Abstract
Hypomagnesemia can cause ventricular tachycardia, cardiac necrosis, or torsades de
pointes. Diuretic treatment can result in Mg2+ depletion, as many diuretics inhibit the reabsorption of filtered Mg2+ in the proximal or distal tubule. As plasma Mg2+ constitutes only about 3% of total body Mg2+ stores, intracellular Mg2+ determinations may be more useful for assessing total body Mg2+ content. Therefore we studied the effect of a thiazide diuretic (trichlormethiazide
4 mg/day), a combination of a thiazide and a potassium-sparing diuretic (trichlormethiazide
and amiloride 2 mg/day each), and the loop diuretic piretanide (6 mg/day) on intracellular
Mg2+ in patients with mild essential hypertension before and after 6 and 10 weeks of therapy.
Mg2+ measurements were performed in blood plasma and in red blood cells by atomic absorption
spectroscopy, using a Video 12 apparatus. There was a significant decrease in intracellular
Mg2+ content under trichlormethiazide therapy (p<0.05). Furthermore, our results show that diuretic treatment with a combination of
a thiazide and a potassium-sparing diuretic or with the loop diuretic piretanide may
have the advantage of avoiding intracellular Mg2+ depletion.