Memantine hydrochloride

Memantine, a derivative of amantadine, is a low-affinity, voltage-dependent, non-competitive N-methyl-D-aspartate (NMDA) antagonist with strong voltage dependency and rapid unblocking kinetics. Memantine acts on activated NMDA receptor by binding to a site located in the channel of the receptor and inhibiting the Ca²⁺ influx. Its IC₅₀ value is around 1 µM at -70 mV⁵.

Memantine has neuroprotective effects, preventing glutamatergic over-stimulation and the neurotoxicity caused by it by decreasing glutamate excitotoxicity. In rats, memantine shows increased levels of brain-derived neurotrophic factor (BDNF) thus influencing synaptic plasticity, β-amyloid-induced apoptotic death and neuroinflammation in the hippocampus¹.

Proper NMDA function is required for synaptic plasticity. NMDA receptors can be found in dendrites of pyramidal cells in the hippocampus and cortex.

Memantine is currently in clinical use for treatment of Alzheimer´s disease symptoms with significant benefits on cognitive, functional, and general status². The drug is well tolerated with fast course of action and uncommon adverse effects such as: dizziness, confusion, somnolence, hallucinations, and nausea which disappear after discontinuation or dose reduction³.

Some studies have suggested to considering administration of memantine in the treatment of bipolar disorders that do not respond to standard mood stabilizers⁴.