related hospital visits (OR 1.00; 95% CI 0.94-1.07). CONCLUSIONS Among patients on a generic AED, refilling the same AED was associated with an elevated risk of seizure-related event; however, there was no additional risk from switching during that refill to a different manufacturer. Generic AEDs available to US patients, with Food and Drug Administration-validated bioequivalence, appear to be safe clinical choices.
Collapse
Affiliation(s)
- Aaron S Kesselheim
- From the Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.
| | - Katsiaryna Bykov
- From the Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Joshua J Gagne
- From the Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Shirley V Wang
- From the Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Niteesh K Choudhry
- From the Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| |
Collapse
|
44
|
Greenberg RG, Melloni C, Wu H, Gonzalez D, Ku L, Hill KD, Hornik CP, Zheng N, Jiang W, Cohen-Wolkowiez M, Guptill JT. Therapeutic Index Estimation of Antiepileptic Drugs: A Systematic Literature Review Approach. Clin Neuropharmacol 2016; 39:232-40. [PMID: 27428884 PMCID: PMC5026556 DOI: 10.1097/wnf.0000000000000172] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Our study aimed to determine whether data obtained from the medical literature can be used to estimate the therapeutic index of 5 antiepileptic drugs (AEDs): carbamazepine, lamotrigine, phenobarbital, phenytoin, and valproate. METHODS We performed a literature search using PubMed and EMBASE to collect published safety, efficacy, and therapeutic monitoring data for 5 AEDs and extracted all relevant information into a drug- and study-specific drug database. For each AED, we summarized (1) type, severity, and incidence of toxicity-related adverse events and toxicity-associated range of drug doses or concentrations; (2) effective versus toxic concentration and dose (therapeutic range); and (3) therapeutic drug monitoring practices. We defined therapeutic index as the ratio of the minimum toxic concentration to the minimum effective concentration. RESULTS We reviewed a total of 810 full-text articles and extracted data from 163. The literature suggests that the therapeutic index of phenytoin is 2. The therapeutic indices of phenobarbital and valproate exceed 2. There were insufficient data to precisely quantify the therapeutic indices of carbamazepine and lamotrigine. CONCLUSIONS For some drugs, this approach offers a low-cost method of therapeutic index estimation. Our results can serve as preliminary data for future trials and as guidance for US Food and Drug Administration decision making regarding narrow therapeutic index classification.
Collapse
Affiliation(s)
| | | | - Huali Wu
- Duke Clinical Research Institute, Durham, NC
| | - Daniel Gonzalez
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC
| | - Lawrence Ku
- Duke Clinical Research Institute, Durham, NC
| | | | | | - Nan Zheng
- Office of Generic Drugs, US Food and Drug Administration, Silver Spring, MD
| | - Wenlei Jiang
- Office of Generic Drugs, US Food and Drug Administration, Silver Spring, MD
| | | | | |
Collapse
|
45
|
Alyautdin RN, Romanov BK, Pasternak EY, Bunyatyan ND, Merkulov VA. Analysis of Factors Influencing the Interchangeability of Antiepileptic Drugs. Pharm Chem J 2016. [DOI: 10.1007/s11094-016-1418-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
46
|
Gagne JJ, Polinski JM, Jiang W, Dutcher SK, Xie J, Lii J, Fulchino LA, Kesselheim AS. Switch-backs associated with generic drugs approved using product-specific determinations of therapeutic equivalence. Pharmacoepidemiol Drug Saf 2016; 25:944-52. [PMID: 27102378 DOI: 10.1002/pds.4009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 03/15/2016] [Accepted: 03/17/2016] [Indexed: 11/09/2022]
Abstract
PURPOSE US Food and Drug Administration approval for generic drugs relies on demonstrating pharmaceutical equivalence and bioequivalence; however, some drug products have unique attributes that necessitate product-specific approval pathways. We evaluated rates of patients' switching back to brand-name versions from generic versions of four drugs approved via such approaches. METHODS We used data from Optum LifeSciences Research Database to identify patients using a brand-name version of a study drug (acarbose tablets, salmon calcitonin nasal spray, enoxaparin sodium injection, and venlafaxine extended release tablets) or a control drug. We followed patients to identify switching to generic versions and then followed those who switched to identify whether they switched back to brand-name versions. We calculated switch and switch-back rates and used Kaplan-Meier and log-rank tests to compare rates between study and control drugs. RESULTS Our cohort included 201 959 eligible patients. Brand-to-generic switch rates ranged from 66 to 106 switches per 100 person-years for study drugs and 80 to 110 for control drugs. Rates of switch-back to brand-name versions ranged from 5 to 37 among study drugs and 3 to 53 among control drugs. Switch-back rates were higher for venlafaxine vs. sertraline (p < 0.01) and calcitonin vs. alendronate (p = 0.01). Switch-back rates were lower for venlafaxine vs. paroxetine (p < 0.01) and acarbose vs. nateglinide (p < 0.01). Rates were similar for acarbose vs. glimepiride (p = 0.97) and for enoxaparin vs. fondiparinux (p = 0.11). CONCLUSION As compared to control drugs, patients were not more likely to systematically switch back from generic to brand-name versions of the four study drugs. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Joshua J Gagne
- Program on Regulation, Therapeutics, And Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Jennifer M Polinski
- Program on Regulation, Therapeutics, And Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Wenlei Jiang
- Office of Generic Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Sarah K Dutcher
- Office of Generic Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Jing Xie
