Does mirabegron relieve ureteric stent-related discomfort?  A prospective, randomized, multicentre study. 
To evaluate the effects of 50 mg mirabegron once daily for ureteric stent-related discomfort after ureteroscopic procedures by conducting a multicentre randomized study.  A total of 100 patients with indwelling ureteric stents after ureteroscopic stone removal or retrograde intrarenal surgery (RIRS) were randomized 1:1 to receive either no treatment or mirabegron during the stenting period.  At the time of stent removal, the validated Ureteral Stent Symptom Questionnaire (USSQ), International Prostate Symptom Score (IPSS), total amount of analgesics administered, and post-voiding residual urine volume were reported for each patient.  Overall, 96 patients were enrolled for analysis.  The postoperative USSQ body pain score (21.96 vs 13.96; P = 0.007) and overall pain score (5.58 vs 2.83; P = 0.002) were lower in the mirabegron group than in the control group.  The USSQ urinary symptom scores (32.58 vs 27.92; P = 0.582) and USSQ general health score (17.71 vs 14.00; P = 0.281) were also lower in the mirabegron group, but the difference was not significant.  Postoperative IPSS total scores and quality-of-life scores were lower in the mirabegron group, but the difference was not significant.  The change in IPSS storage symptom score, however, was lower in the mirabegron group than in the control group (3.58 ± 3.58 vs 1.83 ± 4.39; P = 0.035).  Post-void residual urine volume did not differ between the two groups (P > 0.05).  The use of 50 mg mirabegron once daily has the potential to reduce ureteric stent-related discomfort.  Prospective larger-scale, placebo-controlled studies are warranted to further evaluate the beneficial effects of mirabegron on stent-related symptoms.