Memantine in everyday clinical practice: a comparison of studies in Germany and Greece

Results from German and Greek non-interventional studies were compared to investigate possible differences concerning efficacy, tolerability and compliance between both countries.

In two open-label, multicentre, non-interventional studies, 4,305 patients with mild to severe Alzheimer's disease (AD) were treated with daily doses of 20 mg memantine for 6 months. Efficacy was assessed using the Mini-Mental State Examination (MMSE) and instrumental activities of daily living (IADL) scales. Safety and tolerability were recorded.

After 6 months, the patients showed an improvement of their cognitive performance by 2 MMSE points compared to baseline (p < 0.001). MMSE values were improved in 67.4% of the patients, while 15.1% remained stable, and MMSE deteriorated in 17.5% only. The ability to perform IADL increased, as is indicated by lower values (baseline: 70.5; after 6 months: 66.6 points). Improvement of cognition and IADL was nearly identical in both countries. Treatment discontinuation was significantly more frequent in the Greek population, mainly due to non-adherence (9.4% of the safety population). 345 adverse events were recorded in 245 patients (6.3%), and they were significantly associated with country and age.

The results correspond to those of clinical trials and support the efficacy and good tolerability of memantine in a realistic setting. Differences between the countries were observed regarding the baseline characteristics of patients (more female, older and more severe patients in Germany as well as less pretreatment with cholinesterase inhibitors) and regarding premature discontinuation and reported adverse drug reactions, which were both higher in Greece.