Phencyclidine was first synthesized in Germany in 1926. The details of the synthesis were reported in the German Journal für Praktische Chemie, and resulted from investigations into nitrile leaving-group intermediates for achieving nucleophilic substitution of amine derivatives. Much intensive research was being done on nitriles during the time-frame in which this paper was published.

The next significant event in the history of this compound is exemplified by the publication in 1948 of a paper entitled Chemical Constitution and Insecticidal Action, [Ainley et. al., 1] in which 2-substituted alpha-aminonitriles were investigated for their insecticidal effects. Mortality rates for many varieties of insects commonly regarded as "problematic" or nuisances were quite high, and thus these nitrile compounds were characterized by high overall toxicity. One of the compounds synthesized during the course of this insecticidal research was 1-(piperidino)cyclohexanecarbonitrile (PCC), which was to become a commonly utilized intermediate in the synthesis of phencyclidine itself, both in pharmaceutical and illicit clandestine laboratory settings.



PCC, known as 'Compound 44' in the original article, demonstrated ability to effect 100% (i.e., total) mortality in aphids at concentrations of 0.35 percent, and 60% mortality at concentrations of 0.2 percent. Quite a high toxicity was thus observed for this compound, in addition to many of the other closely related aminonitriles studied. This toxicity would later prove to have devastating consequences for the uninformed street drug user (as well as many clandestine chemists themselves), through historical developments which will be further discussed later in this article.

While much of the organic chemically synthetic research foundations had been laid for arylcyclohexylamine derivative compounds in the 1920s and 1930s, the real beginning for phencyclidine pertaining to the context in which it is now known was to come about through a pharmaceutical research division based in Detroit, MI, USA. The research laboratories of Parke-Davis and Co. (formerly part of Pfizer but recently dissolved/no longer in existence) began investigations into new and safer anesthetic drugs, primarily for human use; particularly for field-surgical settings (i.e., third world/underdeveloped countries, and during times of war/tactical combat field situations). This was a major motivation, though most certainly not the exclusive reason for the research initiative.

One of the compounds investigated was synthesized in the laboratories of Parke-Davis in 1952 by a team of researchers led by V. Harold Maddox and Robert F. Parcell, both at the time employed with the Parke-Davis research division [Maddox et. al, J. Med Chem, 1965, [3].]

A brief excerpt from their 1965 paper is henceforth presented:

various 1-arylcyclohexylamines were synthesized for evaluation as central nervous system depressants. The compounds were prepared by several procedures. 1-(1-Phenylcyclohexyl)piperidine, the first compound of this type synthesized, was prepared from 1-piperidinocyclohexanecarbonitirle by replacement of the cyano group with phenyl using phenylmagnesium bromide. These compounds were tested for cataleptoid activity and antitonic extensor properties.

During an investigation of the reaction of Grignard reagents with hindered nitriles, 1-piperidinocycohexanecarbonitrile 1 was employed. The product formed by the reaction with phenylmagnesium bromide, 1-(1-phenylcyclohexyl)piperidine hydrochloride, was found to be a potent anesthetic agent in animals without significant effect on the respiration, heart rate, blood pressure, and body temperature. 2 Clinical application of phencyclidine 3 at total doses ranging from 0.138-1 mg./kg. of body weight produced profound analgesia without depression of circulation, respiration, or disturbance of cardiac rhythm. 4 Additional applications in human therapy are recorded. 5

Thus, the extraordinary analgesic and anesthetic potency of phencyclidine was discovered; 0.138 mg/kg in the average adult male human would equate to roughly 9.38 milligrams. (this is based on a "average" body weight of 70 kg).

Therefore, at dosages of around 10 mg, PCP exhibits what clinical investigations referred to as "profound analgesia". At dosages ranging from 25-70 mg, depending on the patient/user, phencyclidine induces a state of total and complete dissociative anesthesia. No other compound with a history of legitimate medical/veterinary usage with so high a potency level is currently known to science, in the context of the dissociative anesthetics.

