Phase 3
Completed N=19
Phentermine/Topiramate for Uric Acid Stones
Obesity · Uric Acid Stones · Type 2 Diabetes Mellitus in Obese · Pre-Diabetes
Source: ClinicalTrials.gov NCT04621929 ↗
Enrolled (actual)
19
Serious AEs
0.0%
Results posted
Jan 2026
Primary outcomePrimary: Kidney Stone Size (mm^3) Determined by Non-contrast CAT Scan — 6540; 4650; 3120; 5041 mm^3
◆ Published Evidence
No publication linked
No peer-reviewed publication reporting this trial's results has been linked yet. This can indicate results are unpublished — a known publication-bias signal. We re-check periodically.
Summary
The investigator proposes an 18 month, feasibility pilot study, randomizing obese and diabetic individuals with pure uric acid nephrolithiasis (UAN) or mixed calcium oxalate (CO) UAN to either phentermine/topiramate or a pragmatic control group who will remain on their standard medication regimen (citrate salts, allopurinol, diet, etc.).
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Kidney Stone Size (mm^3) Determined by Non-contrast CAT Scan |
6540; 4650; 3120; 5041 | — |
| SECONDARY Weight (kg) |
121.4; 101.2; 111.2; 104.1 | — |
| SECONDARY Urinary pH Parameters |
5.3; 5.3; 6.2; 5.5 | — |
| SECONDARY %Hemoglobin A1c |
6.6; 6.2; 6.4; 6.7 | — |
| SECONDARY Urinary Citrate Parameters |
634; 673; 309; 951 | — |
| SECONDARY Urinary Calcium Parameters |
172; 154; 224; 167 | — |
| SECONDARY Urinary Uric Acid Supersaturation (SS) |
2.2; 2.4; 0.7; 1.8 | — |
Eligibility Criteria
Inclusion Criteria
- have recurrent pure uric acid nephrolithiasis (UAN) or mixed calcium oxalate (CO)/UAN. Recurrent stone disease is defined as at least two spontaneous kidney stone passages, two previous kidney stone procedures, or one previous stone passage and one previous procedure. Pure UAN is defined as at least one previous stone analysis demonstrating 100% uric acid mineral content. Mixed COUAN will be defined as at least one previous stone analysis with any mix of uric acid ≥80% and ≤20% calcium oxalate. If participant has more than one stone analysis, the most recent will be considered the current stone type.
- have obesity, defined as BMI > 30 kg/m2.
- have type 2 diabetes mellitus or pre-diabetes, defined as previously diagnosed by laboratory testing (hemoglobin A1c, fasting plasma glucose, or oral glucose tolerance test) or as demonstrated by use of anti-hyperglycemic medications or insulin.
- have at least one 24-hour urine study off medications demonstrating urine pH = 10, history of suicidal ideation or behavior with intent to act (versus exclude those with depression); current pregnancy or attempting to conceive; pre-existing chronic kidney disease with eGFR 160 systolic), hyperthyroidism; monoamine oxidase inhibitor use; current history of drug or alcohol abuse.
Data sourced from ClinicalTrials.gov (NCT04621929). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.