Sadowsky_2005_Prim.Care.Companion.J.Clin.Psychiatry_7_43

Background: Transitioning patients between cholinesterase inhibitors was thought to require a washout period to avoid cholinergic toxicity; however, evidence suggests that abrupt discontinuation of donepezil may lead to cognitive decline. We evaluated the safety and tolerability of an immediate switch from donepezil to rivastigmine.Method: This is an analysis of the safety and tolerability data from the first 28 days of an open-label, multicenter, prospective trial, conducted from August 2002 to August 2003, in which patients satisfying NINCDS-ADRDA criteria for probable Alzheimer's disease were administered rivastigmine 1.5 mg b.i.d. within 24 to 36 hours of donepezil discontinuation. Results are compared with adverse event rates from a retrospective analysis of a pivotal, placebo-controlled trial examining patients not previously treated with a cholinesterase inhibitor.Results: Fifty-eight of 61 patients completed the first 28 days, with no suspected drug-related discontinuations during this period. Incidence of overall gastrointestinal adverse events at day 7 was 8.2%, and at day 28 was 11.5%. The corresponding rate for rivastigmine-treated patients in the retrospective analysis of the pivotal trial for day 7 was 3.3%.Conclusion: These study results suggest that transitioning patients from donepezil to rivastigmine without a washout period is safe and well tolerated.