PHENCYCLIDINE

Phencyclidine, commonly initialized as PCP and known colloquially as angel dust, KJ or wet, is a recreational dissociative drug. Formerly used as an anesthetic agent, PCP exhibits hallucinogenic effects

PCP, developed in the 1950s as an intravenous surgical anesthetic, is classified as a dissociative anesthetic: Its sedative and anesthetic effects are trance-like, and patients experience a feeling of being "out of body" and detached from their environment.

PCP was used in veterinary medicine but was never approved for human use because of problems that arose during clinical studies, including delirium and extreme agitation experienced by patients emerging from anesthesia.

During the 1960s, PCP in pill form became widely abused, but the surge in illicit use receded rapidly as users became dissatisfied with the long delay between taking the drug and feeling its effects, and with the unpredictable and often violent behavior associated with its use.

Powdered PCP - known as "ozone," "rocket fuel," "love boat," "hog," "embalming fluid," or "superweed" - appeared in the 1970s. In powdered form, the drug is sprinkled on marijuana, tobacco, or parsley, then smoked, and the onset of effects is rapid. Users sometimes ingest PCP by snorting the powder or by swallowing it in tablet form. Normally a white crystalline powder, PCP is sometimes colored with water-soluble or alcohol-soluble dyes.

When snorted or smoked, PCP rapidly passes to the brain to disrupt the functioning of sites known as NMDA (N-methyl-D-aspartate) receptor complexes, which are receptors for the neurotransmitter glutamate. Glutamate receptors play a major role in the perception of pain, in cognition - including learning and memory - and in emotion. In the brain, PCP also alters the actions of dopamine, a neurotransmitter responsible for the euphoria and "rush" associated with many abused drugs.

EFFECTS

Some studies found that, like other NMDA receptor antagonists, phencyclidine can cause a kind of brain damage called Olney's lesions in rats. Studies conducted on rats showed that high doses of the NMDA receptor antagonist dizocilpine caused reversible vacuoles to form in certain regions of the rats' brains. All studies of Olney's lesions have only been performed on non-human animals and may not apply to humans.

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.

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 anesthesia. 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. 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, such as in the case of Big Lurch, a former rapper who claimed his room mate was the devil and ate part of her lung. 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 10,000 lbs of force to break a stainless steel chain of typical diameter), 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.