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Blank LJ, Agarwal P, Kwon CS, Jetté N. Association of first anti-seizure medication choice with injuries in older adults with newly diagnosed epilepsy. Seizure 2023; 109:20-25. [PMID: 37178662 PMCID: PMC10686518 DOI: 10.1016/j.seizure.2023.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/05/2023] [Accepted: 05/07/2023] [Indexed: 05/15/2023] Open
Abstract
BACKGROUND Epilepsy incidence increases exponentially in older adults, who are also at higher risk of adverse drug effects. Anti-seizure medications (ASM) may be associated with sedation and injuries, but discontinuation can result in seizures. We sought to determine whether there was an association between prescribing non-guideline concordant ASM and subsequent injury as this could inform care models. METHODS Retrospective cohort study of adults 50 years or older with newly-diagnosed epilepsy in 2015-16, sampled from the MarketScan Databases. The outcome of interest was injury within 1-year of ASM prescription (e.g., burns, falls) and the exposure of interest was ASM category (recommended vs. not recommended by clinical guidelines). Descriptive statistics characterized covariates and a multivariable Cox-regression model was built to examine the association between ASM category and subsequent injury. RESULTS 5,931 people with newly diagnosed epilepsy were prescribed an ASM within 1-year. The three most common ASMs were: levetiracetam (62.86%), gabapentin (11.73%), and phenytoin (4.45%). Multivariable Cox-regression found that medication category was not associated with injury; however, older age (adjusted hazard ratio (AHR) 1.01/year), history of prior injury (AHR 1.77), traumatic brain injury (AHR 1.55) and ASM polypharmacy (AHR 1.32) were associated with increased hazard of injury. CONCLUSIONS Most older adults appear to be getting appropriate first prescriptions for epilepsy. However, a substantial proportion still receives medication that guidelines suggest avoiding. In addition, we show that ASM polypharmacy is associated with an increased hazard of injury within 1- year. Efforts to improve prescribing in older adults with epilepsy should consider how to reduce. both polypharmacy and exposure to medications that guidelines recommend avoiding.
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Affiliation(s)
- Leah J Blank
- Department of Neurology, Division of Health Outcomes & Knowledge Translation Research, Icahn school of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1137, New York, NY, United States; Department of Population Health and Policy, Institute for Healthcare Delivery, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1077, New York, NY, United States.
| | - Parul Agarwal
- Department of Neurology, Division of Health Outcomes & Knowledge Translation Research, Icahn school of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1137, New York, NY, United States; Department of Population Health and Policy, Institute for Healthcare Delivery, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1077, New York, NY, United States
| | - Churl-Su Kwon
- Departments of Neurology, Epidemiology, Neurosurgery and the Gertrude H. Sergievsky Center, Columbia University, 622 West 168th Street, New York, NY PH19-106, United States
| | - Nathalie Jetté
- Department of Neurology, Division of Health Outcomes & Knowledge Translation Research, Icahn school of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1137, New York, NY, United States; Department of Population Health and Policy, Institute for Healthcare Delivery, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1077, New York, NY, United States
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Welton J, Stratton G, Schoeninger B, Low MH, Moody A, D'Souza W. Shortages of antiseizure medications in Australia and the association with patient switching, and adherence in a community setting. Epilepsy Behav 2023; 141:109145. [PMID: 36913876 DOI: 10.1016/j.yebeh.2023.109145] [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: 11/20/2022] [Revised: 01/31/2023] [Accepted: 02/12/2023] [Indexed: 03/15/2023]
Abstract
PURPOSE To quantify sponsor-reported shortages of oral antiseizure medications in Australia, estimate the number of patients impacted, and the association between shortages and brand or formulation switching, and changes in adherence. METHODS A retrospective cohort study of sponsor-reported shortages (defined as where the supply of a medicine will not or will not be likely to meet the demand over a 6-month period) of antiseizure medications reported to the Medicine Shortages Reports Database (Therapeutic Goods Administration, Australia); cross-referencing shortages to the IQVIA-NostraData Dispensing Data (LRx) database, a deidentified, population-level dataset collecting longitudinal dispensation data on individual patients from ∼75% of Australian community pharmacy scripts. RESULTS Ninety-seven sponsor-reported ASM shortages were identified between 2019 and 2020; of those, 90 (93%) were shortages of generic ASM brands. Of 1,247,787 patients dispensed ≥1 ASMs, 242,947 (19.5%) were impacted by shortages. Sponsor-reported shortages occurred more frequently before the COVID-19 pandemic versus during the pandemic, however, shortages were estimated to affect more patients during the pandemic than before the pandemic. An estimated 330,872 patient-level shortage events were observed, and 98.5% were associated with shortages of generic ASM brands. Shortages occurred at a rate of 41.06 shortages per 100 person-years in patients on generic ASM brands versus 0.83 shortages per 100 person-years in patients on originator ASM brands. In patients taking a formulation of levetiracetam affected by a shortage, 67.6% switched to a different levetiracetam brand or formulation during shortages compared with 46.6% in non-shortage periods. CONCLUSIONS Approximately 20% of patients on ASMs were estimated to have been impacted by an ASM shortage in Australia. The rate of patient-level shortages was approximately 50 times higher for patients on generic ASM brands versus originator brands. Shortages of levetiracetam were associated with formulation and brand switching. Improved supply chain management amongst sponsors of generic ASMs is needed to maintain the continuity of supply in Australia.
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Affiliation(s)
- Jeremy Welton
- UCB Pharma, Level 1, 1155 Malvern Road, Malvern, VIC 3144, Australia; Department of Medicine - St Vincent's Hospital, The University of Melbourne, Clinical Sciences Building, Level 4 / 29 Regent Street, Fitzroy, VIC 3065, Australia.
| | - Giles Stratton
- IQVIA Australia, 8/201 Pacific Hwy, St Leonards, NSW 2065, Australia
| | | | - Min Hui Low
- IQVIA Australia, 8/201 Pacific Hwy, St Leonards, NSW 2065, Australia
| | - Anita Moody
- UCB Pharma, Level 1, 1155 Malvern Road, Malvern, VIC 3144, Australia
| | - Wendyl D'Souza
- Department of Medicine - St Vincent's Hospital, The University of Melbourne, Clinical Sciences Building, Level 4 / 29 Regent Street, Fitzroy, VIC 3065, Australia
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Analyzing Excipient-Related Adverse Events in Antiseizure Drug Formulations. Epilepsy Res 2022; 184:106947. [DOI: 10.1016/j.eplepsyres.2022.106947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 04/15/2022] [Accepted: 05/16/2022] [Indexed: 11/18/2022]
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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.
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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
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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.
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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).
