Low-dose thiazide diuretics in children with idiopathic renal hypercalciuria.

AIM

To evaluate the therapeutic effect of hydrochlorothiazide in idiopathic renal hypercalciuria.

METHODS

We retrospectively analysed the data of 28 children (6.0±4.1 years, M:F=19:9) diagnosed as having idiopathic renal hypercalciuria from the years 1991 to 2008. The dose of hydrochlorothiazide was initially 0.5 mg/kg/day and gradually increased to achieve the appropriate hypocalciuric effect (urinary calcium/creatinine<0.2 mg/mg) in some unresponsive patients.

RESULTS

Twenty-two patients (79%) had gross haematuria, 6 (21%) microscopic haematuria, 2 left flank pain, 6 (21%) urolithiasis and 9 (32%) urinary tract infection at the diagnosis of hypercalciuria. The low doses (0.5 mg/kg/day) of hydrochlorothiazide reduced urinary calcium excretion in 25 patients (89%) and 3 (11%) required the increased doses (1-2 mg/kg/day). Haematuria and urolithiasis gradually resolved in accordance with the improvement of hypercalciuria. Nineteen patients (68%) maintaining hypocalciuria during hydrochlorothiazide therapy were discontinued after 12.5±5.3 months of treatment. Eleven of the 19 patients maintained normocalciuria, while 8 showed increased urinary calcium excretion at 2.9±2.3 months after treatment was stopped, requiring thiazide retreatment.

CONCLUSION

Our results suggest that low dose (0.5 mg/kg/day) of hydrochlorothiazide may be safe and effective in controlling renal hypercalciuria in children.