OBJECTIVES: To investigate the impact of long-term treatment with darifenacin, a muscarinic M3 selective receptor antagonist, on quality of life (QoL) in patients with overactive bladder (OAB). METHODS: Patients with OAB for „d6 months who participated in two 12-week, placebo-controlled, double-blind feeder studies of darifenacin controlled release 3.75, 7.5 or 15 mg qd were enrolled into this 2-year, multicentre, open-label extension. During the first 2 weeks of the extension all patients received darifenacin 7.5 mg, after which titration between darifenacin 15 and 7.5 mg was permitted. The King's Health Questionnaire [KHQ] was used to assess QoL. Here, we report data from patients who received darifenacin 7.5 or 15 mg during the feeder studies and had a gap of „T3 treatment days before entering the extension. RESULTS: 303 patients who had received darifenacin 7.5 or 15 mg during the feeder studies entered the extension (22-89 years; 86.5% female) and 199 patients (65.7%) completed the study. Darifenacin 7.5/15 mg was associated with significant improvements in eight of nine KHQ domains (Incontinence impact, Severity measures, Role limitations, Physical limitations, Social limitations, Emotions, Personal relationships and Sleep/energy) from baseline to the end of the 12-week, double-blind feeder studies (all p<0.001 vs feeder study baseline). These changes were maintained or further improved during the open-label extension, such that significant improvements (p<0.001 vs feeder study baseline) were observed for darifenacin 7.5/15 mg in the same eight KHQ domains after a further 24 months of treatment. Darifenacin was well tolerated and the overall long-term safety profile was consistent to that observed in the 12 week phase III studies. CONCLUSIONS: Darifenacin significantly improves QoL in patients with OAB, with improvements maintained for 2 years during open-label treatment.