Empiric Versus Selective Prevention Strategies for Kidney Stone Disease

Vanderbilt University Medical Center

Status and phase: Completed; Phase 4

Conditions: Kidney Stones; Nephrolithiasis

Treatments: Behavioral: Empiric Therapy: Diet; Drug: Empiric Therapy: Drug; Behavioral: Selective Therapy: Diet; Drug: Selective Therapy: Drug

Study type: Interventional

Funder types: Other

Identifiers

NCT05365477

200238

Details and patient eligibility

About

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.

Full 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.

Enrollment: 56 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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56 participants in 2 patient groups

Empiric Therapy

Active Comparator group

Description:

Diet intervention and drug intervention not based on 24 hour urine results

Treatment:

Drug: Empiric Therapy: Drug

Behavioral: Empiric Therapy: Diet

Selective Therapy

Experimental group

Description:

Diet intervention and drug intervention based on 24 hour urine results

Treatment:

Drug: Selective Therapy: Drug

Behavioral: Selective Therapy: Diet