Let it Flow: Tamsulosin For Kidney Stone Expulsion

Clinical Scenario:
A middle- aged man with no significant past medical history presents with acute onset right flank pain.  A CT renal stone protocol scan finds a 4 mm kidney stone.  You provide hydration and pain control, and soon the patient starts to feel better.  As you are preparing to discharge the person, what is the evidence that tamsulosin helps with stone expulsion?

Image source: modified from gopixpic.com

Literature review:

A 2014 meta-analysis published in the Canadian Journal of Emergency Medicine [Ref 1] selected 22 studies which were all randomized, had radiologic confirmation of renal stone, and compared tamsulosin (mostly 0.4mg daily) against placebo with standard therapy given to all patients (NSAIDs, hydration, and/or opioids).  The primary outcome was percent of spontaneous passage of distal ureterolithiasis of less than or equal to 10mm, while secondary outcomes evaluated mean time to expulsion, complications/side effects, and impact of varying stone size on expulsion.  Many of the studies had a high risk of bias secondary to poor descriptions of the randomization process.  Of the 22 studies, there was an overall suggested benefit for stones less than or equal to 5mm (RR 1.50 95% CI 1.31-1.71) and among the studies that were double-blind and randomized there was a suggested benefit (1.22 95% CI 1.06-1.41).  However, of the studies that were considered to have low risk of bias, there was no statistically significant relation between tamsulosin and expulsion (RR 1.15 95% CI 0.92-1.47). Thirteen studies analyzed mean time to expulsion of distal stones, and it was found that tamsulosin decreased expulsion time by 3.33 days.  There did not seem to be a significant association for the number of hospitalizations, urology consults, or average number of pain episodes with the use of tamsulosin.  Again, when limited to studies with low risk of bias, there was no significant gain in mean time to expulsion with tamsulosin.  The most common side effects were orthostatic hypotension and retrograde ejaculations.

A 2014 meta-analysis published by the Cochrane Database [Ref 2] presented data more in favor of the use of tamsulosin.  Tamsulosin had better rate of expulsion (RR 1.48, 95% CI 1.32 to 1.67, P < 0.00001) as well as time to expulsion with 2.91 days shorter when compared to control (95% CI -4.00 to -1.81, P < 0.00001).  It did not significantly affect pain scoring, but slightly reduced the number of pain episodes.  Patients using tamsulosin were more likely to experience side effects compared to standard therapy and placebo including dizziness, palpitations, headache, retrograde ejaculations, fatigue, and postural hypotension.

Take Home:
-Tamsulosin seems to shorten time to expulsion of kidney stones
-Tamsulosin does not reduce pain from kidney stones
-Most common side effects are orthostatic hypotension and retrograde ejaculations

References:
1. Malo C, Audette-Côté JS, Emond M, Turgeon AF. Tamsulosin for treatment of unilateral distal ureterolithiasis: a systematic review and meta-analysis. CJEM. 2014 May 1;16(3):229-42.
2. Campschroer T, Zhu Y, Duijvesz D, Grobbee DE, Lock MT. Alpha-blockers as medical expulsive therapy for ureteral stones. Cochrane Database Syst Rev. 2014 Apr 2;4:CD008509.

Submitted by Lydia Luangruangrong, PGY-3.

Edited by  Steven Hung (@DocHungER), PGY-2

Faculty reviewed by Joan Noelker