Phencyclidine (PCP)
Drugs of abuse
Drugs of abuse
A dissociative drug («angel dust») that blocks NMDA glutamate receptors; it can cause psychosis, violent agitation, hyperthermia and coma.
Also called: PCP, Angel dust
Quick facts
- Group
- Drugs of abuse
- Target
- NMDA glutamate receptor channel (pore site shared with ketamine)
- Used for
- No medical use · Clinical relevance
- Key effects
- Horizontal · Tachycardia and hypertension · Numbness
- Monitor
- Temperature · Creatine kinase
No doses: the clinician sets them by the current guideline.
Mechanism of action
The figure shows phencyclidine in the pore of the rat GluN1a–GluN2B NMDA receptor; no human structure with PCP is available.
Phencyclidine enters the open NMDA receptor channel and blocks it, so glutamate cannot depolarise neurons through this receptor in the cortex and limbic system. This «dissociates» perception from the self and the body, and produces psychosis that closely resembles schizophrenia. It was developed as a general anaesthetic in the 1950s and abandoned because of postoperative delirium; ketamine is its shorter-acting relative. Its anticholinergic and sympathomimetic actions add to the toxic picture.
- PCP enters the open NMDA receptor channel
- It blocks glutamate-driven depolarisation
- Dissociation, hallucinations and psychosis
- High doses: rigidity, hyperthermia, stupor, coma
Indications
- No medical use; abandoned as a human anaesthetic
- Clinical relevance: dissociative drug intoxication with agitation, nystagmus and psychosis Hallucinogen and dissociative drug intoxication (LSD, PCP, ketamine) →
Adverse effects
Common
- Horizontal, vertical or rotatory nystagmus
- Tachycardia and hypertension
- Numbness, ataxia and slurred speech
- Feeling detached from the body; distorted sights and sounds
Contraindications
- No medical use: there is no safe dose
- Especially dangerous with schizophrenia or other psychotic illness, which it worsens
Key interactions
- Alcohol and other CNS depressants
- Deeper coma and respiratory depression; a common factor in fatal cases
- Antipsychotics with strong anticholinergic action (for example chlorpromazine)
- Add to PCP's anticholinergic effects; they are avoided
What is monitored
- Temperature, heart rate, blood pressure and airway
- Creatine kinase, potassium and kidney function
- Level of consciousness and seizures
- Injuries from agitation or restraint
Pregnancy and breastfeeding
Use in pregnancy has been linked to congenital abnormalities.
Nursing care
- Approach calmly with enough staff; minimise stimuli
- Prefer chemical sedation (benzodiazepines) over prolonged physical restraint
- Cool actively if hyperthermic; keep fluids running and urine output measured
- Watch for sudden swings from agitation to coma
- Arrange psychiatric review if psychosis persists
Pharmacokinetics
- Absorption
- Smoked, snorted, swallowed or injected; often sprinkled on cannabis or tobacco
- Distribution
- Lipid-soluble; it lingers in the brain and fat
- Metabolism
- Liver
- Onset and duration
- Effects and coma can last for days
Test yourself
Think of the answer, then tap the question to see it.
What receptor does phencyclidine block, and which anaesthetic shares its site?
The NMDA glutamate receptor channel; ketamine binds the same pore site.
Which eye sign suggests PCP rather than LSD intoxication?
Nystagmus (horizontal, vertical or rotatory).
Why is prolonged physical restraint avoided in PCP agitation?
Struggling against restraint worsens hyperthermia and rhabdomyolysis and has been linked to deaths; benzodiazepine sedation is preferred.
Connections
← Back to the class: Drugs of abuse
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Psychedelic and Dissociative Drugs (National Institute on Drug Abuse (NIDA), 2026); Drugs A to Z (National Institute on Drug Abuse (NIDA), 2025).
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Representative model, for educational purposes only.