Switching from oral donepezil to rivastigmine transdermal patch in Alzheimer's disease: 20-week extension phase results.

Objective: To evaluate the long-term safety, tolerability, and efficacy of 2 strategies for switching from donepezil to rivastigmine transdermal patches in patients with mild to moderate Alzheimer's disease.

Method: This was a prospective, 25-week, randomized, open-label, parallel-group study to evaluate an immediate or delayed switch (7-day withdrawal) from donepezil (5 to 10 mg/d) to rivastigmine transdermal patches (4.6 mg/24 h). Participants included male and female patients, aged ≥ 50 years, with a DSM-IV-TR diagnosis of mild to moderate dementia of the Alzheimer's type, defined as a Mini-Mental State Examination score of 10-24, inclusive. Patients were enrolled between February 2007 and February 2008. The study was split into a 5-week core phase and a 20-week extension phase. Safety and efficacy results from the extension phase are presented.

Results: Both switching strategies were well tolerated. Rates of discontinuation for any reason were similar between the groups. Discontinuations due to adverse events were also similar, and the incidence of gastrointestinal adverse events was low. Apart from Alzheimer's Disease Cooperative Study-Activities of Daily Living Scale scores, at the end of the study, there was no statistically significant change from baseline in cognitive, behavioral, or global outcomes. Over half of the patients preferred rivastigmine transdermal patches to a tablet.

Conclusions: This study suggests that the majority of patients receiving donepezil tablets can be safely switched to rivastigmine transdermal patches without significant deterioration in cognition, behavior, and global functioning.

Trial Registration: clinicaltrials.gov Identifier: NCT00305903.