Memantine

Abstract

Memantine (Ebixa, Namenda, Axura) is an uncompetitive NMDA receptor antagonist used in the management of patients with moderate-to-severe Alzheimer's disease. It is currently the only drug approved for use in these more advanced stages of the disease. Significant reductions in functional and cognitive decline have been demonstrated with memantine relative to placebo in randomised, double-blind trials in this patient population. Clinical trial and postmarketing surveillance data indicate that the drug is generally well tolerated. Two fully published modelled cost-effectiveness analyses of memantine in moderate-to-severe Alzheimer's disease have been conducted in the UK and Finland, in which patient progression was simulated through health states related to dependency, residential setting and cognitive function. Although the specific costs included in the analyses varied, as did the study perspective and geographical location, results of the base-case analyses consistently showed that memantine was dominant over no pharmacological treatment. In the UK and Finnish analyses, memantine increased the duration of independence by 1.3 and 4.1 months, respectively, and the time to institutionalisation by 0.8 and 1 month. Mean total per-patient costs were reduced by 1963 pounds over 2 years (2003 costs) in the UK analysis and by 1687 eurossover 5 years (2001 costs) in the Finnish analysis. Memantine was also associated with a small gain in quality-adjusted life expectancy in the UK model. In sensitivity analyses, memantine remained dominant for almost all plausible changes to key variables. Memantine reduced total societal costs by $1090 per patient per month (1999 costs) compared with no pharmacological treatment over 28 weeks in a resource utilisation and cost analysis conducted alongside a pivotal US trial in patients with moderate-to-severe Alzheimer's disease. Results were primarily driven by reductions in total caregiver costs, which included the opportunity cost of time spent in caregiving tasks, and in direct nonmedical costs, which included the cost of care in a nursing home or similar institution.In conclusion, in patients with moderate-to-severe Alzheimer's disease, memantine is associated with significant reductions in functional and cognitive decline compared with no pharmacological treatment. Available pharmacoeconomic data from Europe and the US, despite some inherent limitations, support the use of memantine as a cost-effective treatment in this patient population, although definitive conclusions are not feasible because of limited data.