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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]
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Bunniran S, Lee E, Kamble P, Suehs B, Franks B, Schwartz J, Thal G, Spalding J. Healthcare utilization and costs with fixed-source versus variable-source tacrolimus in patients receiving a kidney transplant. J Med Econ 2018; 21:1067-1074. [PMID: 30032686 DOI: 10.1080/13696998.2018.1503596] [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] [Indexed: 10/28/2022]
Abstract
AIMS Switching drug manufacturers in transplant patients may require an increased intensity of therapeutic monitoring, leading to additional healthcare visits, associated laboratory tests, and perhaps hospitalizations. As real-world studies examining the interchangeability of tacrolimus from different manufacturers are limited, the purpose of this study was to examine the healthcare resource utilization (HRU) and economic impact of tacrolimus-switching in kidney transplantation. MATERIALS AND METHODS This cross-sectional, retrospective study examined HRU and healthcare costs (HCCs) among patients with a kidney transplant who were prescribed tacrolimus from fixed-source (FS) vs variable-source (VS) manufacturers using claims data from the large US health plan Humana from October 1, 2012, to December 31, 2013. RESULTS Overall, 1,024 patients were identified (FS: n = 674, 66%; VS: n = 350, 34%). The number of therapeutic drug monitoring (TDM) events for the VS group was 13% greater than for the FS group after controlling for demographics, comorbidity score, and number of medications (incidence rate ratio = 1.13, p = .033). Adjusted total HCCs were 9% lower for VS (US$28,054 vs US$30,823, p = .045). In the unadjusted analysis, VS had greater emergency department (ED) utilization (45% vs 35%, p < .002). In the VS group, the mean (standard deviation [SD]) number of days from manufacturer switch to first outpatient visit was 23.8 (33.6), and the number of days (SD) to first TDM event was 43.6 (56.2). LIMITATIONS Study limitations include the lack of availability of many transplant-specific variables within the Humana database, potential errors/omissions in claims coding, and restriction of cross-sectional data examination to a 1-year period. CONCLUSIONS VS patients had greater TDM and lower total HCCs. Further research is warranted to understand the drivers of ED use among the VS group, and to determine factors associated with delayed TDM after regimen modification. Opportunities may exist to improve the quality of care for patients receiving immunosuppressant treatment with tacrolimus.
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Affiliation(s)
- Suvapun Bunniran
- a Comprehensive Health Insights , Humana Inc. , Louisville , KY , USA
| | - Edward Lee
- b Formerly Medical Affairs , Astellas Pharma Global Development, Inc. , Northbrook , IL , USA
| | - Pravin Kamble
- c Formerly Comprehensive Health Insights , Humana Inc. , Louisville , KY , USA
| | - Brandon Suehs
- a Comprehensive Health Insights , Humana Inc. , Louisville , KY , USA
| | - Billy Franks
- d Real-World Informatics , Astellas Pharma Global Development, Inc. , Leiden , Netherlands
| | - Jason Schwartz
- e Medical Affairs , Astellas Pharma Global Development, Inc. , Northbrook , IL , USA
| | - Gary Thal
- e Medical Affairs , Astellas Pharma Global Development, Inc. , Northbrook , IL , USA
| | - James Spalding
- e Medical Affairs , Astellas Pharma Global Development, Inc. , Northbrook , IL , USA
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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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Belleudi V, Trotta F, Vecchi S, Amato L, Addis A, Davoli M. Studies on drug switchability showed heterogeneity in methodological approaches: a scoping review. J Clin Epidemiol 2018; 101:5-16. [PMID: 29777799 DOI: 10.1016/j.jclinepi.2018.05.003] [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: 02/26/2018] [Revised: 04/18/2018] [Accepted: 05/09/2018] [Indexed: 10/16/2022]
Abstract
BACKGROUND AND OBJECTIVE Several drugs share the same therapeutic indication, including those undergoing patent expiration. Concerns on the interchangeability are frequent in clinical practice, challenging the evaluation of switchability through observational research. The objective of this study was to conduct a scoping review of observational studies on drug switchability to identify methodological strategies adopted to deal with bias and confounding. METHODS We searched PubMed, EMBASE, and Web of Science (updated January 31, 2017) to identify studies evaluating switchability in terms of effectiveness/safety outcomes or compliance. Three reviewers independently screened studies extracting all characteristics. Strategies to address confounding, particularly previous drug use and switching reasons, were considered. All findings were summarized in descriptive analyses. RESULTS Thirty-two studies, published in the last 10 years, met the inclusion criteria. Epilepsy, cardiovascular, and rheumatology were the most frequently represented clinical areas. Seventy-five percent of the studies reported data on effectiveness/safety outcomes. The most frequent study design was cohort (65.6%) followed by case-control (21.9%) and self-controlled (12.5%). Case-control and case-crossover studies showed homogeneous methodological strategies to deal with bias and confounding. Among cohort studies, the confounding associated with previous drug use was addressed introducing variables in multivariate model (47.3%) or selecting only adherent patients (14.3%). Around 30% of cohort studies did not report reasons for switching. In the remaining 70%, clinical parameters or previous occurrence of outcomes was measured to identify switching connected with lack of effectiveness or adverse events. CONCLUSION This study represents a starting point for researchers and administrators who are approaching the investigation and assessment of issues related to interchangeability of drugs.
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Affiliation(s)
- Valeria Belleudi
- Department of Epidemiology, Lazio Regional Health Service, Rome, Italy.
| | - Francesco Trotta
- Department of Epidemiology, Lazio Regional Health Service, Rome, Italy
| | - Simona Vecchi
- Department of Epidemiology, Lazio Regional Health Service, Rome, Italy
| | - Laura Amato
- Department of Epidemiology, Lazio Regional Health Service, Rome, Italy
| | - Antonio Addis
- Department of Epidemiology, Lazio Regional Health Service, Rome, Italy
| | - Marina Davoli
- Department of Epidemiology, Lazio Regional Health Service, Rome, Italy
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Trimboli M, Russo E, Mumoli L, Tripepi G, Fortunato F, Mastroianni G, Abate F, De Sarro G, Gambardella A, Labate A. Brand-to-generic levetiracetam switching: a 4-year prospective observational real-life study. Eur J Neurol 2018; 25:666-671. [DOI: 10.1111/ene.13568] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 12/27/2017] [Indexed: 11/29/2022]
Affiliation(s)
- M. Trimboli
- Department of Medical Sciences; Institute of Neurology; University Magna Graecia; Catanzaro Italy
| | - E. Russo
- Science of Health Department; School of Medicine; University Magna Graecia; Catanzaro Italy
| | - L. Mumoli
- Department of Medical Sciences; Institute of Neurology; University Magna Graecia; Catanzaro Italy
| | - G. Tripepi
- Institute of Clinical Physiology; Research Unit of Reggio Calabria; National Research Council (IFC-CNR); Reggio Calabria Italy
| | - F. Fortunato
- Department of Medical Sciences; Institute of Neurology; University Magna Graecia; Catanzaro Italy
| | - G. Mastroianni
- Department of Medical Sciences; Institute of Neurology; University Magna Graecia; Catanzaro Italy
| | - F. Abate
- Department of Medical Sciences; Institute of Neurology; University Magna Graecia; Catanzaro Italy
| | - G. De Sarro
- Science of Health Department; School of Medicine; University Magna Graecia; Catanzaro Italy
| | - A. Gambardella
- Department of Medical Sciences; Institute of Neurology; University Magna Graecia; Catanzaro Italy
| | - A. Labate
- Department of Medical Sciences; Institute of Neurology; University Magna Graecia; Catanzaro Italy
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Sarpatwari A, Lee MP, Gagne JJ, Lu Z, Dutcher SK, Jiang W, Campbell EG, Kesselheim AS. Generic Versions of Narrow Therapeutic Index Drugs: A National Survey of Pharmacists' Substitution Beliefs and Practices. Clin Pharmacol Ther 2017; 103:1093-1099. [PMID: 29165800 DOI: 10.1002/cpt.884] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 09/05/2017] [Accepted: 09/08/2017] [Indexed: 02/04/2023]
Abstract
Small changes in bioavailability of narrow therapeutic index (NTI) drugs can alter clinical outcomes, raising concern over generic NTI substitution. We surveyed pharmacists to identify their perceptions of generic NTI drugs, their frequency of performing generic NTI substitution, and predictors of this behavior. Of 710 respondents (33% response rate), 87% perceived generic NTI drugs as effective as their brand-name versions and 94% as safe. Whereas 82% almost always performed generic NTI substitution for initial prescriptions, only 60% did for refills. Pharmacists in non-chain settings (odds ratio (OR) = 2.37; 95% confidence interval (CI) = 1.40-4.02), in practice longer (per year OR = 1.04; 95% CI = 1.02-1.06), in states with affirmative patient consent laws (OR = 1.88; 95% CI = 1.06-3.32), and in states with NTI-specific substitution requirements (OR = 1.95; 95% CI = 1.16-3.26) were more likely not to substitute initial prescriptions. Education of non-chain and veteran pharmacists and elimination of affirmative patient consent and NTI-specific substitution requirements could increase generic NTI substitution.
