Oral potassium citrate (C6H5K3O7) is known to reduce the risk of formation of kidney stones (nephrolithiasis). Potassium citrate also helps in dissolution of kidney stones.
AdvertisementsCitrate is a weak acid, synthesized by the human body in Krebs' cycle. Many food sources, especially citrus fruits, contain citrate or citric acid. Certain optimum level of citrate excretion is necessary for preventing urine acidity and renal calculi formation.
Decrease in citrate excretion is brought about by metabolic acidosis, hypokalemia, distal renal tubular acidosis, bowel dysfunction, excess sodium excretion, low serum magnesium and starving. Kidney calculi may form as crystals of calcium oxalate (CAOX), calcium phosphate (Brushite), uric acid and struvite (ammonium magnesium phosphate). The calcium oxalate calculi are the most common kidney stones.
Potassium citrate for kidney stonesHypocitraturia is a condition wherein citrate excretion falls below 320 mg ((1.67 mmol) per day. Several people suffering from kidney stones were found to have hypocitraturia. Urinary citrate inhibits kidney stone formation by forming a soluble complex with calcium and reducing the concentration of free calcium in the urine.
The calcium supersaturation gets limited and nucleation of both calcium oxalate and calcium phosphate is prevented. It is believed that interactions with Tamm-Horsfall protein (uromodulin) partly affect the formation of calcium-containing kidney stones. Further alkaline citrate binds to the surface of calcium oxalate crystal and prevents its agglomeration as well as its adhesion to the renal epithelial cells.
Low levels of potassium (hypokalemia) is associated with hypocitraturia. Low levels of potassium, apart from causing intracellular acidosis, induces tubular PH decrease. These changes in potassium status, increases citrate uptake by the renal cells. Potassium citrate preparations provide alkali load and enhance urinary citrate. In uric acid, cystine and infection-related renal calculi formative conditions the potassium citrate prevents nephrolithiasis and helps in the dissolution of calculi.
NASA-ISS study on potassium citrate for kidney stone riskThe International Space Station (ISS) conducted experiments during August 2001 - April 2007, to test the function of potassium citrate as a countermeasure to decrease the risk of renal stone formation in space. The formation of kidney calculi in a crew member can negatively impact the success of the space mission.
In space travel, microgravity induces a number of physiological changes in the human body. Even emptying the bladder is not easy. There is bone loss, urine acidity, decrease in urine output, decrease in urine volume and urinary citrate and increase in calcium and sodium concentration in the urine. The risk of developing kidney calculi is greatly increased during and after flight.
The experiment was a double blind study. Some astronauts were given potassium citrate (K-Cit) pill supplements and others were given placebos. Urine samples were collected and analyzed before, during, and after mission. The dietary information was also recorded.
Results suggest that these supplements may decrease the risk for developing three types of kidney stones (calcium oxalate, uric acid, and brushite) both during and immediately after missions.
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2.Trinchieri A, Esposito N, Castelnuovo C. Dissolution of radiolucent renal stones by oral alkalinization with potassium citrate/potassium bicarbonate. Arch Ital Urol Androl. 2009 Sep;81(3):188-91.
3.Antonia Fabris, Antonio Lupo, Patrizia Bernich, Cataldo Abaterusso, Nicola Marchionna, Antonio Nouvenne, Giovanni Gambaro. Long-Term Treatment with Potassium Citrate and Renal Stones in Medullary Sponge Kidney. CJASN September 2010 vol. 5 no. 9 1663-1668.
4. Whitson PA, Pietrzyk RA, Jones JA, Nelman-Gonzalez MA, Hudson EK, Sams CF. Effect of Potassium Citrate Therapy on the Risk of Renal Stone Formation During Spaceflight. Journal of Urology. 2009; 182: 2490-2496.
5.Fink HA, Wilt TJ, Eidman KE, Garimella PS, MacDonald R, Rutks IR, Brasure M, Kane RL, Monga M. Recurrent Nephrolithiasis in Adults: Comparative Effectiveness of Preventive Medical Strategies. Comparative Effectiveness Review No. 61. AHRQ Publication No. 12-EHC049-EF. The Agency for Healthcare Research and Quality's (AHRQ) mission.
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