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Emergency And Acute Medicine – Phencyclidine Poisoning
Phencyclidine (PCP) is a dissociative anesthetic structurally related to ketamine that produces decreased perception of pain, agitation, and dissociation. It has a half-life of approximately 21–24 hours, which may be prolonged in overdose. Enterohepatic recirculation can contribute to prolonged or recurrent symptoms. PCP is a drug of abuse and is frequently encountered as an adulterant of marijuana. Street names include Angel Dust, Wicky Stick, Wicky Weed, Wacky Weed, Wet, Illy, Embalming Fluid, and Sherman. Pediatric exposure has been reported in toddlers through passive exposure.
Clinical presentation primarily involves the central nervous system. Patients may exhibit altered mental status ranging from agitation, bizarre or violent behavior, and belligerence to coma and seizures. Nystagmus—vertical, horizontal, or rotatory—is a characteristic finding. Cardiovascular manifestations include hypertension and tachycardia. Musculoskeletal complications are common due to decreased pain perception and intense muscle activity, leading to traumatic injuries and rhabdomyolysis. Hyperthermia may occur. History should focus on route of exposure, including smoking (often with marijuana) or ingestion.
Physical examination may reveal agitation or coma, hypertension, tachycardia, diaphoresis, nystagmus, hyperthermia, and vigorous muscle contractions. A careful assessment for occult trauma is essential because patients may not report pain appropriately.
Diagnosis is primarily clinical and supported by urine toxicology screening. However, false positives may occur with dextromethorphan, ketamine, and tramadol. Evaluation must exclude other causes of altered mental status. Laboratory studies include CBC, electrolytes, renal function, glucose, ethanol level, urinalysis for myoglobin, and creatine phosphokinase when rhabdomyolysis is suspected. Imaging such as chest radiography, extremity or spine radiographs, and head CT should be obtained when trauma or aspiration is suspected.
Differential diagnosis includes intoxication with cocaine, amphetamines, methamphetamine, MDMA, alcohols, ketamine, and other sympathomimetics. Drugs associated with nystagmus, such as lithium, carbamazepine, sedative–hypnotics, phenothiazines, alcohol, and dextromethorphan, should also be considered.
Management begins with attention to airway, breathing, and circulation. Combative patients may require restraints and additional personnel to ensure safety. Cardiac monitoring and IV access are indicated. In altered mental status, administer naloxone, thiamine, and glucose as appropriate. The patient should be placed in a quiet, low-stimulation environment. Benzodiazepines are first-line agents for agitation and seizures, with lorazepam or diazepam given in incremental doses. Haloperidol may be used cautiously but may lower the seizure threshold. Activated charcoal may be considered for recent oral coingestion. Aggressive IV hydration with normal saline is recommended, and sodium bicarbonate or mannitol may be used for rhabdomyolysis with a target urine pH of approximately 7.
Patients require admission if they have prolonged altered mental status, significant trauma, rhabdomyolysis, or hyperthermia. Those who become lucid after approximately six hours of observation without complications may be discharged. Psychiatry or social work referral is recommended for patients with suicidal ideation or chronic substance use.
PCP intoxication can result in severe traumatic injuries and life-threatening complications. Adequate chemical restraint with benzodiazepines is essential to prevent excessive muscle activity and subsequent rhabdomyolysis. False-positive urine toxicology screens may occur with dextromethorphan or tramadol. Ketamine abuse produces similar clinical features and should be considered in the differential diagnosis.
Phencyclidine (PCP) is a dissociative anesthetic structurally related to ketamine that produces decreased perception of pain, agitation, and dissociation. It has a half-life of approximately 21–24 hours, which may be prolonged in overdose. Enterohepatic recirculation can contribute to prolonged or recurrent symptoms. PCP is a drug of abuse and is frequently encountered as an adulterant of marijuana. Street names include Angel Dust, Wicky Stick, Wicky Weed, Wacky Weed, Wet, Illy, Embalming Fluid, and Sherman. Pediatric exposure has been reported in toddlers through passive exposure.
Clinical presentation primarily involves the central nervous system. Patients may exhibit altered mental status ranging from agitation, bizarre or violent behavior, and belligerence to coma and seizures. Nystagmus—vertical, horizontal, or rotatory—is a characteristic finding. Cardiovascular manifestations include hypertension and tachycardia. Musculoskeletal complications are common due to decreased pain perception and intense muscle activity, leading to traumatic injuries and rhabdomyolysis. Hyperthermia may occur. History should focus on route of exposure, including smoking (often with marijuana) or ingestion.
Physical examination may reveal agitation or coma, hypertension, tachycardia, diaphoresis, nystagmus, hyperthermia, and vigorous muscle contractions. A careful assessment for occult trauma is essential because patients may not report pain appropriately.
Diagnosis is primarily clinical and supported by urine toxicology screening. However, false positives may occur with dextromethorphan, ketamine, and tramadol. Evaluation must exclude other causes of altered mental status. Laboratory studies include CBC, electrolytes, renal function, glucose, ethanol level, urinalysis for myoglobin, and creatine phosphokinase when rhabdomyolysis is suspected. Imaging such as chest radiography, extremity or spine radiographs, and head CT should be obtained when trauma or aspiration is suspected.
Differential diagnosis includes intoxication with cocaine, amphetamines, methamphetamine, MDMA, alcohols, ketamine, and other sympathomimetics. Drugs associated with nystagmus, such as lithium, carbamazepine, sedative–hypnotics, phenothiazines, alcohol, and dextromethorphan, should also be considered.
Management begins with attention to airway, breathing, and circulation. Combative patients may require restraints and additional personnel to ensure safety. Cardiac monitoring and IV access are indicated. In altered mental status, administer naloxone, thiamine, and glucose as appropriate. The patient should be placed in a quiet, low-stimulation environment. Benzodiazepines are first-line agents for agitation and seizures, with lorazepam or diazepam given in incremental doses. Haloperidol may be used cautiously but may lower the seizure threshold. Activated charcoal may be considered for recent oral coingestion. Aggressive IV hydration with normal saline is recommended, and sodium bicarbonate or mannitol may be used for rhabdomyolysis with a target urine pH of approximately 7.
Patients require admission if they have prolonged altered mental status, significant trauma, rhabdomyolysis, or hyperthermia. Those who become lucid after approximately six hours of observation without complications may be discharged. Psychiatry or social work referral is recommended for patients with suicidal ideation or chronic substance use.
PCP intoxication can result in severe traumatic injuries and life-threatening complications. Adequate chemical restraint with benzodiazepines is essential to prevent excessive muscle activity and subsequent rhabdomyolysis. False-positive urine toxicology screens may occur with dextromethorphan or tramadol. Ketamine abuse produces similar clinical features and should be considered in the differential diagnosis.
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