Long-term combined treatment with thiazide and potassium citrate in nephrolithiasis does not lead to hypokalemia or hypochloremic metabolic alkalosis

BACKGROUND: Potassium citrate is commonly used in combination with a thiazide diuretic in the medical management of recurrent hypercalciuric nephrolithiasis. However, concerns have been raised that administration of this nonchloride potassium alkali with a kaliuretic and natriuretic agent such as thiazide may not be efficacious in correcting or preventing hypokalemia, and may produce hypochloremic metabolic alkalosis. This retrospective analysis was conducted to determine if these two potential complications are encountered in patients on long-term potassium citrate and thiazide therapy. METHODS: Data were collected on 95 patients who had been on combination therapy for at least 4 months from the stone clinics of the University of Texas Southwestern Medical Center, Duke University Medical Center, and Ochsner Clinic. RESULTS: Mean serum potassium concentration remained within normal limits without a significant decrease during combined therapy. Serum chloride was significantly lower from pretreatment but by only 1 mEq/L and remained within normal limits throughout treatment. There was a small increase in serum bicarbonate concentration compared to the baseline level of less than 1 mEq/L at 8 to 12 and 18 to 24 months, but not at other treatment periods. CONCLUSION: Co-administration of potassium citrate did not induce hypokalemia or hypochloremic metabolic alkalosis in our thiazide-treated patient population.