Use of antidepressant drugs in the study of the role of biogenic amines in ethanol narcosis.

The interaction with ethanol of antidepressant drugs, imipramine (IMI), amitryptiline (AMI) and nomifensine (NOM), which differ in their activity on neuronal uptake of serotonin and catecholamines, was studied in the duration of narcosis in mice, normal and pretreated with p-chlorophenylalanine (PCPA) or alphamethyl-p-tyrosine (AMPT) and compared with similar experiments with pentobarbital. PCPA and AMPT pretreatment significantly reduced and prolonged respectively, ethanol narcosis but did not modify the effect of pentobarbital. IMI and less markedly AMI increased ethanol narcosis and antagonized the effect of PCPA. contrarily, NOM decreased the duration of ethanol narcosis, potentiated PCPA and antagonized the influence of AMPT. None of these antidepressants did modify pentobarbital narcosis. The alcohol blood level at awakening revealed that no important changes in ethanol metabolism are produced in the different experimental conditions. These results reinforce the hypothesis that serotonin favours the narcotic effect of ethanol, while noradrenaline reduces it. The influence of dopamine needs further studies.