NMDA receptor antagonist Any substance that inhibits the action of N-methyl-D-aspartate (NMDA) receptors. They tend to induce a state known as dissociative anesthesia, marked by catalepsy, amnesia, and analgesia, while side effects can include hallucinations, nightmares, and confusion. Due to their psychotomimetic effects, many NMDA receptor antagonists are used as recreational drugs. CHEBI:60643 CHEBI:60797 N-methyl-D-aspartate receptor antagonist N-methyl-D-aspartate receptor antagonists NMDA receptor antagonists NMDAR antagonist NMDAR antagonists chebi_ontology excitatory amino acid antagonist