(No article came in March and April due to payment dispute)

For MAY 2001 issue

SCIENCE IN CRIME DETECTION

A NEW NARCOTIC DRUG OF ABUSE

-Dr. Anil Aggrawal

This time I am going to to tell you about a rare drug of abuse, about which you might hardly have heard. This drug is called PCP or phencyclidine. It has recently leaped into the forefront of the drug scene and is a veterinary anaesthetic. The name PCP is an acronym of the chemical name for the drug phencyclohexyl- piperidine, and from this acronym has sprung up a highly imaginative slang term `peace pill’. It is also known by numerous other exotic names, like ‘angel dust’,’embalming fluid’, ‘gorilla biscuits’, ‘magic mist’ and ‘rocket fuel’. Though first discovered in 1926, its anaesthetic potential was realised as late as in 1957. In 1958 phencyclidine was marketed as a general anaesthetic for experimental use on humans. Obeserving the serenity the drug produced in monkeys, the manufacturer Parke-Davis & Co. chose the trade name Sernyl. Most general anaesthetics produce respiratory depression, thus forcing anaesthetists to assist respiration during anaesthesia. Sernyl did not have this drawback and was thus widely promoted for its lack of respiratory depression. But in 1956, human use had to be discontinued because of some adverse effects caused by Sernyl. These included unpleasant sensations, delirium, extreme agitation, hallucinations and loss of the sense of time and space. About one in very five patients experienced these symptoms, which persisted for eighteen hours. The effects produced by Sernyl resembled those seen in mental disorders, and thus Sernyl began to be used to produce model psychoses for psychiatric investigations.

In 1967, phencyclidine was reintroduced as Sernylan (addition of ‘an’ after the orignal name) for use as a veterinary anaesthetic. That same year, the drug made its debut on the streets of San Francisco. It was then that it began to be called the ‘peace pill’. Unlike heroin, PCP was orally ingested. The after-effects of PCP were quite unpredictable. Because of its unpredictability and also because of frequent overdoses, the ‘peace pill’ vanished from the illicit drug scene of the San Francisco Bay area in less than a year. Shortly thereafter, it reappeared on the east coast of USA as ‘hog’, but there also its street life was transient.

In early 1970, phencyclidine resurfaced again on the streets, this time as a drug of deceit. Since it was easily and cheaply synthesised in clandestine ‘kitchen’ laboratories without the risk of illegal importation, it was frequently substitued for and sold on the street as some other narcotic such as THC, Mescaline, Psilocybin, LSD, amphetamine, cocaine, etc. In fact, it was seen that only 30 per cent of sheet drug samples that contained PCP were sold as PCP. THC, which actually is not available on the street, was the most frequent misrepresentation.

By mid-1970, PCP abuse had reached epidemic proportions. One estimate was that in the US alone some seven million people had used PCP on an occasional basis and that one million used it at least once a week. PCP became the drug of choice for many addicts particularly for teenagers in the age of fourteen. Recent trends however indicate that PCP abuse has lessened over the years.

WHAT IS PCP?

PCP is a white crystalline solid, readily soluble in both water and alcohol. It is usually sold on the street as the hydrochloride under the most common name of ‘angel dust’. Since the powder causes the addict to hallucinate and makes him ‘see’ heaven-like views, it was assumed that angels consumed this powder and hence this imaginative name.

PCP abusers feel the onset of drug effects in two to five minutes when it is smoked, compared with thirty to sixty minutes when ingested orally. The peak effect is reached in fifteen to thirty minutes after smoking the drug, and the addicts stay ‘loaded’ for four to six hours, before becoming normal in the next twenty-four to fourty-eight hours.

PCP has a high tendency to leave the bloodstream and penetrate into the tissues. After an intake of PCP by any route, it is seen that concentrations of PCP in the brain are ten times higher than that in the blood. Similarly its concentration in the fatty tissue is about hundred times higher than that in the blood. This higher degree of tissue distribution of PCP explains the prolonged durations of effects of the drug, sometimes even when doctors fail to detect any PCP in the blood.

