Using sodium bicarbonate to change 24-hour urine measurements in people with low urine citrate or uric acid kidney stones

Impact of Sodium Bicarbonate on 24-hour Urine Parameters in Hypocitriuric and Uric Acid Stone Formers

PHASE1 · University of California, Irvine · NCT06335537

This will see if taking sodium bicarbonate instead of potassium citrate changes 24-hour urine measurements in adults with low urine citrate or uric acid kidney stones.

Quick facts

PhasePHASE1
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years to 80 Years
SexAll
SponsorUniversity of California, Irvine (other)
Locations1 site (Orange, California)
Trial IDNCT06335537 on ClinicalTrials.gov

What this trial studies

This Phase 1 interventional study at the University of California, Irvine will switch eligible adults from potassium citrate (Urocit-K) to sodium bicarbonate and measure changes in 24-hour urine chemistry. Participants are adults with hypocitraturia (<320 mg/24 h) who form calcium oxalate or uric acid stones and are already on Urocit-K. The trial compares urinary citrate, urine pH, and other 24-hour urine parameters before and after the intervention. The protocol excludes people with reduced kidney function, diabetes, certain GI or metabolic disorders, pregnancy, or those taking thiazides or ACE inhibitors.

Who should consider this trial

Good fit: Adults aged 18–79 who form calcium oxalate or uric acid stones, have low urine citrate (<320 mg/24 h), are currently taking Urocit-K, and do not have excluded conditions like reduced kidney function, diabetes, pregnancy, or certain GI/metabolic disorders.

Not a fit: Patients with impaired kidney function (eGFR <60), active diabetes, pregnancy or breastfeeding, those on thiazides or ACE inhibitors, or people whose stones are not related to low citrate or acidic urine are unlikely to benefit from this approach.

Why it matters

Potential benefit: If successful, sodium bicarbonate could offer a lower-cost alternative to potassium citrate to improve urine chemistry and lower stone recurrence risk.

How similar studies have performed: Potassium citrate is well established to raise urinary citrate, but substituting sodium bicarbonate as a lower-cost alternative has been less studied and remains relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* \> 18 years of age and \< 80 years of age,
* Hypocitriuric (\<320 mg/24 hours), Calcium Oxalate Stone or Uric Acid stone formers, currently on Urocit-K therapy as the standard of care.

Exclusion Criteria:

* Male or female \<18 years old or \> 80 years old.
* Currently taking thiazides or ACE inhibitor medications
* Pregnant women.
* Women who are breastfeeding or plan to breastfeed during study period
* History of abnormal renal function (defined as eGFR \<60 mL/min/1.73 m2), active urinary tract infection, diabetes, cystinuria, renal tubular acidosis, inflammatory bowel disease, chronic diarrhea, primary hyperparathyroidism, peptic ulcer disease.

Where this trial is running

Orange, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Uric Acid Stones, uric acid, hypocitraturia

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.