Moderate
Established
Deskripsi
Phenytoin reduces topiramate plasma levels via enzyme induction, potentially compromising seizure control when topiramate is added to phenytoin therapy.
Mekanisme
Phenytoin is a potent CYP3A4 and CYP2C19 inducer that increases topiramate metabolic clearance by approximately 48%.
Signifikansi Klinis
Topiramate levels may be halved by phenytoin co-administration; dose adjustments are typically required to maintain therapeutic effect.
Penatalaksanaan
Monitor seizure control and topiramate levels; titrate topiramate to therapeutic effect with awareness of enhanced clearance.