Generic versions of a reference antiseizure medication (ASM) can differ from each other in bioequivalence^10,11

Generic bioequivalence

• Generic versions of ASMs must be bioequivalent to the original reference drug, but do not need to be bioequivalent to other generic versions^10,11

Generic-to-generic switching

• One study found that some generic-to-generic switches in ASMs could potentially produce larger differences in pharmacokinetics (PK) than reference-to-generic product substitutions¹⁰

National Institute for Health and Care Excellence (NICE) guidelines recommend consistency

• NICE guidelines for epilepsy management recommend that patients receive a consistent supply of a particular manufacturer’s ASMs preparation. Different preparations of some ASMs may vary in bioavailability or PK profiles, and care needs to be taken to avoid reduced effect or excessive side effects¹²