PCP Toxicity Medication

Updated: Jan 23, 2021
  • Author: Stephan Brenner, MD, MPH; Chief Editor: Stephen L Thornton, MD  more...
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Medication Summary

No proven antidotes for phenylcyclohexyl piperidine (PCP), also known as phencyclidine, toxicity are known. Pharmacologic therapy facilitates supportive care and seizure control with special attention to respiratory and cardiac function.


Sedative/hypnotic and anticonvulsant agents

Class Summary

Benzodiazepines are first-line agents for controlling seizures in patients with PCP toxicity. Barbiturates, propofol, or both provide a useful adjunct in the treatment of seizures or treatment of status epilepticus unresponsive to benzodiazepines. All of these agents are helpful in sedating patients with extreme agitation.

Diazepam (Valium)

Depresses all levels of CNS (eg, limbic and reticular formation), possibly by increasing activity of GABA. Although seizures may be promptly controlled, seizure activity resumes in a significant proportion of patients, presumably because of the short duration of action with an initial dose of IV diazepam. Rapidly distributes to other body fat stores. Twenty minutes after initial IV infusion, serum concentration drops to 20% of Cmax.

Lorazepam (Ativan)

By increasing the action of GABA, (major inhibitory neurotransmitter in the brain), may depress all levels of CNS, including limbic and reticular formation

Pentobarbital (Nembutal)

Short-acting barbiturate with sedative, hypnotic, and anticonvulsant properties; can produce all levels of CNS mood alteration.

Propofol (Diprivan)

Phenolic compound that is a sedative hypnotic agent used for induction and maintenance of anesthesia or sedation. Has also been shown to have anticonvulsant properties.


Decontamination agents

Class Summary

Consider activated charcoal decontamination in patients with oral PCP overdose who present within 4 hours of ingestion.

Activated charcoal (Actidose-Aqua, Liqui-Char)

Emergency treatment in poisoning caused by drugs and chemicals. Network of pores present in activated charcoal adsorbs 100-1000 mg of drug per gram of charcoal. Does not dissolve in water.



Class Summary

These are used for treatment for acute ketamine-induced dystonia.

Diphenhydramine (Benadryl)

First-generation antihistamine with anticholinergic effects that binds to H1 receptors in the CNS and the body.

Competitively blocks histamine from binding to H1 receptors. Has significant antimuscarinic activity and penetrates CNS, which causes pronounced tendency to induce sedation. Approximately half of those treated with conventional doses experience some degree of somnolence. A small percentage of children paradoxically respond to diphenhydramine with agitation.

DOC for initial treatment of acute dystonia or akathisia not caused by antihistamines. Use diazepam for treatment of acute dystonia secondary to antihistamines.


Antihypertensive agents

Class Summary

Recommended treatment agents for PCP-induced malignant hypertension with end-organ damage, if blood pressure control continues to be inadequate after agitation treatment.

Nitroprusside (Nitropress)

Produces vasodilation and increases inotropic activity of the heart. At higher dosages it may exacerbate myocardial ischemia by increasing the heart rate.

Phentolamine (OraVerse, Regitine)

Alpha-1 and alpha-2 adrenergic blocking agent that blocks circulating epinephrine and norepinephrine action, reducing hypertension that results from catecholamine effects on the alpha receptors.