Efficacy, Safety and Tolerability of Rivastigmine Patch in Patients With Mild to Moderate Alzheimer's Disease Switched From Cholinesterase Inhibitors

Inclusion Criteria: * A diagnosis of dementia of the Alzheimer's type according to the DSM-IV criteria * A clinical diagnosis of probable AD according to NINCDS/ADRDA criteria * An MMSE score of \> or = 10 and \< or = 23 * Continuous treatment with donepezil ≤ 5 mg/day or galantamine ≤ 24 mg/day for 4 weeks prior to baseline visit * Patients having difficulties being treated orally with ChE inhibitors (donepezil or galantamine) as judged by the investigator. Difficulties are defined as: * Inadequate compliance with the ChE inhibitors at screening and baseline * Presence of caregiver's burden for administering drugs orally at screening and baseline * Inadequate treatment (efficacious dose cannot be reached or inadequate compliance) with the ChE inhibitors because of adverse events at screening and baseline * Patients with swallowing difficulties at screening and baseline Exclusion Criteria: * A current DSM-IV diagnosis of major depression * Taken rivastigmine in the past * A score of \> 5 on the Modified Hachinski Ischemic Scale (MHIS) Other protocol-defined inclusion/exclusion criteria may apply