<unk>  has a potential for drug interactions. Drugs that decrease breaking down of<unk>  or otherwise increase its levels include erythromycin, cimetidine, propoxyphene, and calcium channel blockers. Grapefruit juice raises the bioavailability of<unk>  by inhibiting the enzyme CYP3A4 in the gut wall and in the liver. Lower levels of<unk>  are seen when administrated with phenobarbital, phenytoin, or primidone, which can result in breakthrough seizure activity. Valproic acid and valnoctamide both inhibit microsomal epoxide hydrolase (mEH), the enzyme responsible for the breakdown of the active metabolite<unk> -10,11-epoxide into inactive metabolites. By inhibiting mEH, valproic acid and valnoctamide cause a build-up of the active metabolite, prolonging the effects of<unk>  and delaying its excretion.<unk> , as an inducer of cytochrome P450 enzymes, may increase clearance of many drugs, decreasing their concentration in the blood to subtherapeutic levels and reducing their desired effects. Drugs that are more rapidly metabolized with<unk>  include warfarin, lamotrigine, phenytoin, theophylline, valproic acid, many benzodiazepines, and methadone.<unk>  also increases the metabolism of the hormones in birth control pills and can reduce their effectiveness, potentially leading to unexpected pregnancies.
Carbamazepine
Oxcarbazepine
Capsazepine
Propazepine
Nitroxazepine
Eslicarbazepine acetate
Phenytoin
Lamotrigine