Excitatory amino acid receptor antagonistAn excitatory amino acid receptor antagonist, or glutamate receptor antagonist, is a chemical substance which antagonizes one or more of the glutamate receptors.Examples include: AP5 Barbiturates Dextromethorphan Dextrorphan Dizocilpine Ethanol Ibogaine Ifenprodil Ketamine Kynurenic acid Memantine Nitrous oxide Perampanel Phencyclidine