Phenylcyclohexyl Piperidine Intoxication DSM-5 292.89 (F16.929)

Phenylcyclohexyl Piperidine Intoxication DSM-5 292.89 (F16.929)

DSM-5 Category: Substance/Medication-Induced Mental Disorders


Phenylcyclohexyl piperidine (PCP), also known as phencyclidine Intoxication, and popularly known as angel dust (Drug Enforcement Administration, 2013). PCP started as a type of anesthesia (Drug Enforcement Administration, 2013). PCP being reasonably priced makes it easily available. PCP is often mixed with other substances like methamphetamine, marijuana, and LSD, which decreases manufacturing costs, and exposes many people naively to PCP (Drug Enforcement Administration, 2013). Since PCP can be used in multiple forms, either intravenously or through inhalation. PCP is very powerful, long-acting, and results in noticeable behavioral, physiologic, and neurologic toxic effects in humans (Drug Enforcement Administration, 2013). These include agitation, confusion, delirium, and delirium.

In 2011, an estimated 75,538 emergency department (ED) visits were related to PCP, with 69 percent being male and 45 percent ranging between the ages of 25 and 34 (Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality, 2013). As a result of the pain-relieving effects of PCP and lack of normal pain reaction, PCP-intoxicated patients may exhibit extraordinary strength, even while in restraints (Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality, 2013). They can be a danger to themselves as well as others.

Since PCP results in jumbled thought processes, it may not always be possible to get a consistent history from the patient (Drug Enforcement Administration, 2013). Additionally since PCP is often adulterated, patients are not likely to know that they have ingested PCP. It is important to ask the patient’s family and friends, to achieve a better understanding of the circumstances (Kumar, Fitz-Gerald, Kablinger, & Arnold, 2010). This also helps to rule out other illicit drugs as well as a manic episode in bipolar disorder.

Symptoms of Phencyclidine Intoxication

The identification of PCP intoxication is normally made clinically. PCP exposure is indicated by the intoxicated patient's irregular behavior, nystagmus, motor disturbances, and autonomic stimulation (Galanter & Kleber, 2014). With PCP intoxication, presentation can vary from either a depressed and comatose state, to being drunk and calm, to sometimes being very aggressive.

Signs and Clinical Features
Further autonomic signs seen with mild intoxication (less than 5 mg) include tachycardia, hypertension, tachypnea with shallow breathing, flushing, salivation, and diaphoresis (Galanter & Kleber, 2014). In some cases, loss of muscular coordination is seen, as well as generalized numbness of extremities (Kumar, Fitz-Gerald, Kablinger, & Arnold, 2010). A patient with PCP intoxication may exhibit motor disturbances such as facial grimacing, tremor, and catalepsy. With severe intoxication (10 mg or more), there may be a drop in blood pressure, heart rate and respirations. This is frequently seen with blurred vision, drooling, ataxia, nausea, vomiting, and dizziness. High doses of PCP, such as those exceeding 200 mg can lead to seizures, coma, and even death (Kumar, Fitz-Gerald, Kablinger, & Arnold, 2010). The latter may occur when an intoxicated patient suffers an accidental injury or commits suicide while under the influence of PCP. If taken alongside alcohol or benzodiazepines, the patient may present with coma.
Ketamine, a derivative of PCP, creates physical effects analogous to PCP; though, symptoms are often of shorter period (Drug Enforcement Administration, 2013).

The criteria for PCP Intoxication from the DSM-5 are as follows (American Psychiatric Association, 2013):

A. Current use of phencyclidine.

B. Clinically noteworthy maladaptive behavioral modifications, such as hostility, assaultiveness, impetuosity, volatility, psychomotor agitation, impaired judgment, or impaired social or occupational functioning) that started throughout, or right after using PCP.

