Minor
Suspected
Descrição
Phenytoin, a potent CYP inducer, can increase the metabolism of montelukast, potentially reducing its plasma levels and therapeutic efficacy.
Mecanismo
Phenytoin induces CYP2C8 and CYP3A4, the principal enzymes responsible for montelukast oxidative metabolism, accelerating clearance and reducing AUC.
Significância Clínica
The interaction is predicted based on known enzyme induction by phenytoin; formal pharmacokinetic studies in humans are lacking but CYP induction by phenytoin is well established.
Conduta
Monitor asthma or allergic rhinitis control in patients starting or stopping phenytoin; consider increasing montelukast dose if symptom breakthrough occurs.