Citrate for Kidney Stones

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Chicago

Must not be taking: Diuretics, Alkali supplements

Disqualifiers: Uric acid stones, Chronic kidney disease, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 2

Duration: 1 day

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial examines how two compounds commonly found in food, oxalate and citrate, affect kidney stone formation. Researchers will administer potassium citrate (a type of medication) to participants to observe changes in the levels of these compounds in their urine. The trial includes two groups: individuals who have had calcium-based kidney stones and those who have not. Those with at least one calcium-based kidney stone fit the stone-forming group, while individuals with no history of kidney stones are suitable for the control group. As an unphased trial, this study offers participants the chance to contribute to valuable research that could enhance the understanding and prevention of kidney stones.

Will I have to stop taking my current medications?

If you are taking diuretic medication or alkali supplements, you will need to stop them for the duration of the study.

Is there any evidence suggesting that potassium citrate is likely to be safe for humans?

Research has shown that potassium citrate is generally safe and effective as a treatment. It is often used to prevent kidney stones, particularly in individuals with specific conditions like certain kidney problems or gout. Studies have found that potassium citrate can reduce the recurrence of kidney stones by binding to calcium in the intestines and urine, thereby lowering the risk of stone formation.

Most individuals respond well to potassium citrate, with about 80-90% success in cases with low citrate levels in the urine. Some may experience mild side effects, such as an upset stomach, but these are usually not serious. Overall, evidence suggests that potassium citrate is safe for most people when used as directed. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Potassium citrate is unique because it works by increasing the citrate levels in urine, which helps prevent the formation of kidney stones. Unlike standard treatments that might focus on pain relief or breaking down existing stones, potassium citrate aims to prevent stones from forming in the first place. Researchers are excited because it could offer a proactive approach, reducing the need for more invasive treatments and potentially lowering recurrence rates for kidney stone formers.

What evidence suggests that potassium citrate might be an effective treatment for kidney stones?

Research has shown that potassium citrate can help reduce kidney stones by increasing citrate in urine and decreasing calcium, both of which prevent stones. One study found that potassium citrate significantly lowered the number of kidney stone incidents. It can also stop new stones from forming and reduce the size of existing stones compared to no treatment. Most patients in that study experienced a significant drop in the rate of stone formation. In this trial, one arm will include kidney stone formers receiving potassium citrate, while a control cohort will consist of non-stone-forming subjects. These findings suggest that potassium citrate could be a useful option for people who frequently develop kidney stones. ^{2 6 7 8 9}

Are You a Good Fit for This Trial?

This trial is for individuals who have had kidney stones or are healthy without any history of kidney issues. Participants will be studied to understand how their bodies handle certain compounds related to kidney stone formation.

Inclusion Criteria

I am between 18-70 years old and have had at least one calcium kidney stone.

Exclusion Criteria

I have had kidney stones made of uric acid, cysteine, or struvite.

History of severe acid-base abnormality, very low (<100mg/day) or very high (>1500mg/day) urine citrate

NSF and SF with extreme levels of urine citrate will be excluded from this small initial study to reduce heterogeneity and remove focus from the extremes of citrate levels.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Treatment

Participants receive a potassium citrate load and undergo urine and serum measurements over six hours

1 day

1 visit (in-person)

Follow-up

Participants are monitored for changes in urine oxalate and citrate levels after treatment

1-2 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Potassium Citrate

Trial Overview The study focuses on the response of urinary oxalate and citrate levels after consuming potassium citrate. It aims to determine if this can influence the likelihood of developing kidney stones.

How Is the Trial Designed?

Group I: Kidney stone formers Experimental Treatment 1 Intervention

12 stone-forming subjects will be enrolled in this arm.

Group II: Control cohort Experimental Treatment 1 Intervention

12 non-stone-forming subjects will be enrolled in this arm.

Who Is Running the Clinical Trial?

University of Chicago

Lead Sponsor

Trials

1,086

Recruited

844,000+

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Collaborator

Trials

2,513

Recruited

4,366,000+

Published Research Related to This Trial

Many over-the-counter supplements contain more citrate than advertised, with Moonstone® powder showing the highest citrate content per serving (63.9 mEq), which could help prevent kidney stone recurrence.

While Moonstone offers the most citrate, it is more expensive compared to other products like NOW® potassium citrate, which is the least costly option ($0.04/10 mEq alkali citrate), highlighting the need to consider both efficacy and cost when choosing a citrate supplement.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Alkali Citrate Content of Common Over-the-Counter and Medical Food Supplements. Dai, JC., Maalouf, NM., Hill, K., et al.[2023]

Potassium citrate is an effective treatment for managing various types of kidney stones, including calcium stones associated with renal tubular acidosis and hypocitraturic calcium oxalate nephrolithiasis.

It also helps in treating uric acid stones, demonstrating its broad utility in stone disease management, particularly for patients with specific underlying conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Citrate and renal calculi. Pak, CY.[2013]

In a study of 15 patients treated with granulated potassium citrate for one month, significant biochemical changes were observed, including improvements in serum potassium, creatinine, and urinary pH, citrate, and potassium levels.

The treatment was well tolerated, confirming that potassium citrate is an effective and user-friendly option for preventing oxalocalcium kidney stones.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Granulated potassium citrate in the prevention of calcium oxalate lithiasis]. Campoy Martínez, P., Arrabal Martín, M., Quintero Rodríguez, R., et al.[2013]

Potassium citrate is effective in preventing the formation and relapse of certain types of kidney stones, with a one-year remission rate of 70-75% in patients treated for stone disease.

