Efficacy and safety of memantine in moderate-to-severe Alzheimer disease: the evidence to date.

Memantine, a moderate-affinity, uncompetitive N-methyl-D-aspartate receptor antagonist, is currently the only agent approved for moderately severe to severe Alzheimer disease (AD) in Europe and for moderate-to-severe Alzheimer disease in the United States. In clinical trials, memantine has consistently demonstrated a reduced rate of deterioration on global, cognitive, functional, and behavioral measures, across a range of outcome measures compared with usual care. Notably, improvements versus placebo were seen in individual activities of daily living and behavior, particularly agitation. Efficacy was demonstrated in patients with newly diagnosed Alzheimer disease, patients previously or currently receiving acetylcholinesterase inhibitors, and both institutionalized and community-dwelling Alzheimer disease patients. Memantine has a tolerability profile similar to placebo. This review presents the results of key clinical trials, and includes clinically relevant analyses, such as numbers-needed-to-treat and effect sizes. Increased dependency and institutionalization are significant cost drivers in Alzheimer disease. Memantine is able to reduce dependency, caregiver time required, and mean monthly caregiver and societal costs. Recent studies of the relationship between Alzheimer disease progression, caregiver burden, and healthcare costs emphasize the need for treatments such as memantine that can slow the rate of decline in Alzheimer disease.