Prospects for clinically tolerated NMDA antagonists: open-channel blockers and alternative redox states of nitric oxide.

Several acute and chronic neurological diseases might be mediated, at least in part, via stimulation of excitatory amino acid receptors, such as the N-methyl-D-aspartate (NMDA) receptor. Antagonists of excitatory amino acid receptors ameliorate neurotoxic damage in several animal models of these disorders. This review focuses on the potential for clinically tolerated NMDA receptor antagonists, with emphasis on agents that have been in clinical use for other conditions and that recently have been shown to inhibit NMDA receptor activity by a mechanism of open-channel block or redox modification.