A Phase 1/2 interventional study of Potassium Citrate and Sodium Bicarbonate in Kidney Stones, Urolithiasis, Hypocitraturia and Nephrolithiasis, sponsored by University of California, Los Angeles. Not yet recruiting at 6 sites in 3 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-12.
Sponsored by University of California, Los Angeles · Phase 1/2, Interventional, and Treatment
Kidney stones affect 1 in every 11 people in the US each year. In patients with kidney stones who are prescribed medications for stone management, only 30.2% are adherent to a medication regime and even fewer, only 13.4 % are adherent with citrate medications.
Prescription potassium citrate can be expensive for many patients, leading to non-compliance. Sodium bicarbonate is a potential medication alternative that is cheaper and can potentially alkalinize the urine and/or decrease the risk of future kidney stones. However, efficacy of alternatives to potassium potassium citrate are not well studied.
This study seeks to evaluate sodium bicarbonate and assess its ability to alkalinize urine in a cohort of patients with kidney stones and compare this to prescription potassium citrate.
Kidney stones affect 1 in every 11 people in the United States each year. A recurrence rate of 50% at 10 years highlights the importance of metabolic management, which has shown to be effective at decreasing the recurrence of stone disease. Specialty guidelines have recommended that clinicians offer pharmacologic therapy to recurrent stone formers. However, among kidney stone patients prescribed medication for stone management, only 30.2% are adherent to a medication regimen and even fewer, only 13.4%, are adherent with citrate medications.
Prescription potassium citrate (Kcit) can be cost-prohibitive for many patients, leading to non-compliance. The combination of the effectiveness of medication with the prohibitory cost of the prescriptions has led to the exploration of treatment alternatives which promise to alkalinize the urine and/or decrease the risk of future kidney stones, including sodium bicarbonate. However, the efficacy of these alternatives in comparison to Kcit are not well studied and often include other alkali equivalents.
A short-term study with limited sample size suggests sodium bicarbonate to be a viable alternative to Kcit. Our goal is to evaluate sodium bicarbonate and assess its ability to alkalinize urine in a cohort of stone-forming patients and compare this to prescription Kcit.
509 studies on the registry are indexed under Kidney Calculi; 146 are open to participants now.
This study's planned enrollment of 30 is below the median of 86 across 391 interventional studies indexed under Kidney Calculi.
Browse Kidney Calculi studies →University of California, Los Angeles is the lead sponsor of 1,170 studies on the registry; 195 are open to participants now.
Of its 95 completed or terminated interventional studies of FDA-regulated products, 70 (74%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Receives 1 week of sodium bicarbonate, then 1 week of potassium citrate after washout.
Drug: Potassium Citrate · Drug: Sodium Bicarbonate
1 week of potassium citrate first, then sodium bicarbonate after a washout.
Drug: Potassium Citrate · Drug: Sodium Bicarbonate
20 mEq Kcit twice a day (40 mEq daily
650 mg sodium bicarbonate twice a day (35.2 mEq daily)
Change in 24-Hour Urinary Citrate Excretion from 24-Hour Urine Collection
Change in 24-hour urinary citrate excretion measured from 24-hour urine collections obtained at baseline and after intervention. To determine if sodium bicarbonate is not significantly worse than potassium citrate by more than a clinically acceptable margin of -10 Unit: mg/day
Time frame: 14 days
Change in Urine pH Measured from 24-Hour Urine Collection
Change in urine pH measured from 24 hour urine collections obtained at baseline and after intervention units: pH
Time frame: 14 days
Change in 24 hour Urinary Ammonia Excretion from 24 Hour Urine Collection
Change in 24 hour urinary ammonia excretion from 24 hour urine collections obtained at baseline and after intervention Unit: mmol/day
Time frame: 14 days
Incidence of Side Effects
Number of participants experiencing side effects attributed to the intervention Unit: number of participants with ≥1 adverse event
Time frame: 14 days
Plan to share: Yes — De-identified individual participant data that underlie the results reported in this study, along with the Study Protocol and Statistical Analysis Plan, will be made available to qualified researchers upon request. Interested parties should direct their inquiries and research proposals to KScotland@mednet.ucla.edu. To gain access, requestors will be required to provide a methodologically sound proposal and sign a formal Data Use Agreement (DUA) to ensure participant confidentiality. Data will be available beginning 6 months after the publication of the primary results and will remain accessible for a period of 3 years. The study team will review all requests to determine if the proposed use of the data aligns with the original study's ethical approvals and scientific objectives.
Supporting information: Study protocol, Statistical analysis plan
Time frame: Starting 6 months after publication Ending 3 years after publication
Access criteria: Researchers who submit a research proposal with justified rationale for why they need to access the data along with sound methodological approach, pending approval by the corresponding author. De-identified IPD (ie. baseline characteristics, outcomes, and adverse events) reported from this study will be made available along with study protocol and statistical analysis plan.
Start is estimated for Feb 2026; primary completion for Aug 2026, 6 months later.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Studies of the drugs tested here: Potassium Citrate · Sodium Bicarbonate
University of California, Los Angeles →