Acetylcholinesterase inhibitors are of use for treating a variety of diseases and conditions including Alzheimer's disease. They also affect circadian rhythms. In order to optimize the use of such compounds, the present invention provides dosage forms and methods of treatment wherein an effective amount of a centrally-acting acetylcholinesterase inhibitor is formulated so as to delay its activity for a predetermined period. Suitable acetylcholinesterase inhibitors include galanthamine, lycoramine, analogs thereof and rivastigmine.
