Phencyclidine
Encyclopedia
Phencyclidine commonly initialized as PCP and known colloquially as angel dust, is a recreational dissociative drug
. Formerly used as an anesthetic
agent, PCP exhibits both hallucinogenic and neurotoxic
effects.
First synthesized in 1926, it was eventually 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. Other NMDA receptor antagonists include ketamine
, tiletamine
, dextromethorphan
and nitrous oxide
. Although the primary psychoactive effects of PCP last for a few hours, its total elimination rate from the body typically extends eight days or longer.
As a recreational drug, PCP may be ingested, smoked, or snorted.
in rats and in rat brain homogenate. As such, PCP is an NMDA receptor antagonist. NMDA receptors mediate excitation, however, studies have shown that PCP unexpectedly produces substantial cortical activation in humans and rodents.
Research also indicates that PCP inhibits nicotinic acetylcholine
(nACh) receptors. Analogues of PCP exhibit varying potency at nACh receptors and NMDA receptors. In some brain regions, these effects are believed to act synergistically by inhibiting excitatory activity.
PCP, like ketamine
, also acts as a D2 receptor partial agonist
in rat brain homogenate. This activity may be associated with some of the more psychotic features of PCP intoxication, which is evidenced by the successful use of D2 receptor antagonists (such as haloperidol
) in the treatment of PCP psychosis.
The relative immunity to pain is likely produced by indirect interaction with the endogenous endorphin
and enkephalin
system, as has been suggested by studies involving rats.
PCP may also work as a dopamine reuptake inhibitor
.
, PPC
and PCAA
.
When smoked, some of it is broken down by heat into 1-phenyl-1-cyclohexene (PC) and piperidine
.
More than 30 different analogues of PCP were reported as being used on the street during the 1970s and 1980s, mainly in the USA. The best known of these are PCPy (rolicyclidine
, 1-(1-phenylcyclohexyl)pyrrolidine); PCE (eticyclidine
, N-ethyl-1-phenylcyclohexylamine); and TCP (tenocyclidine
, 1-(1-(2-Thienyl)cyclohexyl)piperidine). These compounds were never widely-used and did not seem to be as well-accepted by users as PCP itself, however they were all added onto Schedule I of the Controlled Substance Act because of their putative similar effects.
The generalized structural motif required for PCP-like activity is derived from structure-activity relationship studies of PCP analogues, and summarized below. All of these analogues would have somewhat similar effects to PCP itself, although, with a range of potencies and varying mixtures of anesthetic, dissociative and stimulant effects depending on the particular substituents used. In some countries such as the USA, Australia, and New Zealand, all of these compounds would be considered controlled substance analogue
s of PCP, and are hence illegal drugs, even though many of them have never been made or tested.
s, phencyclidine can cause a certain kind of brain damage
called Olney's lesions
in rats. Studies conducted on rats showed that high doses of the NMDA receptor antagonist MK-801
caused reversible vacuole
s to form in certain regions of the rats' brains. All studies of Olney's lesions have only been performed on animals and may not apply to humans. The research into the relationship between rat brain metabolism and the creation of Olney's Lesions has been discredited and may not apply to humans, as has been shown with ketamine.
Phencyclidine has also been shown to cause schizophrenia
-like changes in N-acetylaspartate and N-acetylaspartylglutamate in the rat brain, which are detectable both in living rats and upon necropsy examination of brain tissue. It also induces symptoms in humans that mimic schizophrenia.
The full extent of the pharmacology of this compound in the human CNS is not fully understood; it binds to many different receptor sites. The primary interactions are as a non-competitive antagonist at the 3A-subunit [epsilon subunit] of the NMDA receptor. Phencyclidine is known to bind, with relatively high affinity, to the D1 subunit of the human DAT (Dopamine Transporter), in addition to displaying a positive antagonistic effect at the α7-subunit of the Nicotinic Acetylcholine Receptor (nAChR). It also binds to the mu-opioid receptor, which seems to be a central part of the mechanism of action of drugs in this class. (For example, Dizocilpine [MK-801] shows little appreciable analgesic effect despite having a high specificity for the NMDA-3A and NMDA-3B subunits – this may well be mediated by the lack of related efficacy at the mu-opioid receptor, though the NMDAR may play a role in transmission of pain signals).
as a surgical anesthetic
. Because of its adverse side effects
, such as hallucination
s, 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. In surveys, the number of high school
students admitting to trying PCP at least once fell from 13% in 1979 to less than 3% in 1990.
PCP comes in both powder and liquid forms (PCP base is dissolved most often in ether
), but typically it is sprayed onto leafy material such as cannabis
, mint
, oregano
, parsley
, or ginger
leaves, then smoked.
