Why is Aricept given at bedtime?

Aricept -- a drug used to treat Alzheimer's disease -- is given at bedtime so that's its full effect and usefulness can be felt during the day. This is often the case with drugs that take a long time to take effect or that have brief side effects that may not be noticed or would be less noticable during sleep. In some cases, however, it can be given in the morning.