Tamsulosin for the Expulsion of Ureteral Stones
You are working in TCC one busy evening, kicking ass and saving lives. In the middle of the primary survey of a critically ill level one trauma, you are suddenly hit by a sharp, 10 out of 10 pain in your right side. Thinking that Doug Schueurer might have punched you, you turn around swiftly and see that he is on the other side of the room. After the patient is stabilized, you run to bathroom and begin vomiting. Dr. Wagner knocks on the door and tells you to quit being dramatic and get back to work, which you faithfully do.
The pain continues though to the end of your shift, at which time you check yourself in as a patient. You vitals are stable, with a heart rate of 105. You have some improvement in your pain with IV morphine and toradol. Your creatinine is normal and your UA shows a moderate amount of blood, with no signs of infection. An ultrasound (which you remember from a previous journal club is useful for diagnosing ureteral stones) reveals a 4 mm stone in the right distal ureter with mild hydronephrosis.
After tolerating a PO challenge (and yes, eating one of our turkey sandwiches is a challenge), you are ready to home. You leave with prescriptions for zofran, vicodin, and Flomax. Having heard horror stories about people developing orthostatic hypotension while taking Flomax, you wonder if there is any real efficacy. When you get home, you decide to do a literature search and see what the evidence shows.
Population: Adult patients with ureteral stones not requiring urgent surgical intervention
Comparison: Usual treatment (oral hydration, pain control, etc.)
Outcome: Time to stone passage, pain level, need for surgical intervention, quality of life, patient satisfaction
The articles chosen for the 2008 journal club were reviewed, and the meta-analysis used at that time was chosen as one of the articles. PubMed was then searched using the terms “tamsulosin AND (stones or colic)” limited to the last 10 years (http://tinyurl.com/jj8qysm). This results in 167 studies, of which 3 relevant randomized controlled trials were selected.
Article 1: Singh A, Alter HJ, Littlepage A. A systematic review of medical therapy to facilitate passage of ureteral calculi. Ann Emerg Med. 2007 Nov;50(5):552-63.
Article 2: Vincendeau S, Bellissant E, Houlgatte A, Doré B, Bruyère F, Renault A, Mouchel C, Bensalah K, Guillé F; Tamsulosin Study Group. Tamsulosin hydrochloride vs placebo for management of distal ureteral stones: a multicentric, randomized, double-blind trial. Arch Intern Med. 2010 Dec 13;170(22):2021-7.
Article 3: Pickard R, Starr K, MacLennan G, et al. Medical expulsive therapy in adults with ureteric colic: a multicentre, randomised, placebo-controlled trial. Lancet. 2015 Jul 25;386(9991):341-9.
Article 4: Furyk JS, Chu K, Banks C, Greenslade J, Keijzers G, Thom O, Torpie T, Dux C, Narula R. Distal Ureteric Stones and Tamsulosin: A Double-Blind, Placebo-Controlled, Randomized, Multicenter Trial. Ann Emerg Med. 2016 Jan;67(1):86-95.e2.
In 2008, the Washington University emergency medicine journal club looked at the efficacy of medical expulsive therapy in the management of ureteral stones. The conclusion at that time, based largely on a systematic review and meta-analysis from the Annals of EM the year before, was that tamsulosin and nifedipine may “improve moderate sized (more than 5mm) distal kidney stone expulsion rates compared with standard medical therapy.” This review did suggest the need for further large randomized controlled trials to further evaluate this topic, given that the results were based largely on “Low-quality RCT’s.”
Since then, several larger RCT’s have been performed. One study with mostly small stones (70% being 2-3 mm in diameter) found that tamsulosin did not improve time to stone expulsion or need for urgent intervention (Vincendeau 2010). This finding was supported by a subsequent trial in which ~75% of stones were < 5 mm in diameter (Pickard 2015). Despite a trend toward improved spontaneous stone passage at 4 weeks (the primary outcome) in patients with stones > 5 mm in size receiving tamsulosin, the authors of this paper haughtily conclude that “further trials involving these agents for increasing spontaneous stone passage rates will be futile.” Ignoring this advice, an additional study was recently published in Annals of EM (Furyk 2016). While this study also did not demonstrate improved stone passage when considering all patients (absolute risk reduction 5.1%; 95% CI -3.0% to 13.0%), a prespecified subset analysis of patients with stones 5-10 mm in diameter resulted in a significant improvement in this outcome (ARR 22.4%; 95% CI 3.1% to 41.6%; NNT = 4.5.)
This body of data, overall, suggests that tamsulosin likely provides no benefit to patients with small kidney stones (i.e. those smaller than 5 to 6 mm in diameter), but does seem to provide benefit in larger stones. A recent meta-analysis that includes all of these studies came to a similar conclusion (Wang 2016). For patients with stones 5-10 mm in diameter, this meta-analysis found an ARR of 22% (95% confidence interval 12% to 33%) with a NNT of 5.