Preventing calcium oxalate kidney stones

Empiric vs Selective Medical Therapy for Calcium Oxalate Stone Prevention: A Randomized Controlled Trial

Phase 4 Interventional Icahn School of Medicine at Mount Sinai · NCT07225764

This test compares giving empiric preventive treatment right after kidney stone surgery to using 24-hour urine tests to guide treatment for people with calcium oxalate stones.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment80 (estimated)
Ages18 Years and up
SexAll
SponsorIcahn School of Medicine at Mount Sinai Academic / other
Drugs / interventionsdenosumab
Locations1 site (New York, New York)
Trial IDNCT07225764 on ClinicalTrials.gov

What this trial studies

This single-center randomized controlled trial at Mount Sinai West will enroll 80 adults undergoing percutaneous nephrolithotomy for predominantly calcium oxalate stones. After surgery participants are randomized to empiric therapy (based on stone composition and urinalysis, including chlorthalidone and a low-oxalate diet) or selective therapy guided by a 24-hour urine metabolic evaluation. The primary endpoint is the change in calcium oxalate supersaturation at four weeks. The study is designed to see whether an empiric approach can achieve comparable short-term biochemical outcomes while simplifying access to preventive treatment.

Who should consider this trial

Good fit: Adults (≥18 years) scheduled for PCNL for predominantly calcium oxalate stones with preoperative eGFR >70 mL/min/1.73 m², a negative urine culture, and not currently on active stone prevention therapy are ideal candidates.

Not a fit: Patients with non–calcium oxalate stones, gastrointestinal malabsorption or prior bypass surgery, hyperparathyroidism or renal tubular acidosis, reduced kidney function, current use of thiazides or other stone prevention meds, or allergies to the study drugs are unlikely to benefit.

Why it matters

Potential benefit: If successful, empiric treatment could simplify and speed access to stone prevention without waiting for 24-hour urine results, potentially lowering recurrent stone risk.

How similar studies have performed: Thiazide diuretics and low-oxalate diets individually have evidence to reduce calcium oxalate recurrence, but directly comparing empiric versus 24-hour urine–guided selective therapy is relatively novel and not well established.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Adult age of 18 years
* Diagnosed with kidney stones and scheduled for PCNL.
* Calcium Oxalate Stone Former
* Pre-operative CT-scan within 90 days of surgery and stone density with \> 1000 Hounsfield units
* Non-pregnant or breastfeeding
* Able and willing to provide informed consent.
* Pre-operative eGFR greater than 70 mL/min/1.73 m² -Negative pre-operative urine culture

Exclusion Criteria:

* Documented history of gastric or intestinal bypass, liver disease, history of gastrointestinal malabsorptive disease (Crohn's disease, ulcerative colitis, and short-gut syndrome)
* Hyperparathyroidism -Renal tubular acidosis
* Active kidney stone prevention treatment (use of thiazides, alkaline therapy, or low oxalate diet) at the time of surgery
* History of hypokalemia or baseline hypotension
* Allergy to medications used in trial or sulfa-containing medications
* Patient prescribed thiazide, loop diuretics, carbonic anhydrase inhibitors, xanthine oxidase inhibitors, active Vitamin D, bisphosphonates, denosumab, glucocorticoids, or potassium supplementation

Where this trial is running

New York, New York

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Kidney Stoneskidney stonescalcium oxalatenephrolithiasis
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.