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Affiliation(s)
- Ameet Sarpatwari
- 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, Massachusetts, USA
| | - Moa P Lee
- 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, Massachusetts, USA
| | - 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, Massachusetts, USA
| | - Zhigang Lu
- 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, Massachusetts, USA
| | - Sarah K Dutcher
- Office of Generic Drugs, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Wenlei Jiang
- Office of Generic Drugs, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Eric G Campbell
- Mongan Institute for Health Policy Center, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, 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, Massachusetts, USA
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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.
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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
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Kwan P, Palmini A. Association between switching antiepileptic drug products and healthcare utilization: A systematic review. Epilepsy Behav 2017. [PMID: 28641169 DOI: 10.1016/j.yebeh.2017.05.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
AIMS There is ongoing concern whether switching between different antiepileptic drug (AED) products may compromise patient care. We systematically reviewed changes in healthcare utilization following AED switch. METHODS We searched MEDLINE and EMBASE databases (1980-October 2016) for studies that assessed the effect of AED switching in patients with epilepsy on outpatient visits, emergency room visits, hospitalization and hospital stay duration. RESULTS A total of 14 articles met the inclusion criteria. All were retrospective studies. Four provided findings for specific AEDs only (lamotrigine, topiramate, phenytoin and divalproex), 9 presented pooled findings from multiple AEDs, and 1 study provided both specific (lamotrigine, topiramate, oxcarbazepine, and levetiracetam) and pooled findings. Three studies found an association between a switch of topiramate and an increase in healthcare utilization. Another three studies found that a brand-to-generic lamotrigine switch was not associated with an increased risk of emergently treated events (ambulance use, ER visits or hospitalization). The outcomes of the pooled AED switch studies were inconsistent; 5 studies reported an increased healthcare utilization while 5 studies did not. CONCLUSION Studies that have examined the association between an AED switch and a change in healthcare utilization report conflicting findings. Factors that may explain these inconsistent outcomes include inter-study differences in the type of analysis undertaken (pooled vs individual AED data), the covariates used for data adjustment, and the type of switch examined. Future medical claim database studies employing a prospective design are encouraged to address these and other factors in order to enhance inter-study comparability and extrapolation of findings.
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Affiliation(s)
- Patrick Kwan
- Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia; Department of Neurology, Royal Melbourne Hospital, Parkville, Victoria, Australia.
| | - André Palmini
- Faculty of Medicine, Neurology Service & Porto Alegre Epilepsy Surgery Program, Hospital São Lucas, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.
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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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Jennum P, Pickering L, Christensen J, Ibsen R, Kjellberg J. Welfare cost of childhood- and adolescent-onset epilepsy: A controlled national study. Epilepsy Behav 2016; 61:72-77. [PMID: 27317897 DOI: 10.1016/j.yebeh.2016.04.044] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Revised: 04/28/2016] [Accepted: 04/29/2016] [Indexed: 11/17/2022]
Abstract
OBJECTIVES Epilepsy is associated with a significant burden to patients and society. We calculated the factual excess in direct and indirect costs associated with childhood- and adolescent-onset epilepsy. METHODS Using records from the Danish National Patient Registry (1998-2002), we identified 3123 and 5018 patients with epilepsy aged 0-5years and 6-20years at the time of diagnosis, respectively. The two age groups of patients with epilepsy were matched to 6246 and 10,036 control persons without epilepsy, respectively, by gender, age, and geography. The controls were randomly chosen from the Danish Civil Registration System. Welfare costs included outpatient services, inpatient admissions, and emergency room visits based on the Danish National Patient Registry and information from the primary health-care sector based on data from the Danish Ministry of Health. This allowed the total health-care cost of epilepsy to be estimated. The use and costs of drugs were based on data from the Danish Medicines Agency. The frequencies of visits to outpatient clinics and hospitalizations and costs from primary sectors were based on data obtained from the National Patient Registry. RESULTS Children with epilepsy had higher welfare costs than controls. The highest cost was found one year after diagnosis, with higher costs up to 10years after diagnosis compared with controls. Children aged 0-5years incurred greater health-care costs than those aged 6-20years. CONCLUSION Epilepsy has major socioeconomic consequences for the individual person with epilepsy and for society.
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Affiliation(s)
- Poul Jennum
- Danish Center for Sleep Medicine, Neurophysiology Clinic, Faculty of Health Sciences, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark.
| | - Line Pickering
- Danish Center for Sleep Medicine, Neurophysiology Clinic, Faculty of Health Sciences, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark.
| | - Jakob Christensen
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark.
| | - Rikke Ibsen
- itracks, Klosterport 4E, 4, Aarhus, Denmark.
| | - Jakob Kjellberg
- Danish National Institute for Local and Regional Government Research, Copenhagen, Denmark.
