Alkalinizing agents: a review of prescription, over-the-counter, and medical food supplements.

Introduction: Kidney stones affect 1 in every 11 people in the United States each year. There is a significant high recurrence rate without a stone prevention protocol. Alkali citrate is beneficial in decreasing stone recurrence, but because of the cost and gastrointestinal side effects there is a low adherence rate. This study aims to serve as a review of some of the most commonly used alkalizing over-the-counter supplements that are advertised to prevent and treat kidney stones. Methods: Data were gathered by a comprehensive online literature search and company inquiries for kidney stone prevention supplements. An additional informal poll of the authors selected supplements that are most commonly taken by their patients. A total of eight supplements were evaluated for cost, alkali equivalent provided, dosing, and regulatory information. Results: Eight of the most commonly used supplements were reviewed with a focus on alkalizing agents. Information reviewed revealed dosing recommendations resulting in decreased citrate alkali equivalents per day compared with prescription-strength potassium citrate. Cost, peer-reviewed study results, and regulatory data were reviewed, tabulated, and analyzed. Cost per alkali equivalent was substantially decreased for each supplement compared with the prescribed drug. All supplements were found to be readily available online. Conclusion: Over-the-counter alkalizing agents are available to patients and may be an appropriate alternative to cost-prohibitive potassium citrate when treating urolithiasis patients. Additional testing will be necessary in the future to determine the efficacy of these supplements in the treatment and prevention of urinary stone disease.