Fourteen RCTs (939 patients) were included.
All RCTs combined (12 RCTs): medical treatment significantly reduced stone recurrence; the RD was -22.6% (95% CI: -29, -16.3, P<0.001).
Thiazide diuretics plus indapamide (8 RCTs, 496 people): 6 RCTs found that thiazides significantly reduced stone recurrence. Two RCTs with a treatment duration of less than 2 years found no significant difference between thiazides and control. Thiazides significantly reduced stone recurrence; the RD (6 RCTs) was -21.3% (95% CI: -29.2, -13.4, P<0.001).
Allopurinol (4 RCTs, 134 people): one RCT (60 people, the largest RCT) found that allopurinol significantly reduced stone recurrence compared with placebo or no treatment in hyperuricosuric, normocalcuric patients. The other 3 RCTs found no significant difference between allopurinol and placebo.
Phosphate (3 RCTs, 103 patients): none of the RCTs found any significant difference in stone recurrence between phosphate and placebo or no treatment.
Magnesium (2 RCTs, 89 patients): neither RCT found any significant difference in stone recurrence between magnesium and placebo or no treatment in unselected patients.
Alkali citrate (3 RCTs, 117 patients): the results differed. One RCT found that potassium citrate significantly reduced stone recurrence compared with placebo or no treatment in patients with isolated hypocitraturia. Another RCT found that potassium magnesium citrate significantly reduced stone recurrence compared with placebo or no treatment in unselected patients. The remaining RCT found no significant difference between sodium potassium citrate and no treatment in unselected patients.