diamode and Altaryl Interactions

Interactions between diamode(loperamide) and Altaryl (diphenhydrAMINE)

diphenhydrAMINE and loperamide (Moderate Drug-Drug)

MONITOR: Coadministration with drugs that possess significant anticholinergic activity may potentiate the antimotility effect of loperamide. An isolated case report describes an incident of fatal gastroenteritis during concomitant treatment with clozapine and loperamide. A 36-year-old man who had been treated with clozapine 500 mg/day and was previously in good health died after taking a total of 6 mg of loperamide during an outbreak of intestinal disease in a Finnish hospital. The patient received no other medications. The authors theorized that the anticholinergic effect of clozapine in combination with the antimotility effect of loperamide may have led to toxic megacolon. However, causality has not been determined.

MANAGEMENT: Until further information is available, loperamide should be used with caution in combination with drugs that possess significant anticholinergic activity (e.g., antihistamines; antispasmodics; neuroleptics; phenothiazines; skeletal muscle relaxants; tricyclic antidepressants; class IA antiarrhythmics especially disopyramide). Ambulatory patients should also be made aware of the possibility of additive CNS effects (e.g., drowsiness, dizziness, lightheadedness, confusion) and counseled to avoid activities requiring mental alertness until they know how these agents affect them.