A 12-Week, Randomized, Double-Blind, Placebo Controlled, Parallel Group, Multicenter Trial In Overactive Bladder Subjects To Confirm The Efficacy Of 8 Mg Fesoterodine Compared To 4 Mg Fesoterodine.

This study is designed to confirm if 8mg of fesoterodine is more effective in reducing overactive bladder symptoms than 4mg of fesoterodine. In addition the study is designed to assess if the higher dose reduces the overall effect of overactive bladder on the subject's daily life more than the lower dose. The study also assesses the side effects and safety of the two doses.