It is generally safe when used at therapeutic doses, causing only mild transient metabolic alkalosis and no significant changes in blood biochemical parameters, while effectively reducing urine calcium and increasing oxalate calcium phosphate excretion.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Therapeutic use of potassium citrate]. Zmonarski, SC., Klinger, M., Puziewicz-Zmonarska, A., et al.[2022]

Potassium citrate therapy significantly reduced new stone formation in patients with mild to moderately severe stone disease, achieving a remission rate of 96% (from 0.52 to 0.02 stones per patient per year, p < 0.001).

In contrast, conservative measures or placebo trials only decreased new stone formation by 54% (from 0.54 to 0.25 stones per patient per year), indicating that potassium citrate provides a more effective treatment beyond standard conservative approaches.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparative efficacy of "specific" potassium citrate therapy versus conservative management in nephrolithiasis of mild to moderate severity. Preminger, GM., Harvey, JA., Pak, CY.[2019]

In a study involving five calcium oxalate stone formers, the ingestion of minimum doses of potassium citrate significantly increased citraturia and crystallization inhibitory capacity in urine samples.

The most effective timing for taking potassium citrate was after dinner, suggesting that this method could help reduce the risk of kidney stone formation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Chronopharmacological studies on potassium citrate treatment of oxalocalcic urolithiasis. Grases, F., Conte, A., March, JG., et al.[2019]

In a study of 313 children on the ketogenic diet for epilepsy, those who received potassium citrate (Polycitra K) had a significantly lower incidence of kidney stones (2.0%) compared to those who did not receive the supplement (10.5%).

Starting potassium citrate supplementation at the onset of the ketogenic diet resulted in an even lower kidney stone incidence of 0.9%, demonstrating its effectiveness in preventing kidney stones by alkalinizing urine without reported adverse effects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Empiric use of potassium citrate reduces kidney-stone incidence with the ketogenic diet. McNally, MA., Pyzik, PL., Rubenstein, JE., et al.[2021]

In a study of 8 pediatric patients with distal renal tubular acidosis (RTA), potassium citrate at a dosage of 4 mEq/kg/d effectively corrected most urinary abnormalities associated with nephrolithiasis, particularly reducing elevated urinary saturation for calcium oxalate.

The study found that while potassium citrate normalized several urinary ratios, the elevated urinary saturation for calcium phosphate could not be corrected, indicating that while potassium citrate is beneficial, it may not address all urinary issues in distal RTA.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dosage of potassium citrate in the correction of urinary abnormalities in pediatric distal renal tubular acidosis patients. Domrongkitchaiporn, S., Khositseth, S., Stitchantrakul, W., et al.[2013]

In a study of 9 patients with incomplete distal renal tubular acidosis, oral potassium citrate therapy significantly increased urinary pH and citrate levels while decreasing urinary calcium, which helps prevent kidney stone formation.

Over a mean treatment period of 34 months, none of the patients developed new kidney stones, demonstrating the long-term efficacy of potassium citrate in managing calcium nephrolithiasis associated with this condition.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Prevention of recurrent calcium stone formation with potassium citrate therapy in patients with distal renal tubular acidosis. Preminger, GM., Sakhaee, K., Skurla, C., et al.[2022]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC2974409/

Long-Term Treatment with Potassium Citrate and Renal ... Results: Parallel to a significant rise in urinary citrate and decreased urinary calcium (all P < 0.001), KC led to a dramatic reduction in the stone event rate ...

2. journals.lww.com journals.lww.com/ursc/fulltext/2025/09000/efficacy_and_tolerability_of_potassium_citrate.4.aspx

Efficacy and tolerability of potassium citrate sachet versus Previous studies have demonstrated that potassium citrate effectively inhibits the formation of calcium oxalate, uric acid, and cystine stones ...

3. aafp.org aafp.org/pubs/afp/issues/2017/0501/p552.html

Citrate Salts for Preventing and Treating Calcium- ... Citrate supplementation reduces stone size to less than 5 mm and prevents new stone formation when compared with placebo or no intervention.

4. sciencedirect.com sciencedirect.com/science/article/pii/S0085253815337844

Successful management of uric acid nephrolithiasis with ... Remission was experienced in 94.4% of patients, and the group stone formation rate declined by 99.2%. Detailed case reports were obtained in five patients ...

5. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC4657843/

Effect of Potassium Citrate on Calcium Phosphate Stones ... Oral citrate would be expected to decrease calcium available for absorption, decrease bone resorption, and increase renal tubular calcium reabsorption, all of ...

6. mayoclinic.org mayoclinic.org/drugs-supplements/potassium-citrate-oral-route/description/drg-20074773

Potassium citrate (oral route) - Side effects & dosage Potassium citrate is used to treat a kidney stone condition called renal tubular acidosis. It is also used to prevent kidney stones that may occur with gout.

7. sciencedirect.com sciencedirect.com/science/article/pii/S0272638612806354

Citrate and Renal Calculi: New Insights and Future Directions Potassium citrate is useful therapeutically, because it can often restore normal urinary citrate. Hypocitraturia often results from dietary aberrations, ...

8. emedicine.medscape.com emedicine.medscape.com/article/444968-overview

Hypocitraturia Overview of Potassium Citrate and Calcium ... Approximately 80-90% of patients with hypocitraturia are treated successfully with potassium citrate to raise their urine citrate levels. This ...

9. aafp.org aafp.org/pubs/afp/issues/2019/0415/p490.html

Kidney Stones: Treatment and Prevention Patients should increase daily fluid intake to 2.5 to 3 L per day to prevent recurrence of kidney stones. Thiazide diuretics, potassium citrate ...