Memantine is the first in a novel class of Alzheimer's disease medications acting on the glutamatergic system by blocking NMDA glutamate receptors. Memantine is marketed under the brands Axura and Akatinol by Merz, Namenda by Forest, Ebixa and Abixa by Lundbeck and Memox by Unipharm.

Memantine has been associated with a moderate decrease in clinical deterioration in Alzheimer's disease. A systematic review of randomised controlled trials found that memantine has a small positive effect on cognition, mood, behaviour, and the ability to perform daily activities in moderate to severe Alzheimer's disease, but an unknown effect in mild to moderate disease.

Memantine is also being tested for opioid dependence, systemic lupus erythematosus, depression, obsessive compulsive disorder, Tourette Syndrome, problem gambling, attention-deficit hyperactivity disorder (ADHD), glaucoma, tinnitus, neuropathic pain, pervasive developmental disorders, HIV associated dementia, nystagmus, and multiple sclerosis.

Memantine is generally well-tolerated. Common adverse drug reactions (≥1% of patients) include: confusion, dizziness, drowsiness, headache, insomnia, agitation, and/or hallucinations. Less common adverse effects include: vomiting, anxiety, hypertonia, cystitis, and increased libido. On the other hand; it has been reported to induce reversible neurological impairment in multiple sclerosis, that led to stop an ongoing clinical trial. Though exceedingly rare, extrapyramidal side effects (such as dystonic reactions, etc) may occur, particularly in the younger population.

Memantine acts as a non-competitive antagonist at the 5HT3 receptor, with a potency similar to that for the NMDA receptor. The clinical significance of this serotonergic activity in the treatment of Alzheimer's disease is unknown.

Memantine acts as a non-competitive antagonist at different neuronal nicotinic acetylcholine receptors (nAChRs) at potencies possibly similar to the NMDA and 5-HT3 receptors, but this is difficult to ascertain with accuracy because of the rapid desensitization of nAChR responses in these experiments. It has been shown that the number of nicotinic receptors in the brain are reduced in Alzheimer's disease, even in the absence of a general decrease in the number of neurons, and nicotinic receptor agonists are viewed as interesting targets for anti-Alzheimer drugs.

Memantine acts as an agonist at the dopamine D2 receptor.

Before taking any prescription medicine, it is important that you consult your doctor!