Alterations of serum magnesium under chronic therapy with diuretics and/or angiotensin-converting enzyme inhibitors in hypertensive patients

Diuretic drugs (both thiazide and loop diuretics) have been the mainstay of treatment for arterial hypertension and congestive heart failure 1,3; however, the prolonged use of thiazide diuretics and (to a lesser extent) of loop-acting diuretics is accompanied by a variable depression of serum and tissue levels of potassium and magnesium and reduced concentrations of sodium-potassium pumps in muscle 4–6. These diuretic - induced electrolytic disturbances have been associated with cardiac arrhythmias (ventricular ectopic activity 7,8, torsade de pointes 9 and sudden death), especially in elderly patients with hypertension, left ventricular hypertrophy, and/or congestive heart failure 9,10, although in a Editorial Review the cardiotoxicity of diuretics is thought to be the result of “much speculation and little substance” 11.