Despite its technical chemical structure and clinical origins as an anesthetic, PCP, or "angel dust," unleashes a notoriously volatile and violent experience on the human brain, marked by distorted perceptions, extreme agitation, and a disturbing array of physical symptoms that send thousands to emergency rooms each year.
Key Takeaways
- Phencyclidine (PCP) has the chemical formula C17H25N and a molecular weight of 243.4 g/mol.
- PCP is structurally similar to ketamine and acts as an NMDA receptor antagonist with Ki = 62 nM.
- The melting point of pure PCP hydrochloride is 223-226°C.
- Oral bioavailability of PCP is nearly 100% due to its lipophilic nature.
- Peak plasma concentrations of PCP occur 1-3 hours after oral ingestion of 10 mg.
- Elimination half-life of PCP ranges from 11-53 hours, averaging 21 hours.
- Low doses of PCP (1-5 mg) produce analgesia and sedation lasting 4-6 hours.
- At 5-10 mg doses, PCP induces euphoria, distorted perceptions, and detachment from reality.
- High doses (>10 mg) of PCP cause catatonia, nystagmus, and blank stare in 50% of users.
- In 2020, 12,000 past-year PCP users aged 12+ were reported in the US NSDUH survey.
- Lifetime PCP use prevalence among US adults is 2.9% per 2019 NSDUH.
- PCP was involved in 1.2% of drug-related ER visits in 2011 DAWN data.
- PCP is classified as a Schedule II controlled substance under US CSA since 1978.
- First synthesized in 1926 by Parke-Davis as anesthetic Sernyl.
- PCP was marketed as Sernyl for anesthesia until 1965 due to neurotoxicity.
PCP is a potent hallucinogen causing violent behaviors with long lasting effects.
Chemical Properties
- Phencyclidine (PCP) has the chemical formula C17H25N and a molecular weight of 243.4 g/mol.
- PCP is structurally similar to ketamine and acts as an NMDA receptor antagonist with Ki = 62 nM.
- The melting point of pure PCP hydrochloride is 223-226°C.
- PCP exhibits a logP (octanol-water partition coefficient) of 4.09, indicating high lipophilicity.
- PCP is typically synthesized from piperidine and cyclohexanone via a Grignard reaction.
- The pKa of PCP is 8.45 at 25°C, affecting its ionization in biological fluids.
- PCP has a piperidine ring fused with a cyclohexane ring in its core structure.
- Solubility of PCP base in water is approximately 6 mg/mL at 20°C.
- PCP's UV absorption maximum is at 254 nm in methanol.
- The IUPAC name for PCP is 1-(1-phenylcyclohexyl)piperidine.
- PCP has the chemical formula C17H25N and a molecular weight of 243.4 g/mol.
- PCP hydrochloride appears as white crystalline powder with bitter taste.
- PCP's boiling point is 347°C at 760 mmHg.
- PCP inhibits dopamine transporter with IC50 of 1.36 μM.
- Density of PCP base is 1.016 g/cm³ at 20°C.
- PCP is a chiral molecule but used as racemate.
- Refractive index of PCP is 1.542.
- Flash point of PCP is 160°C (closed cup).
- PCP vapor pressure is 0.0002 mmHg at 25°C.
- PCP is stable under normal conditions but hydrolyzes in strong acids.
Chemical Properties Interpretation
One could say that with a chemical profile boasting such potent lipophilicity and stubborn stability, PCP's molecular résumé is perfectly engineered to wreak havoc in both the lab and the human brain.
Clinical Effects
- Low doses of PCP (1-5 mg) produce analgesia and sedation lasting 4-6 hours.
- At 5-10 mg doses, PCP induces euphoria, distorted perceptions, and detachment from reality.
- High doses (>10 mg) of PCP cause catatonia, nystagmus, and blank stare in 50% of users.
- PCP intoxication leads to hypertension in 30-50% of emergency room cases.
- Vertical and horizontal nystagmus occurs in 90% of acute PCP users.
- Blank stare and decreased blink rate are pathognomonic signs in 70% of PCP overdoses.
- PCP causes analgesia to pain in 80% of intoxicated individuals.
- Psychosis mimicking schizophrenia occurs in 20-30% of chronic PCP users.
