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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.
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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
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Frade VP, Paiva MJND, Martins I, Castro WVD, Belo VS, Baldoni AO, Lima PDF, Sanches C. Interchangeability among carbamazepine formulations: the impact over epilepsy patients. BRAZ J PHARM SCI 2022. [DOI: 10.1590/s2175-97902022e19594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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3
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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.
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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.
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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.
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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
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5
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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.
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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
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Affiliation(s)
- Martin Holtkamp
- Epilepsy-Center Berlin-Brandenburg, Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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7
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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.
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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.
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8
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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
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9
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Wheless JW, Phelps SJ. A Clinician's Guide to Oral Extended-Release Drug Delivery Systems in Epilepsy. J Pediatr Pharmacol Ther 2018; 23:277-292. [PMID: 30181718 DOI: 10.5863/1551-6776-23.4.277] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Epilepsy is one of the most common chronic neurologic disorders that affects individuals of all ages. It is primarily managed with antiepileptic drugs (AEDs), with the goal of maintaining complete seizure control combined with minimal or no adverse effects. Oral administration is the mainstay of AED delivery for patients with chronic epilepsy and consists essentially of immediate-release (IR) and modified-release (delayed-release and extended-release [ER]) dosage formulations. Extended-release formulations (hydrophilic or hydrophobic matrix systems, reservoir systems, and osmotic-release systems) release a drug in a controlled manner during an extended period of time following administration. Extended-release formulations have many advantages compared with IR formulations, including simplification of dosing regimens, reduction in pill burden, and reduction in the peak-to-trough fluctuations in serum drug concentration that may be associated with a decreased risk of adverse effects and of seizures. These advantages have the potential to increase adherence to antiepileptic therapy, improve the quality of life of patients, and reduce health care costs. This article, which is intended as a practical guide for clinicians, reviews the properties of the different ER AED formulations currently available and discusses the advantages of ER over IR formulations. Subsequently, an explanation of the technologic basis of the different oral ER formulations, the critical attributes that differentiate ER products, and their individual strengths and weaknesses is provided. Specific recommendations to practitioners on treating patients with ER formulations are included.
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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.
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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
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11
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Hammami MM, De Padua SJS, Hussein R, Al Gaai E, Khodr NA, Al-Swayeh R, Alvi SN, Binhashim N. Generic-reference and generic-generic bioequivalence of forty-two, randomly-selected, on-market generic products of fourteen immediate-release oral drugs. BMC Pharmacol Toxicol 2017; 18:78. [PMID: 29216899 PMCID: PMC5721559 DOI: 10.1186/s40360-017-0182-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 11/22/2017] [Indexed: 12/21/2022] Open
Abstract
Background The extents of generic-reference and generic-generic average bioequivalence and intra-subject variation of on-market drug products have not been prospectively studied on a large scale. Methods We assessed bioequivalence of 42 generic products of 14 immediate-release oral drugs with the highest number of generic products on the Saudi market. We conducted 14 four-sequence, randomized, crossover studies on the reference and three randomly-selected generic products of amlodipine, amoxicillin, atenolol, cephalexin, ciprofloxacin, clarithromycin, diclofenac, ibuprofen, fluconazole, metformin, metronidazole, paracetamol, omeprazole, and ranitidine. Geometric mean ratios of maximum concentration (Cmax) and area-under-the-concentration-time-curve, to last measured concentration (AUCT), extrapolated to infinity (AUCI), or truncated to Cmax time of reference product (AUCReftmax) were calculated using non-compartmental method and their 90% confidence intervals (CI) were compared to the 80.00%–125.00% bioequivalence range. Percentages of individual ratios falling outside the ±25% range were also determined. Results Mean (SD) age and body-mass-index of 700 healthy volunteers (28–80/study) were 32.2 (6.2) years and 24.4 (3.2) kg/m2, respectively. In 42 generic-reference comparisons, 100% of AUCT and AUCI CIs showed bioequivalence, 9.5% of Cmax CIs barely failed to show bioequivalence, and 66.7% of AUCReftmax CIs failed to show bioequivalence/showed bioinequivalence. Adjusting for 6 comparisons, 2.4% of AUCT and AUCI CIs and 21.4% of Cmax CIs failed to show bioequivalence. In 42 generic-generic comparisons, 2.4% of AUCT, AUCI, and Cmax CIs failed to show bioequivalence, and 66.7% of AUCReftmax CIs failed to show bioequivalence/showed bioinequivalence. Adjusting for 6 comparisons, 2.4% of AUCT and AUCI CIs and 14.3% of Cmax CIs failed to show bioequivalence. Average geometric mean ratio deviation from 100% was ≤3.2 and ≤5.4 percentage points for AUCI and Cmax, respectively, in both generic-reference and generic-generic comparisons. Individual generic/reference and generic/generic ratios, respectively, were within the ±25% range in >75% of individuals in 79% and 71% of the 14 drugs for AUCT and 36% and 29% for Cmax. Conclusions On-market generic drug products continue to be reference-bioequivalent and are bioequivalent to each other based on AUCT, AUCI, and Cmax but not AUCReftmax. Average deviation of geometric mean ratios and intra-subject variations are similar between reference-generic and generic-generic comparisons. Trial registration ClinicalTrials.gov identifier: NCT01344070 (registered April 3, 2011). Electronic supplementary material The online version of this article (doi:10.1186/s40360-017-0182-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Muhammad M Hammami
- Clinical Studies and Empirical Ethics Department, King Faisal Specialist Hospital and Research Center, P O Box # 3354, MBC 03, Riyadh, 11211, Saudi Arabia. .,Alfaisal University College of Medicine, Riyadh, Saudi Arabia.
