Effects of hydrochlorothiazide on kidney stone therapy with extracorporeal shock wave lithotripsy

OBJECTIVE The aim of this investigation was to assess the efficacy of hydrochlorothiazide as a hypocalciuric diuretic on stone-free rate of renal pelvic calculi after extracorporeal shock wave lithotripsy (ESWL). MATERIALS AND METHODS A double-blind, placebo-controlled randomized clinical trial was conducted and 52 patients with renal pelvic calculi (diameter ≤2 cm) were enrolled from February 2010 to September 2010. ESWL protocol was performed by 2,500 shocks per session. The patients were randomized into two groups: (1) 26 patients who were given 25 mg hydrochlorothiazide twice daily; and (2) 26 patients who received placebo. The stone-free rate was defined as residual calculus size ≤4 mm in controlled ultrasound on 2(nd) week, 1 month and 3 months after ESWL. RESULTS 19 (78%) of the first group and 9 (42.9%) of the second group were stone-free after one session of ESWL (P = 0.02). 88% of the group 1 and 47.8% of the group 2 were stone-free on 1 month after ESWL (P = 0.003); however, this effect of hydrochlorothiazide was not related to the patients' body mass index, age and gender. The accessory treatment procedures were applied in 24% of the group 1 compared with 19% of the group 2 during 3 months (P = 0.68). All patients in both groups were stone-free on 3 months following lithotripsy. CONCLUSIONS Hydrochlorothiazide did not impact on the stone-free rate and using accessory procedure within 3 months; however, it decreased duration of stone-free status and number of ESWL sessions.