Ketamine
"Ketamine is a drug used 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. 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. Ketamine 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."
Taken from Wikipedia (http://en.wikipedia.org/wiki/Ketamine)