| | - Sophia J S De Padua
- Clinical Studies and Empirical Ethics Department, King Faisal Specialist Hospital and Research Center, P O Box # 3354, MBC 03, Riyadh, 11211, Saudi Arabia
| | - Rajaa Hussein
- Clinical Studies and Empirical Ethics Department, King Faisal Specialist Hospital and Research Center, P O Box # 3354, MBC 03, Riyadh, 11211, Saudi Arabia
| | - Eman Al Gaai
- Clinical Studies and Empirical Ethics Department, King Faisal Specialist Hospital and Research Center, P O Box # 3354, MBC 03, Riyadh, 11211, Saudi Arabia
| | - Nesrine A Khodr
- Clinical Studies and Empirical Ethics Department, King Faisal Specialist Hospital and Research Center, P O Box # 3354, MBC 03, Riyadh, 11211, Saudi Arabia
| | - Reem Al-Swayeh
- Clinical Studies and Empirical Ethics Department, King Faisal Specialist Hospital and Research Center, P O Box # 3354, MBC 03, Riyadh, 11211, Saudi Arabia
| | - Syed N Alvi
- Clinical Studies and Empirical Ethics Department, King Faisal Specialist Hospital and Research Center, P O Box # 3354, MBC 03, Riyadh, 11211, Saudi Arabia
| | - Nada Binhashim
- Clinical Studies and Empirical Ethics Department, King Faisal Specialist Hospital and Research Center, P O Box # 3354, MBC 03, Riyadh, 11211, Saudi Arabia
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12
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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
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13
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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.
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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
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14
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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: 45] [Impact Index Per Article: 5.6] [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.
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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
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15
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van Dijkman SC, Alvarez-Jimenez R, Danhof M, Della Pasqua O. Pharmacotherapy in pediatric epilepsy: from trial and error to rational drug and dose selection - a long way to go. Expert Opin Drug Metab Toxicol 2016; 12:1143-56. [PMID: 27434782 DOI: 10.1080/17425255.2016.1203900] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Whereas ongoing efforts in epilepsy research focus on the underlying disease processes, the lack of a physiologically based rationale for drug and dose selection contributes to inadequate treatment response in children. In fact, limited information on the interindividual variation in pharmacokinetics and pharmacodynamics of anti-epileptic drugs (AEDs) in children drive prescription practice, which relies primarily on dose regimens according to a mg/kg basis. Such practice has evolved despite advancements in pediatric pharmacology showing that growth and maturation processes do not correlate linearly with changes in body size. AREAS COVERED In this review we aim to provide 1) a comprehensive overview of the sources of variability in the response to AEDs, 2) insight into novel methodologies to characterise such variation and 3) recommendations for treatment personalisation. EXPERT OPINION The use of pharmacokinetic-pharmacodynamic principles in clinical practice is hindered by the lack of biomarkers and by practical constraints in the evaluation of polytherapy. The identification of biomarkers and their validation as tools for drug development and therapeutics will require some time. Meanwhile, one should not miss the opportunity to integrate the available pharmacokinetic data with modeling and simulation concepts to prevent further delays in the development of personalised treatments for pediatric patients.
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Affiliation(s)
- Sven C van Dijkman
- a Division of Pharmacology , Leiden Academic Centre for Drug Research , Leiden , The Netherlands
| | - Ricardo Alvarez-Jimenez
- a Division of Pharmacology , Leiden Academic Centre for Drug Research , Leiden , The Netherlands
| | - Meindert Danhof
- a Division of Pharmacology , Leiden Academic Centre for Drug Research , Leiden , The Netherlands
| | - Oscar Della Pasqua
- b Clinical Pharmacology and Discovery Medicine , GlaxoSmithKline , Stockley Park , UK.,c Clinical Pharmacology and Therapeutics , University College London , London , UK
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16
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Vossler DG, Anderson GD, Bainbridge J. AES Position Statement on Generic Substitution of Antiepileptic Drugs. Epilepsy Curr 2016; 16:209-11. [PMID: 27330454 PMCID: PMC4913860 DOI: 10.5698/1535-7511-16.3.209] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- David G. Vossler
- Department of Neurology, University of Washington, Seattle, and UW Medicine, Valley Medical Center, Renton, WA
| | | | - Jacquelyn Bainbridge
- Skaggs School of Pharmacy and Pharmaceutical Sciences and Department of Neurology, University of Colorado Anschutz Medical Campus, Denver
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17
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French JA, Berg MJ. The place of generic modified-release formulations for epilepsy. Neurology 2016; 86:1572-3. [DOI: 10.1212/wnl.0000000000002620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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18
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Johnson EL, Chang YT, Davit B, Gidal BE, Krauss GL. Assessing bioequivalence of generic modified-release antiepileptic drugs. Neurology 2016; 86:1597-604. [PMID: 27016518 DOI: 10.1212/wnl.0000000000002607] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 12/28/2015] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES The purpose of this study was to determine how closely generic modified-release antiepileptic drugs (MR-AEDs) resemble reference (brand) formulations by comparing peak concentrations (Cmax), total absorption (area under the curve [AUC]), time to Cmax (Tmax), intersubject variability, and food effects between generic and reference products. METHODS We tabulated Cmax and AUC data from the bioequivalence (BE) studies used to support the approvals of generic Food and Drug Administration-approved MR-AEDs. We compared differences in 90% confidence intervals of the generic/reference AUC and Cmax geometric mean ratios, and intersubject variability, Tmax and delivery profiles and food effects. RESULTS Forty-two MR-AED formulations were studied in 3,175 healthy participants without epilepsy in 97 BE studies. BE ratios for AUC and Cmax were similar between most generic and reference products: AUC ratios varied by >15% in 11.4% of BE studies; Cmax varied by >15% in 25.8% of studies. Tmax was more variable, with >30% difference in 13 studies (usually delayed in the fed compared to fasting BE studies). Generic and reference MR products had similar intersubject variability. Immediate-release AEDs showed less intersubject variability in AUC than did MR-AEDs. CONCLUSIONS Most generic and reference MR-AEDs have similar AUC and Cmax values. Ratios for some products, however, are near acceptance limits and Tmax values may vary. Food effects are common with MR-AED products. High variability in pharmacokinetic values for once-a-day MR-AEDs suggests their major advantage compared to immediate-release AED formulations may be the convenience of less frequent dosing to improve adherence.
