Conditioned tolerance provides protection against ethanol lethality.

To produce conditioned drug tolerance, mice were given twice daily injections of 3.5 g/kg of ethanol for four days and were tested on the fifth day in the same environment or in a novel environment. A range of doses of ethanol were utilized on the test day to assess lethality. The LD50 for ethanol was higher in mice tested in the environment previously associated with the administration of ethanol than in those tested in a novel environment. Therefore, conditioned tolerance can provide protection against ethanol lethality.