In the report by Papademetriou and colleagues,1 approximately 50% of their patients with diuretic-induced hypokalemia failed to normalize their serum potassium levels despite potassium chloride or triamterene administration. The question arises as to whether hypokalemia refractory to potassium repletion may have been, in part, an expression of coexisting hypomagnesemia and magnesium depletion.2,3 Diuretics can be potent renal wasters of not only potassium, but magnesium as well.4 Estimates of the extent of coexisting hypomagnesemia in hospitalized patients with hypokalemia range from 38%5 to 42%.6 It would be of interest to know whether serum magnesium levels were measured in these patients, and, if so, whether correction of hypomagnesemia-normalized serum potassium levels in those patients who were previously refractory to potassium repletion.
Whang R. To the Editor.—. Arch Intern Med. 1986;146(5):1026. doi:10.1001/archinte.1986.00360170284044