Post published:January 30, 2016

Allan S. Brett, MD reviewing Furyk JS et al. Ann Emerg Med 2016 Jan.

The efficacy of α-blockers (e.g., tamsulosin) to facilitate passage of ureteral stones is unclear. In a 2014 meta-analysis of mostly small studies, tamsulosin shortened time to stone passage, but study quality was not rated highly (Cochrane Database Syst Rev 2014; 4:CD008509). In a subsequent large trial, tamsulosin was not superior to placebo, but stone passage was not confirmed by imaging (NEJM JW Gen Med Jul 1 2015 and Lancet 2015; 386:341).

Now, in a double-blind, randomized trial conducted in five Australian emergency departments, 403 adults with computed tomography (CT)–confirmed distal ureteral stones received daily tamsulosin (0.4 mg) or placebo for 28 days. Stone size was <5 mm in 74% of patients and 5 to 10 mm in 26%; patients were excluded if stone size exceeded 10 mm.

In patients with smaller stones, stone passage (confirmed by absence of stone on CT at 28 days) occurred with equal frequency (≈90%) in the tamsulosin and placebo groups. In contrast, stones measuring 5 to 10 mm passed significantly more often with tamsulosin than with placebo (83% vs. 61%). Median time to stone passage (i.e., time to patient-reported stone retrieval or to a 48-hour pain-free period) was 7 days with tamsulosin and 11 days with placebo (P=0.10); this endpoint was not reported separately for small and large stones. At 28 days, 13 patients (5 in the tamsulosin group and 8 in the placebo group) had undergone urologic intervention. Pain scores were similar in the tamsulosin and placebo groups throughout follow-up.

Comment

In this study, tamsulosin increased the probability that 5- to 10-mm distal ureteral stones would be passed. The clinical importance of this finding depends on whether tamsulosin lowered overall need for invasive urologic interventions (both during and after 28-day follow-up)