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Affiliation(s)
- Emily L Johnson
- From the Department of Neurology (E.L.J., G.L.K.), The Johns Hopkins University School of Medicine, Baltimore, MD; Johnson & Johnson (Y.-T.C.), New Brunswick; Merck & Co., Inc. (B.D.), Kenilworth, NJ; and University of Wisconsin (B.E.G.), School of Pharmacy, Madison, WI.
| | - Yi-Ting Chang
- From the Department of Neurology (E.L.J., G.L.K.), The Johns Hopkins University School of Medicine, Baltimore, MD; Johnson & Johnson (Y.-T.C.), New Brunswick; Merck & Co., Inc. (B.D.), Kenilworth, NJ; and University of Wisconsin (B.E.G.), School of Pharmacy, Madison, WI
| | - Barbara Davit
- From the Department of Neurology (E.L.J., G.L.K.), The Johns Hopkins University School of Medicine, Baltimore, MD; Johnson & Johnson (Y.-T.C.), New Brunswick; Merck & Co., Inc. (B.D.), Kenilworth, NJ; and University of Wisconsin (B.E.G.), School of Pharmacy, Madison, WI
| | - Barry E Gidal
- From the Department of Neurology (E.L.J., G.L.K.), The Johns Hopkins University School of Medicine, Baltimore, MD; Johnson & Johnson (Y.-T.C.), New Brunswick; Merck & Co., Inc. (B.D.), Kenilworth, NJ; and University of Wisconsin (B.E.G.), School of Pharmacy, Madison, WI
| | - Gregory L Krauss
- From the Department of Neurology (E.L.J., G.L.K.), The Johns Hopkins University School of Medicine, Baltimore, MD; Johnson & Johnson (Y.-T.C.), New Brunswick; Merck & Co., Inc. (B.D.), Kenilworth, NJ; and University of Wisconsin (B.E.G.), School of Pharmacy, Madison, WI
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19
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20
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O'Leary A, Usher C, Lynch M, Hall M, Hemeryk L, Spillane S, Gallagher P, Barry M. Generic medicines and generic substitution: contrasting perspectives of stakeholders in Ireland. BMC Res Notes 2015; 8:790. [PMID: 26670010 PMCID: PMC4678461 DOI: 10.1186/s13104-015-1764-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 11/30/2015] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND The Health (Pricing and Supply of Medical Goods) Act 2013 passed into law in July 2013 and legislated for generic substitution in Ireland. The aim of the study was to ascertain the knowledge and perceptions of stakeholders i.e. patients, pharmacists and prescribers, of generic medicines and to generic substitution with the passing of legislation. METHODS Three stakeholder specific questionnaires were developed to assess knowledge of and perceptions to generic medicines and generic substitution. Purposive samples of patients, prescribers and pharmacists were analysed. Descriptive quantitative and qualitative analyses were undertaken. RESULTS AND DISCUSSION A total of 762 healthcare professionals and 353 patients were recruited. The study highlighted that over 84% of patients were familiar with generic medicines and are supportive of the concept of generic substitution. Approximately 74% of prescribers and 84% of pharmacists were supportive of generic substitution in most cases. The main areas of concern highlighted by the healthcare professionals that might impact on the successful implementation of the policy, were the issue of bioequivalence with generic medicines, the computer software systems used at present in general practitioner (GP) surgeries and the availability of branded generics. The findings from this study identify a high baseline rate of acceptance to generic medicines and generic substitution among patients, prescribers and pharmacists in the Irish setting. The concerns of the main stakeholders provide a valuable insight into the potential difficulties that may arise in its implementation, and the need for on-going reassurance and proactive dissemination of the impact of the generic substitution policy. CONCLUSION The existing positive attitude to generic medicines and generic substitution among key stakeholders in Ireland to generic substitution, combined with appropriate support and collaboration should result in the desired increase in rates of prescribing, dispensing and use of generic medicines.
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Affiliation(s)
- A O'Leary
- National Centre for Pharmacoeconomics, St. James's Hospital, Dublin 8, Ireland.
- School of Pharmacy, Royal College of Surgeons, St. Stephens Green, Dublin 2, Ireland.
| | - C Usher
- National Centre for Pharmacoeconomics, St. James's Hospital, Dublin 8, Ireland.
| | - M Lynch
- School of Pharmacy, Royal College of Surgeons, St. Stephens Green, Dublin 2, Ireland.
| | - M Hall
- Department of Pharmacology and Therapeutics, St. James's Hospital, Dublin 8, Ireland.
| | - L Hemeryk
- Department of Pharmacology and Therapeutics, St. James's Hospital, Dublin 8, Ireland.
| | - S Spillane
- National Centre for Pharmacoeconomics, St. James's Hospital, Dublin 8, Ireland.
| | - P Gallagher
- School of Pharmacy, Royal College of Surgeons, St. Stephens Green, Dublin 2, Ireland.
| | - M Barry
- National Centre for Pharmacoeconomics, St. James's Hospital, Dublin 8, Ireland.
- Department of Pharmacology and Therapeutics, St. James's Hospital, Dublin 8, Ireland.