After this highly valued research was conducted, Parke-Davis subsequently petitioned the government for the right to conduct official clinical trials of phencyclidine for human medical/surgical anesthesia under the trade name of Sernyl. As legend would have it, the name was selected to evoke feelings of "serenity", "tranquility" and an overall sense of peacefulness. With the FDA giving the green light, clinical trials in voluntary human subjects began in 1957. Initial results looked extremely promising for this new substance, which was hailed as a sort of "miracle" or "wonder" drug in its early history by medicinal chemists and medical professionals alike.

After a time, however, certain undesirable and unwanted side-effects could be seen in patients during the "emergence" phase (the period after which the procedure is complete, and the plasma concentrations are beginning to fall to a level where the patient begins to regain conscious awareness). As a result of these strange and occasionally outright disturbing "emergence phenomena", which included subjects manifesting states of psychologically enraptured fixation, repeated axial motor movements for extended periods, postural fixation for extended periods, manic excitation and excessive movement, manic aggression/agitation with violent destruction of property/inanimate physical objects (which sometimes required tranquilization with pentobarbital to get the patient under control), agitated psychosis, schizophrenia-like states, and other complications, Parke-Davis voluntarily discontinued clinical trials in 1962.

Sernyl (Phencyclidine Hydrochloride injectable solution) was officially withdrawn from the human clinical market in 1965, and pharmaceutical batch-scale manufacture was discontinued. Two years later, in 1967, Parke-Davis re-introduced the drug, this time for the veterinary market, under the trade name of Sernylan.

During the summer of that same year there appeared in the Haight-Ashbury district of San Francisco, California a previously unknown drug known simply as the 'Peace Pill' or 'PeaCePills'. Though the term 'PCP' is certainly a logical derivation from the proper chemical name, the usage of the acronym 'PCP' to refer to phencyclidine has its origin in the street drug scene; no mention of the drug as "PCP" was ever made in official publications or literature on the substance prior to its appearance as a street recreational drug. It is believed that 'PCP' was derived as a shortening of the name 'PeaCePills'; regardless of specific chronological origin or the true source, the acronym 'PCP' seems well-fitting and appropriate for this compound.

Usage of PCP on the street seems to have appeared almost simultaneously in the San Francisco and Los Angeles areas as well as in Miami, Philadelphia, New York City, and Chicago; the drug was sold under various names including 'HOG', 'THC/Tic', and 'PeaCePills'. Widespread acceptance did not occur, however, with the oral tablets that were sold on the street; the drug quickly gained a negative reputation and nearly faded away altogether after 1968.

Then a new series of developments began that would lead to its much more widespread use and acceptance. Starting around 1969 in Southern California, PCP began to be made available in powder and liquid forms, which were sold and accepted under various names including 'Angel Dust' and 'Embalming Fluid' - a term used to describe the somatic 'numbing' effect of the drug, and one which in later years would tragically be confused with actual embalming fluid, leading some to smoke actual formaldehyde or formaldehyde laced with PCP. This practice is incredibly foolish and risky, and results from a street misunderstanding/misinterpretation of the original street name for PCP, originating some 15-20 years before the later practice came into favor.

Users were able to better manage and control the at many times unpredictable effects of the drug through smoking and/or insufflating the drug. Smoking produced the most powerful and rapid-onset effects, while insufflation provided a somewhat more mild and still rapid effect. Users described being able to take as little as 1-2 hits from a cigarette or marijuana joint dipped in liquid PCP, and still experience a profound high. The awesome potency of the drug was no doubt a contributing factor in its later reputation as a powerful monster of a drug.