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Jennum P, Christensen J, Ibsen R, Kjellberg J. Long-term socioeconomic consequences and health care costs of childhood and adolescent-onset epilepsy. Epilepsia 2016; 57:1078-85. [DOI: 10.1111/epi.13421] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2016] [Indexed: 11/27/2022]
Affiliation(s)
- Poul Jennum
- Department of Clinical Neurophysiology; Faculty of Health Sciences; Danish Center for Sleep Medicine; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - Jakob Christensen
- Department of Neurology; Aarhus University Hospital; Aarhus C Denmark
| | | | - Jakob Kjellberg
- Danish National Institute for Local and Regional Government Research; Copenhagen Denmark
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De Lott LB, Burke JF, Kerber KA, Skolarus LE, Callaghan BC. Medicare Part D payments for neurologist-prescribed drugs. Neurology 2016; 86:1491-8. [PMID: 27009256 DOI: 10.1212/wnl.0000000000002589] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 01/07/2016] [Indexed: 01/16/2023] Open
Abstract
OBJECTIVE To describe neurologists' Medicare Part D prescribing patterns and the potential effect of generic substitutions and price negotiation, which is currently prohibited. METHODS The 2013 Medicare Part D Prescriber Public Use and Summary files were used. Payments for medications were aggregated by provider and drug (brand or generic). Payment, proportion of generic claims or day's supply, and median payment per monthly supply of medication were calculated by physician specialty and drug. Savings from generic substitution were estimated for brand drugs with a generic available. Medicare prices were compared to drug prices negotiated by the federal government with pharmaceutical manufacturers for the Veterans Administration (VA). RESULTS Neurologists comprised 13,060 (1.2%) providers with $5.0 billion (4.8%) in total payments, third highest of all specialties, with a median monthly payment of $141 (interquartile range $85-225). Multiple sclerosis drugs had the highest payments ($1.8 billion). Within neurologic disease groups ($3.4 billion in payments), 54.2%-91.8% of monthly supplies were generic, but 11.9%-71.3% of the payment was for generic medications. Generic substitution resulted in a $269 million (6.5%) payment decrease. VA pricing resulted in $1.5 billion (44.5% of $3.4 billion) in savings. CONCLUSIONS High payment per monthly supply of medication underlies the high total neurology drug payments and is driven by multiple sclerosis drugs. Lowering drug expenditures by Medicare should focus on drug prices.
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Affiliation(s)
- Lindsey B De Lott
- From the Department of Neurology, University of Michigan, Ann Arbor.
| | - James F Burke
- From the Department of Neurology, University of Michigan, Ann Arbor
| | - Kevin A Kerber
- From the Department of Neurology, University of Michigan, Ann Arbor
| | - Lesli E Skolarus
- From the Department of Neurology, University of Michigan, Ann Arbor
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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.
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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
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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.
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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
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22
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Comparative effectiveness of generic versus brand-name antiepileptic medications. Epilepsy Behav 2015; 52:14-8. [PMID: 26386779 DOI: 10.1016/j.yebeh.2015.08.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Revised: 07/06/2015] [Accepted: 08/12/2015] [Indexed: 11/21/2022]
Abstract
OBJECTIVE The objective of this study was to compare treatment persistence and rates of seizure-related events in patients who initiate antiepileptic drug (AED) therapy with a generic versus a brand-name product. METHODS We used linked electronic medical and pharmacy claims data to identify Medicare beneficiaries who initiated one of five AEDs (clonazepam, gabapentin, oxcarbazepine, phenytoin, zonisamide). We matched initiators of generic versus brand-name versions of these drugs using a propensity score that accounted for demographic, clinical, and health service utilization variables. We used a Cox proportional hazards model to compare rates of seizure-related emergency room (ER) visit or hospitalization (primary outcome) and ER visit for bone fracture or head injury (secondary outcome) between the matched generic and brand-name initiators. We also compared treatment persistence, measured as time to first 14-day treatment gap, between generic and brand-name initiators. RESULTS We identified 19,760 AED initiators who met study eligibility criteria; 18,306 (93%) initiated a generic AED. In the matched cohort, we observed 47 seizure-related hospitalizations and ER visits among brand-name initiators and 31 events among generic initiators, corresponding to a hazard ratio of 0.53 (95% confidence interval, 0.30 to 0.96). Similar results were observed for the secondary clinical endpoint and across sensitivity analyses. Mean time to first treatment gap was 124.2 days (standard deviation [sd], 125.8) for brand-name initiators and 137.9 (sd, 148.6) for generic initiators. SIGNIFICANCE Patients who initiated generic AEDs had fewer adverse seizure-related clinical outcomes and longer continuous treatment periods before experiencing a gap than those who initiated brand-name versions.
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Divino V, Petrilla AA, Bollu V, Velez F, Ettinger A, Makin C. Clinical and economic burden of breakthrough seizures. Epilepsy Behav 2015; 51:40-7. [PMID: 26255884 DOI: 10.1016/j.yebeh.2015.06.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 05/14/2015] [Accepted: 06/06/2015] [Indexed: 11/19/2022]
Abstract
PURPOSE The purpose of this study was to measure health-care resource utilization and costs in treatment-adherent, previously seizure-free patients with epilepsy who were treated in the inpatient/emergency room (ER) setting for new-onset seizures, compared with matched controls. METHODS The study used a retrospective case/control study design using administrative claims from the IMS PharMetrics™ database. We identified adult patients with epilepsy with 1+ ER visit/hospitalization with primary diagnosis of epilepsy between 1/1/2006 and 3/31/2011, preceded by 6months of seizure-free activity and antiepileptic drug (AED) treatment adherence (≥80% of days covered by any AED); the first observed seizure defined the "breakthrough" seizure/index event. Treatment-adherent patients with epilepsy without any ER/hospital admission for seizures served as controls: an outpatient epilepsy-related medical claim within the selection window was chosen at random as the index date. The following were continuous enrollment requirements for all patients: ≥12-month pre- and ≥6-month postindex. Each case matched 1:1 to a control using propensity score matching. All-cause and epilepsy-related (epilepsy/convulsion diagnosis, AED pharmacy) resource utilization and unadjusted and adjusted direct health-care costs (per person, 2012 US dollars (USD)) were assessed in a 6-month follow-up period. PRINCIPAL RESULTS There were 5729 cases and 14,437 controls eligible. The final sample comprised 5279 matched case/control pairs. In unadjusted analyses, matched cases had significantly higher rates of all-cause hospitalization and ER visits compared to controls and significantly higher total all-cause direct health-care costs (median $12,714 vs. $5095, p<0.001) and total epilepsy-related costs among cases vs. controls (median $7293 vs. $1712, p<0.001), driven by higher inpatient costs. Among cases, costs increased with each subsequent seizure (driven by inpatient costs). Cases had 2.3 times higher adjusted all-cause costs and 8.1 times higher adjusted epilepsy-related costs than controls (both p<0.001). CONCLUSION Inpatient/ER-treated breakthrough seizures occurred among 28.4% of our treatment-adherent study sample and were associated with significant incremental health-care utilization and costs, primarily driven by hospitalizations. Our findings suggest the need for better seizure control via optimal patient management and the use of effective AED therapy, which can potentially lower health-care costs.
