GV 150526A (gavestinel) is an investigational drug for a neuroprotective therapy of acute ischemic stroke within 6 hours of symptom onset. It is a potent and selective non-competitive antagonist at the glycine site of the N-methyl-D-aspartate receptor (NMDA) which reduces infarct volume in experimental stroke models. Gavestinel acts at the strychnine-insensitive glycine binding site of the NMDA receptor-channel complex with nanomolar affinity (pKi = 8.5), coupled with high glutamate receptor selectivity. Gavestinel displays higher than 1000-fold selectivity over NMDA, AMPA and kainate binding sites and is orally bioavailable and active in vivo. GV 150526A inhibited convulsions induced by NMDA in mice, when administered by both IV and po routes (ED50 = 0.06 and 6 mg/kg, respectively). The safety and efficacy of GV150526 were studied in two phase III randomized placebo-controlled clinical trials of acute ischemic stroke patients within 6 h from onset [The Glycine Antagonist in Neuroprotection (GAIN) International and GAIN Americas Trials] sponsored by GlaxoSmithKline. The results of these trials suggested that gavestinel was not of substantial benefit or harm to patients with primary intracerebral hemorrhage.

Remacemide is a low-affinity noncompetitive NMDA receptor antagonist with sodium channel blocking properties. It has been studied for a number of conditions including acute ischemic stroke, epilepsy, Parkinsons Disease, and Huntington's disease. It was concluded, that was unlikely that remacemide would be further developed as an antiepileptic drug. As for other conditions, there no any information in the literature, why remacemide is no longer being developed for them.

Dextrorphan is an active metabolite of dextromethorphan, is an antitussive agent, which was found in cough medicines. Dextrorphan is a noncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist, sigma 1 receptor agonist, so as is an agonist of mu and kappa opioid receptors. In addition was found, that dextrorphan possessed anticonvulsive and neuroprotective effects.

Etoxadrol is an NMDA receptor antagonist. It exerts phencyclidine-like properties. Etoxadrol has anticonvulsant and anesthetic activity. Intravenous etoxadrol was clinically tested as an anesthetic.

Etoxadrol is an NMDA receptor antagonist. It exerts phencyclidine-like properties. Etoxadrol has anticonvulsant and anesthetic activity. Intravenous etoxadrol was clinically tested as an anesthetic.

Racemethorphan is racemic mixture of Dextromethorphan and Levomethorphan. Racemethorphan is listed under the Single Convention on Narcotic Drugs 1961 and is therefore listed in the United States as a Controlled Substance, specifically as a Narcotic in Schedule II. Dextromethorphan is a non-narcotic morphine derivative widely used as an antitussive. Dextromethorphan is a cough suppressant in many over-the-counter cold and cough medicines. In 2010, the FDA approved the combination product dextromethorphan/quinidine for the treatment of pseudobulbar affect. Dextromethorphan suppresses the cough reflex by a direct action on the cough center in the medulla of the brain. Levomethorphan is an opioid analgesic of the morphinan family that has never been marketed.