Abstract: PUB091
Indapamide and Chlorthalidone to Reduce Urine Supersaturation for Secondary Prevention of Kidney Stones: A Randomized, Double-Blind Crossover Trial (INDAPACHLOR Trial)
Session Information
Category: Fluid, Electrolytes, and Acid-Base Disorders
- 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical
Authors
- Scoglio, Martin, Inselspital Universitatsspital Bern Universitatsklinik fur Nephrologie und Hypertonie, Bern, Switzerland
- Bargagli, Matteo, Inselspital Universitatsspital Bern Universitatsklinik fur Nephrologie und Hypertonie, Bern, Switzerland
- Fuster, Daniel G., Inselspital Universitatsspital Bern Universitatsklinik fur Nephrologie und Hypertonie, Bern, Switzerland
Background
Kidney stones constitute a major global healthcare problem characterized by high recurrence rates. The majority of kidney stones consist of calcium and a high urine calcium (“hypercalciuria”) is the predominant metabolic abnormality in patients with kidney stones. The NOSTONE trial recently demonstrated that hydrochlorothiazide (HCT) has limited efficacy in preventing recurrence. Our objective is to assess whether indapamide or chlorthalidone are more effective than HCT in reducing urine supersaturations (RSRs) for calcium oxalate and calcium phosphate, which are validated predictors of stone recurrence.
Methods
INDAPACHLOR is a single-center, randomized, double-blind, cross-over trial evaluating the efficacy of indapamide or chlorthalidone compared to hydrochlorothiazide in lowering urine RSRs for calcium oxalate and calcium phosphate in individuals with idiopathic calcium kidney stones. Participants are allocated to indapamide 2.5 mg once daily, chlorthalidone 25 mg once daily, and hydrochlorothiazide 50 mg once daily in a random sequence. The three consecutive active treatment periods of 28 days each are separated by wash-out periods of 28 days. The primary outcomes are the changes of the RSR calcium oxalate and RSR calcium phosphate from baseline to day 28 of each treatment period. Secondary outcomes include changes in 24 h urine and blood parameters from baseline to day 28 of each treatment period. The study targets enrollment of 99 participants to achieve 80% power for detecting a 20% reduction in RSR calcium oxalate or calcium phosphate when treated with indapamide or chlorthalidone compared to HCT.
Results
The INDAPACHLOR trial is registered at ClinicalTrials.gov (NCT06111885). Approval of the cantonal Ethics Commission Bern, Switzerland was obtained on May 28 2024 (approval # 2024_00477), and authorization from the Competent Authority Swissmedic was received on June 27 2024 (approval # 701824). Patient recruitment commenced in December 2024. As of mid-April 2026, a total of 94 patients have been recruited. Of these, 48 participants completed the study. The study was initially expected to conclude by the end of 2027; however, current recruiting rates indicate it may finish in Q1 2027.
Conclusion
No conclusions available — study in progress.
Funding
- Government Support – Non-U.S.