Phencyclidine (PCP): some human studies

Studies on the effects of PCP have been conducted in volunteers in the Army Laboratories and elsewhere and in illicit users. The present review has summarized the observations of many investigators which showed that the acute effects of PCP following several routes of administration were shown to be dose-related. High doses of PCP produce disturbing manifestations including psychosis, numbness, light-headedness, vertigo, ataxia, and nystagmus due to acute intoxication. Furthermore, some subjects became irritable, argumentative or negative under the conditions of social stress and demanding tasks. In addition to a variety of central action, PCP has also been shown to affect cardiovascular function, heat storage, and exercise performance. PCP can also induce, although rarely, prolonged toxic psychosis in chronic abusers and precipitate psychotic episodes in psychotic and prepsychotic personalities. Tolerance, but not physical dependence, develops to the effects of PCP. Psychologic dependence as indicated by craving for the drug has however been reported.