After a 1-month single-blind run in phase, 910 subjects will be titrated, over a period of up to 8 weeks, to target doses of either: 0 (placebo); 24 mg/day galantamine; 16 mg/day galantamine; or 8 mg/day galantamine, in a 2:2:2:1 randomization ratio. Double-blind treatment will continue for a total of 5 months. The change from baseline in ADAS-cog and CIVIC-plus scores at Month 5 will be the primary efficacy endpoints. Tolerability will be evaluated based on adverse event reports, laboratory values, ECG, and vital signs with particular focus on the adverse event rates in the slower titration schedule for 24 mg/day. Efficacy of 24 mg/day and 16 mg/day galantamine will be compared with that of placebo. Information on the dose response relationship of galantamine will be evaluated.

Inclusion Criteria:

• Probable Alzheimer's disease
• Mini-Mental State Examination (MMSE) 10-22 and ADAS greater than or equal to 18
• Alzheimer's Disease Assessment Scale cognitive portion (ADAS-cog-11) score of at least 18
• Opportunity for Activities of Daily Living
• Caregiver
• Subjects who live with or have regular daily visits from a responsible caregiver (visit frequency: preferably daily but at least 5 days/week). This includes a friend or relative or paid personnel. The caregiver should be capable of assisting with the subject's medication, prepared to attend with the subject for assessments, and willing to provide information about the subject.

Exclusion Criteria:

• Conditions that could confound diagnosis
• Neurodegenerative disorders
• Acute cerebral trauma
• Psychiatric disease
• More than one infarct on CT/MRI scans
• History of alcohol or drug abuse
• Contradictions for a cholinominetic agent: seizures; ulcers; pulmonary conditions (including severe asthma); unstable angina; Afib; bradycardia less than 50; and AV block.