“My soul left my body and flew in space, sometimes at speed higher than a rocket and other times at snail’s speed. Sounds were seen and colors were heard with great brilliance and intensity. I felt very strange and got into a panic. Everything looked incredibly beautiful or horrible. I laughed and wept and was elated and depressed. Although the experience ceased after sometime, I had unpredictable flashbacks of such a fantasy for many months”.
Phencyclidine (PCP) is basically an agent of its own type. It is unique in a way that it can produce anesthetic, stimulant, depressant, and hallucinogenic effects  at the same time. The best I can explain is that it produces different effects at different concentrations which would be elaborated later. Despite the fact that PCP is officially banned, it is illegally used on streets solely for recreational purpose.
PCP was first identified as a surgical anesthetic agent in 1926, but was not much appreciated by the researchers. Hallucinations, excitation and disorientation which occur during recovery from this anesthetic agent were proved serious enough that the drug was withdrawn from the market until 1960s. Among the PCP analogs, Ketamine is the only which is approved currently for medical use as a “dissociative anesthetic”. In fact, benzodiazepines are given pre-operatively to such patients to reduce the post-operative hallucinogenic effects of ketamine.
But the story doesn’t ends here and the culprit PCP re-emerged during 1970s. This time we found the culprit in the form of liquid, crystalline powder and tablets. The wicked street dealers have made it a raw material in number of abusive street drugs like marijuana, heroin, LSD and also in fillers like parsley and talc. Therefore, individuals may become PCP-dependent by unknowingly inhaling PCP-laced marijuana cigarettes.
PCP can be used in several ways; ingesting, smoking, snorting, and injecting either intravenously or subcutaneously have all been reported; but most commonly it is smoked in either PCP-laced cigarettes or in marijuana.
The main mechanism of action of PCP is thought to be the non-competitive inhibition at NMDA-glutamate receptors  . The drug is also known to cause dopamine, norepinephrine, and serotonin reuptake inhibition  at moderate oral doses. PCP-induced activation of σ-opioid receptors, as well as nicotinic, muscarinic and GABA receptors is also known. All these complex receptor interactions of PCP make the drug able to produce a wide range of symptoms and indeed a picture which is quite unmanageable outside a medical facility.
Classic PCP intoxication presents symptoms which include violent behavior, nystagmus, tachycardia, hypertension, anesthesia, and analgesia. Since the effects are dose-dependent, the clinical picture may vary from extreme agitation to sedation.
Ingestion of doses ranging from 1-5 mg of PCP typically produces slurred speech, violent behavior, blank staring, horizontal, vertical, or rotatory nystagmus, ataxia, hyperthermia, and seizures along with sedation and loss of inhibition.
5 to 10 mg of oral doses of PCP tend to induce acute schizophrenia, including agitation, psychosis, audiovisual hallucinations, paranoid delusions, and catatonia. Schizophrenia mimicking symptoms of PCP in human and laboratory animals are so unique that it is widely applied as a pharmacological model of schizophrenia to investigate the neurochemical basis of the disorder. Higher doses may make patient unconscious which may lead to pulmonary aspiration and collapse. Doses greater than 10mg result in coma.
Also children may become victimized by passive inhalation of secondhand smoke. Listlessness, irritability, and poor feeding in newborns may raise suspicion for PCP intoxication. In children, mild intoxication may be presented as lethargy alternating with agitation, a dull trance-like stare, horizontal or vertical nystagmus, miosis, truncal ataxia, choreoathetosis, hypersalivation, and mild hypertension. Fortunately, mortality in children associated with PCP has not been reported yet.
Owing to its euphoric effects, PCP’s street popularity is increasingly evidenced in this decade. In fact youngsters do try it in a spirit of adventure, just for kicks. Individuals may use PCP in a desire to escape from realities to enter a fantasy world where they can feel more creative or super-human.
The drug is known to produce unpredictable mood alterations that cause some individuals to become animated and others to become detached. And all these effects result from an alteration in mood, thinking and perception processes that PCP produces at molecular level. The psychotropic effect produced by PCP and other related agents is called “a trip”. These trips could be normal or bad trips.
Normal trips are due to thrilling effects of the drug which include dreamy state, loss of awareness of body boundaries, uniquely altered sensory perception that make sounds seen and colors heard and an ambivalent mood changes such as happiness and sadness simultaneously.
Bad trip consists of a panic reaction characterized by paranoid delusions, violent behavior, automatism and depression. Most of the PCP-related accidents have been reported during this bad trip phase inclusive of drowning and car crashes. Also patient is more prone to get indulged in self-mutilation acts.
The immediate management of PCP-intoxicated patient remains to be supportive. Sedation is helpful in more serious cases and also to prevent self-infliction. Psychotherapy may help in long-term stability of the patient. Mild intoxications usually resolve in about four to eight hours, whereas larger ingestions may take weeks to resolve. Patient showing delayed recovery should be closely monitored to prevent development of severe psychiatric disorders during recovery period.
Lastly, it would worth mentioning here that PCP may manifest long-term effects including flashbacks and emotional problems. In contrast to other psychoactive drugs, PCP aftershocks manifest physically and involve actual drug effects which have been known to occur even weeks or months after the last use. Furthermore, these long-term effects of PCP could be devastating owing to its sufficient body deposition in muscles and adipose tissue.
Help for addicts & awareness among general population are both important components to help curb this curse from our society. Responsible authorities now need to start spreading the word. We can also make more and more people aware using our print and electronic media as these are readily accessible.
REFERENCES AND FURTHER READINGS:
3. Li Z, Boules M, Williams K, Peris J, Richelson E. The novel neurotensin analog NT69L blocks phencyclidine (PCP)-induced increases in locomotor activity and PCP-induced increases in monoamine and amino acids levels in the medial prefrontal cortex. Brain Res. 2010 Jan 22;1311:28-36. [PubMed]