Prolonged administration of subanesthetic dosages of ketamine, which suppresses activity at NMDA receptors, can provide a damaged central nervous system with an opportunity to use its innate healing processes to “reset” NMDA receptors which were pushed into an unwanted hyper-sensitized state by unusually high activity. However, such treatments can cause permanent brain damage, if the ketamine dosage is too heavy or prolonged. Certain types of “safener” drugs have previously been identified, which can block or at least reduce those unwanted side effects. It is disclosed that if two classes of safener drugs are combined, which will simultaneously suppress activity at both (i) muscarinic acetylcholine receptors, and (ii) the kainate and AMPA classes of glutamate receptors, those safener drug combinations can provide exceptionally potent and reliable safening activity, which can enable the safe use of potent NMDA antagonist drugs for a number of highly beneficial purposes.