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Affiliation(s)
- Victoria Divino
- IMS Health, 8280 Willow Oaks Corporate Drive, Suite 775, Fairfax 22031, VA, USA.
| | - Allison A Petrilla
- IMS Health, 8280 Willow Oaks Corporate Drive, Suite 775, Fairfax 22031, VA, USA
| | - Vamsi Bollu
- Sunovion Pharmaceuticals Inc., 84 Waterford Drive, Marlborough 01752, MA, USA
| | - Fulton Velez
- Sunovion Pharmaceuticals Inc., 84 Waterford Drive, Marlborough 01752, MA, USA
| | - Alan Ettinger
- Albert Einstein College of Medicine, Neurological Surgery, PC, 1991 Marcus Avenue, Suite 108, Lake Success 11042, NY, USA
| | - Charles Makin
- IMS Health, 8280 Willow Oaks Corporate Drive, Suite 775, Fairfax 22031, VA, USA
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Polard E, Nowak E, Happe A, Biraben A, Oger E. Brand name to generic substitution of antiepileptic drugs does not lead to seizure-related hospitalization: a population-based case-crossover study. Pharmacoepidemiol Drug Saf 2015; 24:1161-9. [DOI: 10.1002/pds.3879] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 08/18/2015] [Accepted: 08/27/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Elisabeth Polard
- Department of Pharmacology, Pharmacovigilance, Pharmacoepidemiology and Drug Information Center; Rennes University Hospital; Rennes France
- Pharmacoepidemiology team (CTAD-PEPI); Rennes University Hospital; Rennes France
| | - Emmanuel Nowak
- Pharmacoepidemiology team (CTAD-PEPI); Rennes University Hospital; Rennes France
| | - André Happe
- Pharmacoepidemiology team (CTAD-PEPI); Rennes University Hospital; Rennes France
| | - Arnaud Biraben
- Department of Neurology; Rennes University Hospital; Rennes France
| | - Emmanuel Oger
- Department of Pharmacology, Pharmacovigilance, Pharmacoepidemiology and Drug Information Center; Rennes University Hospital; Rennes France
- Pharmacoepidemiology team (CTAD-PEPI); Rennes University Hospital; Rennes France
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Abstract
BACKGROUND To test the interchangeability of the commercially available (in Germany) latanoprost drugs and their generics respectively, the concentration of the active substance was tested. Guidelines of the European Medicines Agency postulate a sufficient bioequivalence, if the range of the agent is within 80-125% of the original drug. METHODS All compounds of latanoprost were procured registered. The concentration of latanoprost and benzalkoniumchloride was measured by high-performance liquid chromatography (HPLC) in a validated reference labroratory for 23 generics. In addition, the mean volume of drops and the pH of the formulation were measured. The packaging label and the readability of the enclosed information leaflet were checked. RESULTS All products contained less than 50 μg/ml latanoprost. The deviating reduction of the active substance (mean: - 7.39%, ± 2.8%) was accompanied by fluctions of the eyedrops' mass (mean: 0.03 g, ± 0.002 g). The concentration of benzalkonium chloride was mostly increased (median: 5.45%, min: - 2.5%, max: 11.5%). The pH of the original drug and the generics (median 6.78, min: 6.62, max: 6.81) was similar to the original drug, but was significantly different from an unpreserved formulation (pH 7.18). Due to type size, the packaging leaflet was illegible for humans with impaired vision. CONCLUSIONS Before prescribing generics in ophthalmology, different factors have to be considered, which might influence the amount of IOP lowering in effect. In the absence of healthcare research it is still unclear, how different bottle forms of eyedrops--such as appearance (e.g. Cyrillic characters) or pressure point (administration)--reduce the adherence of glaucoma patients.
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Shcherbakova N, Rascati K, Brown C, Lawson K, Novak S, Richards KM, Yoder L. Factors associated with seizure recurrence in epilepsy patients treated with antiepileptic monotherapy: A retrospective observational cohort study using US administrative insurance claims. CNS Drugs 2014; 28:1047-58. [PMID: 25086640 DOI: 10.1007/s40263-014-0191-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Few studies examine predictors of seizures in medically treated patients with epilepsy receiving antiepileptic monotherapy using a large patient population. OBJECTIVE Our objective was to identify clinical, medication, and demographic factors associated with seizure recurrence in medically treated patients with epilepsy receiving one of four antiepileptic monotherapy regimens: lamotrigine, levetiracetam, oxcarbazepine, or topiramate. STUDY DESIGN A retrospective cohort study was conducted using Innovus Invision™ Data Mart paid medical and prescription US commercial insurance claims data from January 2007 to September 2010. METHODS Patients aged 18-64 years with a primary or secondary diagnosis of epilepsy and one or more prescription claim for an antiepileptic drug (AED) pre-index were included. The primary outcome was incidence of a seizure or seizure-related event, defined as an emergency room visit, ambulance service use, or inpatient hospitalization medical claim with a primary or secondary diagnosis of epilepsy during the 1-year follow-up. The factors included AED adherence, somatic comorbidity (measured via Charlson Comorbidity Index), mental health comorbidity, pre-index seizure, type of epilepsy diagnosis, presence of AED-interacting medications and any bioequivalent AED switch. The covariates included age, gender, and geographic region of residence. RESULTS A total of 5.3 % (166/3,140) of patients on AED monotherapy had experienced a seizure or a seizure-related event requiring urgent care at 1-year follow-up. The multivariate analysis of the combined cohort showed that pre-index seizures/seizure-related events (odds ratio [OR] 4.23; 95 % confidence interval [CI] 2.77-6.46), any mental health comorbidity (OR 3.50; 95 % CI 2.14-5.70), and Charlson Comorbidity Index ≥1 (OR 2.91; 95 % CI 1.98-4.28) were significantly associated with post-index seizures/seizure-related events. Patients residing in Northeastern USA had a higher likelihood of a post-index seizure (OR 1.90; 95 % CI 1.17-3.08) than patients residing in the Southern region of the USA. Bioequivalent AED switch, type of epilepsy diagnosis, AED adherence, and presence of AED-interacting medications were not associated with seizure recurrence in the combined cohort analysis (p > 0.05). CONCLUSIONS Epilepsy patients with comorbid conditions (both mental and somatic diseases) and prior seizures were more likely to experience seizures at 1-year follow-up. Non-adherent patients and patients with bioequivalent AED switches appeared to show no increased likelihood of seizure at follow-up. Clinicians may consider these findings before starting or transitioning to an AED monotherapy.