PCP is a Schedule II substance in the United States, a Schedule I drug by the Controlled Drugs and Substances act in Canada, a List I drug of the Opium Law
in the Netherlands
and a Class A
substance in the United Kingdom.
, diethyl ether
, or tetrahydrofuran
). Upon treatment with hydrogen chloride
gas, or isopropyl alcohol
saturated with hydrochloric acid
, this oil precipitates into white-tan crystals or powder (PCP hydrochloride). In this, the salt form, PCP can be insufflated
, depending upon the purity. However, most PCP on the illicit market often 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. These contaminants can range from unreacted piperidine
and other precursors
, to carcinogen
s like benzene
and cyanide
-like compounds such as PCC (piperidinocyclohexyl carbonitrile).
The term "embalming fluid" is often used to refer to the liquid PCP in which a cigarette is dipped, to be ingested through smoking, commonly known as "boat" or "water." The name most likely originated from the somatic "numbing" effect and feelings of dissociation induced by PCP, and has led to the widespread and mistaken belief that the liquid is made up of or contains real embalming fluid
. Occasionally, however, some users and dealers could have, believing this myth, used real embalming fluid mixed with, or in place of, PCP. Smoking PCP is known as "getting wet", and a cigarette
or joint
which has been dipped in PCP may be referred to on the street as a "fry stick," "sherm," "amp," "lovely," "KJ (an abbreviation for 'Killer Joint')," "toe tag", "dipper", "happy stick," or "wet stick." "Getting wet" may have once been a popular method of using PCP, especially in the western United States
where it may have been sold for about $10 to $25 per cigarette.
. High doses may lead to convulsions. Users frequently do not know how much of the drug they are taking due to the tendency of the drug to be made illegally in uncontrolled conditions.
Psychological effects include severe changes in body image
, loss of ego boundaries
, paranoia
and depersonalization
. Hallucination
s, 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.
However, studies by the Drug Abuse Warning Network
in the 1970s show that media reports of PCP-induced violence are greatly exaggerated and that incidents of violence were unusual and often (but not always) limited to individuals with reputations for aggression regardless of drug use. The reports in question often dealt with a supposed increase in strength imparted by the drug; this could partially be explained by the anaesthetic effects of the drug. The most commonly-cited types of incidents included self-mutilation of various types, breaking handcuffs (a feat reportedly requiring about 550 lbf (2.4 kN) of force), inflicting remarkable property damage, and pulling one's own teeth.
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. Users generally report they feel detached from reality, or that one's consciousness seems somewhat disconnected from reality.
Symptoms are summarized by the mnemonic
device RED DANES: rage, erythema
(redness of skin), dilated pupils, delusions, amnesia
, nystagmus (oscillation of the eyeball when moving laterally), excitation, and skin dryness.
s, such as lorazepam
, are the drugs of choice to control agitation and seizures (when present). Typical antipsychotics such as phenothiazine
s and haloperidol
have been used to control psychotic symptoms, but may produce many undesirable side effects — such as dystonia
— and their use is therefore no longer preferred; phenothiazines are particularly risky, as they may lower the seizure threshold
, worsen hyperthermia
, and boost the anticholinergic
effects of PCP. If an antipsychotic is given, intramuscular
haloperidol has been recommended.
Forced acid diuresis
(with ammonium chloride
or, more safely, ascorbic acid
) may increase clearance of PCP from the body, and was somewhat controversially recommended in the past as a decontamination
measure. However, it is now known that only around 10% of a dose of PCP is removed by the kidneys, which would make increased urinary clearance of little consequence; furthermore, urinary acid
ification is dangerous, as it may induce acidosis
and worsen rhabdomyolysis
(muscle breakdown), which is not an unusual manifestation of PCP toxicity.
Dissociative drug
Dissociatives are a class of psychoactive drugs which are said to reduce or block signals to the conscious mind from other parts of the brain...
. Formerly used as an anesthetic
Anesthesia
Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
agent, PCP exhibits both hallucinogenic and neurotoxic
Neurotoxicity
Neurotoxicity occurs when the exposure to natural or artificial toxic substances, which are called neurotoxins, alters the normal activity of the nervous system in such a way as to cause damage to nervous tissue. This can eventually disrupt or even kill neurons, key cells that transmit and process...
effects.
First synthesized in 1926, it was eventually patented in 1952 by the Parke-Davis
Parke-Davis
Parke-Davis is a subsidiary of the pharmaceutical company Pfizer. Although no longer an independent corporation, it was once America's oldest and largest drug maker, and played an important role in medical history.- History :...
pharmaceutical company and marketed under the brand name Sernyl. In chemical
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
structure, PCP is an arylcyclohexylamine
Arylcyclohexylamine
Arylcyclohexylamines, also known as arylcyclohexamines or arylcyclohexanamines, are a chemical class of pharmaceutical, designer, and experimental drugs.- History :...
derivative, and, in pharmacology
Pharmacology
Pharmacology is the branch of medicine and biology concerned with the study of drug action. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function...
