Phencyclidine is a recreational, dissociative drug formerly used as an anesthetic agent, exhibiting hallucinogenic and neurotoxic effects. Developed in 1926, it was first patented in 1952 by the Parke-Davis pharmaceutical company and marketed under the brand name Sernyl. In chemical structure, PCP is an arylcyclohexylamine derivative, and, in pharmacology, it is a member of the family of dissociative anesthetics. PCP works primarily as an NMDA receptor antagonist, which blocks the activity of the NMDA receptor and, like most antiglutamatergic hallucinogens, is significantly more dangerous than other categories of hallucinogens. Users tend to demonstrate symptoms that mimic schizophrenia such as delusions, hallucinations, paranoia and disordered thinking. The full extent of the pharmacology of this compound in the human central nervous system is not fully understood; it binds to many different receptor sites.

PCP was first synthesized in 1926, and later tested after World War II as a surgical anesthetic. Because of its adverse side effects, such as hallucinations, mania, delirium, and disorientation, it was shelved until the 1950s. In 1953, it was patented by Parke-Davis and named Sernyl (referring to serenity), but was only used in humans for a few years because of side-effects. In 1967, it was given the trade name Sernylan and marketed as a veterinary anesthetic, but was again discontinued. Its side effects and long half-life in the human body made it unsuitable for medical applications.

PCP began to emerge as a recreational drug in major cities in the United States in 1967. In 1978, People magazine and Mike Wallace of 60 Minutes called PCP the country's "number one" drug problem. Although recreational use of the drug had always been relatively low, it began declining significantly in the 1980s. PCP is a Schedule II substance in the United States, a List I drug of the Opium Law in the Netherlands and a Class A substance in the United Kingdom. Psychological effects include severe changes in body image, loss of ego boundaries, paranoia and depersonalization. Hallucinations, euphoria, suicidal impulses and aggressive behavior are reported. The drug has been known to alter mood states in an unpredictable fashion, causing some individuals to become detached, and others to become animated. Intoxicated individuals may act in an unpredictable fashion, possibly driven by their delusions and hallucinations. PCP may induce feelings of strength, power, and invulnerability as well as a numbing effect on the mind. Occasionally, this leads to bizarre acts of violence. Included in the portfolio of behavioral disturbances are acts of self-injury including suicide, and attacks on others or destruction of property. The analgesic properties of the drug can cause users to feel less pain, and persist in violent or injurious acts as a result. Recreational doses of the drug can also induce a psychotic state that resembles schizophrenic episodes which can last for months at a time with toxic doses.

Formal Chemical Name (IUPAC)
1-(1-phenylcyclohexyl)piperidine

References

http://en.wikipedia.org/wiki/Phencyclidine