Pharmacological interventions for preventing complications in patients with idiopathic hypercalciuria: A systematic...

To assess the effects of pharmacological interventions in patients with idiopathic hypercalciuria.

We performed a search of multiple databases, trial registries, grey literature and conference proceedings up to October 2019. We included randomized and quasi-randomized controlled trials that examined any pharmacological intervention for preventing complications of idiopathic hypercalciuria (given for at least four months and six of follow-up). The primary outcomes were stone-free patients, urinary symptoms and severe adverse events.

We included five RCTs (n=446 patients, all adults, 4 in individuals with kidney stones and 1 in postmenopausal women with osteoporosis). Diuretics were likely to increase the number of stone-free patients (RR 1.61, 95% CI 1.33-1.96, moderate quality of evidence (QoE)); 274 more stone-free patients/1000 patients treated (95% CI: 148-432) and produced a slight decrease in the stone formation rate (mean difference -0.18, 95% CI -0.30 to -0.06, low QoE); 180 fewer stones/year/1000 patients treated (95% CI: 300 r to 60). No data on urinary symptoms were reported. The association between diuretic use and severe adverse events was uncertain (RR 5.00, 95% CI 0.60-41.88, very low QoE); 4 more severe adverse events/1000 patients treated (95% CI: 0 fewer to 39 more).

The addition of diuretics to a normal or modified diet probably reduces the number of stone recurrences and may decrease the stone formation rate. It is uncertain whether diuretics increase the occurrence of severe adverse events. There were no studies investigating other outcomes or in children.