Ketamine + alcohol or opiates: deficiency of consciousness of the effects on the depressant drugs, which can result in taking excessive and vomiting, slowed respiration, coma, and Demise. Cytochrome P450 3A4 would be the principal enzyme to blame for ketamine N-demethylation to norketamine, with minor contributions from CYP2B6 and CYP2C9 iso