[Glutamate antagonists in neurology]

Glutamate is the major excitatory neurotransmitter of the central nervous system. Besides its importance in many physiological processes, increased glutamate release and subsequent excessive stimulation of the various glutamate receptors are thought to play critical roles in the pathophysiological mechanisms underlying many neurologic diseases. Experimental data suggest that blockade of glutamate receptors or inhibition of glutamate release has positive effects in many disease models. Glutamate antagonists are already in clinical use for the treatment of Parkinson's disease, epilepsy, spasticity, and neuropathic pain. Overall, glutamate antagonists have not been found clinically effective for neuroprotective treatment of cerebral ischemia or chronic neurodegenerative diseases, with one exception. Side effects of glutamate antagonists can be mainly attributed to central mechanisms and include psychosis, agitation, and disorientation. It is to be hoped that further development of new glutamate antagonists that block disease-relevant subtypes of glutamate receptors will lead to more effective drugs with fewer side effects.