Ketamine is a rapidly acting general anesthetic. Its pharmacological profile is essentially the same as phencyclidine. Like PCP, ketamine is referred to as a dissociative anesthetic because patients feel detached or disconnected from their pain and environment when anesthetized with this drug. Unlike most anesthetics, ketamine produces only mild respiratory depression and appears to stimulate, not depress, the cardiovascular system. In addition, ketamine has both analgesic and amnesic properties and is associated with less confusion, irrationality, and violent behavior than PCP. Use of ketamine as a general anesthetic for humans has been limited due to adverse effects including delirium and hallucinations. Today, it is primarily used in veterinary medicine, but has some utility for emergency surgery in humans.
Ketamine powder (right) is clandestinely sold at "rave" parties and is usually snorted. Although ketamine has been marketed in the United States for many years, it was only recently associated with significant diversion and abuse. Known in the drug culture as "Special K" or "Super K," ketamine has become a staple at dance parties or "raves." Ketamine is supplied to the illicit market by the diversion of legitimate pharmaceuticals (Ketaset®, Ketalar®). It is usually distributed as a powder obtained by removing the liquid from the pharmaceutical products. As a drug of abuse, ketamine can be administered orally, snorted, or injected. It is also sprinkled on marijuana or tobacco and smoked. After oral or intranasal administration, effects are evident in about 10 to 15 minutes and are over in about an hour.
After intravenous use, effects begin almost immediately and reach peak effects within minutes. Ketamine can act as a depressant or a psychedelic. Low doses produce vertigo, ataxia, slurred speech, slow reaction time, and euphoria. Intermediate doses produce disorganized thinking, altered body image, and a feeling of unreality with vivid visual hallucinations. High doses produce analgesia, amnesia, and coma.