Assessment of efficacy of mirabegron, solifenacin, tadalafil 5 mg and combination therapy in female patients with overactive bladder: a double blinded multicenter prospective placebo-controlled trial.

Background: This study assess the efficacy of mirabegron, solifenacin, tadalafil 5 mg, and tadalafil 5 mg combination with solifenacin and mirabegron in the treatment of female patients with overactive bladder (OAB), comparing these to a placebo in a double-blinded, prospective, randomized, placebo-controlled trial.

Methods: A total of 483 female patients diagnosed with OAB and confirmed detrusor overactivity were recruited from three university hospitals (Tanta, Kafrelsheikh, and Menoufia) between January and July 2024. Participants were randomly assigned to one of six groups: tadalafil 5 mg (Group I), solifenacin 5 mg (Group II), mirabegron 50 mg (Group III), mirabegron 50 mg + tadalafil 5 mg (Group IV), solifenacin 5 mg + tadalafil 5 mg (Group V), or placebo (Group VI). Assessments were performed at baseline, 1, 2, and 3 months.

Results: At 3 months, the combination therapies (Groups IV and V) demonstrated significantly greater improvements in OABSS compared to mono-therapy groups (Groups I, II, III) and placebo (Group VI). Group V (tadalafil 5 mg + solifenacin) achieved the greatest symptom reduction, comparable with Group IV (tadalafil 5 mg + mirabegron). Urodynamic improvements were also notable in the combination therapy groups, with significant increases in bladder capacity and compliance, and reduction in detrusor contractions compared to placebo. With the exception of high post voiding residual was high with solifenacin monotherapy Adverse effects were similar across groups, with no significant differences in overall incidence.

Conclusions: The novel combination therapies of tadalafil 5mg with solifenacin or mirabegron are more effective in reducing OAB symptoms and improving urodynamic parameters compared to single-agent therapies and placebo. These findings suggest that combination therapy is alternative pathway which can enhance outcomes for female patients with OAB. Further research is warranted to validate these results and explore long-term efficacy and safety.