The MHRA recommend that patients on certain antiepileptic drugs remain on the same brand where possible. In order to help decide which anti-epileptics may or may not be switched the MHRA have classified anti-epileptics in to 3 categories.
Category 1 - the patient should be maintained on a specific manufacturer’s product (carbamazepine, phenobarbital and phenytoin)
Category 2 - the need for continued supply of a particular manufacturer’s product should be based on clinical judgement and consultation with patient and/or carer, taking into account factors such as seizure frequency and treatment history (clobazam, clonazepam, eslicarbazepine acetate, lamotrigine, oxcarbazepine, perampanel, retigabine, rufinamide, sodium valproate, topiramate, and zonisamide).
Category 3 - usually unnecessary to ensure that patients are maintained on a specific manufacturer’s product unless there are specific reasons such as patient anxiety and risk of confusion or dosing errors (acetazolamide, brivaracetam, ethosuximide, gabapentin, lacosamide, levetiracetam, pregabalin, stiripentol, and vigabatrin).