April 11, 2025
1 min read
Key takeaways:
- Researchers found a notable interaction based on patients’ prior history of kidney stones.
- Hypokalemia was more common for patients on chlorthalidone regardless of stone history.
BOSTON — Long-acting diuretic chlorthalidone may increase the risk for kidney stones in adults who have previously had them, according to findings presented at the National Kidney Foundation Spring Clinical Meetings.
Researchers analyzed data from 13,523 adults older than 65 years with hypertension who were enrolled in the Diuretic Comparison Project and randomly assigned to continue hydrochlorothiazide or switch to shorter-term chlorthalidone.
Researchers found a notable interaction based on patients’ prior history of kidney stones. Image: Adobe Stock.
The goal of the work was to “determine if thiazide diuretics are equally effective in reducing kidney stones,” Areef Ishani, MD, MS, vice chair and professor of medicine at the University of Minnesota in Minneapolis, told Healio.
Researchers wanted to determine which method carried more risk for kidney stones. Patients had a systolic blood pressure of at least 120 mm Hg, and 12,359 patients had no history of the condition while 1,164 patients did.
The main outcome was the occurrence of kidney stones, tracked over a mean 4.2 years.
Researchers found no substantial differences in new kidney stone events between the chlorthalidone (4.9%) and hydrochlorothiazide (5.2%) groups (HR = 0.94; 95% CI, 0.82-1.08), according to the study. However, there was a notable interaction based on patients’ prior history of kidney stones, Ishani said.
Patients with no previous history of kidney stones had a minor risk reduction on chlorthalidone (HR = 0.81; 95% CI, 0.65-1.01), whereas patients with a history had a significant risk increase (HR = 1.25; 95% CI, 1.01-1.53). In addition, researchers found hypokalemia was more common in the chlorthalidone group regardless of stone history. Hypokalemia occurred in 10.2% of patients without stone history on chlorthalidone vs. 8.3% on hydrochlorothiazide. In patients with a history, chlorthalidone rates were 13.8% and 11.5% for hydrochlorothiazide.
“Overall, the drugs were similar for reducing kidney stones,” Ishani said. “However, in those with a history of kidney stones, hydrochlorothiazide was more effective at reducing kidney stones than chlorthalidone,” Ishani said.
For more information:
Areef Ishani, MD, MS, can be reached at areef.ishani@va.gov.
Sources/Disclosures
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Ishani A. Abstract LB-01. Presented at: NKF Spring Clinical Meetings; April 9-13, 2025; Boston.
Disclosures:
Ishani reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.