A prospective open-label randomized comparative study in Alzheimer’s disease between two commonly used drugs in coastal Indian population

Background: Currently, therapy for Alzheimer’s disease (AD) is only symptomatic. Only two classes of drugs are approved by the United States Food and Drug Administration. Our study aimed at comparing efficacy and safety of memantine and donepezil in moderate to severe AD patients.Methods: Totally, 22 patients with moderate to severe AD were randomized into the 2 arms of the study. The study was divided into an initial 4 weeks for determination of onset of efficacy and subsequent 28 weeks of the treatment phase. Onset of efficacy and response was defined as >20% and >50% reduction in the mean total score of functional dementia scale (FDS) and clinical global impression scale (CGIS) from baseline to the study end, respectively.Results: Onset of efficacy on FDS and CGIS was 16.7% (mean-time 61.25 days) and 80% (mean-time 36 days) with memantine and donepezil, respectively. Response was 89.3% and 40% with memantine and Donepezil, respectively. Total reduction in FDS and CGIS score of from baseline to the study end was 39.50, 40.00, and 25.60, 27.20 with memantine and donepezil, respectively. Tolerability was 86.33% and 20% with memantine and donepezil, respectively. Anorexia, muscle cramps, constipation, headache, and insomnia, were the common side-effects and self-limiting. Safety was 100% in both groups.Conclusions: Onset of efficacy was faster with donepezil seen at 2 weeks. Response, improvement in CGIS, FDS, and tolerability were better seen with memantine at 40 weeks. Thus, in similar clinical settings, memantine can be preferred