- Program on Regulation, Therapeutics, And Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Joyce Lii
- Program on Regulation, Therapeutics, And Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Lisa A Fulchino
- Program on Regulation, Therapeutics, And Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Aaron S Kesselheim
- Program on Regulation, Therapeutics, And Law (PORTAL), Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| |
Collapse
|
47
|
Atif M, Azeem M, Sarwar MR. Potential problems and recommendations regarding substitution of generic antiepileptic drugs: a systematic review of literature. SPRINGERPLUS 2016; 5:182. [PMID: 27026878 PMCID: PMC4766158 DOI: 10.1186/s40064-016-1824-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 02/15/2016] [Indexed: 12/22/2022]
Abstract
Despite the availability of generic antiepileptic drugs (AEDs), still patients and neurologists hesitate to make a switch due to assorted reasons. The objectives of this review were to evaluate the risks associated with the generic substitution of AEDs. In this context, we also summarized the recommendations of various international societies to treat epileptic patients. We used a number of electronic databases to identify the relevant published studies which demonstrated the potential problems and recommendations regarding generic substitution of AEDs. Of 204 articles found initially, 153 were selected for additional review. Subsequently, 68 articles were finally selected. This review concluded that potential problems linked with the generic substitution of AEDs could be bioequivalence issues, failure of drug therapy, emergence of adverse events and increase in the frequency of seizures. The reasons could be the pharmacokinetics properties of AEDs and unique characteristics of some epilepsy patients. Consequently, the generic substitution of AEDs affects the successful treatment and quality of life of the patients. Various guidelines recommend the well-controlled epileptic patients to avoid switching from brand-to-generic products, generic-to-brand products or generic to some other generic products.
Collapse
Affiliation(s)
- Muhammad Atif
- Department of Pharmacy, Faculty of Pharmacy and Alternative Medicine, The Islamia University of Bahawalpur, Bahawalpur, Punjab Pakistan
| | - Muhammad Azeem
- Department of Pharmacy, Faculty of Pharmacy and Alternative Medicine, The Islamia University of Bahawalpur, Bahawalpur, Punjab Pakistan
| | - Muhammad Rehan Sarwar
- Department of Pharmacy, Faculty of Pharmacy and Alternative Medicine, The Islamia University of Bahawalpur, Bahawalpur, Punjab Pakistan
| |
Collapse
|
48
|
Privitera MD, Welty TE, Gidal BE, Diaz FJ, Krebill R, Szaflarski JP, Dworetzky BA, Pollard JR, Elder EJ, Jiang W, Jiang X, Berg M. Generic-to-generic lamotrigine switches in people with epilepsy: the randomised controlled EQUIGEN trial. Lancet Neurol 2016; 15:365-72. [PMID: 26875743 DOI: 10.1016/s1474-4422(16)00014-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 01/09/2016] [Accepted: 01/12/2016] [Indexed: 11/26/2022]
Abstract
BACKGROUND Patients and clinicians share concerns that generic drug substitution might lead to loss of efficacy or emergence of adverse events. In this trial, we assessed US Food and Drug Administration (FDA) bioequivalence standards by studying the effects of switching between two disparate generic immediate-release lamotrigine products in patients with epilepsy. METHODS The Equivalence among Generic Antiepileptic Drugs (EQUIGEN) chronic-dose study was a randomised, double-blind, crossover study that enrolled adults (aged ≥18 years) with epilepsy from six epilepsy centres at academic institutions across the USA who were receiving immediate-release lamotrigine dosed at 100 mg, 200 mg, 300 mg, or 400 mg twice daily. Eligible patients were randomly allocated (1:1) to one of two treatment sequences (sequence 1 or sequence 2), comprising four study periods of 14 days each. During each 14-day treatment period, patients received balanced doses of an oral generic lamotrigine product every 12 h (200-800 mg total, identical to lamotrigine dose prior to study enrolment); after each 14-day period, patients were crossed over to receive the other generic product. Computer-based randomisation was done using random permuted blocks of size two or four for each site to prevent sequence predictability. Both patients and study personnel were masked to the generic products selected, their predicted exposure (ie, "high" vs "low"), and their group allocation. The primary outcome of this trial was bioequivalence between the generic products, which was assessed at the end of the study through a comparison of maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC) for each product in the analysis population (all patients who completed all four treatment periods). Bioequivalence was established if the 90% CIs of the ratios of these two parameters for the two products were within equivalence limits (80-125%) in the analysis population. This study is registered with ClinicalTrials.gov\, number NCT01713777. FINDINGS Between April 25, 2013, and Aug 12, 2014, 35 eligible patients were enrolled and randomly assigned to treatment sequence 1 (n=15) or treatment sequence 2 (n=20). 33 patients completed all four treatment periods and were included in the primary outcome analysis. The 90% CIs of the ratios of both Cmax and AUC were within equivalence limits (AUC 90% CI 98-103, Cmax 90% CI 99-105), showing that lamotrigine exposures were equivalent between the generic products. No significant changes in seizure frequency or adverse events were recorded. No deaths, study-related serious adverse events, or changes in clinical laboratory values or vital signs occurred during this study. INTERPRETATION Disparate generic lamotrigine products in patients with epilepsy showed bioequivalence with no detectable difference in clinical effects, confirming that US Food and Drug Administration bioequivalence standards are appropriate. FUNDING American Epilepsy Society, Epilepsy Foundation, and US Food and Drug Administration.
