Groups of male CD-1 mice (n = 12/group) were injected intraperitoneally (IP) with 5 g ethanol/kg of body weight. After loss of righting reflex, they were given vehicle or one of 2-3 doses of reputed or potential antagonists of ethanol intravenously (IV). Sleep time was measured from loss to return of righting reflex. Mean sleep time (MST) was increased significantly (P less than 0.05) by a large dose of dl-amphetamine (24 mg/kg) and by 4-aminopyridine (1, 5 mg/kg). Significant (P less than 0.01) increases were also produced by small and large doses of aminophylline (25, 100 mg/kg) and by yohimbine (1, 5 mg/kg). MST was not altered significantly by small and medium doses of dl-amphetamine (6, 12 mg/kg), a medium dose of aminophylline (50 mg/kg), or by any doses of naloxone, thyrotropin-releasing hormone, propranolol, physostigmine, doxapram, or Ro 15-4513. When Ro 15-4513 was given IP 15 minutes before ethanol (n = 6/group), onset and duration of narcosis were not altered. None of the compounds tested was an effective IV antidote for deep ethanol narcosis because of drug side effects, toxicity, prolongation of MST, or insufficient shortening of MST.