PHENCYCLIDINE

Uses

Anesthetic.

Definition

ChEBI: A member of the class of piperidines that is piperidine in which the nitrogen is substituted with a 1-phenylcyclohexyl group. Formerly used as an anaesthetic agent, it exhibits both hallucinogenic and neurotoxic effects.

brand name

Sernylan (Parke-Davis).

General Description

Phencyclidine was introduced as a dissociative anestheticfor animals. Its close structural relative ketamine is still soused and may be used in humans. In humans,PCP produces a sense of intoxication, hallucinogenic experiencesnot unlike those produced by the anticholinergic hallucinogens,and often, amnesia.
The drug affects many systems, including those of NE,DA, and 5-HT. It has been proposed that PCP (and certainother psychotomimetics) produces a unique pattern of activationof ventral tegumental area dopaminergic neurons.Itblocks glutaminergic N-methyl-D-aspartate receptors.Thisaction is the basis for many of its CNS effects. PCP itself appearsto be the active agent. The psychotic state produced bythis drug is also cited as a better model than amphetaminepsychosis for the psychotic state of schizophrenia.

Pharmacology

PCP acts as a biocide through its ability to uncouple mitochondrial oxidative phosphorylation.

Safety Profile

Poison by intraperitoneal route. Experimental reproductive effects. Caution: This is a controlled substance (depressant) listed in the U.S. Code of Federal Regulations, Title 21 Part 1308.12 (1985). The ethylamine, pyrrolidine and thiophene analogs are l

Metabolic pathway

When mice and rats are administered phencyclidine intraperitoneally, several hydroxylated metabolites are identified in the urine. A new metabolite, 1-phenyl-1- (1-piperidinyl-3-ol)cyclohexane, is identified in the urine and liver microsomal preparations.

Metabolism

Pentachlorophenolwas metabolized in rats by conjugation with glucuronic acid and eliminated as the glucuronide. P450 catalyzed oxidative dechlorination also occurred to form tetrachlorohydroquinone, and this was conjugated to form a monoglucuronide representing 27% of the dose administered. Other metabolites have been reported, including isomeric tetrachlorophenols, tetrachlorocatechol and tetrachlororesorcinol. Trace amounts of benzoquinones were also noted.
Metabolites in female rats were tetrachloromonophenols, diphenols, and hydroquinones.

Toxicity evaluation

The toxicology has been addressed in a recent risk assessment (119). Acutely, pentachlorophenol was reported to have LD₅₀ values in the rat of 12 mg/kg (inhalation) and 146 mg/kg (M)–175 mg/kg (F) by oral gavage. More detailed studies of the toxicology of pentachlorophenol have been compromised by the toxicity of impurities present in most of the earlier samples used in the evaluation process.