Treating overactive bladder symptoms after transurethral prostatic surgery for benign prostatic hyperplasia - Which medication to choose?

Objectives: Overactive bladder (OAB) symptoms are often encountered in patients after transurethral resection of the prostate (TUR-P) or transurethral incision of the prostate (TUI-P) for benign prostatic obstruction (BPO). Either antimuscarinics or β-3 agonist has been found effective in relieving OAB symptoms. However, urologists usually do not prescribe such medication immediately after TUR-P or TUI-P to avoid an increase in postvoid residual and risk of urinary tract infection. If OAB medication can be used and adverse events (AEs) can be reduced to minimum, patients' quality of life after bladder outlet obstruction surgery could be improved. This study compared the safety and efficacy between solifenacin and mirabegron in men undergoing TUR-P or TUI-P.

Materials and methods: This prospective, randomized trial compared the safety and efficacy of OAB medication on the reduction in Urgency Severity Score (USS), OAB Symptoms Score (OABSS), International Prostate Symptom Score, and urgency urinary incontinence episodes in men with BPO undergoing surgical intervention. All patients could void smoothly after catheter removal and were randomly received daily solifenacin 5 mg, mirabegron 50 mg, or no interventions for 4 weeks. At 2 and 4 weeks postoperatively, participants' OAB symptoms and AEs were evaluated.

Results: A total of 57 men were enrolled in this study with a mean age of 70.8 ± 6.1 years. At 2 weeks postoperatively, USS (1.56 ± 1.72 vs. 2.39 ± 1.72 vs. 2.26 ± 1.73, P < 0.011) and OABSS (5.33 ± 3.65 vs. 7.67 ± 4.19 vs. 8.58 ± 4.31, P < 0.000) were significantly reduced in patients taking solifenacin, mirabegron, or control, respectively. Two patients in the solifenacin group developed urinary retention. However, the changes of variables at 4 weeks postoperatively were insignificant among the three groups.

Conclusion: Solifenacin and mirabegron are two different drug classes both equally effective in treating immediate OAB symptoms after TUR-P or TUI-P. However, OAB symptoms could be relieved at 4 weeks without any medication. Considering AEs, β-3 agonist has a more favorable safety profile than antimuscarinics.