For the treatment of moderate to severe dementia of the Alzheimer's type.
Namenda Mechanism Of Action:
Namenda exerts its action through uncompetitive NMDA receptor antagonism, binding preferentially to the NMDA receptor-operated cation channels. Prolonged increased levels of glutamate in the brain of demented patients are sufficient to counter the voltage-dependent block of NMDA receptors by Mg2+ ions and allow continuous influx of Ca2+ ions into cells and ultimately neuronal degeneration. Studies suggest that memantine binds more effectively than Mg2+ ions at the NMDA receptor, and thereby effectively blocks this prolonged influx of Ca2+ ions through the NMDA channel whilst preserving the transient physiological activation of the channels by higher concentrations of synaptically released glutamate. Thus memantine protects against chronically elevated concentrations of glutamate.
Namenda Drug Interactions:
Acetazolamide Possible increased levels of memantine
Dichlorphenamide Possible increased levels of memantine
Methazolamide Possible increased levels of memantine
Sodium bicarbonate Possible increased levels of memantine
Amantadine Increased risk of CNS adverse effects with this association
Dextromethorphan Increased risk of CNS adverse effects with this association
Ketamine Increased risk of CNS adverse effects with this association
Side effects include pain, abnormal crying, leg pain, fever, increased apetite. Adverse drug reactions include: dizziness, confusion, headache, hallucinations, tiredness. Less common side effects include: vomiting, anxiety, hypertonia, cystitis, and increased libido. Doses of up to 400 mg have been tolerated.