Potassium citrate vs. hydrochlorothiazide to reduce urinary calcium excretion in calcium oxalate stone patients with hypercalciuria: a prospective randomized study.

PURPOSE

Calcium oxalate (Ca-Ox) is the most common stone composition and one of the most common 24-h urine anomalies is hypercalciuria. The purpose of this study was to evaluate the efficacy of potassium citrate (K-CIT) for prevention of hypercalciuria in comparison with hydrochlorothiazide (HCT) in patients with calcium oxalate stones and hypercalciuria.

MATERIALS AND METHODS

In this prospective randomized study, patients were randomized to receive either HCT (50 mg/day) or K-CIT (40 mEq/day) following achieving stone-free status. Treatment was continued for 6 months. 24 h urine analysis was performed prior to treatment and repeated at third month and measured parameters were volume, calcium, oxalate, citrate, sodium, and uric acid. Stone recurrence was evaluated with KUB and ultrasonography at 6th and 12th months.

RESULTS

Data of 40 patients in each arm were evaluated. Mean 24 h urine calcium levels decreased to 205 ± 54.5 mg/day and 220.6 ± 96.3 mg/day in the K-CIT and HCT groups, respectively, and difference was not significant (p = 0.931). The reduction compared to pretreatment values was statistically significant in both groups. Urinary citrate levels also significantly increased in both groups and level of increase was significantly higher in K-CIT group. At 12th month, ultrasonography revealed stones in two patients in HCT group, and in one patient in the K-CIT group.

CONCLUSIONS

K-CIT provided significantly reduced calcium and increased citrate excretion in patients Ca-Ox stone patients with hypercalciuria. The efficacy in decreasing calcium excretion was comparable to HCT treatment. K-CIT can be used for medical prophylaxis of Ca-OX stone patients with hypercalciuria.