Antiseizure medication (ASM)

An antiseizure medication is a drug prescribed to reduce the frequency or severity of seizures by calming abnormal electrical activity in the brain.

The class is also called anticonvulsants or antiepileptic drugs, though clinicians increasingly prefer antiseizure medication because the drugs manage seizures rather than epilepsy itself. Members work through different mechanisms, including blocking sodium or calcium channels, enhancing GABA signaling, or dampening glutamate release. Valproate, clobazam, levetiracetam and lamotrigine are common examples, and many people with drug-resistant epilepsy take two or more at once.

A purified cannabidiol prescription product is an approved antiseizure medication for Dravet syndrome, Lennox-Gastaut syndrome and tuberous sclerosis complex, which makes this the one area where cannabinoid evidence reaches the level of regulatory approval. Cannabidiol also interacts with several other antiseizure medications through liver enzymes, most notably raising blood levels of clobazam's active metabolite, so drug-drug interaction monitoring is part of its prescribing information. Over-the-counter hemp products are not antiseizure medications and are not studied or approved as such.