The invention concerns the use of a gaseous mixture containing gas xenon and gas nitrous oxide, and advantageously oxygen, for making all or part of an inhalable medicine for preventing or treating neurointoxication in a human. The xenon/nitrous oxide mixture of the invention acts on one or more cerebral receptors to reduce the release and/or the effects of dopamine, glutamate, serotonin, taurin, GABA, noradrenaline and/or any other neurotransmitter. The proportion by volume of xenon of the mixture ranges between 5 and 45%, and the proportion by volume of nitrous oxide ranges between 10 and 50%, the balance is preferably oxygen.