Level 2: Mid-level evidence
A systematic review evaluated the efficacy of calcium channel blockers or alpha blockers for the treatment of urinary stones in nine randomized trials with 693 patients (Lancet. 2006;368:1171-1179). In all trials, stone passage rates were higher with treatment than with placebo. In eight of the trials, the rates of stone passage ranged from 75%-100% with treatment vs. 35%-80% for controls. In one outlier trial, the rate of stone passage was 53% with treatment vs. 20% for controls. There was no significant heterogeneity in a meta-analysis, and promotion of stone passage had an NNT of 4.
Results were confounded by additional medications. The use of concomitant medications (e.g., corticosteroids) varied across trials; seven trials also provided nonsteroidal anti-inflammatory drugs to both treatment and control groups. Treatment duration was seven days to six weeks, and follow-up ranged from 15 to 48 days. Only 12 patients dropped out across all nine trials. Sensitivity analyses showed similar results with higher-quality trials.