Ketamine is a drug for use in human and veterinary medicine developed by Parke-Davis (today a part of Pfizer) in 1962. Its hydrochloride salt is sold as Ketanest, Ketaset, and Ketalar. Pharmacologically, ketamine is classified as an NMDA receptor antagonist, and at high, fully anesthetic level doses, ketamine has also been found to bind to opioid μ receptors and sigma receptors. Like other drugs of this class such as tiletamine and phencyclidine (PCP), it induces a state referred to as "dissociative anesthesia" and is used as a recreational drug.
Ketamine has a wide range of effects in humans, including analgesia, anesthesia, hallucinations, elevated blood pressure, and bronchodilation. It is primarily used for the induction and maintenance of general anesthesia, usually in combination with some sedative drug. Other uses include sedation in intensive care, analgesia (particularly in emergency medicine), and treatment of bronchospasm. It is also a popular anesthetic in veterinary medicine.
Ketamine is a chiral compound. Most pharmaceutical preparations of ketamine are racemic; however, some brands reportedly have (mostly undocumented) differences in enantiomeric proportions. The more active enantiomer, S-ketamine, is also available for medical use under the brand name Ketanest S. Ketamine is a core medicine in the World Health Organization's "Essential Drugs List", which is a list of minimum medical needs for a basic health care system.