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Phencyclidine

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Phencyclidine (a contraction of the chemical name phenylcyclohexylpiperidine), abbreviated PCP, is a dissociative drug formerly used as an anaesthetic agent, exhibiting hallucinogenic and neurotoxic effects.

PCP was commercially developed in the 1950s by the Parke-Davis pharmaceutical company. Internationally, PCP is a Schedule II drug under the Convention on Psychotropic Substances."List of pychotropic substances under control, in accordance with the Convention on Pychotropic Substances of 1971": [Report from 2003] (pdf)

Contents

Chemistry and pharmacology

Chemically and pharmacologically it is a member of the family of dissociative anesthetics, which also includes ketamine, tiletamine and high doses of dextromethorphan. Although the primary psychoactive effects of the drug only last hours, total elimination from the body is prolonged, typically extending over weeks.

Toxicology

PCP is a neurotoxin. It is more toxic than other dissociatives and its toxicity is more complex. The damages concern different brain regions and probably affect diverse receptor systems.R. Nakki et al. (1995): "Cerebellar toxicity of phencyclidine", [J. Neurosci. Seite 2097-108] F.R. Sharp et al. (1994): "Neuronal injury produced by NMDA antagonists can be detected using heat shock proteins and can be blocked with antipsychotics", [Psychopharmacol. Bull. 30 (4), 555-60]

Medical and veterinary use

PCP was first tested after World War I as a surgical anaesthetic. Because of its adverse side-effects, it was shelved until the 1950s. It was then patented by Parke-Davis and named Sernyl (supposedly referring to serenity), but was again withdrawn from the market because of side effects. It was soon renamed Sernylan, and marketed as a veterinary anaesthetic, but again discontinued. Its side effects and long half-life in the human body made it unsuitable for medical applications. It is retained in fatty tissue and is broken down by the human metabolism into PCHP, PPC and PCAA. When smoked, some of it is broken down by heat into 1-phenyl-1-cyclohexene (PC) and piperidine.

Conversion of PCP into PC and piperidine by heat. (Image in the PD)

Recreational use

PCP is consumed recreationally, mainly in the United States. The limited demand is met by illegal production. The drug is sold in an extremely limited number of cities, such as Washington, DC and Los Angeles. It is available as a liquid (PCP base dissolved most often in ether), but typically it is sprayed onto leafy material such as marijuana, mint, oregano, or parsley, and smoked. 
Biochemical action

The N-methyl-L-Aspartate (NMDA) receptor, a type of ionotropic receptor, is found on the dentrites of neurons and receives signals in the form of neurotransmitters. Ingestion of PCP causes prolonged depolarization of the neuron and psychotic symptoms.



Method of absorption




Illicit PCP seized by the DEA in several forms.

Enlarge

Illicit PCP seized by the DEA in several forms.






The term "embalming fluid" is often used to refer to the liquid PCP which a cigarette or joint is dipped in, to be ingested through smoking. There is much confusion over the practice of dipping cigarettes in "embalming fluid" leading some to think that real embalming fluid may actually be used. This is a misconception that may cause serious health consequences beyond those of consuming PCP.


In its powder form, PCP can be insufflated (snorted). This method is almost the universal method of absorption in Eastern Canada, including Quebec and the Atlantic provinces.


In its pure form, PCP is a white crystalline powder that readily dissolves in water. However, most PCP on the illicit market contains a number of contaminants as a result of makeshift manufacturing, causing the color to range from tan to brown, and the consistency to range from powder to a gummy mass.



Effects

Whether PCP has any strong and consistent effects which are markedly different from other similar compounds is controversial. Some think that the drug's effects are as varied as its appearance. It may be that a moderate amount of PCP will cause users to feel detached, distant, and estranged from their surroundings. Numbness, slurred speech, and loss of coordination may be accompanied by a sense of strength and invulnerability. A blank stare, rapid and involuntary eye movements, diarrhea, and an exaggerated gait are alleged to be among the more observable effects. Acts of violence have been committed by people high on the drug; a well-known example is Brenda Ann Spencer, who claimed to have committed her school massacre while under the influence of alcohol and PCP.


According to the National Institute on Drug Abuse: at high doses of PCP, blood pressure, pulse rate, and respiration drop. This may be accompanied by nausea, vomiting, blurred vision, nystagmus, drooling, loss of balance, and dizziness. High doses of PCP can also cause seizures, coma, and death (though death more often results from accidental injury or suicide during PCP intoxication). High doses can cause symptoms that mimic schizophrenia, such as delusions, hallucinations, paranoia, disordered thinking, a sensation of distance from one’s environment, and catatonia. Speech is often sparse and garbled.



Trends

PCP use is extremely prevalent in the Metro Washington DC area, especially in Prince George's County, Maryland and Southeast DC. In the Washington, DC area, it is often referred to as a dipper (cigarette dipped in PCP). PCP production is centered in the greater Los Angeles metropolitan area. Los Angeles-based street gangs, primarily the Crips, continue to distribute PCP to many cities in the United States using their cocaine trafficking operations. These gangs pose a particular problem due to their propensity for violence. During the late 1980s and early 1990s, the widespread availability and use of crack cocaine displaced demand for PCP. More recently, however, reporting suggests that PCP abuse is increasing slightly in many cities, as some crack addicts return to the use of this drug. For instance, the DEA Portland District Office reports a resurgence in the popularity of liquid PCP, also known as "sherm", among Portland area gangs. California street gangs reportedly are responsible for
the reemergence of PCP in the Pacific Northwest. Treated cigarettes, which have a yellow tint caused by the liquid PCP, were first observed on the street in 1996, costing between $15 and $20 each. The DEA Philadelphia Field Division also reports that PCP was available readily in the region in 1998. The DEA seized three clandestine PCP laboratories in 2004.



Mythology and appearances in pop culture








See also



External links



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