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Affiliation(s)
- Natalia Shcherbakova
- Department of Pharmaceutical and Administrative Sciences, College of Pharmacy, Western New England University, 1215 Wilbraham Road, Springfield, MA, 01119, USA,
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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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Sander JW, Ryvlin P, Stefan H, Booth DR, Bauer J. Generic substitution of antiepileptic drugs. Expert Rev Neurother 2014; 10:1887-98. [DOI: 10.1586/ern.10.163] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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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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Boehm G, Yao L, Han L, Zheng Q. Development of the generic drug industry in the US after the Hatch-Waxman Act of 1984. Acta Pharm Sin B 2013. [DOI: 10.1016/j.apsb.2013.07.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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Hansen RN, Nguyen HP, Sullivan SD. Bioequivalent antiepileptic drug switching and the risk of seizure-related events. Epilepsy Res 2013; 106:237-43. [PMID: 23726541 DOI: 10.1016/j.eplepsyres.2013.04.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 04/12/2013] [Accepted: 04/27/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND Older antiepileptic drugs (AEDs) are known to have a narrow therapeutic index. As a consequence, switching between bioequivalent AEDs remains controversial in the management of epilepsy. We investigated the association between A-rated switching of each class of currently available AED and emergent treatment for a seizure-related event. METHODS We used a case-control method and claims data from the 2010 to 2011 Truven Health MarketScan(®) Commercial Claims Database to estimate the risk of seizure following a medication switch. Cases and controls with an epilepsy diagnosis were identified by emergency/inpatient or outpatient visit claims, respectively. Cases and controls (N=9110) were matched 1:1 by age, epilepsy diagnosis category and seizure medication. The exposure was defined as a switch between A-rated AEDs during the 90 days prior to index date. Conditional logistic regression was used to estimate the association, adjusting for gender, baseline Deyo-Charlson Comorbidity Index (0, 1, 2, or 3+), region (Northeast, Central, South, and West), and total AED medications. RESULTS A switch between A-rated AEDs occurred in 1053 (23.2%) cases and 827 (18.1%) matched controls. The unadjusted and adjusted odds ratios of a seizure-related event for switching were 1.38 (95% CI: 1.25-1.52) and 1.27 (95% CI: 1.14-1.41), respectively. The independent risk of an event also increased with each category increase in the Charlson score (CCI=1: 1.17, 95% CI: 1.02-1.33; CCI=2: 1.33, 95% CI: 1.09-1.62; CCI=3+: 1.99, 95% CI: 1.64-2.41). Older AEDs had infrequent switches compared to newer agents and were not associated with events. DISCUSSION We found a modest association between AED switching and seizure-related events. Our analysis suggests that the behavior of switching alone may lead to seizure-related events regardless of the medication or type of switch. Other disease or environmental characteristics may contribute to this association. Based on these and other findings, health care professionals and patients should be cautious about switching bioequivalent AEDs.
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Affiliation(s)
- Ryan N Hansen
- Pharmaceutical Outcomes Research and Policy Program, University of Washington, Seattle, WA, United States.
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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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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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Talati R, Scholle JM, Phung OP, Baker EL, Baker WL, Ashaye A, Kluger J, Coleman CI, White CM. Efficacy and safety of innovator versus generic drugs in patients with epilepsy: a systematic review. Pharmacotherapy 2012; 32:314-22. [PMID: 22461121 DOI: 10.1002/j.1875-9114.2012.01099.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Generic antiepileptic drugs achieve blood concentrations similar to those of innovator drugs in healthy volunteers, but their comparative effectiveness has not been well evaluated. Thus, we assessed the efficacy, tolerability, and safety of innovator versus generic antiepileptic drugs. We searched the MEDLINE database, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Web of Science for studies that evaluated innovator and generic antiepileptic drugs in patients with epilepsy and reported data on prespecified outcomes. We extracted data on study design, interventions, quality criteria, study population, baseline characteristics, and outcomes. Compared with initiation of innovator antiepileptic drugs, initiation of generic antiepileptic drugs did not significantly alter seizure occurrence (relative risk [RR] 0.87, 95% confidence interval [CI] 0.64-1.18; strength of evidence: low) or frequency (standardized mean difference 0.03, 95% CI -0.08-0.14; strength of evidence: low), withdrawals due to lack of efficacy (RR 1.02, 95% CI 0.41-2.54; strength of evidence: low) or adverse events (RR 0.79, 95% CI 0.28-2.20; strength of evidence: low), pharmacokinetic concentrations (maximum, minimum, or area under the curve [strength of evidence: low]), or a myriad of adverse events (strength of evidence: low or insufficient) in clinical trials. In qualitatively evaluated observational studies, switching between forms of antiepileptic drug (innovator to generic, generic to generic) may increase the risk of hospitalization (strength of evidence: low), hospital stay duration (strength of evidence: low), and a composite end point of medical service utilization (strength of evidence: insufficient) but may not increase outpatient service utilization (strength of evidence: low). Data are limited predominantly to carbamazepine, phenytoin, and valproic acid. Clinical trials are limited by small sample size, short-term nature, and lack of specification of A-rated generic products (generics that the United States Food and Drug Administration has deemed bioequivalent to the innovator drug). Observational trials lack full accounting for confounders and have inherent limitations. With a low strength of evidence, it appears that initiating an innovator or generic antiepileptic drug will provide similar efficacy, tolerability, and safety but that switching from one form to the other may be associated with more hospitalizations and longer hospital stays.
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Affiliation(s)
- Ripple Talati
- University of Connecticut/Hartford Hospital, Evidence-Based Practice Center, Hartford, Connecticut 06102-5037, USA
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Kinikar SA, Delate T, Menaker-Wiener CM, Bentley WH. Clinical outcomes associated with brand-to-generic phenytoin interchange. Ann Pharmacother 2012; 46:650-8. [PMID: 22550275 DOI: 10.1345/aph.1q601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Concerns that antiepileptic brand-to-generic interchange results in disruption of seizure control are widespread. However, little within-patient evidence exists examining such interchanges. OBJECTIVE To compare within-patient seizure control before and after the interchange of a branded to a single-source generic phenytoin among patients with seizures in a managed care organization. METHODS This was a pre-post, self-controlled, retrospective study. Adults with a history of seizure who used Dilantin Kapseals 100 mg extended phenytoin sodium, USP, capsules and whose therapy was interchanged to Taro Pharmaceuticals' AB-rated generic extended phenytoin sodium capsules, USP, 100 mg between July 2007 and May 2008 were included. Study outcomes included the comparisons of the proportions of patients with at least emergency department (ED) visit/inpatient hospitalization and medical office visit/nonoffice consultation for acute seizure in the 6 months before and after interchange. Outcomes were confirmed with manual chart reviews and adjusted for potential confounding medication use. RESULTS A total of 222 patients were included in the study. Patients were primarily middle-aged (mean 56 years), equally mixed by sex (47% female); most had nonintractable seizures. The majority of patients (~70%) were on phenytoin as monotherapy and had equivalent rates of purchases for potentially confounding medications in both pre- and postinterchange time periods (all p > 0.05). Low serum concentrations were detected more often in the postinterchange study period (adjusted p < 0.001). Despite this, there were low proportions of patients with confirmed seizure events that resulted in an ED visit/inpatient hospitalization in both pre- and postinterchange periods (both 6.3%, adjusted p = 0.937). The proportion of patients with confirmed seizure events diagnosed at a medical office visit was not significantly different between the preinterchange and postinterchange periods (12.2% vs 11.3%, adjusted p = 0.545). CONCLUSIONS No increased proportion of seizures was observed within patients when branded phenytoin was interchanged to an AB-rated, single-source, generic equivalent. More rigorous studies should be conducted to more thoroughly evaluate patient tolerability and drug efficacy when antiepileptic drugs are interchanged from brand to generic formulations.