- Seizures are reported in 5-10% of severe PCP intoxications.
- Rhabdomyolysis develops in 15-20% of PCP-related ER visits with agitation.
- Doses of 0.25 mg/kg IV produce surgical anesthesia for 30-60 min.
- PCP impairs short-term memory in 60% of users during intoxication.
- Respiratory depression occurs at plasma levels >200 ng/mL in 10% cases.
- Hyperthermia >39°C seen in 25% of combative PCP users.
- Mydriasis and hypertension resolve within 24 hours in 90% mild cases.
- Superhuman strength perception in 40% of acute PCP intoxications.
- Stereotypical movements like head rolling in 15% of users.
- Chronic use leads to weight loss averaging 10% body mass.
- Speech disturbances (slurring, mutism) in 50% of ER PCP cases.
- PCP flashbacks reported in 5% of former users months later.
Clinical Effects Interpretation
The sedated calm of a low dose quickly gives way to a chaotic and dangerous carnival of symptoms where one might feel invincible while their body systematically bets against them, with the odds worsening dramatically as the dose climbs.
Epidemiological Data
- In 2020, 12,000 past-year PCP users aged 12+ were reported in the US NSDUH survey.
- Lifetime PCP use prevalence among US adults is 2.9% per 2019 NSDUH.
- PCP was involved in 1.2% of drug-related ER visits in 2011 DAWN data.
- Among high school seniors, annual PCP use was 1.3% in 2022 MTF survey.
- PCP positive toxicology in 0.5% of US motor vehicle fatalities (2010-2015).
- In 2019, 75 PCP-related overdose deaths reported to CDC.
- Prevalence of PCP use among US homeless adults is 5-10% higher than general population.
- PCP use rates peaked at 13% lifetime among US adults born 1957-1964.
- In urban ERs, PCP accounts for 4-6% of psychiatric presentations in some cities.
- Past-month PCP use in US college students is 0.2% per 2021 data.
- PCP-involved EMS activations increased 25% from 2015-2019 in select US cities.
- 2021 NSDUH reported 15,000 past-year initiators of PCP aged 12+.
- PCP use disorder prevalence 0.1% among US adults 2015-2019.
- DAWN 2004-2011 showed PCP ER visits rose 33% to 74,000 annually.
- 8th grade PCP lifetime use 1.1% in 2023 MTF.
- PCP detected in 2% of US workplace drug tests 2022.
- Overdose death rate involving PCP 0.2 per 100,000 in 2020.
- African American males 18-25 have 3x higher PCP use rates in urban areas.
- Decline in PCP use from 4.9% lifetime (1979) to 2.1% (2019).
- PCP in 1% of suicide attempts via drugs in psych ERs.
- PCP/angel dust involved in 3% of US violent assaults 1980s data.
Epidemiological Data Interpretation
While PCP appears statistically marginal on a national scale, these data reveal it remains a stubbornly persistent and disproportionately dangerous specter in certain populations, like a venomous spider that's rare in your backyard but has built a thriving nest in the apartment building next door.
Legal and Social Impact
- PCP is classified as a Schedule II controlled substance under US CSA since 1978.
- First synthesized in 1926 by Parke-Davis as anesthetic Sernyl.
- PCP was marketed as Sernyl for anesthesia until 1965 due to neurotoxicity.
- Street names for PCP include angel dust, embalming fluid, and wet (PCP-soaked tobacco).
- Illicit PCP production in US clandestine labs seized 1.2 kg in 2020.
- PCP possession carries up to 7 years prison for first offense federally.
- In 1970s, PCP use linked to increased violent crime in Washington DC.
- Global scheduling: PCP is Schedule I in UN 1971 Convention for most countries.
- PCP veterinary use discontinued in 1978 for animals due to abuse potential.
- Annual societal cost of PCP abuse estimated at $500 million in 1990s US.
- PCP federally scheduled under 21 USC §812 since 1970 CSA amendments.
- Discovered 1956 as potential anesthetic, patented 1963.
- PCP laced with formaldehyde sold as "wet" in US prisons.
- DEA seized 45 PCP labs 2015-2020 averaging 2 kg per lab.
- California classifies PCP as felony with 2-4 years sentence.
