Drug Interaction Report

MONITOR: Theoretically, topical administration of minoxidil may potentiate the hypotensive effects of systemic minoxidil and other vasodilators. Although systemic absorption of topical minoxidil is generally minimal (approximately 1.6% to 3.9% of an applied dose), adverse cardiovascular effects such as edema, palpitations, blood pressure decreases, and increased pulse rate have been reported in a few patients. Increased systemic absorption may occur when topical minoxidil is used in excess of normally recommended dosages or applied to compromised skin.

MANAGEMENT: Patients prescribed topical minoxidil in combination with systemic vasodilators or peripherally-acting antiadrenergic agents should be monitored for orthostatic signs and symptoms, including increase in heart rate, decrease in standing blood pressure, dizziness, and headache.