In a study of people with mild cognitive impairment (MCI), those who took the drug donepezil were at reduced risk of progressing to a diagnosis of Alzheimer’s disease (AD) during the first year of the trial, but by the end of the 3-year study there was no benefit from the drug. Vitamin E was also tested in the study and was found to have no effect at any time point in the study when compared with placebo.
These findings, from the Memory Impairment Study, are the first to suggest than any agent can delay the clinical diagnosis of AD in people with MCI. The effects of the drug measured in this study “did not provide support for a clear recommendation for the use of donepezil” generally to forestall the diagnosis of AD in people with MCI, the researchers stated in their report, but they did note the potential importance of the findings for some patients. The data, they said, “could prompt a discussion” between clinicians and patients on the possibility of donepezil therapy in certain cases.
