Disclosed herein are pharmaceutical compositions comprising a therapeutically effective amount of
extended release fesoterodine, or a pharmaceutically acceptable salt thereof, and a therapeutically effective amount of
pilocarpine, or a pharmaceutically acceptable salt thereof. Also disclosed herein are methods of treating a patient suffering from
overactive bladder, the method comprising identifying a patient in need thereof, and administering to the patient a therapeutically effective amount of
extended release fesoterodine, or a pharmaceutically acceptable salt thereof, and a therapeutically effective amount of
pilocarpine, or a pharmaceutically acceptable salt thereof. Also disclosed herein are methods of alleviating a
side effect of treatment for
overactive bladder in a patient suffering therefrom, the method comprising identifying a patient in need thereof, and administering to the patient a therapeutically effective amount of
extended release fesoterodine, or a pharmaceutically acceptable salt thereof, and a therapeutically effective amount of
pilocarpine, or a pharmaceutically acceptable salt thereof.