Hydrochlorothiazide not better than placebo for preventing kidney stone recurrence

Treatment with hydrochlorothiazide, regardless of dose, does not appear to significantly reduce the incidence of kidney stone recurrence as compared with placebo, according to a study.

The study included 416 participants with recurrent calcium-containing kidney stones. They were randomly assigned to receive hydrochlorothiazide at a dose of 12.5 mg (n=105), 25 mg (n=108), or 50 mg (n=101), or placebo (n=102). Treatment was administered once daily, with the participants followed-up for a median of 2.9 years.

The primary endpoint was a composite of symptomatic or radiologic recurrence of kidney stones, defined as the appearance of new stones on imaging or the growth of pre-existing stones that had been identified on the baseline image. Safety was also evaluated.

The number of patients who had symptomatic or radiologic recurrence was comparable across the treatment groups: 60 (59 percent) in the placebo group, 62 (59 percent) in the 12.5-mg hydrochlorothiazide group (rate ratio [RR], 1.33, 95 percent confidence interval [CI], 0.92–1.93), 61 (56 percent) in the 25-mg group (RR, 1.24, 95 percent CI, 0.86–1.79), and 49 (49 percent) in the 50-mg group (RR, 0.92; 95 percent CI, 0.63–1.36).

Hydrochlorothiazide dose had no significant effect on the occurrence of a primary endpoint event (p=0.66).

In terms of safety, events such as hypokalemia, gout, new-onset diabetes mellitus, skin allergy, and a plasma creatinine level exceeding 150 percent of the baseline level occurred more frequently among hydrochlorothiazide-treated participants than among those who received placebo.