Clobazam

Clobazam is a prescription benzodiazepine antiseizure medication used mainly in certain severe childhood epilepsies, often alongside other seizure drugs.

The drug is metabolized in the liver into an active compound, N-desmethylclobazam, which itself contributes to the antiseizure effect and to side effects such as sedation. That metabolite is cleared largely by the enzyme CYP2C19. Clobazam appears in cannabinoid discussions because prescription cannabidiol and clobazam are frequently co-prescribed, and cannabidiol inhibits CYP2C19, which causes the active metabolite of clobazam to accumulate.

In clinical trials, participants taking both drugs experienced more somnolence and sedation than those on either alone, and prescribing information advises monitoring and possible dose adjustment of clobazam. This interaction is one of the best-documented examples of a CBD drug-drug interaction. It illustrates why anyone taking a prescription medication, especially one processed by cytochrome P450 enzymes, is advised to discuss cannabinoid use with a prescriber or pharmacist before combining the two.