<unk>  is a medication primarily used for induction and maintenance of anesthesia. It induces dissociative anesthesia, a trance-like state providing pain relief, sedation, and amnesia. The distinguishing features of<unk>  anesthesia are preserved breathing and airway reflexes, stimulated heart function with increased blood pressure, and moderate bronchodilation. At lower, sub-anesthetic doses,<unk>  is a promising agent for pain and treatment-resistant depression. However, the antidepressant action of a single administration of<unk>  wanes with time, and the effects of repeated use have not been sufficiently studied. Psychiatric side effects are frequent as well as raised blood pressure and nausea. Liver and urinary toxicity are common among regular users of high doses of<unk>  for recreational purposes.<unk>  is an NMDA receptor antagonist and that accounts for most of its actions except the antidepressive effect, the mechanism of which is a matter of much research and debate.<unk>  was first synthesized in 1962 and approved for use in the United States in 1970. It was regularly used on dogs and horses and extensively used for surgical anaesthesia in the Vietnam War.<unk>  is also used as a recreational drug, both in powder and liquid form, often referred to as "Special<unk> " for its hallucinogenic and dissociative effects. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication.
Ketamine
Propofol
Remifentanil
Alfentanil
Fentanyl
Etomidate
Esketamine
Sevoflurane