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Affiliation(s)
- Shilpa A Kinikar
- Pharmacy Department, Kaiser Permanente Colorado, Denver, CO, USA.
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Acevedo C, Acevedo K. Epilepsy treatment in developing countries: drug treatment. HANDBOOK OF CLINICAL NEUROLOGY 2012; 108:925-941. [PMID: 22939076 DOI: 10.1016/b978-0-444-52899-5.00038-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Affiliation(s)
- Carlos Acevedo
- University of Los Andes, Clínica Alemana, Alemana, Santiago, Chile.
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Yamada M, Welty TE. Generic Substitution of Antiepileptic Drugs: A Systematic Review of Prospective and Retrospective Studies. Ann Pharmacother 2011; 45:1406-15. [DOI: 10.1345/aph.1q349] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Objective: To systematically review the literature on generic antiepileptic drugs (AEDs), evaluate the efficacy and safety of generic AED substitution, and perform pharmacokinetic (PK) analysis using the American Academy of Neurology (AAN) scheme to classify evidence. Data Sources: PubMed and Cumulative Index to Nursing and Allied Health Literature searches from January 1, 1980, to October 15, 2010, were performed using the search terms anticonvulsant, antiepileptic drug, carbamazepine, divalproex, ethosuximide, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, phénobarbital, Phenytoin, primidone, topiramate, valproate, valproic acid, and zonisamide; bioavailability, bioequivalence, bioequivalency, bioequivalent, and substitution; and generic. Study Selection and Data Extraction: Retrospective and prospective controlled studies of generic substitution of AEDs were included in the review. Non-English-language articles and uncontrolled clinical studies were excluded, Published articles were categorized using the AAN criteria for systematic reviews. Data Synthesis: We identified 156 articles. Of these, 20 met our inclusion criteria; 7 were retrospective studies, 6 were prospective studies in patients with epilepsy, and 7 were prospective studies in healthy subjects. All articles were rated Class I to Class III, using AAN criteria. The retrospective studies were categorized as Class III and showed a significant relationship between generic substitution and increased use of health care resources because of seizures or AED toxicity. Prospective studies were categorized as Class I, II, and III. Prospective studies in patients showed no differences between brand and generic drugs in PK parameters of bioequivalence. Three prospective studies in healthy subjects reported significant differences in maximum drug concentrations. Comparison of brand and generic drugs revealed no significant difference in seizure frequency; however, some prospective studies showed significant differences in PK parameters, primarily those not used for bioequivalence determinations. Conclusions: There is inconsistency between retrospective and prospective studies of generic AED substitution. The highest levels of evidence indicate that there should not be a problem with generic substitution, although some patients are more prone to problems with the generic products. Some evidence suggests that switches between multiple generic AED products in certain individuals may be problematic.
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Affiliation(s)
- Mikiko Yamada
- Department of Pharmacy Practice, School of Pharmacy, University of Kansas, Kansas City, KS
| | - Timothy E Welty
- Department of Pharmacy Practice, School of Pharmacy, University of Kansas
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Krauss GL, Caffo B, Chang YT, Hendrix CW, Chuang K. Assessing bioequivalence of generic antiepilepsy drugs. Ann Neurol 2011; 70:221-8. [PMID: 21717495 DOI: 10.1002/ana.22452] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 03/22/2011] [Accepted: 04/01/2011] [Indexed: 11/10/2022]
Affiliation(s)
- Gregory L Krauss
- Department of Neurology, Johns Hopkins University, Baltimore, MD, USA.
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Erickson SC, Le L, Ramsey SD, Solow BK, Zakharyan A, Stockl KM, Harada ASM, Curtis B. Clinical and pharmacy utilization outcomes with brand to generic antiepileptic switches in patients with epilepsy. Epilepsia 2011; 52:1365-71. [PMID: 21692778 DOI: 10.1111/j.1528-1167.2011.03130.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To determine if switching from select branded to generic equivalent antiepileptic drugs (AEDs) in patients with epilepsy is associated with adverse outcomes. METHODS A retrospective cohort study using a large health insurance plan claims database comparing patients with epilepsy who switched from brand to generic equivalent phenytoin, lamotrigine, or divalproex after 6 months (switch cohorts) to matched patients who remained on the brand (nonswitch cohorts). Primary outcomes measured include the incidence rate ratio (IRR) of discontinuation of the index AED; change in dose of index AED or addition of another AED; and the event rate ratio (ERR) of the composite of all-cause emergency department (ED) visits or hospitalizations. KEY FINDINGS Lamotrigine and divalproex showed no differences in AED utilization changes between the switchers and nonswitchers [IRR for lamotrigine 1.00, 95% confidence interval (CI) 0.84-1.19; IRR for divalproex 1.02, 95% CI, 0.88-1.42]. Compared with nonswitchers, the phenytoin switch cohort had greater incidence of AED utilization changes (IRR 1.85, 95% CI 1.50-2.29). The switch versus nonswitch cohorts did not demonstrate differences in ED visits or hospitalizations for the studied AEDs (ERR for phenytoin 0.96, 95% CI 0.80-1.16; ERR for lamotrigine 0.97, 95% CI 0.80-1.17; ERR for divalproex 0.83, 95% CI 0.66-1.06). SIGNIFICANCE Brand to generic switching of phenytoin was not associated with more clinical events but was associated with increased index drug discontinuations, dose changes, or therapy augmentations. Lamotrigine or divalproex brand to generic switching was not associated with increased incidence of events or utilization changes compared with patients remaining on the branded product. Changes in AED utilization may be more sensitive than ED visits and hospitalizations for detecting adverse outcomes.
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Affiliation(s)
- Sara C Erickson
- Clinical Analytics andOutcomes Research, Prescription Solutions, 2300 Main Street, Irvine, CA 92614, U.S.A.
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Trinka E, Krämer G, Graf M. Requirements for generic antiepileptic medicines: a clinical perspective. J Neurol 2011; 258:2128-32. [DOI: 10.1007/s00415-011-6126-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 05/25/2011] [Accepted: 05/26/2011] [Indexed: 11/27/2022]
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Interchangeability of generic anti-epileptic drugs: a quantitative analysis of topiramate and gabapentin. Eur J Clin Pharmacol 2011; 67:1007-16. [DOI: 10.1007/s00228-011-1041-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Accepted: 03/21/2011] [Indexed: 10/18/2022]
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45
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Jennum P, Gyllenborg J, Kjellberg J. The social and economic consequences of epilepsy: A controlled national study. Epilepsia 2011; 52:949-56. [DOI: 10.1111/j.1528-1167.2010.02946.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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46
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Hagemann G, Zinke J, Fuchs M, Witte OW. [Change from original preparations to generics. A case example with oxcarbazepine]. DER NERVENARZT 2010; 81:1498-1500. [PMID: 20509018 DOI: 10.1007/s00115-010-3033-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Affiliation(s)
- G Hagemann
- Hans Berger Klinik für Neurologie, Friedrich-Schiller-Universität, Jena.
