The α-adrenergic receptor blocker tamsulosin does not increase passage of small, symptomatic ureteral stones, reports a randomized clinical trial in JAMA Internal Medicine.
The two-phase trial included 512 adults seen in the emergency department with symptomatic ureteral stones. All patients had a symptomatic ureteral stone measuring less than 9 mm in diameter (mean 3.8 mm) on computed tomography. About three-fourths of patents were male and one-fourth were non-white; the mean age was 40.6 years.
Patients were assigned to 28 days of treatment with tamsulosin, 0.4 mg, or placebo. The main outcome of interest was stone passage by 28 days, determined by the patient’s visualization or capture of the stone.
In 497 patients evaluated, there was no significant difference in stone passage rates: 50% with tamsulosin and 47% with placebo. The two groups were also similar in terms of secondary outcomes, including crossover to tamsulosin, time to stone passage, hospitalization, surgery, and repeated ED visits. Exploratory analysis showed no benefit of tamsulosin in patient subgroups according to stone location, size, or location.
Tamsulosin is widely used as “medical expulsive therapy” for patients with urinary stones seen in the ED. Some studies suggest that this treatment is effective mainly for larger stones, reflecting the high rate of spontaneous passage for smaller stones.
This placebo-controlled trial finds no increase in stone passage rate with tamsulosin prescribed to ED patients with symptomatic ureteral stones smaller than 9 mm. The investigators conclude: “Although tamsulosin may still play a role in medical expulsive therapy for larger stones, guidelines that recommend tamsulosin for ureteral stones may need to be revised” [Meltzer AC, et al. Effect of Tamsulosin on Passage of Symptomatic Ureteral Stones: A randomized clinical trial. JAMA Intern Med 2018; 178: 1051–1057].
