Ketamine + alcohol amplify each other in two directions:
- Sedation and respiratory depression — both depress the CNS, and the combined effect is not linearly predictable
- Aspiration risk — ketamine reduces the swallowing reflex, alcohol reduces consciousness, vomiting becomes more frequent and more dangerous
Compared to ketamine + GHB/GBL, the combination with alcohol is less acutely respiratory-depressant, but the aspiration risk is high. Fatal outcomes are documented.
A K-hole on ketamine alone is usually transient (15–60 min). With alcohol, the episode can last longer and breathing can become borderline.
Low-threshold recommendation: use them separately or leave one out entirely. If you do combine: low ketamine dose (≤ ½ the usual dose), alcohol to a minimum, never alone, not near water (bath, pool).