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22
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Petruševska M, Berglez S, Krisch I, Legen I, Megušar K, Peternel L, Abrahamsson B, Cristofoletti R, Groot D, Kopp S, Langguth P, Mehta M, Polli JE, Shah VP, Dressman J. Biowaiver Monographs for Immediate Release Solid Oral Dosage Forms: Levetiracetam. J Pharm Sci 2015; 104:2676-87. [DOI: 10.1002/jps.24350] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 12/04/2014] [Accepted: 12/11/2014] [Indexed: 11/10/2022]
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23
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Ting TY, Jiang W, Lionberger R, Wong J, Jones JW, Kane MA, Krumholz A, Temple R, Polli JE. Generic lamotrigine versus brand-name Lamictal bioequivalence in patients with epilepsy: A field test of the FDA bioequivalence standard. Epilepsia 2015. [PMID: 26201987 DOI: 10.1111/epi.13095] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To test the current U.S. Food and Drug Administration (FDA) bioequivalence standard in a comparison of generic and brand-name drug pharmacokinetic (PK) performance in "generic-brittle" patients with epilepsy under clinical use conditions. METHODS This randomized, double-blind, multiple-dose, steady-state, fully replicated bioequivalence study compared generic lamotrigine to brand-name Lamictal in "generic-brittle" patients with epilepsy (n = 34) who were already taking lamotrigine. Patients were repeatedly switched between masked Lamictal and generic lamotrigine. Intensive PK blood sampling at the end of each 2-week treatment period yielded two 12-h PK profiles for brand-name and generic forms for each patient. Steady-state area under the curve (AUC), peak plasma concentration (Cmax ), and minimum plasma concentration (Cmin ) data were subjected to conventional average bioequivalence (ABE) analysis, reference-scaled ABE analysis, and within-subject variability (WSV) comparisons. In addition, generic-versus-brand comparisons in individual patients were performed. Secondary clinical outcomes included seizure frequency and adverse events. RESULTS Generic demonstrated bioequivalence to brand. The 90% confidence intervals of the mean for steady-state AUC, Cmax , and Cmin for generic-versus-brand were 97.2-101.6%, 98.8-104.5%, and 93.4-101.0%, respectively. The WSV of generic and brand were also similar. Individual patient PK ratios for generic-versus-brand were similar but not identical, in part because brand-versus-brand profiles were not identical, even though subjects were rechallenged with the same product. Few subjects had seizure exacerbations or tolerability issues with product switching. One subject, however, reported 267 focal motor seizures, primarily on generic, although his brand and generic PK profiles were practically identical. SIGNIFICANCE Some neurologists question whether bioequivalence in healthy volunteers ensures therapeutic equivalence of brand and generic antiepileptic drugs in patients with epilepsy, who may be at increased risk for problems with brand-to-generic switching. Bioequivalence results in "generic-brittle" patients with epilepsy under clinical conditions support the soundness of the FDA bioequivalence standards. Adverse events on generic were not related to the small, allowable PK differences between generic and brand.
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Affiliation(s)
- Tricia Y Ting
- Department of Neurology, University of Maryland, Baltimore, Maryland, U.S.A
| | - Wenlei Jiang
- Food and Drug Administration, White Oak, Maryland, U.S.A
| | | | - Jessica Wong
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland, U.S.A
| | - Jace W Jones
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland, U.S.A
| | - Maureen A Kane
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland, U.S.A
| | - Allan Krumholz
- Department of Neurology, University of Maryland, Baltimore, Maryland, U.S.A
| | - Robert Temple
- Food and Drug Administration, White Oak, Maryland, U.S.A
| | - James E Polli
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland, U.S.A
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Therapeutic continuity in the treatment of psychiatric disorders. GLOBAL & REGIONAL HEALTH TECHNOLOGY ASSESSMENT 2015. [DOI: 10.5301/grhta.5000197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Lessing C, Ashton T, Davis P. The impact on health outcomes and healthcare utilisation of switching to generic medicines consequent to reference pricing: the case of lamotrigine in New Zealand. APPLIED HEALTH ECONOMICS AND HEALTH POLICY 2014; 12:537-546. [PMID: 25005492 DOI: 10.1007/s40258-014-0110-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
BACKGROUND Many countries have implemented generic reference pricing and substitution as methods of containing pharmaceutical expenditure. However, resistance to switching between medicines is apparent, especially in the case of anti-epileptic medicines. OBJECTIVES This study sought to exploit a nation-wide policy intervention on generic reference pricing in New Zealand to evaluate the health outcomes of patients switching from originator to generic lamotrigine, an anti-epileptic medicine. METHODS A retrospective study using the national health collections and prescription records was conducted comparing patients who switched from originator brand to generic lamotrigine with patients who remained on the originator brand. Primary outcome measures included switch behaviour, changes in utilisation of healthcare services at emergency departments, hospitalisations and use of specialist services, and mortality. RESULTS Approximately one-quarter of all patients using the originator brand of lamotrigine switched to generic lamotrigine, half of whom made the switch within 60 days of the policy implementation. Multiple switches (three or more) between generic and brand products were evident for around 10% of switchers. Switch-back rates of 3% were apparent within 30 days post-switch. No difference in heath outcome measures was associated with switching from originator lamotrigine to a generic equivalent and hence no increased costs could be found for switchers. CONCLUSIONS Switching from brand to generic lamotrigine is largely devoid of adverse health outcomes; however, creating an incentive to ensure a greater proportion of patients switch to generic lamotrigine is required to achieve maximal financial savings from a policy of generic reference pricing.
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Affiliation(s)
- Charon Lessing
- Health Systems Section, School of Population Health, University of Auckland, Private Bag 92019, Auckland, New Zealand,
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26
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Gwaza L, Gordon J, Welink J, Potthast H, Leufkens H, Stahl M, García-Arieta A. Adjusted Indirect Treatment Comparison of the Bioavailability of WHO-Prequalified First-Line Generic Antituberculosis Medicines. Clin Pharmacol Ther 2014; 96:580-8. [DOI: 10.1038/clpt.2014.144] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 06/25/2014] [Indexed: 11/10/2022]
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Dylst P, Vulto A, Simoens S. Demand-side policies to encourage the use of generic medicines: an overview. Expert Rev Pharmacoecon Outcomes Res 2014; 13:59-72. [DOI: 10.1586/erp.12.83] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Sommet A, Georgel B, Poutrain JC, Oustric S, Bourrel R, Montastruc JL, Birebent J. [Generic substitution in primary care in 2011: differences according to pharmacological classes?]. Rev Epidemiol Sante Publique 2013; 61:539-44. [PMID: 24211149 DOI: 10.1016/j.respe.2013.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 08/23/2013] [Accepted: 08/29/2013] [Indexed: 10/26/2022] Open
Abstract
BACKGROUND Generic substitution has been permitted for several years in France and is promoted in order to reduce health expenditures. However, reluctance concerning use of generic drugs exists for different reasons: suspicions about their efficacy and/or safety, differences in content (excipients) and discussions about bioequivalency. The aim of our study was to determine whether or not the substitution ratio differs according to pharmacological classes used in primary care. METHODS We conducted a descriptive study in the French Health Insurance Database using reimbursement data on drugs prescribed and delivered in the Midi-Pyrénées administrative district between March 2010 and March 2011. We selected different pharmacological classes largely used in primary care. For each class, a substitution ratio was calculated (DDD of generics delivered/DDD of brand name plus generics). A Chi(2) test was used in order to detect a difference between these substitution ratios. RESULTS The global substitution ratio was 72.32%. Values varied from 28.36% for thyroid hormones to 90.39% for antibiotics, with significant statistical difference (P<0.001). The substitution ratio was less than 50% for thyroid hormones (28.36%) and antiepileptics (45.28%). Higher substitution ratios were observed for protein pump inhibitors (88.81%), statins (87.81%), antidepressors (87.37%) and diuretics (86.1%). CONCLUSION This study highlights major differences in terms of the generic substitution ratio between different pharmacological classes. This difference can be explained in part by published guidelines. Further studies are needed to ascertain the precise point of view of patients, general practitioners and pharmacists concerning this issue.
