Dilantin and Adrenal Insufficiency

Abstract: Various drugs may interact with a corticosteroid, altering its bioavailability. Phenytoin is one example which reduces the bioavailability of a corticosteroid via enzyme induction through the CYP450 system. In this case report, we examine an adrenally insufficient patient on steroid therapy who developed an acute adrenal crisis following phenytoin administration. We list other major drugs that interact with corticosteroids and discuss alternative antiepileptics that have less interaction.