Correction of thiazide-induced hypomagnesemia by potassium-magnesium citrate from review of prior trials.

PURPOSE

To ascertain whether hypomagnesemia develops during short-term thiazide treatment in normal subjects and if it can be corrected by potassium-magnesium citrate (Relyte) supplementation.

METHODS

Serum magnesium data were retrieved from 242 normal subjects from prior 4 trials. After 1-3 weeks of treatment with hydrochlorothiazide 50 mg/day, subjects received supplementation with Relyte or a related compound while continuing on thiazide for 3 weeks.

RESULTS

Hypomagnesemia (< or =1.8 mg/dl) was disclosed in 19.4% of 242 subjects on thiazide alone. In such patients, Relyte treatment significantly increased serum magnesium concentration to the normal range, whereas supplementation with potassium citrate or potassium chloride did not. In the Relyte group comprised of 131 subjects, the frequency of hypomagnesemia decreased from 22.9% on thiazide alone to 4.6% after 4 weeks of Relyte supplementation. In contrast, the frequency of hypomagnesemia displayed a non-significant increase from 15.7% on thiazide alone to 20-24% on potassium citrate or potassium chloride.

CONCLUSION

Mild hypomagnesemia develops in about one fifth of normal subjects during short-term thiazide treatment. Relyte can readily correct it.