A Cochrane review included 5 studies with a total of 316 subjects. 4 studies compared thiazides with standard treatment (periodic clinical follow-up and increased water intake) or specific dietary recommendations and 1 study compared potassium phosphate with placebo. There was a significant decrease in the number of new stone recurrences (RR 1.61, 95% CI 1.33 to 1.96; 4 studies, n=285) and in the stone formation rate (number of stones/patient/year, MD -0.18, 95% CI -0.30 to -0.06; 3 studies, n=247) in those treated with thiazides. A slow-release neutral potassium phosphate salt in comparison to placebo for a period of 3 months decreased the excretion of urinary calcium (MD - 86.00 mg/24 h, 95% CI -118.36 to -53.64; 1 study, n=31).
No studies in children were identified and there were no studies investigating the use of drug treatment for those with hypercalciuria but were symptom free.
Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment and lack of blinding).