Is tamsulosin (Flomax) effective in promoting stone passage in patients with distal ureteral stones?
Tamsulosin promotes stone passage of distal ureteral stones that are 5 to 10 mm in size. You would need to treat five such patients to get one stone passage. Smaller stones tend to pass on their own at a rate of 86% in this study. (Level of Evidence = 1a)
The benefit of tamsulosin for the passage of ureteral stones 10 mm or smaller is uncertain given the conflicting results in recent randomized controlled trials. In this study, investigators searched Medline, Embase, and Central databases, reviewed bibliographies of identified studies, and consulted with experts to find randomized double-blind, placebo-controlled trials that evaluated the effectiveness of tamsulosin on the passage of ureteral stones that were 10 mm or smaller. Two reviewers independently selected studies, abstracted data, and performed a quality assessment. Eight studies with 1,384 participants were included in the meta-analysis, and all were considered at low risk of bias. Overall, seven of the eight studies enrolled only patients with distal ureteral stones. Tamsulosin, 0.4 mg per day, was used in all eight studies, most commonly for 28 days. The outcome of interest was stone passage, defined in seven studies as the absence of the stone on imaging and in one study as the absence of urologic intervention.
Tamsulosin led to increased stone passage (85% vs. 66%; risk difference = 17%; 95% confidence interval, 6% to 27%), but there was significant heterogeneity in these results, likely because of differences in outcomes based on stone size. Preplanned subgroup analyses showed that tamsulosin was more effective than placebo for 5- to 10-mm distal stones (79% vs. 57%; risk difference = 22%; 95% confidence interval, 12% to 33%; number needed to treat = 5), but not for those smaller than 5 mm. Because smaller stones are likely to pass spontaneously, treatment would not necessarily add any benefit. Increases in adverse effects, specifically dizziness and orthostatic hypotension, were not seen in the tamsulosin cohort, although there was much heterogeneity in the incidence of dizziness among the eight trials. Finally, although there was evidence of publication bias, the authors did a thorough job of searching for possible unpublished reports and did not find any of high quality.
Study design: Meta-analysis (randomized controlled trials)
Funding source: Government
Setting: Various (meta-analysis)
Reference:Wang RC, Smith-Bindman R, Whitaker E, et al. Effect of tamsulosin on stone passage for ureteral stones: a systematic review and meta-analysis [published ahead of print September 7, 2016]. Ann Emerg Med. http://www.annemergmed.com/article/S0196-0644(16)30364-X/fulltext. Accessed November 19, 2016.