My Husband .85.. Has Been On DONEZIPIL For 3 Weeks

My husband .85.. has been on DONEZIPIL for 3 weeks and is experiencing many of these side effects. HE had an MRI and it showed a slight short term memory loss I would like him to get off f this as I am seeing changes in him I don't like and think it is due to this med. We do everything as naturally as we can.. Your thoughts.