CaOx Stone Prevention

Purpose

This single-center randomized controlled trial at Mount Sinai West will enroll 80 patients undergoing percutaneous nephrolithotomy for calcium oxalate stones. Participants will be randomized to receive either empiric therapy or selective therapy guided by 24-hour urine evaluation. The primary outcome is change in calcium oxalate supersaturation at 4 weeks, aiming to determine whether empiric therapy can provide outcomes comparable to selective therapy while simplifying access to prevention.

Condition

  • Kidney Stones

Eligibility

Eligible Ages
Over 18 Years
Eligible Sex
All
Accepts Healthy Volunteers
No

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

Study Design

Phase
Phase 4
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Primary Purpose
Prevention
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Empiric Therapy 		Patients randomized to the empiric group will receive treatment based on the pH on urinalysis and stone composition. Patients with greater than 50% calcium oxalate monohydrate (COM) stone composition will be counseled on a low oxalate diet by a medical provider. Patients with greater than 50% calcium oxalate dihydrate (COD) stone composition will be prescribed 25 mg of chlorthalidone once a day. In the rare event the stone composition is 50% COM and 50% COD, then those patients will receive both low oxalate diet counseling and a prescription for chlorthalidone.
  • Drug: Chlorthalidone
    Chlorthalidone 25 mg orally once daily is used to reduce urinary calcium excretion and prevent recurrent calcium-containing kidney stones. In this study, it is prescribed either based on stone composition (empiric group) or guided by 24-hour urine results (selective group) for participants meeting criteria for hypercalciuria or calcium oxalate dihydrate stones.
  • Behavioral: Low oxalate diet
    Participants receive counseling to follow a low oxalate diet, limiting high oxalate foods (>50 mg/100 g) and restricting moderate oxalate foods (<50 mg/100 g) to a single four-ounce serving per day. The diet is prescribed either based on stone composition (empiric group) or guided by 24-hour urine results (selective group) for participants with idiopathic hyperoxaluria or calcium oxalate monohydrate stones.
Active Comparator
Selective Therapy 		Patients randomized to the selective group will undergo medical therapy based on the American Urological Association (AUA) guidelines from the 24-hour urine collection results. Patients with idiopathic hyperoxaluria (> 40mg/day) will receive a low oxalate diet and receive the same dietary counseling, handout, and questionnaire as the empiric group. Patients with idiopathic hypercalciuria (> 250mg in men, >200mg in women) will be prescribed 25mg of chlorthalidone once a day.
  • Drug: Chlorthalidone
    Chlorthalidone 25 mg orally once daily is used to reduce urinary calcium excretion and prevent recurrent calcium-containing kidney stones. In this study, it is prescribed either based on stone composition (empiric group) or guided by 24-hour urine results (selective group) for participants meeting criteria for hypercalciuria or calcium oxalate dihydrate stones.
  • Behavioral: Low oxalate diet
    Participants receive counseling to follow a low oxalate diet, limiting high oxalate foods (>50 mg/100 g) and restricting moderate oxalate foods (<50 mg/100 g) to a single four-ounce serving per day. The diet is prescribed either based on stone composition (empiric group) or guided by 24-hour urine results (selective group) for participants with idiopathic hyperoxaluria or calcium oxalate monohydrate stones.

Recruiting Locations

Mount Sinai West
New York, New York 10019
Contact:
Mantu Gupta, MD
212-241-1272
mantu.gupta@mountsinai.org

More Details

Status
Recruiting
Sponsor
Icahn School of Medicine at Mount Sinai

Study Contact

Blair Gallante, MPH
631-991-1159
blair.gallante@mountsinai.org

Detailed Description

This is a single-center, randomized controlled trial evaluating the effectiveness of empiric versus selective medical therapy for the prevention of calcium oxalate kidney stones. The study will enroll 80 patients at Mount Sinai West undergoing percutaneous nephrolithotomy (PCNL) for predominantly calcium oxalate stones. Participants will be randomized postoperatively to receive either empiric therapy (based on stone composition and urinalysis) or selective therapy (based on 24-hour urine metabolic evaluation). The primary endpoint is the change in calcium oxalate supersaturation (ssCaOx) at 4 weeks post-treatment. The study is designed to determine whether an empiric approach can achieve comparable outcomes to selective therapy while simplifying access to preventive treatment.