Empiric Versus Selective Prevention Strategies for Kidney Stone Disease

Phase 4

Recruiting

• Conditions: Nephrolithiasis; Kidney Stones

• Registration Number: NCT05365477
• Lead Sponsor: Vanderbilt University Medical Center

Brief Summary

The aims of this study are to 1) Conduct a randomized clinical trial of selective versus empiric diet plus pharmacologic therapy in high-risk stone formers and 2) Determine adverse effects from, and adherence to selective and empiric strategies.

Detailed Description

Diet and pharmacologic interventions for preventing future kidney stone episodes are effective, however clinical guideline panels disagree on whether clinicians should perform selective therapy: performing 24-hour urine testing to guide choosing interventions to correct abnormal urinary parameters. The alternative strategy is empiric therapy: applying interventions without 24-hour urine testing. While 24-hour urine testing is considered the standard of care by nephrology and urology specialties for higher risk patients, the American College of Physicians does not recommend 24-hour urine testing.

This is a randomized clinical trial of selective versus empiric therapy for patients with presumed idiopathic calcium stone disease, representing \>80% of the kidney stone population. The primary outcome is change in urinary supersaturation, which associates with symptomatic stone recurrence. We will recruit patients with presumed idiopathic calcium stone disease with at least 2 stone events within the previous 5 years. Participants will be randomly assigned to empiric diet plus thiazide with potassium citrate daily, or to selective diet plus pharmacologic therapy based on the 24-hour urine abnormalities identified at baseline and adjusted during follow-up. The primary outcomes will be the calculated calcium oxalate and calcium phosphate supersaturations. In addition, we will determine adverse effects from, and adherence to, selective and empiric strategies.

Study Timeline

• Study First Submitted: 2022-05-04
• Study First Submitted QC: 2022-05-04
• Study First Posted: 2022-05-09
• Study Start: 2022-08-04
• Status Verified: 2025-02
• Last Update Submitted: 2025-02-13
• Last Update Posted: 2025-02-17
• Primary Completion: 2025-05-31
• Study Completion: 2026-03-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 56

Inclusion Criteria

• Two or more symptomatic kidney stone events in the last 5 years
• Adult

Exclusion Criteria

• Medullary sponge kidney or renal tubular acidosis
• Untreated urinary obstruction
• Primary hyperparathyroidism
• Primary hyperoxaluria
• Pregnancy
• Inflammatory bowel disease or bowel resection
• Sarcoidosis
• Cystinuria
• Prior stone composition with uric acid, struvite, cystine, carbonate apatite
• Use of specific medications (thiazides, topiramate, xanthine oxidase inhibitors, citrate, bicarbonate)
• Chronic kidney disease stage 3 or higher (eGFR<60)
• Gouty arthritis or 3 gout episodes in 1 year
• Known allergy to study medications
• Hypokalemia or hyponatremia at screening.
• Age < 18 years

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Calcium oxalate supersaturation	Baseline compared to two months	Calculated calcium oxalate supersaturation in urine
Calcium phosphate supersaturation	Baseline compared to two months	Calculated calcium phosphate supersaturation in urine

Secondary Outcome Measures

Name	Time	Method
Uric acid supersaturation	Baseline compared to two months	Calculated uric acid supersaturation in urine
24hr urine parameters	Baseline compared to two months	Urinary volume, calcium, oxalate, potassium, citrate, pH, uric acid, and sodium

Trial Locations

Locations (1)

Vanderbilt University Medical Center; 🇺🇸 Nashville, Tennessee, United States