Ketamine is used for starting and maintaining anesthesia and induces a trance-like state while providing pain relief, sedation, and memory loss. It can cause confusion and hallucinations as it wears off. Discovered in 1962 it was used in the Vietnam War due to its safety and is on the WHO’s list of essential medicines.
It’s also used as a recreational drug in raves and as a club drug. Due to this, it’s a schedule III substance in the U.S.