Administration of the selective alpha 1A-adrenoceptor antagonist silodosin facilitates expulsion of size 5-10 mm distal ureteral stones, as compared to control

Abstract

Objective: Recently, we reported that alpha 1A-adrenoceptor (AR) is the main participant in phenylephrine-induced human ureteral contraction. We therefore decided to carry out a prospective randomized study to evaluate the effects of silodosin, a selective alpha 1A AR antagonist, as a medical expulsive therapy (MET) for distal ureteral stones.

Methods: A total of 112 male patients, who were referred to our department for the management of symptomatic unilateral distal ureteral calculi of less than 10 mm, were randomly divided into two groups: group A (56 patients) who were instructed to drink 2 L of water daily and group B (56 patients) who received the same instruction and were also given silodosin (8 mg/daily) for a maximum of 4 weeks. Expulsion rate, expulsion time and need for analgesics were examined.

Results: The expulsion rate was 55.3 % (56 patients) for group A and 72.7 % (55 patients) for group B (P = 0.106). The expulsion rate for <5 mm was 92.9 % (28 patients) for group A and 69.2 % (26 patients) for group B (P = 0.053). The expulsion rate for ≥ 5 mm was 17.9 % (28 patients) for group A and 75.9 % (29 patients) for group B (P = 0.001). The expulsion time was 13.40 ± 5.90 and 9.29 ± 5.91 days, respectively (P = 0.012). Analgesics were required 1.5 ± 3.1 and 0.3 ± 0.9 times, respectively (P = 0.382). Stone size in expulsion cases was 3.64 ± 1.25 and 5.23 ± 2.32 mm, respectively (P = 0.003).

Conclusions: Stone size has been identified as an important predictive factor for stone expulsion. Therefore, it is important that administration of silodosin can facilitate expulsion of 1.5 mm or larger distal ureteral stones, as compared to control. We believe that silodosin might have potential as a MET for distal ureteral stones.