, it is a member of the family of dissociative anesthetics. PCP works primarily as an NMDA receptor antagonist
NMDA receptor antagonist
NMDA receptor antagonists are a class of anesthetics that work to antagonize, or inhibit the action of, the N-methyl d-aspartate receptor . They are used as anesthesia for animals and, less commonly, for humans; the state of anesthesia they induce is referred to as dissociative anesthesia...
, which blocks the activity of the NMDA receptor
NMDA receptor
The NMDA receptor , a glutamate receptor, is the predominant molecular device for controlling synaptic plasticity and memory function....
and, like most antiglutamatergic hallucinogens, is significantly more dangerous than other categories of hallucinogens. Other NMDA receptor antagonists include ketamine
Ketamine
Ketamine is a drug used in human and veterinary medicine. Its hydrochloride salt is sold as Ketanest, Ketaset, and Ketalar. Pharmacologically, ketamine is classified as an NMDA receptor antagonist...
, tiletamine
Tiletamine
Tiletamine is a dissociative anesthetic and pharmacologically classified as an NMDA receptor antagonist. It is related chemically and pharmacologically to other anesthetics in this family such as ketamine and phencyclidine...
, dextromethorphan
Dextromethorphan
Dextromethorphan is an antitussive drug. It is one of the active ingredients in many over-the-counter cold and cough medicines, such as Robitussin, NyQuil, Dimetapp, Vicks, Coricidin, Delsym, and others, including generic labels. Dextromethorphan has also found other uses in medicine, ranging...
and nitrous oxide
Nitrous oxide
Nitrous oxide, commonly known as laughing gas or sweet air, is a chemical compound with the formula . It is an oxide of nitrogen. At room temperature, it is a colorless non-flammable gas, with a slightly sweet odor and taste. It is used in surgery and dentistry for its anesthetic and analgesic...
. Although the primary psychoactive effects of PCP last for a few hours, its total elimination rate from the body typically extends eight days or longer.
As a recreational drug, PCP may be ingested, smoked, or snorted.
Pharmacodynamics
PCP is well known for its primary action on ionotropic glutamate receptors, such as the NMDA receptorNMDA receptor
The NMDA receptor , a glutamate receptor, is the predominant molecular device for controlling synaptic plasticity and memory function....
in rats and in rat brain homogenate. As such, PCP is an NMDA receptor antagonist. NMDA receptors mediate excitation, however, studies have shown that PCP unexpectedly produces substantial cortical activation in humans and rodents.
Research also indicates that PCP inhibits nicotinic acetylcholine
Acetylcholine
The chemical compound acetylcholine is a neurotransmitter in both the peripheral nervous system and central nervous system in many organisms including humans...
(nACh) receptors. Analogues of PCP exhibit varying potency at nACh receptors and NMDA receptors. In some brain regions, these effects are believed to act synergistically by inhibiting excitatory activity.
PCP, like ketamine
Ketamine
Ketamine is a drug used in human and veterinary medicine. Its hydrochloride salt is sold as Ketanest, Ketaset, and Ketalar. Pharmacologically, ketamine is classified as an NMDA receptor antagonist...
, also acts as a D2 receptor partial agonist
Partial agonist
Partial agonists bind and activate a given receptor, but have only partial efficacy at the receptor relative to a full agonist...
in rat brain homogenate. This activity may be associated with some of the more psychotic features of PCP intoxication, which is evidenced by the successful use of D2 receptor antagonists (such as haloperidol
Haloperidol
Haloperidol is a typical antipsychotic. It is in the butyrophenone class of antipsychotic medications and has pharmacological effects similar to the phenothiazines....
) in the treatment of PCP psychosis.
The relative immunity to pain is likely produced by indirect interaction with the endogenous endorphin
Endorphin
Endorphins are endogenous opioid peptides that function as neurotransmitters. They are produced by the pituitary gland and the hypothalamus in vertebrates during exercise, excitement, pain, consumption of spicy food, love and orgasm, and they resemble the opiates in their abilities to produce...
and enkephalin
Enkephalin
An enkephalin is a pentapeptide involved in regulating nociception in the body. The enkephalins are termed endogenous ligands, or specifically endorphins, as they are internally derived and bind to the body's opioid receptors. Discovered in 1975, two forms of enkephalin were revealed, one...
system, as has been suggested by studies involving rats.
PCP may also work as a dopamine reuptake inhibitor
Dopamine reuptake inhibitor
A dopamine reuptake inhibitor is a type of drug that acts as a reuptake inhibitor for the neurotransmitter dopamine by blocking the action of the dopamine transporter...
.
