From Wiki:
Ketamine, sold under the brand name Ketalar among others, is a medication mainly used for starting and maintaining anesthesia.[16] It induces a trance-like state while providing pain relief, sedation, and memory loss.[17] Also, ketamine is useful for chronic pain and for sedation in intensive care.[18][19] Heart function, breathing, and airway reflexes generally remain functional during its effects.[17] Effects typically begin within five minutes when given by injection with the main effects lasting up to 25 minutes.[20][16]
Common side effects include psychological reactions as the medication wears off.[21] These reactions may include agitation, confusion, or hallucinations.[16][21][22] Elevated blood pressure and muscle tremors are relatively common, while low blood pressure and a decrease in breathing are less so.[16][22] Spasms of the larynx may rarely occur.[16] Ketamine has been classified as an NMDA receptor antagonist but its mechanisms are not well understood as of 2017.[23]
Ketamine was discovered in 1962, first tested in humans in 1964, and was approved for use in the United States in 1970.[20][24] Shortly after its US approval it was extensively used for surgical anesthesia in the Vietnam War, due to its safety.[24] It is on the World Health Organization’s List of Essential Medicines, the most effective and safe medicines needed in a health system.[25] It is available as a generic medication.[16] The wholesale cost in the developing world is between US$0.08 and US$0.32 per dose.[26] Ketamine is also used as a recreational drug.[27]
Isn't that reassuring?