Extensive amounts of PCP are secreted into the stomach when smoked or snorted. Thus while normally the ingested food is absored from the stomach, PCP is secreted into it. PCP is absorbed mainly in the intestines, from where it goes into the blood (and then into the tissues). However once PCP enters the blood, it is secreted in the stomach cavity, from where it passes into the intestines again to be reabsorbed. This re-circulation explains the waxing and waning course of the recovery phase. So much PCP may be secreted into the stomach that the stomach concentration may become fifty times higher than that in the blood. Thus even when PCP is smoked, the doctor may try to pass a stomach tube in the addicts to wash it out. Knowing the mechanism of PCP circulation, it would look less absurd to the nonplussed onlooker. Since these patients are agitated and restless, passing a stomach tube may become a problem.

EFFECTS OF PCP

Most remarkable effects of PCP are psychological and mental. There may be prominent body image distortions such as an enlarged limb or a detached head laughing at the person himself. There may be severe numbnes. The addict feels inebriated, is usually disoriented and suffers from forgetfulness. He may lose track of his body and is at risk of seriously injuring himself because he does not feel pain. The person might believe he is the devil, or an animal or even God himself. Anxiety and sometimes outright hostility may be present. Disrobing in public is also seen in a small percentage of addicts. The hallmark of PCP intoxication is the recurring delusion of superhuman strength and invulnerability resulting from the analgesic properties of the drug. Intoxicated patients have been known to snap handcuffs and attack police officers. Some have been tried to stop a train by standing in front of an oncoming engine and as a consequence, some have even climbed into a bear’s cave to take a picture or to jump from windows or cliffs. This bizarre behaviour is often violent, as one intoxicated abuser pulled out his front teeth with a pair of pliers. Another woman fried her baby in cooking oil! There are many reported assaults on friends and strangers, both with and without weapons. Many of these violent acts are committed by drug users who were otherwise totally peaceful individuals.

Another hallmark of PCP intoxication is the trembling of the eyeball, known in medical parlance as nystagmus. Nystagmus can be observed by asking the patient to look straight at some distant object, say a picture on the wall, and then closely observing the black of the eye. It is seen to tremble either in a vertical or horizontal direction.

The addict may suffer from generalised seizures. There may be repetitive movements, disturbed gait, and facial grimacing. The person lapses into coma or remains awake with a characteristic blank stare. Other effects are flushing, sweating, vomiting, drooling, retention of urine, high fever, and increase in pulse rate, blood pressure and respiratory rate.

PCP is known to cross the placental barrier. This means that if a pregnant mother consumes PCP, it can ‘leak’ into the foetus through the placental barrier. Placenta is a thick barrier between the mother’s and child’s circulation. It allows only useful products to go to the child’s circulation, but PCP despite being harmful can cross this barrier.This causes the newborn to have nystagmus, seizures, bizarre postures, tremulousness and diarrhoea. When taken in early pregnancy, PCP can cause serious defects in the child or lead to death of the foetus.

Recovery Phase

Patients with mild symptoms usually recover in a matter of hours, but depression and irritability are not uncommon over the ensuing six to twenty-four hours. Some patients experience a prolonged madness for as long as four to six weeks. Unlike schizophrenic psychosis (the usual madness that we know), this drug induced psychosis or madness does not repond to medication. Prolonged ‘phencyclidine psychosis’ may sometimes cause the subsequent development of schizophrenia. About one-fourth of patients suffering from prolonged phencyclidine-induced psychosis return a year after discharge with an acute psychosis, which is more like schizophrenia. It is not precipitated by recurrent drug use, is not as violent as phencyclidine-induced psychosis but is responsive to medications. These patients are found to be truly schizophrenic.

When phencyclidine-induced psychosis resolves, patients often become depressed. The desire to ease this depression stimulates recurrent drug abuse despite the adverse drug reactions already experienced.

How PCP acts:

PCP and related drugs, bind very strongly to specific sites within our nervous system. We have seen that morphine and morphine like compounds act in a similar way. We saw that one of the sites where morphine like compounds have a tendency to stick is known as the receptor. Stimulation of these receptors causes dysphoria and hallucinations. It has been shown experimentally that PCP binds very strongly to receptors. Some of the actions of PCP can be explained by this mechanism.

PCP has also been shown to increase the concentrations of dopamine within our nervous system. We have seen that cocaine acts in a similar way. PCP increases the concentrations of yet another neurotransmitter-norepinephrine. This diabolically sounding name need not worry anyone. Just lile dopamine, norepinephrine can also be visualized as a messenger pigeon within our nervous system. Increase of the concentrations of these two neurotransmitters can explain several other actions produced by PCP.

