[Effect of potassium citrate in the prophylaxis of urinary lithiasis]

The physiologic effects of potassium citrate on urinary solubility have led to their use to facilitate stone passage after lithotripsy. The aim of our study is to evaluate the foregoing effects and the efficacy of long-term treatment with potassium citrate to prevent stone recurrence in patients undergoing extracorporeal shock wave lithotripsy.

A prospective study was conducted on 100 patients with calcium oxalate or calcium phosphate nephrolithiasis that had undergone treatment by extracorporeal shock wave lithotripsy (ESWL). The patients were divided into 4 groups: patients that were stone-free treated with potassium phosphate (25 cases) or fluid diet (25 cases) and patients with persistent residual lithiasis treated with potassium citrate (25 cases) or fluid diet (25 cases). Calculi were classified according to the changes observed during the study compared with the pre-study status as stable (no changes from the pre-study status, with or without residual stone), increased (increase in number or size of the residual stone or recurrence), and decreased (decrease in number or size or passage of the residual stone).

Of the 50 patients treated with potassium citrate, 35 (70%) remained stable, 10 cases (20%) showed a decrease and 5 (10%) showed an increase. Of the 50 patients on fluid diet, 19 (38%) remained stable throughout the study, 4 (8%) showed a decrease and 27 (54%) showed an increase in stone size or number. The number of stone recurrence throughout the study in the 100 patients was 25 (25%); of these, 8 were in patients treated with potassium citrate and 17 of those that did not receive potassium citrate.

Potassium citrate therapy has been found to be statistically significantly effective in the control of post-lithotripsy residual stone and stone recurrence.