An Investigation of the Effect of Combining Tolterodine and Duloxetine in the Treatment of Mixed-Type Urinary Incontinence and the Factors Affecting Success.

Abstract

Background: Mixed urinary incontinence (MUI), particularly the urge-predominant subtype, involves both stress urinary incontinence (SUI) and urge urinary incontinence (UUI), posing a therapeutic challenge. Duloxetine, a serotonin-norepinephrine reuptake inhibitor (SNRI), enhances urethral tone, while tolterodine, an antimuscarinic agent, reduces detrusor overactivity. Their combination may offer synergistic benefits. Aim: The aim of this study was to evaluate the efficacy of duloxetine and tolterodine combination therapy in urge-predominant MUI and identify factors influencing treatment success. Method: A retrospective study was conducted on 106 patients (mean age: 56.45 years) with urge-predominant MUI treated with duloxetine (40 mg twice daily) and tolterodine (4 mg once daily) for 12 weeks. Treatment outcomes were evaluated using the overactive bladder symptom score (OABSS), International Consultation on Incontinence Questionnaire Short Form (ICIQ-SF), 24 h pad test, and Clinical Global Impression Scale (CGI). Univariate and multivariate regression analyses were performed to determine predictors of success. Results: Significant improvements were observed: OABSS decreased from 11.08 to 6.95, ICIQ-SF decreased from 15.69 to 8.84, and pad use decreased from 3.58 to 0.73/day (all p 0.0001). Bladder capacity increased from 315.09 mL to 436.32 mL. Baseline ICIQ-SF scores were independent predictors of success (odds ratio [OR] = 2.919, p = 0.001). Patient satisfaction reached 77.4%, with mild side effects (constipation and dizziness) in 14 patients. Conclusions: Duloxetine and tolterodine combination therapy significantly improved symptoms and quality of life in urge-predominant MUI. Baseline ICIQ-SF scores may predict treatment success. Further prospective studies are needed.