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.
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.
Ketamine is odorless and tasteless, so it can be added to beverages without being detected, and it induces amnesia. Because of these properties, the drug is sometimes given to unsuspecting victims and used in the commission of sexual assaults referred to as “drug rape.”
Ketamine can cause dream-like states and hallucinations. Users report sensations ranging from a pleasant feeling of floating to being separated from their bodies. Some ketamine experiences involve a terrifying feeling of almost complete sensory detachment that is likened to a near-death experience. These experiences, similar to a “bad trip” on LSD, are called the “K-hole.” Low-dose intoxication from ketamine results in impaired attention, learning ability, and memory .In high doses, ketamine can cause delirium, amnesia, impaired motor function, high blood pressure, depression, and potentially fatal respiratory problems.