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Affiliation(s)
- A Sommet
- Équipe de pharmacoépidémiologie, Inserm U 1027, laboratoire de pharmacologie médicale et clinique, faculté de médecine, université de Toulouse, 37, allées Jules-Guesde, 31000 Toulouse, France; Service de pharmacologie clinique, centre Midi-Pyrénées de pharmacovigilance, de pharmacoépidémiologie et d'information sur le médicament, CHU de Toulouse, 31000 Toulouse, France.
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Karalis V, Bialer M, Macheras P. Quantitative assessment of the switchability of generic products. Eur J Pharm Sci 2013; 50:476-83. [DOI: 10.1016/j.ejps.2013.08.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 08/13/2013] [Indexed: 11/24/2022]
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Bankstahl M, Bankstahl JP, Löscher W. Is switching from brand name to generic formulations of phenobarbital associated with loss of antiepileptic efficacy?: a pharmacokinetic study with two oral formulations (Luminal(®) vet, Phenoleptil(®)) in dogs. BMC Vet Res 2013; 9:202. [PMID: 24107313 PMCID: PMC3853146 DOI: 10.1186/1746-6148-9-202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 10/03/2013] [Indexed: 11/22/2022] Open
Abstract
Background In human medicine, adverse outcomes associated with switching between bioequivalent brand name and generic antiepileptic drug products is a subject of concern among clinicians. In veterinary medicine, epilepsy in dogs is usually treated with phenobarbital, either with the standard brand name formulation Luminal® or the veterinary products Luminal® vet and the generic formulation Phenoleptil®. Luminal® and Luminal® vet are identical 100 mg tablet formulations, while Phenoleptil® is available in the form of 12.5 and 50 mg tablets. Following approval of Phenoleptil® for treatment of canine epilepsy, it was repeatedly reported by clinicians and dog owners that switching from Luminal® (human tablets) to Phenoleptil® in epileptic dogs, which were controlled by treatment with Luminal®, induced recurrence of seizures. In the present study, we compared bioavailability of phenobarbital after single dose administration of Luminal® vet vs. Phenoleptil® with a crossover design in 8 healthy Beagle dogs. Both drugs were administered at a dose of 100 mg/dog, resulting in 8 mg/kg phenobarbital on average. Results Peak plasma concentrations (Cmax) following Luminal® vet vs. Phenoleptil® were about the same in most dogs (10.9 ± 0.92 vs. 10.5 ± 0.77 μg/ml), and only one dog showed noticeable lower concentrations after Phenoleptil® vs. Luminal® vet. Elimination half-life was about 50 h (50.3 ± 3.1 vs. 52.9 ± 2.8 h) without differences between the formulations. The relative bioavailability of the two products (Phenoleptil® vs. Luminal® vet.) was 0.98 ± 0.031, indicating that both formulations resulted in about the same bioavailability. Conclusions Overall, the two formulations did not differ significantly with respect to pharmacokinetic parameters when mean group parameters were compared. Thus, the reasons for the anecdotal reports, if true, that switching from the brand to the generic formulation of phenobarbital may lead to recurrence of seizures are obviously not related to a generally lower bioavailability of the generic formulation, although single dogs may exhibit lower plasma levels after the generic formulation that could be clinically meaningful.
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Affiliation(s)
- Marion Bankstahl
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, and Center for Systems Neuroscience, Hannover 30559, Germany.
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Josephson SA, Johnston SC, Hauser SL. Blockbusters for cheap? The difficulties surrounding generic biologics. Ann Neurol 2013; 74:A7-8. [PMID: 24115256 DOI: 10.1002/ana.24023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Johnston A. Equivalence and interchangeability of narrow therapeutic index drugs in organ transplantation. Eur J Hosp Pharm 2013; 20:302-307. [PMID: 24089632 PMCID: PMC3786630 DOI: 10.1136/ejhpharm-2012-000258] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 07/30/2013] [Accepted: 08/01/2013] [Indexed: 01/05/2023] Open
Abstract
The calcineurin inhibitors (CNIs), ciclosporin and tacrolimus, are the mainstay of immunosuppression in solid organ transplantation. Generic formulations of these drugs are now available. With increasing pressure on healthcare budgets and the consequent need to match health expectations to available resources, substitution with a generic product appears an attractive option to reduce costs. Approval of generic products differs from innovator drugs, and narrow therapeutic index drugs (NTIs; including CNIs) bring their own particular considerations. With NTIs, small variations in drug exposure could result in reduced immunosuppression or drug toxicity with potentially adverse effects on patient outcomes. NTIs are subject to stricter regulatory approval versus many other generic drugs. However, different generic formulations may still not necessarily be therapeutically equivalent in individuals, raising the possibility of significant differences in exposure between products. Although regional recommendations vary, many guidelines emphasise the need for NTI drug substitution to be initiated by the transplant physician, thus ensuring careful therapeutic monitoring and reduced negative patient impact. The need for therapeutic monitoring during generic substitution has important implications for the overall costs of generic treatment as these costs have to be factored in to the potential savings made from using generic formulations. The reduced acquisition costs of generic products may not necessarily translate into lower overall healthcare costs. This article examines the issue of equivalence and interchangeability of NTI drugs used in organ transplantation, the implications of the approval process for generic drugs on treatment efficacy and safety, and the effective management of substitutions between products.