Pharmacokinetics
PCP is metabolized into PCHPPCHP
1--4-hydroxypiperidine is a metabolite of phencyclidine . PCHP can be detected in the hair of PCP users....
, PPC
4-Phenyl-4-(1-piperidinyl)cyclohexanol
4-Phenyl-4--cyclohexanol, also known as PPC, is an organic chemical which is a metabolite of phencyclidine . It can be detected in the hair of PCP users.PPC has been shown to cause increases in locomotor activity in lab mice....
and PCAA
PCAA
PCAA, or 5-[N-]-aminopentanoic acid, is a metabolite of phencyclidine . It can be detected in the urine of PCP users by mass spectrometry as means of drug screening....
.
When smoked, some of it is broken down by heat into 1-phenyl-1-cyclohexene (PC) and piperidine
Piperidine
Piperidine is an organic compound with the molecular formula 5NH. This heterocyclic amine consists of a six-membered ring containing five methylene units and one nitrogen atom...
.
Structural analogues
Rolicyclidine
Rolicyclidine is a dissociative anesthetic drug with hallucinogenic and sedative effects. It is similar in effects to phencyclidine but is slightly less potent and has less stimulant effects instead producing a sedative effect described as being somewhat similar to a barbiturate, but with...
, 1-(1-phenylcyclohexyl)pyrrolidine); PCE (eticyclidine
Eticyclidine
Eticyclidine is a dissociative anesthetic drug with hallucinogenic effects. It is similar in effects to phencyclidine but is slightly more potent...
, N-ethyl-1-phenylcyclohexylamine); and TCP (tenocyclidine
Tenocyclidine
Tenocyclidine is a dissociative anesthetic drug with stimulant and hallucinogenic effects. It is similar in effects to phencyclidine but is considerably more potent. TCP has slightly different binding properties to PCP, with more affinity for the NMDA receptors, but less affinity for the sigma...
, 1-(1-(2-Thienyl)cyclohexyl)piperidine). These compounds were never widely-used and did not seem to be as well-accepted by users as PCP itself, however they were all added onto Schedule I of the Controlled Substance Act because of their putative similar effects.
The generalized structural motif required for PCP-like activity is derived from structure-activity relationship studies of PCP analogues, and summarized below. All of these analogues would have somewhat similar effects to PCP itself, although, with a range of potencies and varying mixtures of anesthetic, dissociative and stimulant effects depending on the particular substituents used. In some countries such as the USA, Australia, and New Zealand, all of these compounds would be considered controlled substance analogue
Federal Analog Act
The Federal Analog Act, , is a controversial section of the United States Controlled Substances Act which allowed any chemical "substantially similar" to a controlled substance listed in Schedule I or II to be treated as if it were also listed in those schedules, but only if intended for human...
s of PCP, and are hence illegal drugs, even though many of them have never been made or tested.
Brain effects
Some studies found that, like other NMDA receptor antagonistNMDA receptor antagonist
NMDA receptor antagonists are a class of anesthetics that work to antagonize, or inhibit the action of, the N-methyl d-aspartate receptor . They are used as anesthesia for animals and, less commonly, for humans; the state of anesthesia they induce is referred to as dissociative anesthesia...
s, phencyclidine can cause a certain kind of brain damage
Brain damage
"Brain damage" or "brain injury" is the destruction or degeneration of brain cells. Brain injuries occur due to a wide range of internal and external factors...
called Olney's lesions
Olney's lesions
Olney's lesions, also known as NMDA receptor antagonist neurotoxicity , are a potential form of brain damage. They are named after John Olney, who conducted a study investigating neurotoxicity caused by PCP and related drugs in 1989.-History:...
in rats. Studies conducted on rats showed that high doses of the NMDA receptor antagonist MK-801
Dizocilpine
Dizocilpine , also known as MK-801, is a non-competitive antagonist of the N-methyl-d-aspartate receptor, a glutamate receptor. Glutamate is the brain's primary excitatory neurotransmitter...
caused reversible vacuole
Vacuole
A vacuole is a membrane-bound organelle which is present in all plant and fungal cells and some protist, animal and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain...
s to form in certain regions of the rats' brains. All studies of Olney's lesions have only been performed on animals and may not apply to humans. The research into the relationship between rat brain metabolism and the creation of Olney's Lesions has been discredited and may not apply to humans, as has been shown with ketamine.
Phencyclidine has also been shown to cause schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
-like changes in N-acetylaspartate and N-acetylaspartylglutamate in the rat brain, which are detectable both in living rats and upon necropsy examination of brain tissue. It also induces symptoms in humans that mimic schizophrenia.