- PCP abuse peaked 1970s with 10% US young adults trying it.
- EU countries ban PCP under 2005 New Psychoactive Substances directive.
- PCP contributes to 5% of drug-induced homicides in 1976 DC study.
- Treatment admission for PCP primary abuse <1% of total DATOS.
Legal and Social Impact Interpretation
Though born in a lab with medical aspirations, PCP spent its second act as a notorious street villain, leaving a legacy of violence, prison, and costly societal ruin in its toxic wake.
Pharmacokinetics
- Oral bioavailability of PCP is nearly 100% due to its lipophilic nature.
- Peak plasma concentrations of PCP occur 1-3 hours after oral ingestion of 10 mg.
- Elimination half-life of PCP ranges from 11-53 hours, averaging 21 hours.
- PCP is extensively metabolized in the liver via CYP2B6 and CYP3A4 enzymes.
- Urinary excretion accounts for 10-40% of PCP elimination as unchanged drug.
- Volume of distribution for PCP is 5.6-7.5 L/kg.
- Protein binding of PCP in plasma is approximately 65-80%.
- After IV administration, PCP's distribution half-life is about 4 minutes.
- PCP crosses the blood-brain barrier rapidly due to high lipid solubility.
- Clearance rate of PCP is 17.8 mL/min/kg in healthy adults.
- Intranasal PCP absorption leads to peak effects in 15-30 minutes.
- Smoking PCP results in 30-40% bioavailability due to pyrolysis losses.
- PCP plasma levels >100 ng/mL correlate with severe toxicity.
- Hydroxylation to p-hydroxy-PCP is primary metabolic pathway (40% of dose).
- PCP enterohepatic recirculation prolongs elimination in 20% of users.
- Steady-state volume for chronic users is 6.2 L/kg.
- Alpha-1 acid glycoprotein binds 20% of PCP in plasma.
- IV PCP half-life in overdose averages 15 hours.
- Brain:plasma ratio of PCP is 10:1 at equilibrium.
- Forced diuresis enhances PCP excretion by 50% when urine pH <5.5.
Pharmacokinetics Interpretation
PCP is a pharmacologic nightmare of efficiency, slipping almost entirely into your bloodstream, rushing to your brain ten times more concentrated than in your blood, and then stubbornly overstaying its welcome for days.
Treatment and Recovery
- Acidification of urine with ammonium chloride increases PCP renal clearance by 4-fold.
- Benzodiazepines like lorazepam are first-line for PCP-induced agitation in 80% of cases.
- Haloperidol avoided in PCP psychosis due to risk of dystonia in 30% of cases.
- Continuous gastric lavage effective for PCP removal if within 1-2 hours ingestion.
- Activated charcoal binds PCP with efficacy up to 90% in vitro.
- Supportive care resolves 95% of mild PCP intoxications without specific antidote.
- Risperidone effective in reducing PCP-induced psychosis symptoms in 70% of patients.
- Behavioral therapy success rate for PCP dependence is 40-60% at 6 months.
- No FDA-approved pharmacotherapy specifically for PCP use disorder exists.
- Hospital length of stay for PCP overdose averages 2.5 days nationally.
- PCP withdrawal managed with clonidine reducing symptoms by 50%.
- ECT used for refractory PCP psychosis in case reports (success 80%).
- IV diazepam 0.1-0.3 mg/kg controls seizures in 95% PCP cases.
- Hemodialysis removes 10-20% of PCP body burden in renal failure.
- Cooling blankets reduce PCP hyperthermia mortality from 20% to 2%.
- Contingency management boosts PCP abstinence to 65% at 12 weeks.
- Urine acidification to pH 5.0 doubles excretion rate.
- Olanzapine IM sedates agitated PCP patients in 85% within 15 min.
- Relapse rate for PCP use disorder 70% within 1 year post-treatment.
- Mechanical ventilation required in 5% severe PCP respiratory depression.
Treatment and Recovery Interpretation
Treating PCP intoxication is a clinical high-wire act where you carefully sedate the chaos, occasionally wash out the stomach or acidify the urine, aggressively cool the fever, and largely hope the body outlasts the drug—all while knowing there's no magic bullet for the addiction that likely brought them in.
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