A 54-year-old man presents to the emergency department (ED) with acute onset left flank pain that radiates to the groin. A computed tomography (CT) scan of the abdomen/pelvis without contrast reveals a 7-mm distal ureteral stone. He is deemed appropriate for outpatient management. In addition to pain medications, should you prescribe tamsulosin?
According to the most recent National Health and Nutrition Examination Survey, the population prevalence of kidney stones is 8.8% with a self-reported prevalence in men of 10.6% and a self-reported prevalence in women of 7.1%.2 Most ureteral stones can be treated in the outpatient setting with oral hydration, antiemetics, and pain control with nonsteroidal anti-inflammatory medications as first-line treatment and opioids as a second-line option.3 In addition, alpha-blockers are used for medical expulsive therapy (MET). In fact, the European Association of Urology guideline on urolithiasis states that MET may accelerate passage of ureteral stones.3
Recently, however, uncertainty has surrounded the effectiveness of the alpha-blocker tamsulosin. Two systematic reviews, limited by heterogeneity because some of the studies lacked a placebo control and blinding, concluded that alpha-blockers increased stone passage within one to 6 weeks when compared with placebo or no additional therapy.4,5 However, a recent large multicenter, randomized controlled trial (RCT) revealed no difference between tamsulosin and nifedipine or either one compared with placebo at decreasing the need for further treatment to achieve stone passage within 4 weeks.6
New meta-analysis breaks down results by stone size
This meta-analysis by Wang et al, consisting of 8 randomized, double-blind, placebo-controlled trials of adult patients (N=1384), examined the effect of oral tamsulosin 0.4 mg/d (average of a 28-day course) on distal ureteral stone passage.1 A subgroup analysis comparing stone size (<5 mm and 5-10 mm) was also conducted to determine if stone size modified the effect of tamsulosin.
Although the initial search included studies published between 1966 and 2015, the 8 that were eventually analyzed were published between 2009 and 2015, were conducted in multiple countries (and included regardless of language), and were conducted in ED and outpatient urology settings. The main outcome measure was the risk difference in stone passage between the tamsulosin group and placebo group after follow-up imaging at 3 weeks with CT or plain film radiographs.
Tamsulosin helps some, but not all. The pooled risk of stone passage was higher in the tamsulosin group than in the placebo group (85% vs 66%; risk difference [RD]=17%; 95% confidence interval [CI], 6%-27%), but significant heterogeneity existed across the trials (I2=80.2%). After subgroup analysis by stone size, the researchers found that tamsulosin was beneficial for larger stones, 5 to 10 mm in size (6 trials, N=514; RD=22%; 95% CI, 12%-33%; number needed to treat=5), compared with placebo, but not for smaller stones, <5 mm in size (4 trials, N=533; RD=-0.3%; 95% CI, -4% to 3%). The measure of heterogeneity in the 5- to 10-mm subgroup demonstrated a less heterogeneous population of studies (I2=33%) than that for the <5-mm subgroup (I2=0%).
In terms of adverse events, tamsulosin did not increase the risk of dizziness (RD=.2%; 95% CI, -2.1% to 2.5%) or postural hypotension (RD=.1%; 95% CI, -0.4% to 0.5%) compared with placebo.