C. At least two of following signs are seen within an hour (this time is decreased when smoked, “snorted,” or used intravenously):

(1) vertical or horizontal nystagmus

(2) hypertension or tachycardia

(3) numbness or decreased pain responsiveness

(4) ataxia

(5) dysarthria

(6) muscle stiffness

(7) seizures or coma

(8) oversensitivity to sounds

D. The symptoms are not occurring from a general medical condition and are not as a result of another mental disorder.

Urine Toxicology and Laboratory Testing

Generally when a patient appears to have PCP intoxication, regular laboratory workup should include renal function, fluid balance, electrolyte abnormalities, hypoglycemia, lactic acidosis, serum creatine phosphokinase (CPK) levels, and urine myoglobin levels(CITE). Toxicologic urine screening may stay positive for numerous weeks since PCP has a large quantity of distribution (Kumar, Fitz-Gerald, Kablinger, & Arnold, 2010).

Differential Diagnosis

It is important to separate PCP intoxication from that of other substances. What separates PCP intoxication from that seen in amphetamine is that nystagmus may be seen, vertical, horizontal, or rotator nystagmus. While nystagmus may also be observed with many CNS depressants, this only occurs when the patient is normally sedated (Galanter & Kleber, 2014). On the other hand, with PCP exposure, nystagmus is seen when the patient is awake and combative. A patient with marijuana intoxication can present with hypertension, tachycardia, euphoria, and paranoia. nystagmus and aggressiveness are not normally observed with marijuana or opioid intoxication.

Alcohol is a Central Nervous System depressant and alcohol intoxication presents with confusion, lethargy, incoordination, disinhibition and nystagmus. The nystagmus with alcohol intoxication is normally seen when the patient is sedated. Aggressive behaviors may occur with alcohol intoxication, but hallucinations are not seen (Galanter & Kleber, 2014).
Overdose of PCP can result in death, as the patient may experience unintentional injury while being combative, or may die due to suicide while intoxicated. Constricted pupils are seen with opioid intoxication and not with PCP (Galanter & Kleber, 2014). Tachycardia and NOT bradycardia is what is often seen with PCP intoxication.

Treatment for Phencyclidine Intoxication

The most central approach to management of the combative behavior seen with PCP intoxication is the implementation of secure physical restraints and chemical sedation (Galanter & Kleber, 2014). Restraints should be shunned if feasible since it can lead to muscle breakdown (Galanter & Kleber, 2014). The patient should first be moved to a quiet room with little stimulation, to assist with anxiety and agitation. The first treatment of choice for sedation is benzodiazepines but these should be used with caution, as they may hinder excretion of the drug and consequently should not be administered if not absolutely necessary (Galanter & Kleber, 2014). Some patients present with seizures, for which benzodiazepines are adequate treatment. Ascorbic acid or ammonium chloride may also be beneficial in promoting excretion of PCP, though this will not be the immediate treatment (Galanter & Kleber, 2014).

The patient should be observed for at least 72 hours before being discharged. The best long-term treatment plan should include a referral for drug rehabilitation, which normally includes urine monitoring. PCP intoxication can have long-lasting side effects of inducing or unveiling psychopathologic symptoms, so continuous outpatient therapy is needed. Many patients are said to suffer from relapse soon after discharge, and experience successful treatment from outpatient treatment programs that include urine monitoring. Low-potency traditional antipsychotics may exacerbate PCP intoxication through anticholinergic side effects. In addition, benzodiazepines may hinder drug excretion and should only be used if the patient is extremely agitated.


American Psychiatric Association. (2013). Personality disorders. In Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition ed.). Washington, DC: American Psychiatric Publishing Inc.

Drug Enforcement Administration. (2013, January). Phencyclidine. Retrieved March 13, 2014, from Drug Enforcement Administration.

Galanter, M., & Kleber, H. (2014). Treatment of Acute Intoxication and Withdrawal from Drugs of Abuse. Retrieved March 13, 2014, from United States Department of Veteran Affairs:

Kumar, D., Fitz-Gerald, M., Kablinger, A., & Arnold, T. (2010, September). The psychotic pot smoker. Current Psychiatry, 9(9). Retrieved March 13, 2014, from

Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality. (2013, November 12). Emergency Department Visits Involving Phencyclidine (PCP). The DAWN Report. Rockville, MD. Retrieved March 13, 2014, from

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