Memantine (
Axura,
Ebixa,
Namenda) is an uncompetitive, moderate-affinity
NMDA receptor antagonist that is indicated for the treatment of moderate to severe
Alzheimer's disease. In well designed trials in patients with moderate to severe
Alzheimer's disease, oral
memantine monotherapy improved outcomes in the area of functional ability more than placebo in one trial, but in a second trial, treatment differences did not reach significance.
Memantine has a distinct mode of action compared with that of
acetylcholinesterase (AChE) inhibitors, and in a well designed study, combination
therapy with
memantine plus
donepezil improved outcomes more than
donepezil plus placebo in all four domains (function, cognition, behaviour and global change).
Memantine is generally well tolerated, with adverse events occurring with a similar incidence to that reported with placebo. In modelled cost-effectiveness analyses,
memantine was dominant to no
therapy in regard to cost per quality-adjusted life-year (QALY) gained, and the combination of
memantine plus
donepezil was dominant to
donepezil therapy alone in regard to QALYs gained when treatment periods exceeded 1 year in patients with moderate to severe disease. Thus, in the management of patients with moderate to severe
Alzheimer's disease,
memantine provides an effective treatment option. To date, clinical trial support is greater for
memantine use in combination with an AChE inhibitor, while more data are needed to confirm its efficacy as monotherapy.