CARBAMAZEPINE, OXCARBAZEPINE, TOPIRAMATE & PHENYTOIN. AS AN INDUCER OF CYP ENZYMES INCREASES PERAMPANEL CLEARANCE. OTHER STRONG CYP3A INDUCERS (E.G., RIFAMPIN, ST. JOHN'S WORT) MAY ALSO GREATLY INCREASE CLEARANCE OF PERAMPANEL AND REDUCE PERAMPANEL PLASMA CONCENTRATIONS . CLOBAZAM, CLONAZEPAM, LAMOTRIGINE, LEVETIRACETAM, VALPROATE, AND ZONISAMIDE DID NOT HAVE AN EFFECT ON PERAMPANEL CLEARANCE.
PERAMPANEL UP TO 12 MG/DAY DID NOT SIGNIFICANTLY AFFECT THE CLEARANCE OF CLONAZEPAM, LEVETIRACETAM, PHENOBARBITAL, PHENYTOIN, TOPIRAMATE, OR ZONISAMIDE. IT HAS A STATISTICALLY SIGNIFICANT EFFECT ON THE CLEARANCE OF CARBAMAZEPINE, CLOBAZAM, LAMOTRIGINE, AND VALPROIC ACID, BUT THE INCREASES IN CLEARANCE OF THESE DRUGS WERE EACH LESS THAN 10% AT THE HIGHEST PERAMPANEL DOSE EVALUATED (12 MG/DAY). COADMINISTRATION WITH OXCARBAZEPINE RESULTED IN A 26% DECREASE IN CLEARANCE AND INCREASED ITS CONCENTRATIONS.
NO EFFECT OF PERAMPANEL ON ORAL CONTRACEPTIVES OR LEVODOPA. KETOCONAZOLE INCREASED ITS PLASMA CONC.
PERAMPANEL REDUCES SERUM CONC OF MEDAZOLAM.