An additional development that occurred during the 1969-1970 time frame was the appearance of "designer" analogs of PCP, long before the term "designer drugs" was coined. Narcotics enforcement labs began receiving samples of a drug called N-ethyl-1-phenylcyclohexylamine (PCE), which first appeared in Los Angeles in 1969. In that same area, authorities found the thiophene analog TCP (1-1-(2-thienyl)cyclohexyl)piperidine) in 1970. Over thirty analogs were eventually known to be synthesized in clandestine labs and sold on the street, most of them only sold in the 1970s, and all being sold and accepted as PCP itself. TCP is active at dosages of only a quarter to a third that of PCP, but was sold equally on a weight-for-weight basis. Other analogs that were known to be sold include those employing a pyrrolidine ring in place of piperidine: (1-(1-phenyl)cyclohexylpyrrolidine) or PCPy, and 1-1-(2-thienyl)cyclohexylpyrrolidine), TCPy; additionally, 1-phenylcyclohexylamine (PCA), a precursor but active in its own right, and 1-(1-phenyl)cyclohexylmorpholine, (PCM).

Usage of PCP continued throughout the 1970s, eventually reaching its ultimate peak during the years 1978-1980. In 1978, the DEA seized what is to this day the largest clandestine laboratory of any kind and the largest PCP laboratory ever seized, in Los Angeles, California. The lab had over 900 gallons of liquid PCP in finished form, and precursor chemicals sufficient to manufacture several hundred gallons more. The amount of finished PCP seized was, according to authorities, sufficient for 2-2.5 million individual doses. In 1979, a record number of high school seniors, which has to this day never been equaled let alone surpassed, reported having experimented with PCP. Over 2.4% of high school seniors nationwide reported regular use.

In order to more effectively 'combat' this new 'problem of abuse', the government made piperidine an officially watched chemical in 1978. This correlated with an almost immediate downturn in clandestine production, though other analogs and other routes to the target compound were found; clandestine laboratory operators are a skilled and resourceful bunch, and don't usually tend to give up right away. PCP continued to be widely available throughout the middle of the 1980s, after which it was largely overshadowed by the rising popularity of methamphetamine and crack cocaine.

In April of 1979, the Parke-Davis pharmaceutical company voluntarily withdrew Sernylan, in response to increasing diversion and theft of legitimate veterinary products for street use.

The drug was certainly cemented firmly in popular culture by the end of the 1970s and into the 1980s. This is particularly exemplified by a famous line from the film The Terminator [1984], in which one of the main characters finds herself in an interview at the police station, asking "What about when he punched through the windshield?" in reference to the superhuman strength and stamina of the "terminator" that was "after them". To this, one of the detectives replies: "He was probably on PCP. Broke every bone in his hand, wouldn't feel it for hours..."

Phencyclidine has a very complex neuropharmacological profile, leading to a bewildering array of subjective effects in the user. The intensity of these subjective effects aside, the effects seem to exist on a series of distinct, dose-dependent levels. Different dosages produced what users characterize as four different "levels" of experience:

1. 'buzzed'
2. 'wasted'
3. 'ozoned'
4. 'overdosed'

In the 'buzzed' state, a mild euphoric effect is present, and the drug is much more stimulating than sedating. In this lightly intoxicated state, users were known to participate in normal, everyday activities such as work, school, and social interaction with other people - with little detriment to their performance or abilities. In the 'wasted' state, the user typically experiences a body-wide anesthesia felt most strongly in the limbs (legs and feet, and, to a lesser extent, in the arms). Speech becomes somewhat slurred, and physical coordination of movement becomes difficult. Walking is described by many users as being particularly amusing, since the effects of PCP give the impression that the ground has a "spongy" or "marshmallow-like" consistency, creating an unusual sensation upon attempting to walk from one location to another.

A profound dissociation is also a characteristic of the 'wasted' level; many users described themselves as participants in a sort of "out-of-body" experience.

As one progresses from 'wasted' into the 'ozone', the dissociative anesthetic effects become much stronger, and the drug takes on more of a sedating character, in contrast to the stimulating effect found at lower dosages. In the 'ozoned' state, the user becomes generally non-communicative and immobile, though still remaining conscious.

In the 'overdosed' state, the user loses consciousness altogether, although most street users did not consider this condition to be life-threatening [Feldman et al, 2].