Switching previous therapies for Alzheimer's disease to galantamine

Acetylcholinesterase inhibitors (AChEIs) are the most frequently prescribed drugs for the treatment of Alzheimer's disease (AD). To date, donepezil is prescribed most often, but newer AChEIs have become available. Rivastigmine entered the pharmaceutics market for AD in 2000, and galantamine was approved for use in the United States in February 2001. Some patients with AD may already be taking a cholinesterase inhibitor, but they or their caregivers may want to change therapies for various reasons, such as lack of efficacy or poor tolerability. Therefore, defined protocols for discontinuing one therapy and initiating another therapy (ie, "switching") while maintaining efficacy and minimizing cholinergic toxicity will be essential. A post-hoc analysis of a clinical trial that enrolled patients with and without previous exposure to AChEIs indicated that the efficacy and tolerability of a second and different cholinesterase treatment were similar in both subpopulations of patients. These findings suggest that discontinuation of prior AChEI treatment is not predictive of future poor response to an effective treatment.