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Desmarais JE, Beauclair L, Margolese HC. Switching from brand-name to generic psychotropic medications: a literature review. CNS Neurosci Ther 2010; 17:750-60. [PMID: 21114789 DOI: 10.1111/j.1755-5949.2010.00210.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Generic medications do not undergo the rigorous approval process required of original medications. Their effectiveness and safety is expected to be equal to that of their more expensive counterparts. However, several case reports and studies describe clinical deterioration and decreased tolerability with generic substitution. Pubmed was searched from January 1, 1974 to March 1, 2010. The MeSH term "generic, drugs" was combined with "anticonvulsants," "mood stabilizers," "lithium," "antidepressants," "antipsychotics," "anxiolytics," and "benzodiazepines." Additional articles were obtained by searching the bibliographies of relevant references. Articles in English, French, or Spanish were considered if they discussed clinical equivalence of generic and brand-name medications, generic substitution, or issues about effectiveness, tolerability, compliance, or economics encountered with generics. Clinical deterioration, adverse effects, and changes in pharmacokinetics are described with generic substitution of several anticonvulsants/mood stabilizers (carbamazepine, valproate, lamotrigine, gabapentin, topiramate, lithium), antidepressants (amitriptyline, nortriptyline, desipramine, fluoxetine, paroxetine, citalopram, sertraline, venlafaxine, mirtazapine, bupropion), antipsychotics (risperidone, clozapine), and anxiolytics (clonazepam, alprazolam). Generics do not always lead to the anticipated monetary savings and also raise compliance issues. Although the review is limited by publication bias and heterogeneity of the studies in the literature, we believe there is enough concern to advise generic switching on an individual basis with close monitoring throughout the transition. Health professionals should be aware of the stakes around generic substitution especially when health economics promote universal use of generics.
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Affiliation(s)
- Julie Eve Desmarais
- McGill University Health Centre, Allan Memorial Institute, Clinical Psychopharmacology Unit, Montreal, QC, Canada.
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Gagne JJ, Avorn J, Shrank WH, Schneeweiss S. Refilling and switching of antiepileptic drugs and seizure-related events. Clin Pharmacol Ther 2010; 88:347-53. [PMID: 20631693 PMCID: PMC2996138 DOI: 10.1038/clpt.2010.90] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We sought to estimate the risk of seizure-related events associated with refilling prescriptions for antiepileptic drugs (AEDs) and to estimate the effect of switching between brand-name and generic drugs or between two generic versions of the same drug. We conducted a case-crossover study using health-care databases from British Columbia, Canada, among AED users who had an emergency room visit or hospitalization for seizure (index seizure-related event), defined using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9) codes 345.xx (epilepsy and recurrent seizures) and 780.3x (convulsions), between 1997 and 2005. AED prescription refilling itself was associated with 2.3-fold elevated odds of seizure-related events when the refill occurred within 21 days before the index event (odds ratio (OR) 2.31; 95% confidence interval (CI) 1.56-3.44). The OR was 2.75 (95% CI 0.88-8.64) for refills that involved switching, yielding a refill-adjusted OR for switching of 1.19 (95% CI 0.35-3.99). Refilling the same AED prescription was associated with an elevated risk of seizure-related events whether or not the refill involved switching from a brand-name to a generic product.
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Affiliation(s)
- J J Gagne
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
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Helmers SL, Paradis PE, Manjunath R, Duh MS, Lafeuille MH, Latrémouille-Viau D, Lefebvre P, Labiner DM. Economic burden associated with the use of generic antiepileptic drugs in the United States. Epilepsy Behav 2010; 18:437-44. [PMID: 20580619 DOI: 10.1016/j.yebeh.2010.05.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 04/08/2010] [Accepted: 05/18/2010] [Indexed: 10/19/2022]
Abstract
This study quantifies the economic burden associated with generic-versus-branded use of antiepileptic drugs (AEDs) in the United States. Adult patients with epilepsy receiving carbamazepine, gabapentin, phenytoin, primidone, or zonisamide were selected from the PharMetrics database. By use of an open-cohort design, patients were classified into mutually exclusive periods of generic-versus-branded AED use. Annualized cost differences (CDs) between periods were estimated using multivariate regressions. Results were stratified into stable versus unstable epilepsy and newer-generation versus older-generation AEDs. A total of 33,625 patients (52% male, mean age=51 years) were observed. Periods of generic AED treatment were associated with higher medical service costs (adjusted CD [95% CI]=$3186 [$2359; $4012]), stable pharmacy costs ($69 [$-34; $171]), and greater total costs ($3254 [$2403; $4105]) versus brand use. Epilepsy-related costs represented 30% of incremental costs. Similar findings were observed for patients with stable and unstable epilepsy and users of newer-generation and older-generation AEDs. Significantly higher health care costs were observed during generic AED use across seizure control and AED subgroups.
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Kesselheim AS, Stedman MR, Bubrick EJ, Gagne JJ, Misono AS, Lee JL, Brookhart MA, Avorn J, Shrank WH. Seizure outcomes following the use of generic versus brand-name antiepileptic drugs: a systematic review and meta-analysis. Drugs 2010; 70:605-21. [PMID: 20329806 DOI: 10.2165/10898530-000000000-00000] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The automatic substitution of bioequivalent generics for brand-name antiepileptic drugs (AEDs) has been linked by anecdotal reports to loss of seizure control. To evaluate studies comparing brand-name and generic AEDs, and determine whether evidence exists of superiority of the brand-name version in maintaining seizure control. English-language human studies identified in searches of MEDLINE, EMBASE and International Pharmaceutical Abstracts (1984 to 2009). Randomized controlled trials (RCTs) and observational studies comparing seizure events or seizure-related outcomes between one brand-name AED and at least one alternative version produced by a distinct manufacturer. We identified 16 articles (9 RCTs, 1 prospective nonrandomized trial, 6 observational studies). We assessed characteristics of the studies and, for RCTs, extracted counts for patients whose seizures were characterized as 'controlled' and 'uncontrolled'. Seven RCTs were included in the meta-analysis. The aggregate odds ratio (n = 204) was 1.1 (95% CI 0.9, 1.2), indicating no difference in the odds of uncontrolled seizure for patients on generic medications compared with patients on brand-name medications. In contrast, the observational studies identified trends in drug or health services utilization that the authors attributed to changes in seizure control. Although most RCTs were short-term evaluations, the available evidence does not suggest an association between loss of seizure control and generic substitution of at least three types of AEDs. The observational study data may be explained by factors such as undue concern from patients or physicians about the effectiveness of generic AEDs after a recent switch. In the absence of better data, physicians may want to consider more intensive monitoring of high-risk patients taking AEDs when any switch occurs.
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Affiliation(s)
- Aaron S Kesselheim
- Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02120, USA.
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