Two Macrolides Interact With Calcium Channel Blockers, University of Toronto Study

MedPageToday -- Older patients taking calcium-channel blockers who are given erythromycin or clarithromycin are at risk for hypotension or shock requiring hospitalization, a Canadian study found. A significant association was seen between use of erythromycin, which is a powerful inhibitor of cytochrome P450 isoenzyme 3A4, and hospitalization for hypotension (OR 5.8, 95% CI 2.3 to 15), according to David N. Juurlink, MD, PhD, of the University of Toronto, and colleagues.