Generic substitution in the treatment of epilepsy: patient and physician perceptions.

Generic substitution of branded antiepileptic drugs (AEDs) has sparked recent debates. We sought to understand perceptions about generic AED substitution and how these guide prescribing. Surveys were conducted among 550 adult patients with self-reported epilepsy and 606 physicians who treat patients with epilepsy. Physicians (88%) were concerned about an increase in breakthrough seizures in patients switched from a brand AED to a generic or among generics. Two-thirds of physicians and 34% of patients have linked breakthrough seizures to generic AED substitution. Physicians (75%) and patients (65%) were also concerned about efficacy. About half of physicians were extremely/very likely to request that brand AEDs not be substituted with a generic. In conclusion, perceptions among physicians and patients do not align with the FDA position that generic AEDs have the same clinical effect and safety profile as branded AEDs. Additional investigation on bioequivalence may help address ongoing concerns and inform policy-making decisions.