[Atrioventricular junctional arrhythmia due to oral phenytoin intoxication].

Phenytoin (Dilantin) is the drug of choice for most of the convulsive disorders. However, even when given orally it causes many adverse reactions, mainly affecting the nervous system, both central and peripheral. When administered intravenously, severe cardiovascular reactions may occur, including conduction disorders, sinus arrest, atrioventricular block or hypotension. Medline screening did not reveal previous reports of arrhythmias induced by oral phenytoin. We present a case in which oral phenytoin administered chronically for a convulsive disorder caused atrioventricular junctional arrhythmia.