People who have formed one kidney stone have a higher chance of developing another stone. As such, doctors try to prevent new stones by using a class of drugs called thiazide diuretics. But a new study published in the New England Journal of Medicine suggests they are not useful for this purpose.
According to the National Kidney Foundation, kidney stones occur in about 10% of individuals. These stones can block the tubes of the urinary system. Kidney stones cause severe pain, urinary tract infection and even chronic kidney disease. As such, kidney stones impact patients’ health, finances and quality of life.
Although previous studies suggest thiazide diuretics help prevent a recurrence, the authors of this new study argue that the evidence for their use could be more robust. Previous studies used less sensitive tests and were poorly designed.
For this study, researchers recruited adults aged 18 and above with at least 2 episodes of stones in the past 10 years. They selected only patients with no medical condition that put them at risk of forming stones. All participants were taught dietary changes to help prevent stone formation.
The researchers randomly assigned patients to either receive hydrochlorothiazide (HCT) or a placebo. The patients, treating physicians, investigators and assessors were unaware of what each participant received. All drugs looked alike, and the participants took one capsule every morning.
Before treatment began, each participant was assessed with a plain CT scan. Thereafter, the participants were followed up for symptomatic or radiologic recurrence of stones.
The researchers monitored the participants for about 3 years. At the end of the study, 59% of those who received a placebo formed new stones. Stones also recurred in 59% of those on 12.5mg HCT, 56% of those on 25mg HCT and 49% of those on 50mg HCT. These differences in new stone formation were not statistically significant.
According to an editorial by Alexander R Todd, these findings “call into question the use of what has become the standard medical treatment” for kidney stones. This finding has not changed clinical practice, but one thing is clear. We need drugs that can prevent recurrent kidney stones.