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De Vuono A, Scicchitano F, Palleria C, Russo E, De Sarro G, Gallelli L. Lack of efficacy during the switch from brand to generic allopurinol. J Forensic Leg Med 2013; 20:540-2. [PMID: 23756530 DOI: 10.1016/j.jflm.2013.02.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 01/03/2013] [Accepted: 02/05/2013] [Indexed: 01/17/2023]
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Steinhoff B. Antikonvulsive Pharmakotherapie Jugendlicher und Erwachsener. ZEITSCHRIFT FUR EPILEPTOLOGIE 2013. [DOI: 10.1007/s10309-013-0307-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Interchangeability of Gabapentin Generic Formulations in the Netherlands: A Comparative Bioavailability Study. Clin Pharmacol Ther 2013; 94:519-24. [DOI: 10.1038/clpt.2013.108] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 05/11/2013] [Indexed: 11/08/2022]
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Bialer M, Shekh-Ahmad T, Braun TL, Halvorsen MB. Comparative steady-state pharmacokinetic evaluation of immediate-release topiramate and USL255, a once-daily extended-release topiramate formulation. Epilepsia 2013; 54:1444-52. [PMID: 23692553 DOI: 10.1111/epi.12225] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2013] [Indexed: 11/29/2022]
Abstract
PURPOSE Compare the pharmacokinetic (PK) profiles of immediate- and extended-release formulations of topiramate (TPM) in healthy subjects following multiple dosing, and evaluate maintenance of topiramate exposures after switching formulations. METHODS A randomized, open-label, single-center, two-way crossover, multiple-dose study comparing the steady-state PK profile of once-daily extended-release topiramate (USL255) to immediate-release topiramate (TPM-IR) administered twice-daily. The TPM PK profile was evaluated using standard PK parameters (e.g., AUC0-24 , Cmax , Cmin ) as well as less common PK criteria such as fluctuation index (FI), peak occupancy time (POT), and percent coefficient of variation (%CV). In addition, partial AUC (AUCp ) analyses provided comparisons of the AUC profiles over predetermined time intervals between TPM-IR and USL255. Pharmacokinetic equivalence between formulations was defined as containment of the 90% confidence intervals (CIs) of the USL255/TPM-IR geometric least-squares mean (GLSM) ratio within the equivalence limits of 80-125%. The effect of switching between treatments was assessed by evaluating equivalence of PK parameters between the day prior to formulation switch and the day immediately following formulation switch. Maintenance of steady state after switching formulations was also evaluated by comparing the slope between Cmin values at formulation switch and 24 h postswitch. Tolerability was evaluated through adverse event monitoring, vital sign measurements, and clinical laboratory evaluations. KEY FINDINGS USL255 was well tolerated and provided TPM plasma exposure equivalent to TPM-IR at various time intervals. USL255 also demonstrated a significantly lower Cmax (p < 0.001) and higher Cmin (p < 0.001), longer tmax , lower %CV, and 26% decreased FI, as compared with TPM-IR. Further, switching between TPM-IR and USL255 did not affect TPM concentrations, including Cmin , immediately after transitioning and at steady state. SIGNIFICANCE As compared with TPM-IR, USL255 provided equivalent plasma exposure with an extended absorption profile. Therefore, USL255 offers a once-daily alternative to twice-daily TPM-IR, with reduced TPM fluctuations.
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Affiliation(s)
- Meir Bialer
- Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel.
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Abstract
For economic reasons, the generic substitution of branded medications is common and welcome. These replacements are based on the concept of bioequivalence, which is considered equal to therapeutic equivalence. Regulatory standards for bioequivalence require the 90 % confidence intervals of group averages of pharmacokinetic measures of a generic and the original drug to overlap within ±20 %. However, therapeutic equivalence has been challenged for several psychotropic agents by retrospective studies and case reports. To evaluate the degree of bioequivalence and therapeutic equivalence of branded and generic psychotropic drugs, we performed an electronic search (from database inception until 24 May 2012 and without language restrictions) in PubMed/MEDLINE, Cochrane Library, and Web of Science. Search terms were "(generic) AND (psychotropic OR psychoactive OR antipsychotic OR antiepileptic OR antidepressant OR stimulant OR benzodiazepine)" or the respective individual substances. We included clinical studies, regardless of design, comparing branded with generic psychotropic drug formulations, identifying 35 such studies. We also included case reports/series reporting on outcomes after a switch between brand and generic psychotropics, identifying 145 clinical cases. Bioequivalence studies in healthy controls or animals, in-vitro studies, and health economics studies without medical information were excluded. An overview of the few randomized controlled studies supports that US FDA regulations assure clinically adequate drug delivery in the majority of patients switched from brand to generic. However, with a growing number of competing generic products for one substance, and growing economic pressure to substitute with the currently cheapest generic, frequent generic-generic switches, often unbeknownst to prescribing clinicians, raise concerns, particularly for antiepileptics/mood stabilizers. Generic-generic switches may vary by more than ±20 % from each other in individual patients since the pharmacokinetic properties of each generic may differ from the innovator drug in opposing directions. Ideally, therapeutic equivalence studies in addition to pharmacokinetic equivalence studies would be performed for each generic, reflecting the full variability of clinical responses due to changes of pharmacokinetic properties related to age, sex, ethnicity, genetic factors, and body mass index. This is particularly relevant, as bioequivalence studies are based on single-dose studies in healthy controls who are likely not representative of the patients who are prescribed the psychotropic medications. Additionally, individual case reports suggest potential clinical effects during brand-generic switches. Knowledge and consideration of intra-individual variations can help guide the clinical management during brand-generic or generic-generic switch periods. To optimize outcomes, clinicians need to consider that when using generic psychotropic medications, a change in the patient's clinical status can be related to psychological, interactional, physiological, and pharmacological factors that may or may not be related to the change to a generic drug. In addition, throughout all treatment periods, clinicians need to be aware of the currently dispensed product (i.e., branded or exact generic formulation), particularly when evaluating clinical changes in efficacy, tolerability, and adherence. If clinical problems occur, the first response should be an assessment of adherence and a careful dose adjustments of the generic drug rather than an immediate switch back to the originator.
