Role of High-Dose Hydrochlorothiazide in Idiopathic Hypercalciuric Urolithiasis of Childhood

Introduction. The aim of this study was to evaluate the role of hydrochlorothiazide in pediatric calculus formers with hypercalciuria and define possible factors affecting response to treatment. Materials and Methods. Nineteen pediatric calculus formers, 12 girls and 7 boys, aged 15 days to 60 months, with idiopathic hypercalciuria received high-dose hydrochlorothiazide (1 mg/ kg/d to 2 mg/kg/d) and citric acid-potassium citrate (1 mEq/ kg/d) and were evaluated in a 2-year period. Avoiding high-salt diets was recommended throughout the study and increasing fluid intake was encouraged. Results. The patients received hydrochlorothiazide for 2.5 to 15 months (mean, 6 ± 3 months), and 10 of them (52.6%) reached normacalciuria. Resolution of hypercalciuria was associated with decreased calculi sizes in 1 (5.3%) and stone-free condition in 4 (21.1%). No significant differences were found between responders and nonresponders with regard to age at presentation, gender, family history of calculus, and size and number of calculi. Conclusions. Our study showed that a combination of diet modification and hydrochlorothiazide has reasonable hypocalciuric effects; however, it is not very efficient in stopping calculus formation process. In addition, clinical and radiological data were not helpful to predict patients with better response to treatment.