Cardiovascular toxicity of diuretics related to magnesium depletion.

The chronic administration of common loop or distal tubular diuretics may lead to somatic depletion of Mg2+. The resultant deficiency of this cation causes an increase in intramyocardial cytosolic Ca2+ and aggravates the decrease in intramyocardial K+ provoked by diuretics through their hyperkaliuretic effect. Thus the myocardium is electrically destabilized and cardiac arrhythmias may develop. Mg2+ deficiency positively contributes to the development of atherogenic alterations in lipid metabolism, vasospastic phenomena in the coronary and cerebrovascular territories, myocardial infarction and to the retardation of infarct healing and the occurrence of ventricular arrhythmias during the acute phase of infarction.