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Abstract
Generic substitution of antiepileptic drugs remains a controversial area without a clear consensus to guide clinicians. The US Food and Drug Administration (FDA) requires rigorous testing of generic products and states that all approved products are interchangeable. FDA studies involve single doses in normal subjects so may not represent the performance of generic products in people with epilepsy. Physician surveys, case reports, and retrospective pharmacy database analyses suggest that antiepileptic drug generic substitution is associated with more health problems and high switchback rates, but these studies have insufficient detail on seizure control and blood levels. Several ongoing prospective randomized trials with rigorous pharmacokinetic methods aim to provide more data for decision-making.
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Hensler K, Uhlmann C, Porschen T, Benecke R, Rösche J. Generic substitution of antiepileptic drugs--a survey of patients' perspectives in Germany and other German-speaking countries. Epilepsy Behav 2013; 27:135-9. [PMID: 23416284 DOI: 10.1016/j.yebeh.2012.12.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/03/2012] [Accepted: 12/28/2012] [Indexed: 11/28/2022]
Abstract
In this study, we sought to determine the patients' attitudes towards generic substitution of antiepileptic drugs (AEDs) and their experiences with the usage of generic antiepileptic drugs in Germany and other German-speaking countries. A questionnaire was designed for a cross-sectional study. Two thousand copies of the questionnaire were delivered with a magazine edited by a patients' organization. Additionally, the questionnaire was placed on the internet platform of another patients' organization. Thirty-two percent of the patients who already experienced a switch to generic AEDs complained of problems with the switch. Patients who answered the magazine survey worried significantly more about generic substitution of AEDs than patients who answered the internet version. Patients who had never switched were more concerned about generic substitution than those who had already switched. Moreover, patients' beliefs differed between the use of generic drugs in acute medical conditions such as pain and infections and the use of generic AEDs in epilepsy.
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Affiliation(s)
- Katrin Hensler
- Klinik und Poliklinik für Neurologie, Universitätsmedizin Rostock, Germany
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Meyer J, Fardo D, Fleming ST, Hopenhayn C, Gokun Y, Ryan M. Generic antiepileptic drug prescribing: a cross-sectional study. Epilepsy Behav 2013. [PMID: 23182806 PMCID: PMC4278569 DOI: 10.1016/j.yebeh.2012.10.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The use of generic antiepileptic drugs (AEDs) in patients with epilepsy is controversial. The purpose of this study is to identify patient characteristics associated with increased odds of receiving a generic AED product. A large commercial database was used to identify patients with a primary diagnosis of epilepsy who were prescribed an AED during a three-month window. Data analysis found that those ≥65 years old had 15.7% greater odds of receiving a generic AED (OR = 1.157; 95% CI = 1.056-1.268). Patients with Medicaid were found to have 2.44 times the odds of having had a generic AED prescription (OR = 2.44; CI = 2.168-2.754). Patients residing in the Northeast had 12.6% decreased odds of receiving a generic AED (OR = 0.874; C I= 0.821-0.931). These patient characteristics could signify certain health care disparities and may represent potential confounders to future observational studies.
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Affiliation(s)
- Jennifer Meyer
- University of Kentucky College of Pharmacy, Lexington, KY, USA.
| | - David Fardo
- Department of Biostatistics, University of Kentucky College of Public Health, Lexington, KY, USA
| | - Steven T. Fleming
- Department of Epidemiology, University of Kentucky College of Public Health, Lexington, KY, USA
| | - Claudia Hopenhayn
- Department of Epidemiology, University of Kentucky College of Public Health, Lexington, KY, USA
| | - Yevgeniya Gokun
- University of Kentucky College of Pharmacy, Lexington, KY, USA
| | - Melody Ryan
- University of Kentucky College of Pharmacy, Lexington, KY, USA
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Statistical approaches to indirectly compare bioequivalence between generics: a comparison of methodologies employing artemether/lumefantrine 20/120 mg tablets as prequalified by WHO. Eur J Clin Pharmacol 2012; 68:1611-8. [DOI: 10.1007/s00228-012-1396-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Accepted: 08/29/2012] [Indexed: 11/26/2022]
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Abud-Mendoza C. Medical ethics, research and the pharmaceutical industry. REUMATOLOGIA CLINICA 2012; 8:233-235. [PMID: 22608694 DOI: 10.1016/j.reuma.2011.12.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 11/15/2011] [Accepted: 12/20/2011] [Indexed: 06/01/2023]
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Sirven JI, Noe K, Hoerth M, Drazkowski J. Antiepileptic drugs 2012: recent advances and trends. Mayo Clin Proc 2012; 87:879-89. [PMID: 22958992 PMCID: PMC3538494 DOI: 10.1016/j.mayocp.2012.05.019] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 04/20/2012] [Accepted: 05/02/2012] [Indexed: 12/21/2022]
Abstract
There are now 24 antiepileptic drugs (AEDs) approved for use in epilepsy in the United States by the Food and Drug Administration. A literature search was conducted using PubMed, MEDLINE, and Google for all English-language articles that discuss newly approved AEDs and the use of AEDs in epilepsy in the United States from January 1, 2008, through December 31, 2011. Five new agents were identified that have come onto the market within the past 2 years. Moreover, 3 trends involving AEDs have become clinically important and must be considered by all who treat patients with epilepsy. These trends include issues of generic substitution of AEDs, pharmacogenomics predicting serious adverse events in certain ethnic populations, and the issue of the suicide risk involving the entire class of AEDs. This article discusses the most recent AEDs approved for use in the United States and the 3 important trends shaping the modern medical management of epilepsy.
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Affiliation(s)
- Joseph I Sirven
- Department of Neurology, Division of Epilepsy, Mayo Clinic, Phoenix, AZ 85054, USA.
