Metabolic and clinical effects of oral magnesium supplementation in furosemide-treated patients with severe congestive heart failure

Background: Magnesium depletion and hypomagnesemia are common among furosem ide-treated patients with chronic congestive heart failure. Hypothesis: This investigation evaluated clinical and metabolic effects of oral magnesium supplementation. Methods: Ten patients with severe congestive heart failure maintained on hi gh dose furosemide (greater than or equal to 80 mg/day) received a suppleme nt of oral magnesium citrate 300 mg/daily for 30 days. Clinical parameters were followed, and peripheral blood mononuclear cell magnesium and zinc con tent, serum and urine magnesium, potassium, zinc, calcium, phosphorus, and creatinine were assessed. Results: Peripheral blood mononuclear cell magnesium content and serum pota ssium rose significantly at the end of the study (2.09 +/- 1.89 to 3.99 +/- 2.26 mu g/mg cell protein, p < 0.05, and 4.17 +/- 0.38 to 4.39 +/- 0.27 mE q/l, p < 0.05, respectively), while the other parameters remained unchanged . Conclusion: In some of these patients, oral magnesium supplementation is ef fective in achieving substantial increments in intracellular magnesium and serum potassium which, in turn may have cardioprotective effects.