CaOx Stone Prevention

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.

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