History
Because of the numerous routes of administration, variations in dosage, and possibility of co-ingestants, phencyclidine (PCP) produces a wide variety of physical and behavioral effects. Most commonly, witnesses may report agitation, bizarre actions, or violent behavior. Users of PCP often appear to be having a psychotic episode and may or may not report to the physician that they have taken the drug.
Physical Examination
In a study by McCarron et al that evaluated 1,000 patients presenting with acute phencyclidine (PCP) intoxication, clinical effects ranged from lethargy and coma to extreme agitation and psychosis. [15]
Common physical examination findings include the following:
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Nystagmus (horizontal, vertical, or rotary) - Rotary often considered a hallmark of PCP
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Intoxication (57-89%)
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Hypertension (57%)
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Acute brain syndrome involving confusion, amnesia, disorientation, and violence (37%)
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Agitation and violent behavior (35%)
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Tachycardia (30%)
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Bizarre behavior including public nudity (29%)
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Hallucinations and delusions (19%)
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Miosis - Often reported with a blank stare
Rare findings, usually only seen with high doses, include the following:
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Seizures (3.1%)
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Dystonia
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Ataxia
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Apnea (often seen with co-ingestants)
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Catatonia
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Coma - PCP coma usually presents with nystagmus and the absence of respiratory depression. Unlike opioid-induced coma, it does not improve with naloxone.
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Hypertensive crisis
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Myocardial infarction (non-Q wave, cardiac enzyme leak)
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Intracranial and subarachnoid hemorrhage
Other manifestations include the following:
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Hyperthermia, hyperreflexia, and muscle rigidity have been reported.
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Rhabdomyolysis with or without acute kidney injury may also occur.
