Citrate and renal calculi: new insights and future directions.

Citrate is pathogenetically important in stone formation, because it retards the crystallization of stone-forming calcium salts and because its level in urine is low in many patients with nephrolithiasis. Potassium citrate is useful therapeutically, because it can often restore normal urinary citrate. Hypocitraturia often results from dietary aberrations, including sodium excess, and exaggerated intake of animal proteins. Hypocitraturia is frequently accompanied by a low net gastrointestinal absorption of alkali. New drugs are under development as improvements or refinements of currently available potassium citrate. They are potassium citrate 10-mEq-tablet preparation, effervescent calcium citrate, and potassium-magnesium citrate.