Phencyclidine (fen sye' kli deen) is an arylcyclohexylamine anesthetic that acts as a noncompetitive inhibitor of N-methyl-d-aspartate (NMDA) receptors in the brain.
Clinical use / indications for Phencyclidine
Phencyclidine infusions rapidly produce anesthesia and a unique cataleptic state with profound analgesia, unresponsiveness and amnesia, but often with maintenance of muscle tone, involuntary movements, open eyes and spontaneous breathing. The effect is called dissociative anesthesia, which can be associated with vivid hallucinations, agitation and delirium during emergence. These psychological and behavioral effects can be very disturbing, arise several hours after the anesthesia and persist for days. Because of these effects, phencyclidine (Sernyl) was withdrawn from human use in 1965. Phencyclidine continued to be available as a veterinary anesthetic (Sernylan), but was withdrawn from that use in 1978 in attempts to control its illicit availability.
Side effects of Phencyclidine
These same dissociative effects led to the recreational abuse of phencyclidine and for a period in the late 1960s and 1970s, phencyclidine (commonly known as “angel dust”) became a major drug of abuse. Phencyclidine taken by mouth or inhaled (smoked) in doses of 1 to 10 mg leads to rapid onset of euphoria and feelings of omnipotence, superhuman strength and social and sexual prowess. Use of phencyclidine chronically can be associated with severe violent and aggressive behavior and episodes of acute psychosis. Higher doses cause progressive confusion, disorientation, coma and seizures, and can lead to malignant hyperthermia, shock, rhabdomyolysis, renal failure and sudden death. In recent years, wider knowledge of its dangerous effects and the increasing limitation on its production have led to a decrease in the frequency (but not disappearance) of phencyclidine abuse. Attempts to modify the tertiary amine structure of phencyclidine to develop a safer and more useful anesthetic agent led to the development of ketamine, another anesthetic which has a similar mechanism of action as well as similar, although lesser, potential for abuse.