Thiazides to Prevent Recurrent Kidney Stones?

Thiazide diuretics have long been recommended to decrease recurrent nephrolithiasis in people with calcium stones, based on observational data and small randomized trials. To provide more robust evidence, Swiss researchers randomized 416 adults with at least two previous symptomatic calcium stone events to receive hydrochlorothiazide (at doses of 12.5 mg, 25 mg, or 50 mg daily) or placebo. People with secondary causes of stones (e.g., hyperparathyroidism) were excluded, but those with idiopathic hypercalciuria were permitted to enroll.

The primary composite endpoint consisted of both symptomatic stone events and presence of a new stone or enlargement of a preexisting stone on renal computed tomography (scans were done at baseline and at end …