Memantine is the first in a novel class of Alzheimer's disease medications acting on theglutamatergic system by blocking NMDA-type glutamate receptors. It was first synthesized by Eli Lilly and Company in 1968. Memantine is marketed under the brands Axura andAkatinol by Merz, Namenda by Forest, Ebixa and Abixa by Lundbeck and Memox byUnipharm. Memantine has been shown to have a modest effect in moderate-to-severe Alzheimer's disease.^[1] Despite years of research, there is little evidence of effect in mild Alzheimer's disease.^[2]

Memantine is approved by the U.S. FDA and the European Medicines Agency for treatment of moderate-to-severe Alzheimer's disease,^[3] and has now received a limited recommendation by the UK's National Institute for Clinical Excellence for patients who fail other treatment options.^[4] Within the new guidance memantine is recommended as an option for managing Alzheimer’s disease for people with: moderate Alzheimer’s disease who are intolerant of or have a contraindication to AChE (acetylcholinesterase) inhibitors or those with severe Alzheimer’s disease.

Memantine has been associated with a moderate decrease in clinical deterioration^[5] with only a small positive effect on cognition, mood, behaviour, and the ability to perform daily activities in moderate to severe Alzheimer's disease.^[6] There does not appear to be any benefit in mild disease.^[2]

The drug belongs to a class of drugs called NMDA receptor antagonists, which reduce certain types of brain activity by binding to NMDA receptors on brain cells and blocking the activity of the neurotransmitter glutamate. At normal levels, glutamate aids in memory and learning, but if levels are too high, glutamate appears to overstimulate nerve cells, killing them through excitotoxicity.

 

Research

Memantine is also being tested for generalized anxiety disorder, epilepsy, opioid dependence, systemic lupus erythematosus,depression, obsessive compulsive disorder, Tourette Syndrome, problem gambling, attention-deficit hyperactivity disorder (ADHD),^[29]glaucoma, tinnitus, neuropathic pain including Complex Regional Pain Syndrome,^[30] pervasive developmental disorders, HIV associated dementia,^[31] nystagmus,^[32] multiple sclerosis,^[8] autism,^[33] migraine,^[34] amyotrophic lateral sclerosis,^[35] Down syndrome^[36] and for protection of cognitive function during whole brain radiation.