Hypomagnesemia associated with gentamicin therapy.

Two patients developed symptomatic hypomagnesemia most likely secondary to gentamicin therapy. Both patients were on regular doses of the antibiotic and had hypokalemia and hypocalcemia secondary to hypomagnesemia. Mechanisms postulated for the occurrence of hypomagnesemia secondary to gentamicin therapy include drug-induced hyperaldosteronism and tubular toxicity. Patients on gentamicin therapy should have serum magnesium, calcium, and potassium levels monitored routinely.