Long-term safety and tolerability of rivastigmine in patients with Alzheimer's disease switched from donepezil: an open-label extension study.

Objectives: The objective of this article is to present safety and tolerability data from the long-term extension phase of a core study conducted in patients with Alzheimer's disease (AD) who were immediately switched to rivastigmine.

Method: This was a 26-week open-label extension (OLE) of a prospective, 26-week, open-label, single-arm, multicenter study conducted in the United States from October 2003 to January 2005. Patients had a diagnosis of Alzheimer's disease according to DSM-IV-TR and National Institute of Neurologic and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association criteria. Safety and tolerability of rivastigmine were monitored through monthly telephone contacts. At week 52, patients or caregivers were contacted by telephone to evaluate the patient's well-being.

Results: 146 patients (approximately 79% of patients who completed the core phase) entered this OLE. Most patients (N = 115, 78.8%) completed the full 26 weeks of the extension phase, during which time they received a mean rivastigmine dosage of 10.5 mg/day. The number of patients reporting newly occurring or worsening adverse events decreased considerably during the OLE (N = 84, 57.5%) compared with the core phase (the first 26 weeks; N = 116, 79.5%). Most patients reported adverse events that were mild or moderate in severity. At the end of the OLE, the majority of patients (128/146; 87.7%) were still receiving treatment with rivastigmine. At week 52, most caregivers expressed satisfaction with rivastigmine treatment (77.4%) and with the changes observed in the patient's behavior during the study (71.9%).

Conclusions: For patients not tolerating or not responding to donepezil, treatment with rivastigmine was safe and well tolerated for at least 52 weeks.