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Hartung DM, Middleton L, Svoboda L, McGregor JC. Generic substitution of lamotrigine among medicaid patients with diverse indications: a cohort-crossover study. CNS Drugs 2012; 26:707-16. [PMID: 22731934 PMCID: PMC3677951 DOI: 10.2165/11634260-000000000-00000] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Controversy exists about the safety of substituting generic antiepileptic drugs (AEDs). Lamotrigine, the prototypical newer AED, is often used for psychiatric and neurological conditions other than epilepsy. The safety of generic substitution of lamotrigine in diverse populations of AED users is unclear. OBJECTIVE The objective of this study was to evaluate potential associations between generic substitution of lamotrigine and adverse consequences in a population of diverse users of this drug. STUDY DESIGN This study was a retrospective cohort-crossover design using state Medicaid claims data from July 2006 through June 2009. METHODS Subjects were included in the cohort if they converted from brand to generic lamotrigine and had 2 years of lamotrigine use prior to conversion. The frequency of emergency department (ED) visits, hospitalizations and condition-specific ED visits or hospitalizations were recorded in the 60 days immediately following the conversion to generic lamotrigine, then compared with the incidence of the same events during a randomly selected time period indexed to one of the patient's past refills of branded lamotrigine. Multivariate conditional logistic regression was used to quantify the association between generic conversion and health services utilization while controlling for changes in lamotrigine dose and concurrent drug use. RESULTS Of the 616 unique subjects included in this analysis, epilepsy was the most common diagnosis (41%), followed by bipolar disorder (32%), pain (30%) and migraine (18%). Conversion to generic lamotrigine was not associated with a statistically significant increase in the odds of an ED visit (adjusted odds ratio [AOR] = 1.35; 95% confidence interval [CI] 0.92, 1.97), hospitalization (AOR = 1.21; 95% CI 0.60, 2.50) or condition-specific encounter (AOR 1.75; 95 CI 0.87, 3.51). CONCLUSIONS A statistically significant increase in ED visits, hospitalizations or condition-specific encounters was not observed following the switch from brand to generic lamotrigine, although a type II error cannot be ruled out.
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Affiliation(s)
- Daniel M Hartung
- Oregon State University College of Pharmacy, Oregon Health & Science University, Portland, OR 97239, USA.
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Boon P, Engelborghs S, Hauman H, Jansen A, Lagae L, Legros B, Ossemann M, Sadzot B, Smets K, Urbain E, van Rijckevorsel K. Recommendations for the treatment of epilepsy in adult patients in general practice in Belgium: an update. Acta Neurol Belg 2012; 112:119-31. [PMID: 22544726 PMCID: PMC3375006 DOI: 10.1007/s13760-012-0070-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 04/14/2012] [Indexed: 12/15/2022]
Abstract
In 2008, a group of Belgian epilepsy experts published recommendations for antiepileptic drug (AED) treatment of epilepsies in adults and children. Selection of compounds was based on the registration and reimbursement status in Belgium, the level of evidence for efficacy, common daily practice and the personal views and experiences of the authors. In November 2011 the validity of these recommendations was reviewed by the same group of Belgian epilepsy experts who contributed to the preparation of the original paper. The recommendations made in 2008 for initial monotherapy in paediatric patients were still considered to be valid, except for the first choice treatment for childhood absence epilepsy. This update therefore focuses on the treatment recommendations for initial monotherapy and add-on treatment in adult patients. Several other relevant aspects of treatment with AEDs are addressed, including considerations for optimal combination of AEDs (rational polytherapy), pharmacokinetic properties, pharmacodynamic and pharmacokinetic interaction profile, adverse effects, comorbidity, treatment of elderly patients, AED treatment during pregnancy, and generic substitution of AEDs.
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Affiliation(s)
- Paul Boon
- Department of Neurology, Ghent University Hospital, 185 De Pintelaan, 9000 Ghent, Belgium.
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Acyclovir achieves a lower concentration in African HIV-seronegative, herpes simplex virus 2-seropositive women than in non-African populations. Antimicrob Agents Chemother 2012; 56:2777-9. [PMID: 22330926 DOI: 10.1128/aac.06160-11] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acyclovir pharmacokinetics was evaluated in 68 HIV-seronegative, herpes simplex virus 2 (HSV-2)-seropositive African women, who received a single oral 400-mg dose of acyclovir, with plasma acyclovir concentrations measured over 8 h. Geometric mean peak concentration and area under the concentration-time curve were 0.31 μg/ml and 1.59 h · μg/ml, respectively, 54% and 52% lower than values from non-Africans. Lower acyclovir concentrations may partly explain the reduced acyclovir suppression of HSV-2 genital ulcer recurrence in HPTN 039 African women participants.
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Hottinger M, Liang BA. Deficiencies of the FDA in evaluating generic formulations: addressing narrow therapeutic index drugs. AMERICAN JOURNAL OF LAW & MEDICINE 2012; 38:667-689. [PMID: 23356099 DOI: 10.1177/009885881203800403] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Generic drugs represent a significant portion of the medical arsenal in treating disease. As copies of originator drugs, these drugs have been permitted abbreviated approval under the Hatch-Waxman Act. Yet with the current cost focus upon generic formulations, potential safety issues with generics have arisen. Although there is an established criterion of "bioequivalence" that generic formulations must demonstrate, narrow-therapeutic index drugs for sensitive clinical circumstances such as epilepsy, antiplatelet therapies, and mental health treatments may require different regulatory treatment than other generic drugs. Further, in these circumstances, differences in generic formulations may lead to adverse clinical outcomes due to less stringent bioequivalence tolerances. Yet there is no mandate for comparison between different generic formulations. Countries outside the United States advocate for narrowing tolerance ranges for these high risk health situations and the drugs for their treatment. We argue in this paper that additional patient safety matters must be taken into account for narrow therapeutic disease drugs, and regulatory bodies should emphasize greater tightness in bioequivalence before these narrow-therapeutic drug generic formulations are approved.
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Forum. Pharmaceut Med 2011. [DOI: 10.1007/bf03256875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Privitera M. Is antiepileptic drug generic substitution always safe? Slow progress toward definitive answers. Ann Neurol 2011; 70:192-3. [PMID: 21823152 DOI: 10.1002/ana.22523] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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