Pharmaco-nutrient interactions - a systematic review of zinc and antihypertensive therapy

Antihypertensive medicines are to known to cause diverse disturbances to electrolyte homeostasis; however, their potential to affect zinc is less well known. The primary aim was to explore whether antihypertensive medicines have the potential to affect zinc status.

A review of electronic databases was undertaken. Full-length English language articles describing clinical trials involving antihypertensive medicines and reporting on zinc measurements were reviewed.

Eight eligible studies were identified which involved the use of ACE inhibitors, thiazide diuretics, beta blockers, or ARB drugs of which five included a control group Studies used urinary zinc excretion, plasma zinc levels or erythrocyte zinc as key measures of zinc status. Studies reported increased urinary zinc losses for captopril (from 50 mg/day), enalapril (20 mg/day), losartan (50 mg/day), losartan (50 mg/day) together with hydrochlorothiazide (12.5 mg/day), captopril (75 mg/day) together with frusemide (40 mg/day) and stand-alone hydrochlorothiazide (25 mg/day). Serum levels of zinc decreased with captopril (50-150 mg/day), verapamil (240 mg/day), atenolol (50-150 mg/day) and the combination of losartan (50 mg/day) and hydrochlorothiazide (12.5 mg/day), eryrthrocyte levels decreased with use of valsartan (80 mg/day) and in some studies for captopril, but not for metoprolol (100 mg/day), atenolol (50-150 mg/day), verapamil (240 mg/day), doxazosin (4 mg/day) or amlodipine 10 mg/day). Major limitations were that most studies were small and did not report on dietary zinc intake.

The available evidence suggests that use of ACE inhibitors and angiotensin 2 receptor antagonists or thiazide diuretics have the potential to reduce zinc levels in hypertensive patients. Additional research using larger participant numbers and accounting for dietary zinc intakes are required.