The full extent of the pharmacology of this compound in the human CNS is not fully understood; it binds to many different receptor sites. The primary interactions are as a non-competitive antagonist at the 3A-subunit [epsilon subunit] of the NMDA receptor. Phencyclidine is known to bind, with relatively high affinity, to the D1 subunit of the human DAT (Dopamine Transporter), in addition to displaying a positive antagonistic effect at the α7-subunit of the Nicotinic Acetylcholine Receptor (nAChR). It also binds to the mu-opioid receptor, which seems to be a central part of the mechanism of action of drugs in this class. (For example, Dizocilpine [MK-801] shows little appreciable analgesic effect despite having a high specificity for the NMDA-3A and NMDA-3B subunits – this may well be mediated by the lack of related efficacy at the mu-opioid receptor, though the NMDAR may play a role in transmission of pain signals).
History and medicinal use
PCP was first synthesized in 1926 and later tested after World War IIWorld War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
as a surgical anesthetic
Anesthesia
Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
. Because of its adverse side effects
Adverse effect (medicine)
In medicine, an adverse effect is a harmful and undesired effect resulting from a medication or other intervention such as surgery.An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. If it results from an unsuitable or incorrect dosage or...
, such as hallucination
Hallucination
A hallucination, in the broadest sense of the word, is a perception in the absence of a stimulus. In a stricter sense, hallucinations are defined as perceptions in a conscious and awake state in the absence of external stimuli which have qualities of real perception, in that they are vivid,...
s, mania
Mania
Mania, the presence of which is a criterion for certain psychiatric diagnoses, is a state of abnormally elevated or irritable mood, arousal, and/ or energy levels. In a sense, it is the opposite of depression...
, delirium
Delirium
Delirium or acute confusional state is a common and severe neuropsychiatric syndrome with core features of acute onset and fluctuating course, attentional deficits and generalized severe disorganization of behavior...
, and disorientation, it was shelved until the 1950s. In 1953, it was patented by Parke-Davis
Parke-Davis
Parke-Davis is a subsidiary of the pharmaceutical company Pfizer. Although no longer an independent corporation, it was once America's oldest and largest drug maker, and played an important role in medical history.- History :...
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
Trade name
A trade name, also known as a trading name or a business name, is the name which a business trades under for commercial purposes, although its registered, legal name, used for contracts and other formal situations, may be another....
Sernylan and marketed as a veterinary
Veterinary medicine
Veterinary Medicine is the branch of science that deals with the prevention, diagnosis and treatment of disease, disorder and injury in non-human animals...
anesthetic, but was again discontinued. Its side effects and long half-life
Biological half-life
The biological half-life or elimination half-life of a substance is the time it takes for a substance to lose half of its pharmacologic, physiologic, or radiologic activity, as per the MeSH definition...
in the human body made it unsuitable for medical applications.
Recreational use
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
in 1967. In 1978, People
People (magazine)
In 1998, the magazine introduced a version targeted at teens called Teen People. However, on July 27, 2006, the company announced it would shut down publication of Teen People immediately. The last issue to be released was scheduled for September 2006. Subscribers to this magazine received...
magazine and Mike Wallace
Mike Wallace (journalist)
Myron Leon "Mike" Wallace is an American journalist, former game show host, actor and media personality. During his 60+ year career, he has interviewed a wide range of prominent newsmakers....
of 60 Minutes
60 Minutes
60 Minutes is an American television news magazine, which has run on CBS since 1968. The program was created by producer Don Hewitt who set it apart by using a unique style of reporter-centered investigation....
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. In surveys, the number of high school
High school
High school is a term used in parts of the English speaking world to describe institutions which provide all or part of secondary education. The term is often incorporated into the name of such institutions....
students admitting to trying PCP at least once fell from 13% in 1979 to less than 3% in 1990.
PCP comes in both powder and liquid forms (PCP base is dissolved most often in ether
Diethyl ether
Diethyl ether, also known as ethyl ether, simply ether, or ethoxyethane, is an organic compound in the ether class with the formula . It is a colorless, highly volatile flammable liquid with a characteristic odor...
), but typically it is sprayed onto leafy material such as cannabis
Cannabis
Cannabis is a genus of flowering plants that includes three putative species, Cannabis sativa, Cannabis indica, and Cannabis ruderalis. These three taxa are indigenous to Central Asia, and South Asia. Cannabis has long been used for fibre , for seed and seed oils, for medicinal purposes, and as a...
, mint
Mentha
Mentha is a genus of flowering plants in the family Lamiaceae . The species are not clearly distinct and estimates of the number of species varies from 13 to 18. Hybridization between some of the species occurs naturally...
, oregano
Oregano
Oregano – scientifically named Origanum vulgare by Carolus Linnaeus – is a common species of Origanum, a genus of the mint family . It is native to warm-temperate western and southwestern Eurasia and the Mediterranean region.Oregano is a perennial herb, growing from 20–80 cm tall,...
