This study investigated the efficacy of memantine alone or in combination for the treatment of patients with Alzheimer's disease (AD) in a naturalistic setting, specifically for the cognitive and behavioural symptom domains.

Open-label, 6-month observational study, conducted at 110 sites in Greece. Efficacy was based on the MMSE and NPI scales at baseline, 3 months, and 6 months. Statistical analysis was made on a modified intent-to-treat dataset (ITT: at least one valid post-baseline measurement) using last observation carried forward (LOCF), and observed cases (OC, defined as patients assessed at all 3 visits).

1,469 patients were enrolled. Their mean age was 75.7±6.5 years and the majority were women (52.7%). At baseline the average scores were 17.6 (±5.3) for the MMSE and 30.6 (±25.9) for the NPI. 285 patients (19.4%), received combination treatment (a second AD medication) during the observation period.

Both cognitive and behavioral symptoms were improved at the end of the study, as measured by the MMSE and NPI scales (repeated measures analysis of variance Hotelling's test, p-value< 0.001, both ITT, LOCF and OC analyses). After 3 and 6 months, cognitive function improved for 50.3% and 55.8% of the patients (ITT, LOCF), while behavioral symptoms improved for 56.8% and 62%, respectively.

Memantine was well tolerated, with 3.5% (52) of patients withdrawing from the study for any reason and 7.6% reporting adverse events.

Memantine treatment resulted in significant improvement of cognitive and behavioral symptoms in patients with AD and was well tolerated based on patient withdrawals.