Hi, is he on some other drugs too because other drugs might decrease the level of phenytoin by enhancing its metabolism via induction of enzymes and can lead
to drug drug interction. “Drugs which may decrease
phenytoin levels include: carbamazepine, chronic alcohol abuse, reserpine, and sucralfate. Moban® brand of molindone hydrochloride contains calcium ions which interfere with the absorption of phenytoin.