Efficacy and tolerability of Memantine in Alzheimer's disease - results of an observational study

Background: Memantine is the only approved N-methyl-D-aspartate antagonist in the treatment of Alzheimer´s disease (AD). The efficacy and tolerability of memantine were previously shown in placebo-controlled clinical studies. In this observational study, the efficacy and tolerability of memantine were investigated in outpatients with moderate to severe AD in everyday clinical practice. Methods: Patients were treated according to routine clinical practice for a 6-months observational period. At the beginning of the study, and at weeks 4, 8, 12 and 24, patients´ abilities were assessed using the Mini-Mental State Examination (MMSE), the Functional Assessment Scale (FAST), the Nurses´ Observation Scale for Geriatric Patients (NOSGER) and the Clinical Global Impression of Change (CGIC). Tolerability was assessed with a 4-point scale by physician and adverse events were evaluated. Statistical analysis was descriptive. Results: 2485 patients (mean age 77 years) were observed over 6 months. MMSE score showed improvement in 66% and stabilisation in 11% of memantine-treated patients. Improvement or stabilisation in functional disease stage (FAST) was shown in the majority of patients (25% and 61%, respectively). The assessments by caregivers were in accordance with physicians´ clinical evaluations. The tolerability of memantine was judged as very good and good (59% and 40% of patients). Conclusions: The results of this observational study support the cognitive, functional and behavioural efficacy of memantine in patients with Alzheimer´s disease that has been demonstrated in controlled clinical trials. Furthermore, the good tolerability of memantine was demonstrated in a naturalistic setting.