Potassium-magnesium citrate versus potassium chloride in thiazide-induced hypokalemia

Background The purpose of this study was to compare the value of potassium- magnesium citrate (KMgCit) with potassium chloride in overcoming thiazide-i nduced hypokalemia. Methods. Sixty normal subjects first took hydrochlorothiazide (HCTZ; 50 mg/ day). After three weeks of treatment (or earlier if hypokalemia developed), they were randomized to take KMgCit (42 mEq K, 21 mEq Mg, and 63 mEq citra te/ day) or potassium chloride (42 mEq/day) for three weeks while continuin g on HCTZ. Results. KMgCit significantly increased the serum potassium concentration f rom 3.42 +/- 0.30 mEq/L on HCTZ alone to about 3.8 mEq/L (P < 0.001). Potas sium chloride produced a similar increase in serum potassium concentration from 3.45 +/- 0.44 mEq/L to about 3.8 mEq/L (P < 0.001). KMgCit significant ly increased the serum magnesium concentration by 0.11 to 0.12 mEq/L (P < 0 .01), whereas potassium chloride produced a marginal decline or no signific ant change. KMgCit was less effective than potassium chloride in correcting HCTZ-induced hypochloridemia and hyperbicarbonatemia. KMgCit, but not pota ssium chloride, significantly increased urinary pH (by about 0.6 unit), cit rate (by about 260 mg/day), and urinary magnesium. Conclusions. KMgCit is equally effective as potassium chloride in correctin g thiazide-induced hypokalemia. In addition, KMgCit, but not potassium chlo ride, produces a small but significant increase in serum magnesium concentr ation by delivering a magnesium load, and it confers alkalinizing and citra turic actions.