phencyclidine hydrochloride

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phencyclidine hydrochloride

(fĕn-sĭk′lĭ-dĭn″, -sī′klĭ, -dĭn),


An anesthetic used in veterinary medicine. It is also used illegally as a hallucinogen, and referred to in slang as “PCP” or “angel dust.” The drug is potent; intoxication can occur from passive smoking, and even small doses can produce excitement, hallucinations, and psychotic or extremely violent behavior. Moderate doses also cause elevated blood pressure, rapid pulse, increased skeletal muscle tone, and sometimes, myoclonic jerking. Large doses can cause seizures, ataxia, nystagmus, respiratory depression, and death. The pupils of patients intoxicated with PCP are usually of normal size or small but not the pinpoint size seen in opiate use. This, together with the other physical findings, may help clinicians diagnose overdosed patients.


For agitation caused by acute intoxication, diazepam is indicated. Because PCP abusers are often hostile, aggressive, and dangerous, efforts to pacify these patients are contraindicated. Instead, the patient should be isolated in a quiet room and protective measures taken to avoid injury to self or others.


Despite medication and psychotherapy, the psychotic symptoms produced by PCP may persist for weeks or months.

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