Can citrate therapy prevent nephrolithiasis?

This prospective study was done to help determine whether or not oral citrate therapy can elevate urinary citrate levels and reduce the incidence of recurrent calcium stones in patients with hypocitraturia (urinary citrate less than 320 mg/24 hr). The treatment group (Group I) consisted of 10 patients treated with oral citrate and hydration. The control group (Group II) was treated with hydration alone. In Group I, the new stone formation rate (stones per patient year) fell from 1.17 +/- 0.26 to 0.45 +/- 0.32 (p = 0.07) and the twenty-four-hour urinary citrate excretion rose from 69 +/- 14 mg to 473 +/- 96 mg (p = 0.002). In Group II, the new stone formation rate fell from 0.9 +/- 0.25 to 0.27 +/- 0.13 (p = 0.03). The twenty-four-hour urinary citrate excretion increased, though not significantly, from 166 +/- 21 mg to 326 +/- 77 mg (p = 0.06). We conclude that oral citrate therapy can significantly increase urinary citrate levels in patients with recurrent stones associated with hypocitraturia but that oral citrate therapy and hydration were no better than hydration alone in reducing the incidence of recurrent stones.