RESUMEN
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]. 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. 1[[78%] of the first group and [[42.[%] 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 1[% of the group 2 during 3 months [P = 0.68]. All patients in both groups were stone-free on 3 months following lithotripsy. 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