Flexible dosing with fesoterodine 4 and 8 mg: a systematic review of data from clinical trials

Summary Aims To systematically review dose‐escalation data from flexible‐dose studies of fesoterodine and summarise factors associated with dose‐escalation decisions. Methods A PubMed search was conducted using the terms (fesoterodine AND flexible dose), with no limits. Articles were included if they contained fesoterodine dose‐escalation data for efficacy or safety outcomes or factors associated with dose‐escalation decisions. Results Of 13 articles identified by the search, 10 articles (six clinical studies) met inclusion criteria. In flexible‐dose trials of fesoterodine, 51–63% of subjects initially receiving fesoterodine 4 mg opted for dose escalation to fesoterodine 8 mg. Escalators generally reported significantly more severe overactive bladder (OAB) symptoms, greater OAB symptom bother and worse health‐related quality of life at baseline than non‐escalators. Escalators demonstrated less treatment benefit with fesoterodine 4 mg than non‐escalators. Non‐escalators generally had a higher rate of dry mouth and constipation with fesoterodine 4 mg than escalators. The decision to escalate appeared to be determined by the efficacy/tolerability responses; fesoterodine escalators demonstrated a lower sensitivity (less efficacy and fewer adverse events) before their decision to escalate. By study end (8–11 weeks after escalation decision), the efficacy and tolerability profiles were similar in escalators and non‐escalators. Conclusions Data from flexible‐dose studies provide strong evidence that fesoterodine provides treatment benefit to individual subjects with OAB because of its true dose–response effect. In clinical practice, it can be worthwhile to escalate to fesoterodine 8 mg in individual subjects who require additional efficacy benefit.