Interação entre Fenitoína e Rufinamida

Limited evidence suggests that HLA-B*1502 may be a risk factor for the development of SJS/TEN in patients of Asian ancestry taking other antiepileptic drugs associated with SJS/TEN, including phenytoin.

…defects), and abnormalities characteristic of fetal hydantoin syndrome, including dysmorphic skull and facial features, nail and digit hypoplasia, growth abnormalities (including microcephaly), and cognitive deficits, have been reported among children born to epileptic women who took phenytoin alone or in combination with other antiepileptic drugs during pregnancy.

Phenytoin: The decrease in clearance of phenytoin estimated at typical levels of rufinamide (C avss 15 μg/mL) is predicted to increase plasma levels of phenytoin by 7 to 21%.

As phenytoin is known to have non-linear pharmacokinetics (clearance becomes saturated at higher doses), it is possible that exposure will be greater than the model prediction.

Table 6: Summary of drug-drug interactions of BANZEL with other antiepileptic drugs AED Co-administered Influence of Rufinamide on AED concentration a) Influence of AED on Rufinamide concentration Carbamazepine Decrease by 7 to 13% b) Decrease by 19 to 26% Dependent on dose of carbamazepine Lamotrigine Decrease by 7 to 13% b) No Effect Phenobarbital Increase…

Effects of Other AEDs on BANZEL Potent cytochrome P450 enzyme inducers, such as carbamazepine, phenytoin, primidone, and phenobarbital, appear to increase the clearance of BANZEL (see Table 6).

Effects of BANZEL on other AEDs Population pharmacokinetic analysis of average concentration at steady state of carbamazepine, lamotrigine, phenobarbital, phenytoin, topiramate, and valproate showed that typical rufinamide C avss levels had little effect on the pharmacokinetics of other AEDs.