Safety and efficacy of flexible-dose fesoterodine in British subjects with overactive bladder: insights into factors associated with dose escalation

Introduction and hypothesis

This study evaluated the efficacy and safety of flexible-dose fesoterodine and factors associated with dose escalation in subjects with overactive bladder (OAB).

Methods

In this 12-week, open-label study, 331 adults with OAB symptoms for ≥3 months, ≥8 micturitions and ≥3 urgency episodes per 24?h and who reported at least “some moderate” bladder-related problems were treated with fesoterodine 4?mg once daily for 4?weeks, with the option to escalate to 8?mg for the remaining 8?weeks based on discussion of efficacy and tolerability with the investigator. Factors influencing dose escalation were identified using stepwise logistic regression. Efficacy was assessed via 3-day bladder diaries and patient-reported outcomes.

Results

Of the subjects, 59?% dose escalated at week 4; 93?% of escalators cited insufficient clinical response. The decision to escalate was most often made by the subject (alone or with the investigator). Improvements from baseline were observed in diary and patient-reported outcomes at weeks 4 and 12. Smaller improvements in micturition frequency and worse bladder-related problems at week 4 were significantly associated with increased likelihood of dose escalation; baseline micturition frequency, age, sex, body mass index, antimuscarinic-associated adverse events and OAB symptom duration were not. Non-escalators had greater improvement from baseline to week 4 than escalators; by week 12, improvement was similar among escalators and non-escalators. Fesoterodine was well tolerated.

Conclusions

Treatment with flexible-dose fesoterodine improved bladder diary and patient-reported outcomes. Lower clinical response was related to dose escalation; after escalation, response in escalators approached that of non-escalators.