, parsley
Parsley
Parsley is a species of Petroselinum in the family Apiaceae, native to the central Mediterranean region , naturalized elsewhere in Europe, and widely cultivated as an herb, a spice and a vegetable.- Description :Garden parsley is a bright green hairless biennial herbaceous plant in temperate...
, or ginger
Ginger
Ginger is the rhizome of the plant Zingiber officinale, consumed as a delicacy, medicine, or spice. It lends its name to its genus and family . Other notable members of this plant family are turmeric, cardamom, and galangal....
leaves, then smoked.
PCP is a Schedule II substance in the United States, a Schedule I drug by the Controlled Drugs and Substances act in Canada, a List I drug of the Opium Law
Opium Law
The Opium Law is the section of the Dutch law which covers nearly all psychotropic drugs. All non-psychotropic, but prescription-only drugs are covered by the Medicine Act.- Origin and history :...
in the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
and a Class A
Misuse of Drugs Act 1971
The Misuse of Drugs Act 1971 is an Act of Parliament which represents UK action in line with treaty commitments under the Single Convention on Narcotic Drugs, the Convention on Psychotropic Substances, and the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic...
substance in the United Kingdom.
Methods of administration
In its pure (free base) form, PCP is a yellow oil (usually dissolved in petroleumPetroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
, diethyl ether
Diethyl ether
Diethyl ether, also known as ethyl ether, simply ether, or ethoxyethane, is an organic compound in the ether class with the formula . It is a colorless, highly volatile flammable liquid with a characteristic odor...
, or tetrahydrofuran
Tetrahydrofuran
Tetrahydrofuran is a colorless, water-miscible organic liquid with low viscosity at standard temperature and pressure. This heterocyclic compound has the chemical formula 4O. As one of the most polar ethers with a wide liquid range, it is a useful solvent. Its main use, however, is as a precursor...
). Upon treatment with hydrogen chloride
Hydrogen chloride
The compound hydrogen chloride has the formula HCl. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric humidity. Hydrogen chloride gas and hydrochloric acid are important in technology and industry...
gas, or isopropyl alcohol
Isopropyl alcohol
Isopropyl alcohol is a common name for a chemical compound with the molecular formula C3H8O. It is a colorless, flammable chemical compound with a strong odor...
saturated with hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
, this oil precipitates into white-tan crystals or powder (PCP hydrochloride). In this, the salt form, PCP can be insufflated
Insufflation (medicine)
Insufflation is the practice of inhaling a substance. Insufflation has limited medical use, but is a common route of administration with many respiratory drugs used to treat conditions in the lungs and paranasal sinus .The technique is common for many recreational drugs and is also used for some...
, depending upon the purity. However, most PCP on the illicit market often contains a number of contaminants
Adulterant
An adulterant is a chemical substance which should not be contained within other substances for legal or other reasons. Adulterants may be intentionally added to more expensive substances to increase visible quantities and reduce manufacturing costs or for some other deceptive or malicious purpose...
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. These contaminants can range from unreacted piperidine
Piperidine
Piperidine is an organic compound with the molecular formula 5NH. This heterocyclic amine consists of a six-membered ring containing five methylene units and one nitrogen atom...
and other precursors
Precursor (chemistry)
In chemistry, a precursor is a compound that participates in the chemical reaction that produces another compound. In biochemistry, the term "precursor" is used more specifically to refer to a chemical compound preceding another in a metabolic pathway....
, to carcinogen
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...
s like benzene
Benzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
and cyanide
Cyanide
A cyanide is a chemical compound that contains the cyano group, -C≡N, which consists of a carbon atom triple-bonded to a nitrogen atom. Cyanides most commonly refer to salts of the anion CN−. Most cyanides are highly toxic....
-like compounds such as PCC (piperidinocyclohexyl carbonitrile).
The term "embalming fluid" is often used to refer to the liquid PCP in which a cigarette is dipped, to be ingested through smoking, commonly known as "boat" or "water." The name most likely originated from the somatic "numbing" effect and feelings of dissociation induced by PCP, and has led to the widespread and mistaken belief that the liquid is made up of or contains real embalming fluid
Embalming chemicals
Embalming chemicals are a variety of preservatives, sanitising and disinfectant agents and additives used in modern embalming to temporarily prevent decomposition and restore a natural appearance for viewing a body after death...
