Presenter and lead investigator Gary Figiel, MD, geriatric psychiatrist and Senior Researcher, Southeastern Geriatric Healthcare Group, Atlanta, Georgia, United States, said that patients who had responded inadequately to donepezil either improved or stabilized after switching to rivastigmine.

"As you follow patients being treated with any cholinesterase inhibitor, you'll find that a significant number of patients begin declining after they have been on one cholinesterase inhibitor for 12 to 18 months," Dr. Figiel said. "So the purpose of this study was to address whether patients who were not doing well with one cholinesterase inhibitor – donepezil -- could do well with another -- rivastigmine."

Dr. Figiel said that previous, small pilot studies suggested a possible benefit of switching to rivastigmine those patients who were not responding to donepezil.

In their open-label study, Dr. Figiel and colleagues analyzed 26-week switch data from a study assessing the safety/efficacy of rivastigmine 3-12 mg/day in subjects who were diagnosed with mild-to-moderate Alzheimer's disease and who were either not responding to donepezil or were declining while on donepezil treatment.

They evaluated safety and tolerability using rates of adverse events and patient disposition. They assessed treatment efficacy for global functioning using the Clinical Global Impression of Change (CGIC).

The 166 women and 109 men had a mean age of 78.5 years and mean duration of dementia of 3.5 years.

The investigators reported that 69% of patients completed the study with less than 20% of these subjects discontinuing due to adverse events; 81% reported at least one adverse event during the study, most frequently gastrointestinal system events (52%)..

Results show that 70% of patients experienced improvement or no decline on the CGIC at week 26.

"What also surprised and pleased me, and pleased me as a geriatric psychiatrist, was a very dramatic improvement in behavorial symptoms with patients after they were switched," added Dr. Figiel.

The study was supported by Novartis Pharmaceuticals


[Presentation title: Results of an Open-Label Study Evaluating the Safety and Efficacy of Rivastigmine in Patients Not Responding Adequately to Donepezil. Abstract NR887]

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