The Dawn of a New Age: PCP

April, 1956 : The pharmaceutical company Parke & Davis first synthesize what
they believe to be the perfect anesthetic (Souza, 1995). When administered to
patients, it causes a completely dissociative state, with no significant
respiratory or cardiovascular depression. Patients appear to be awake, eyes
open, breathing normally.but are unaware of their surroundings or the
procedures being performed upon them (Souza, 1995). Indeed, this is the perfect
drug. Unfortunately, like all good things, this one has a darker side. 15% of
patients awake from their slumber with what appeared to be an acute case of
paranoid schizophrenia (Peterson; Stillman, 1978). The drug is PCP, and to this
day it is the scourge of the underground drug community, and the focal point of
intense scientific research. Parke Davis and Company did not know how terrible,
and wonderful, a discovery they made that day; but our world has been changed
forever because of it.quite possibly for the better.

The Dust of Angels

Phencyclidine, more commonly known as PCP, is a polycyclic compound belonging to
the arylcyclohexylamine class of chemicals [figure 1.0] (Souza 1993). In pure
form, it is a white powder which readily dissolves in water. The cyclohexamines
are known for their the potent neurological effects, with PCP being the most
potent. Almost every variation has been administered to, or abused by, humans
at some time (Nintey Fifth Congress, 1978). All these compounds have similar
pharmacological effects, which vary considerably according to the amount
administered. Small doses produce a \'drunken\' state, in which subjects report a
numbness in the extremities, while some species (like dogs and cats) become
quite excited (Halberstadt, 1995). Intermediate doses have anesthetic and
analgesic effects , with the psychic state resembling sensory isolation with
one important exception: the sensory impulses (when tested
electrophysiologically) reach the neocortex but "the neuronal signals are
grossly distorted" (Halberstadt, 1995). Large doses, especially of PCP, may
produce convulsions. Any dose produces cataleptoid muscle effects (Halberstadt,
1995). All the chemicals in this class produce a range a physiological effects,
including tachydardia and hypertension (Halberstadt, 1995). Unlike the other
cyclohexamines, however, PCP causes severe "emergence delirium" when taken in
moderate to anesthetic quantities (Halberstadt, 1995). On the other hand,
ketamine, a close cousin of PCP, produces depressant effects which are more
amplified than PCP without the psychotic aftereffects (although hallucinations
are reported by patients during sedation, (Halberstadt, 1995)). In special
cases, ketamine is still used as an anesthetic. (C.H. Badenhorst M.D, personal
communication).

Ten years after its initial discovery, phencyclidine found a new
audience in the scientific and underground drug culture communities (Nintey
Fifth Congress, 1978). At this time, a few Freudian psychologists carried out
unauthorized experiments in which perfectly healthy patients were given PCP and
observed (Nintey Fifth Congress, 1978). Although their research did not provide
much useful data, it did begin a revolution in our knowledge of the chemical
basis for schizophrenia (Nintey Fifth Congress, 1978). In 1987, the FDA removed
Sernyl (phencyclidine\'s market name) from the human market and reserved it for
use only as an animal tranquilizer, for which it is still used today (Peterson,
1978). Unfortunately, some individuals were still able to obtain the drug,
either through theft or home synthesis in a garage laboratory (Nintey Fifth
Congress, 1978). It was distributed under a number of slang terms, including
PeaCe Pill, THC, and Love Boat; and rapidly spread throughout the country as a
result of its low price and availability (Peterson, 1978). There were many
casualties.not because of the drug, but because of its effects. Hospitals also
noticed a sudden increase in paranoid schizophrenic admissions (Peterson, 1978),
which naturally sparked more interest in this enigma of a drug, and raised many
questions: Why were people addicted to a drug which seldom generated "good
trips"? Why (and more importantly, how) was this drug causing episodes of
paranoid schizophrenia? A new era in drug research for schizophrenia had been
opened.

The Excitory Amino Acid Link

If one takes a moment to consider what a amazing drug PCP is, then it is easy to
see just why scientists were so excited. Here was a single chemical which could
induce schizophrenia (Restak, 1994), a bright arrow pointing to a possible
cause of this terrible disorder. Scientists hypothesized that perhaps there
were naturally occurring phencyclidine-like substances within the brain which
malfunction and caused psychotic states (Restak 1994). This "magic" compound
was jokingly referred to as "Angle Dustin" (Restak, 1994). In truth, these
scientists were much closer to the truth than they thought.but there is an
interesting twist.

In the brain, there are three prevalent amino acid neurotransmitters:
glycine, glutamate, and aspartate; collectively these are referred to as the
excitory amino acids (Restak, 1994).