. Occasionally, however, some users and dealers could have, believing this myth, used real embalming fluid mixed with, or in place of, PCP. Smoking PCP is known as "getting wet", and a cigarette
Cigarette
A cigarette is a small roll of finely cut tobacco leaves wrapped in a cylinder of thin paper for smoking. The cigarette is ignited at one end and allowed to smoulder; its smoke is inhaled from the other end, which is held in or to the mouth and in some cases a cigarette holder may be used as well...
or joint
Joint (cannabis)
Joint is a slang term for a cigarette rolled using cannabis. Rolling papers are the most common rolling medium among industrialized countries, however brown paper, cigarettes with the tobacco removed, and newspaper are commonly used in developing countries. Modern papers are now made from a wide...
which has been dipped in PCP may be referred to on the street as a "fry stick," "sherm," "amp," "lovely," "KJ (an abbreviation for 'Killer Joint')," "toe tag", "dipper", "happy stick," or "wet stick." "Getting wet" may have once been a popular method of using PCP, especially in the western United States
Western United States
.The Western United States, commonly referred to as the American West or simply "the West," traditionally refers to the region comprising the westernmost states of the United States. Because the U.S. expanded westward after its founding, the meaning of the West has evolved over time...
where it may have been sold for about $10 to $25 per cigarette.
Effects
Behavioral effects can vary by dosage. Low doses produce a numbness in the extremities and intoxication, characterized by staggering, unsteady gait, slurred speech, bloodshot eyes, and loss of balance. Moderate doses (5–10 mg intranasal, or 0.01–0.02 mg/kg intramuscular or intravenous) will produce analgesia and anesthesiaAnesthesia
Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
. High doses may lead to convulsions. Users frequently do not know how much of the drug they are taking due to the tendency of the drug to be made illegally in uncontrolled conditions.
Psychological effects include severe changes in body image
Body image
Body image refers to a person's perception of the aesthetics and sexual attractiveness of their own body. The phrase body image was first coined by the Austrian neurologist and psychoanalyst Paul Schilder in his masterpiece The Image and Appearance of the Human Body...
, loss of ego boundaries
Ego Death
Ego death is an experience that reveals the illusory aspect of the ego, sometimes undergone by mystics, shamans, monks, psychologists, and others interested in exploring the depths of the mind....
, paranoia
Paranoia
Paranoia [] is a thought process believed to be heavily influenced by anxiety or fear, often to the point of irrationality and delusion. Paranoid thinking typically includes persecutory beliefs, or beliefs of conspiracy concerning a perceived threat towards oneself...
and depersonalization
Depersonalization
Depersonalization is an anomaly of the mechanism by which an individual has self-awareness. It is a feeling of watching oneself act, while having no control over a situation. Sufferers feel they have changed, and the world has become less real, vague, dreamlike, or lacking in significance...
. Hallucination
Hallucination
A hallucination, in the broadest sense of the word, is a perception in the absence of a stimulus. In a stricter sense, hallucinations are defined as perceptions in a conscious and awake state in the absence of external stimuli which have qualities of real perception, in that they are vivid,...
s, euphoria
Euphoria
Euphoria is an emotional and mental state defined as a sense of great elation and well being.Euphoria may also refer to:* Euphoria , a genus of scarab beetles* Euphoria, a genus name previously used for the longan and other trees...
, suicidal impulses
Suicidal ideation
Suicidal ideation is a common medical term for thoughts about suicide, which may be as detailed as a formulated plan, without the suicidal act itself. Although most people who undergo suicidal ideation do not commit suicide, some go on to make suicide attempts...
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.
However, studies by the Drug Abuse Warning Network
Drug Abuse Warning Network
The Drug Abuse Warning Network is a public health surveillance system in the United States that monitors drug-related visits to hospital emergency departments and drug-related deaths investigated by medical examiners and coroners .-Organization:...
in the 1970s show that media reports of PCP-induced violence are greatly exaggerated and that incidents of violence were unusual and often (but not always) limited to individuals with reputations for aggression regardless of drug use. The reports in question often dealt with a supposed increase in strength imparted by the drug; this could partially be explained by the anaesthetic effects of the drug. The most commonly-cited types of incidents included self-mutilation of various types, breaking handcuffs (a feat reportedly requiring about 550 lbf (2.4 kN) of force), inflicting remarkable property damage, and pulling one's own teeth.
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. Users generally report they feel detached from reality, or that one's consciousness seems somewhat disconnected from reality.
Symptoms are summarized by the mnemonic
Mnemonic
A mnemonic , or mnemonic device, is any learning technique that aids memory. To improve long term memory, mnemonic systems are used to make memorization easier. Commonly encountered mnemonics are often verbal, such as a very short poem or a special word used to help a person remember something,...
device RED DANES: rage, erythema
Erythema
Erythema is redness of the skin, caused by hyperemia of the capillaries in the lower layers of the skin. It occurs with any skin injury, infection, or inflammation...
(redness of skin), dilated pupils, delusions, amnesia
Amnesia
Amnesia is a condition in which one's memory is lost. The causes of amnesia have traditionally been divided into categories. Memory appears to be stored in several parts of the limbic system of the brain, and any condition that interferes with the function of this system can cause amnesia...
, nystagmus (oscillation of the eyeball when moving laterally), excitation, and skin dryness.
