Memantine in neurological disorders - schizophrenia and depression.

Memantine is used in Alzheimer's disease treatment as a non-competitive modern-affinity strong voltage-dependent N-methyl-D-aspartate receptor antagonist. The fundamental role of these receptors is to bind glutamate: the main excitatory neurotransmitter in the brain, believed to play a crucial role in neuronal plasticity and learning mechanisms. Glutamate transmission plays an important role in all internal CNS structures and maintains the physiological state of the brain. Excessive glutamate transmission can lead to enlarged calcium ion current which may cause neurotoxicity; however, insufficient transmission can drastically alter the information flow in neurons and the brain, potentially causing schizophrenia-like symptoms by replacing lost information with completely new stimuli. Hence, it is possible that the modulation of NMDA activity may give rise to pathophysiological states. Available literature and clinical trials indicate that memantine is well tolerated by patients, with very few and light side effects. There is a belief that memantine may also benefit other conditions such as schizophrenia and depression.