Comparative efficacy of "specific" potassium citrate therapy versus conservative management in nephrolithiasis of mild to moderate severity.

It generally is believed that conservative measures of high fluid intake and dietary modification in the setting of a stone clinic could favorably influence the course of renal stone disease. To establish the effect of specific medical treatment from the stone clinic effect, we compared the results of potassium citrate therapy to those of 11 reported conservative or placebo trials. The 54 patients receiving potassium citrate chosen for this comparison had mild to moderately severe stone disease (less than 1 stone per patient per year), similar to that encountered in conservative placebo trials (mean 0.54 stones per patient per year). New stone formation was virtually eliminated by potassium citrate therapy (a decrease from 0.52 to 0.02 stones per patient per year, a remission rate of 96 per cent, p less than 0.001), whereas it continued in 39 per cent of the patients during conservative or placebo trials. However, in patients participating in conservative or placebo trials new stone formation decreased by only 54 per cent (from 0.54 to 0.25 stones per patient per year). The superior response to potassium citrate suggested that this specific medical treatment exerted an additional favorable effect on the course of stone disease above the stone clinic effect.