was 4%. The corresponding pooled result for nifedipine
(nine studies, n = 686) showed that active treatment gave a
50% increased likelihood of stone passage, with an absolute
risk reduction of 26%. The incidence of mild adverse
effects was 15%. Both drugs significantly shortened, by between
2 and 6 days, the average time to stone expulsion
[18]. However, the overall quality of the trials was poor.
In both meta-analyses, the majority of studies involved
stones