There has been much research on N-methyl-D-aspartate (NMDA) antagonists since they were first discovered in mid-part of the 20th century. Initially, it was hoped that that some noncompetitive NMDA antagonists (the most common being ketamine, phencyclidine [PCP], and, more recently, MK-801) could be utilized as a new class of anesthetics with quick onset, short duration, and surprisingly good...