Sodium Bicarbonate as an Alternative to Potassium Citrate for Kidney Stones

February 5, 2026 updated by: Kymora Scotland, MD, PhD, University of California, Los Angeles

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

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.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Canada
      • Montreal, Canada
        • CHUM
  • Iceland
      • Reykjavik, Iceland
        • Landspitali- National University Hospital of Iceland
        • Contact:
          • Johann Ingimarsson
  • United States
    • California
      • Los Angeles, California, United States, 90095
        • University of California, Los Angeles
      • Sacramento, California, United States, 95817
        • University of California, Davis
        • Contact:
          • Noah Canvasser
      • San Diego, California, United States, 92103
        • University of California, San Diego
        • Contact:
          • Seth Bechis
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
        • Brigham & Women's
        • Contact:
          • Daniel Wolen

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adult >18 years of age
  • History of nephrolithiasis
  • One 24h urine collections within one year of enrollment with hypocitraturia.
  • Patients currently utilizing or considering use of Kcit for stone prevention

Exclusion Criteria:

  • Individuals with known metabolic disorders
  • Individuals with other known causes of nephrolithiasis
  • Anyone who, in the opinion of the PI, is unfit or unsuitable to participate in the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Sodium Bicarbonate -> Potassium Citrate
Receives 1 week of sodium bicarbonate, then 1 week of potassium citrate after washout.
Drug: Potassium Citrate
20 mEq Kcit twice a day (40 mEq daily
Drug: Sodium Bicarbonate
650 mg sodium bicarbonate twice a day (35.2 mEq daily)
Experimental: Potassium Citrate -> Sodium Bicarbonate
1 week of potassium citrate first, then sodium bicarbonate after a washout.
Drug: Potassium Citrate
20 mEq Kcit twice a day (40 mEq daily
Drug: Sodium Bicarbonate
650 mg sodium bicarbonate twice a day (35.2 mEq daily)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in 24-Hour Urinary Citrate Excretion from 24-Hour Urine Collection
Time Frame: 14 days

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
14 days

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Urine pH Measured from 24-Hour Urine Collection
Time Frame: 14 days

Change in urine pH measured from 24 hour urine collections obtained at baseline and after intervention

units: pH
14 days
Change in 24 hour Urinary Ammonia Excretion from 24 Hour Urine Collection
Time Frame: 14 days

Change in 24 hour urinary ammonia excretion from 24 hour urine collections obtained at baseline and after intervention

Unit: mmol/day
14 days

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Incidence of Side Effects
Time Frame: 14 days

Number of participants experiencing side effects attributed to the intervention

Unit: number of participants with ≥1 adverse event
14 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of California, Los Angeles

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
University of California, San Diego
Brigham and Women's Hospital
University of California, Davis
Centre hospitalier de l'Université de Montréal (CHUM)
Landspitali University Hospital

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Kymora B Scotland, MD, PhD, University of California, Los Angeles

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 16, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 5, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 12, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 12, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 5, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB-24-5580 (Registry Identifier: University of California, Los Angeles IRB)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

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.

IPD Sharing Time Frame

Starting 6 months after publication

Ending 3 years after publication

IPD Sharing 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.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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