Drug	Suggested dosage	Side effects	Specific cautions
Donepezil (Aricept)	Initial dosage is 5 mg once daily; if necessary, dosage can be increased to 10 mg once daily after 4 to 6 weeks.	Mild side effects, including nausea, vomiting, and diarrhea; these effects can be reduced by taking donepezil with food. Initial increase of agitation in some patients; agitation typically subsides after a few weeks.	Conflicting evidence about possible interactions with cimetidine (Tagamet), theophylline, warfarin (Coumadin), and digoxin(Lanoxin)
Rivastigmine (Exelon)	Initial dosage of 1.5 mg twice daily (3 mg per day) is generally well tolerated; dosage can be increased as tolerated but no more quickly than by 1.5 mg twice daily (3 mg per day) every 4 weeks to maximum of 6 mg twice daily (12 mg per day). Twice-daily dosing is as efficacious as thrice-daily dosing and has comparable tolerability.	Nausea, vomiting, diarrhea, headaches, dizziness, abdominal pain, fatigue, malaise, anxiety, and agitation; these effects can be reduced by taking rivastigmine with food.	Weight loss Interacting drugs include aminoglycosides and procainamide (Procanbid).
Galantamine (Reminyl)	Initial dosage is 4 mg twice daily (8 mg per day) taken with the morning and evening meals for 4 weeks; dosage is then increased to 8 mg twice daily (16 mg per day) for at least 4 weeks. An increase to 12 mg twice daily (24 mg per day) should be considered on an individual basis, depending on clinical benefit and tolerability.	Mild side effects, including nausea, vomiting, and diarrhea; these galantamine with food. No apparent association with sleep disturbances (which can occur treatments)	Contraindicated for use in patients with hepatic or renal impairment effects can be reduced by taking with other cholinergic
Tacrine (Cognex) and procainamide	Initial dosage is 10 mg four times daily (40 mg per day) for 4 weeks; dosage is increased to 20 mg four times daily (80 mg per day) for 4 weeks, then to 30 mg four times daily (120 mg per day) for 4 weeks, etc., until maximum tolerated dosage is achieved. Maximum dosage is 40 mg four times daily (160 mg per day).	High incidence of side effects, problems; these effects can be reduced by taking tacrine with food.	Interacting drugs include theophylline including gastrointestinal Hepatotoxicity is a problem; hence, liver tests should be performed every other week for 16 weeks and every 3 months thereafter.