Collapse
Affiliation(s)
| | - Timothy E Welty
- College of Pharmacy and Health Sciences, Drake University, Des Moines, IA, USA
| | - Barry E Gidal
- University of Wisconsin-Madison School of Pharmacy and Department of Neurology, Madison, WI, USA
| | - Francisco J Diaz
- Department of Biostatistics, The University of Kansas Medical Center, Kansas City, KS, USA
| | - Ron Krebill
- Department of Biostatistics, The University of Kansas Medical Center, Kansas City, KS, USA
| | - Jerzy P Szaflarski
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Barbara A Dworetzky
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - John R Pollard
- Department of Neurology; University of Pennsylvania, Philadelphia, PA, USA
| | - Edmund J Elder
- Zeeh Pharmaceutical Experiment Station, University of Wisconsin-Madison, Madison, WI, USA
| | - Wenlei Jiang
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA
| | - Xiaohui Jiang
- Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, USA
| | - Michel Berg
- Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| |
Collapse
|
49
|
Yu Y, Teerenstra S, Neef C, Burger D, Maliepaard M. A comparison of the intrasubject variation in drug exposure between generic and brand-name drugs: a retrospective analysis of replicate design trials. Br J Clin Pharmacol 2016; 81:667-78. [PMID: 26574160 DOI: 10.1111/bcp.12828] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 10/27/2015] [Accepted: 11/09/2015] [Indexed: 11/29/2022] Open
Abstract
AIMS The aim of the present study was to investigate whether differences in total and peak drug exposure upon generic substitution are due to differences between formulations or to intrasubject pharmacokinetic variability of the active substance. METHODS The study was designed as a retrospective reanalysis of existing studies. Nine replicate design bioequivalence studies representing six drug classes - i.e. for alendronate, atorvastatin, cyclosporin, ebastine, exemestane, mycophenolate mofetil, and ropinirole - were retrieved from the Dutch Medicines Regulatory Authority. RESULTS In most studies, the intrasubject variability in total and peak drug exposure was comparable for the brand-name [in the range 0.01-0.24 for area under the concentration-time curve (AUCt ) and 0.02-0.29 for peak plasma concentration (Cmax ) on a log scale] and generic (0.01-0.23 for AUCt and 0.08-0.33 for Cmax ) drugs, and was comparable with the intrasubject variability upon switching between those drugs (0.01-0.23 for AUCt and 0.06-0.33 for Cmax ). The variance related to subject-by-formulation interaction could be considered negligible (-0.069 to 0.047 for AUCt and -0.091 to 0.02 for Cmax ). CONCLUSION In the investigated studies, the variation in total and peak exposure seen when a patient is switched from a brand-name to a generic drug is comparable with that seen following repeated administration of the brand-name drug in the patient. Only the intrasubject variability seems to play a crucial and decisive role in the variation in drug exposure seen; no additional formulation-dependent variation in exposure is observed upon switching. Thus, our data support that, for the medicines that were included in the present investigation, from a clinical pharmacological perspective, the benefit-risk balance of a generic drug is comparable with that of the brand-name drug.
Collapse
Affiliation(s)
- Yang Yu
- Department of Pharmacology and Toxicology, CARIM, Maastricht University Medical Centre, Maastricht, The Netherlands.,Medicines Evaluation Board, Utrecht, The Netherlands
| | - Steven Teerenstra
- Medicines Evaluation Board, Utrecht, The Netherlands.,Department of Health Evidence, Biostatistics Section, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Cees Neef
- Department of Pharmacology and Toxicology, CARIM, Maastricht University Medical Centre, Maastricht, The Netherlands.,Department of Pharmacology and Toxicology, CAPHRI, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - David Burger
- Department of Pharmacy, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | | |
Collapse
|
50
|
|