Some other highly complex mechanisms seem to be involved. PCP has been shown to decrease the movement of Calcium ions across cell membranes, but how such an action is responsible for the various symptoms produced by PCP is not clear.

While research was being done to find out the mechanism of action of PCP, an interesting fact came to light. A quick recall of some of the properties of nerve cells will be useful before we go further. Nerve cells are extra-sensitive to ischaemia (the lack of oxygen). After a stroke, a heart attack, a severe accident or any condition which involves either loss of blood or a reduction in blood circulation, the tissues face a lack of oxygen. Nerve cells are very quick to die of ischaemia. Brain cells can survive for only 3 minutes in the lack of aduquate oxygen. It has been seen that PCP and related compounds can reduce the death rate of nerve cells if conditions of oxygen lack occur. Whether such an action is responsible for its symptoms is not clear, but one thing is clear. PCP may be a potential future candidate for the treatment of stroke and other related conditions mentioned earlier.

Street Use

PCP is purchased in either powder, tablet, leaf mixture, liquid or 1 gm of ‘rock’ crystal form. The percentage of PCP in these street preparations varies considerably. The powder form, when sold as ‘angel dust’, is usually the purest, containing 88 to 100 per cent of PCP. As ‘crystal’, the concentration is only 50 to 100 per cent, and, when purchased under a variety of other names, the concentration may drop to as low as 10 to 30 per cent. In the tablet form, the dose ranges from 1 to 6 mg, but it is usually about 5 mg. When sold as a leaf mixture with parsley, mint or oregano, the mixture is usually rolled into a ‘joint’ (‘crystal joint’ or ‘KJ’) weighing 100 to 400 mg with an average of 1 mg of PCP per 150 mg of leaves. These ‘joints’ have been found to vary in their PCP concentration from 0.25 to 8 per cent and, when prepared by chronic users, are often ‘dusted’ with as much as 50 mg of PCP powder, thus demonstrating the tolerance that chronic users develop. Though PCP is reputed to be the most often smoked sprinkled on marijuana ‘joints’ (thus giving it the name ‘super grass’) it is rarely sold on the street in this combination. Another practice is to dip legally manufactured, mentholated cigarettes into liquid PCP and later smoke them as ‘superkools’.

Can you recognize PCP user by seeing him. Well, it is not easy, but some drug users have tattooes over their bodies by which they can be recognized. (figure 1 comes here)

Analogues of PCP

PCP has over thirty chemical analogues. These are the chemicals which are very similar to PCP in chemical structure and produce similar effects. The five analogues most frequently abused are ketamine, PHP, PCC, TCP and PCE.

Ketamine is an anaesthetic and is the only PCP analogue to be manufactured legally for human use. On the street, ketamine hydrochloride has been found in capsules sold as ‘green’. Compared with PCP it is less dangerous.

PHP is as potent as PCP and as easily and inexpensively synthesised. Its use has become more prevalent on the street because of its difficult detection by routine analytic methods. As a result, abusers often escape detection by both the legal and medical systems.

PCC is an unstable compound, degrading to piperidine. As a result it can be recognised by the strong fishy odour so characteristic of piperidine. On heating (smoking), PCC liberates the dreadful poison, hydrogen cyanide, as a result of consuming which the abuser may suffer from cynaide poisoning.

TCP was first detected on the street in 1972. The effects of TCP, through similar to those of PCP, are more intense but of shorter duration.

PCE first appeared on the street in late 1960, initially as a wet, yellow to brown gum. By 1971, it was available as a white powder, in appearance indistinguishable from that of PCP, though more potent. It is still a popular narcotic.

Captions to figures

001.jpg: Tattoo mark. Sometimes a drug user can be identified by this mark

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(Dr. Anil Aggrawal is a professor of Forensic Medicine at the Maulana Azad Medical College, New Delhi-110002. His E-mail is dr_anil@hotmail.com and his Website address is: http://members.tripod.com/~Prof_Anil_Aggrawal/index.html

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Note to the Editor: Please make all correspondence at S-299 Greater Kailash-1, New Delhi-110048. Phones (R): 6465460, 6291942, 6413101; (O) 3239271-4

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