Management of intoxication
Management of phencyclidine intoxication mostly consists of supportive care — controlling breathing, circulation, and body temperature — and, in the early stages, treating psychiatric symptoms. BenzodiazepineBenzodiazepine
A benzodiazepine is a psychoactive drug whose core chemical structure is the fusion of a benzene ring and a diazepine ring...
s, such as lorazepam
Lorazepam
Lorazepam is a high-potency short-to-intermediate-acting 3-hydroxy benzodiazepine drug that has all five intrinsic benzodiazepine effects: anxiolytic, amnesic, sedative/hypnotic, anticonvulsant, antiemetic and muscle relaxant...
, are the drugs of choice to control agitation and seizures (when present). Typical antipsychotics such as phenothiazine
Phenothiazine
Phenothiazine is an organic compound that occurs in various antipsychotic and antihistaminic drugs. It has the formula S2NH. This yellow tricyclic compound is soluble in acetic acid, benzene, and ether. The compound is related to the thiazine-class of heterocyclic compounds...
s and haloperidol
Haloperidol
Haloperidol is a typical antipsychotic. It is in the butyrophenone class of antipsychotic medications and has pharmacological effects similar to the phenothiazines....
have been used to control psychotic symptoms, but may produce many undesirable side effects — such as dystonia
Dystonia
Dystonia is a neurological movement disorder, in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures. The disorder may be hereditary or caused by other factors such as birth-related or other physical trauma, infection, poisoning or reaction to...
— and their use is therefore no longer preferred; phenothiazines are particularly risky, as they may lower the seizure threshold
Seizure threshold
A seizure threshold is the balance between excitatory and inhibitory forces in the brain which affects how susceptible one is to seizures. Those diagnosed with epilepsy or certain other neurological conditions are vulnerable to sudden new seizures if the threshold is upset, and so must be...
, worsen hyperthermia
Hyperthermia
Hyperthermia is an elevated body temperature due to failed thermoregulation. Hyperthermia occurs when the body produces or absorbs more heat than it can dissipate...
, and boost the anticholinergic
Anticholinergic
An anticholinergic agent is a substance that blocks the neurotransmitter acetylcholine in the central and the peripheral nervous system. An example of an anticholinergic is dicycloverine, and the classic example is atropine....
effects of PCP. If an antipsychotic is given, intramuscular
Intramuscular injection
Intramuscular injection is the injection of a substance directly into a muscle. In medicine, it is one of several alternative methods for the administration of medications . It is used for particular forms of medication that are administered in small amounts...
haloperidol has been recommended.
Forced acid diuresis
Forced diuresis
Forced diuresis may enhance the excretion of certain drugs in urine and is used to treat drug overdose or poisoning of these drugs and hemorrhagic cystitis.-Diuretics:...
(with ammonium chloride
Ammonium chloride
Ammonium chloride NH4Cl is an inorganic compound with the formula NH4Cl. It is a white crystalline salt that is highly soluble in water. Solutions of ammonium chloride are mildly acidic. Sal ammoniac is a name of natural, mineralogical form of ammonium chloride...
or, more safely, ascorbic acid
Ascorbic acid
Ascorbic acid is a naturally occurring organic compound with antioxidant properties. It is a white solid, but impure samples can appear yellowish. It dissolves well in water to give mildly acidic solutions. Ascorbic acid is one form of vitamin C. The name is derived from a- and scorbutus , the...
) may increase clearance of PCP from the body, and was somewhat controversially recommended in the past as a decontamination
Decontamination
Decontamination is the process of cleansing the human body to remove contamination by hazardous materials including chemicals, radioactive substances, and infectious material...
measure. However, it is now known that only around 10% of a dose of PCP is removed by the kidneys, which would make increased urinary clearance of little consequence; furthermore, urinary acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...
ification is dangerous, as it may induce acidosis
Acidosis
Acidosis is an increased acidity in the blood and other body tissue . If not further qualified, it usually refers to acidity of the blood plasma....
and worsen rhabdomyolysis
Rhabdomyolysis
Rhabdomyolysis is a condition in which damaged skeletal muscle tissue breaks down rapidly. Breakdown products of damaged muscle cells are released into the bloodstream; some of these, such as the protein myoglobin, are harmful to the kidneys and may lead to kidney failure...
(muscle breakdown), which is not an unusual manifestation of PCP toxicity.
External links
- Erowid.org – PCP Information
- National Institute of Drug Abuse InfoFacts: PCP (Phencyclidine)
- Drugs and Human Performance Fact Sheets on Phencyclidine
- A site with information on PCP, Partnership for a Drug-Free America
- Phencyclidine and Ketamine: A View From the Street-1981 article on the use and effects of PCP
- ChemSub Online: Phencyclidine