Purpose: Muscarinic antagonists such as tolterodine are the treatment of choice for overactive bladder (OAB). We determined the impact of concomitant stress incontinence (SI) on the therapeutic effects of tolterodine in patients with OAB with and without concomitant SI.
Materials and methods: Data from an open label, observational study involving 2,250 patients with OAB symptoms were analyzed for baseline frequency, urgency and incontinence, and alterations in these symptoms while on 12-week treatment with 2 mg tolterodine twice daily. Data are shown as the mean +/- SD. The statistical significance of differences in treatment effects was determined by multiple regression analysis, adjusting for gender, age and baseline symptom intensity.
Results: Concomitant I to III degree SI according to the Stamey grading was present in 31%, 15% and 2% of patients, respectively, and it was associated with increasing basal incontinence, although only III degree SI was associated with greater baseline frequency or urgency. In the overall group tolterodine decreased frequency, urgency and urge incontinence from 12.4 +/- 4.3 to 7.7 +/- 2.7, 8.4 +/- 5.1 to 2.0 +/- 3.0 and 3.4 +/- 4.2 to 0.8 +/- 2.0 episodes daily, respectively. On multiple linear regression analysis I and II degree SI had a minor, if any, effect on this improvement, while III degree SI was statistically associated with a smaller decrease in frequency (by 1.4 +/- 0.4 micturitions daily, p = 0.0002) and incontinence (by 2.1 +/- 0.3 episodes daily, p < 0.0001) but with similar alterations in the number of urge episodes.
Conclusions: Concomitant I or II degree SI has little effect on the efficacy of tolterodine in OAB cases. Only patients with concomitant III degree SI have significantly less improvement.