Effects of short and long-term indapamide treatments on urinary calcium excretion in patients with calcium oxalate dihydrate urinary stone disease: a pilot study.

Objective: The aim of this study was to determine the relative calcium-reducing effects of indapamide at 6 and 18 months using a dose of 1.5 mg/day.

Material And Methods: Twenty-two patients with idiopathic hypercalciuria and calcium oxalate dihydrate urinary stone disease (minimum one stone episode) were selected. Each patient began a therapy regime of 1.5 mg indapamide sustained release taken once a day in the evening. Under basal conditions and after 6 and 18 months of treatment, subjects submitted urine and blood samples for analysis. The primary aim of this study was to assess the effects on excretion and concentration of calcium in urine.

Results: For 2 h urine, there was a mean decrease in urinary calcium concentration of 47%, whereas urinary calcium concentrations decreased by 53% in 24 h urine (p < 0.05) at 6 months of treatment. Blood urate levels rose by 19% (p < 0.05). Treatment for 18 months resulted in significant reduction in urinary calcium levels, by approximately 48% (p < 0.05) in both 2 h and 24 h urine. A 21% increase in urate levels in the blood was observed (p < 0.05). The remaining parameters remained unaltered.

Conclusions: Owing to the low effective dosage of indapamide (1.5 mg/day) and the lack of any severe side-effects, this drug would appear to be a good candidate for use in the control of hypercalciuria. As such, it could prove efficacious in the prevention of recurrent kidney stones that are often associated with this condition.