Generic substitution of antiepileptic drugs

Abstract

Substitution of antiepileptic drugs with generic formulations may affect individual people, as well as healthcare systems. Analyses of large medical claims databases suggest that generic substitution of antiepileptic drugs is associated with increased morbidity and greater use of healthcare resources. While a single brand-to-generic switch may be associated with a slight increase in overall medical costs, multiple switches may be associated with higher costs, perhaps because different generic agents are not required to be bioequivalent to each other. Generic substitution also affects the individual: along with the possible increased risk of seizures or adverse events, inconsistency of supply may make the medication appear unfamiliar, thus discouraging adherence. Importantly, substitution is often carried out at the dispensing level, without the knowledge or consent of physicians and affected individuals. Therefore, regulatory and professional bodies advocate that substitution should not be carried out without specific counseling of the individual by healthcare professionals on the details and implications of the change.

Keywords::

• AED
• antiepileptic drugs
• epilepsy
• generic drugs
• switching

Financial & competing interests disclosure

Josemir W Sander has received honoraria, consultancy fees, research grants and travel support from various pharmaceutical companies that are involved in the manufacturing of antiepileptic drugs, including Pfizer, UCB, Eisai, Janssen–Cilag, Sanofi-Aventis and GSK. Jürgen Bauer has spoken at educational symposia sponsored by UCB, Janssen–Cilag, Desitin, Eisai, Novartis, Sanofi–Synthelabo and Pfizer. Hermann Stefan has received honoraria for advisory board participation or lecturing from various pharmaceutical companies, including Cyberonics, 4D-Imaging, VSM, Janssen–Cilag, UCB, Eisai, Pfizer, GlaxoSmithKline and Desitin; there is no conflict of interest with the content of this paper. Philippe Ryvlin has received speaker’s or consultancy fees from the manufacturers of carisbamate and topiramate (Johnson and Johnson), ethosuximide, gabapentin, phenytoin and pregabalin (Pfizer), lamotrigine (GSK), lacosamide and levetiracetam (UCB Pharma), retigabine (Valeant), tiagabine, valproic acid and vigabatrin (Sanofi-Aventis), and rufinamide and zonisamide (Eisai).

Health economic details within the G5 countries were provided by Marina Adami, Ignacio Garcia Gonzalez, Maren Gaudig, Pejvack Motlagh, David Prill and Alessandra Sinibaldi. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Daniel Booth is an employee of Bioscript Stirling Ltd and was funded by Janssen–Cilag EMEA to provide editorial assistance with the drafting and completion of the manuscript. Editorial assistance with this manuscript was provided by Barbara Schäuble, who is an employee of Janssen–Cilag EMEA.

Notes

Data taken from [6,28,61,89,95,96].

Data taken from [202].

Data taken from [46,97–103].