eMedicine Specialties > Psychiatry > Addiction

Phencyclidine (PCP)-Related Psychiatric Disorders: Follow-up

Author: Alan D Schmetzer, MD, Professor, Vice-Chair for Education, and Director of Residency Training in General and Addiction Psychiatry, Department of Psychiatry, Indiana University School of Medicine
Coauthor(s): Roland McGrath, MD, Chairman, Professor, Department of Emergency Medicine, Indiana University School of Medicine; David R Diaz, MD, Assistant Professor of Clinical Psychiatry, Indiana University School of Medicine; Attending Psychiatrist, Adult Service, Larue D Carter Memorial Hospital; Medical Staff Member, Clarian Health Partners
Contributor Information and Disclosures

Updated: May 31, 2009

Follow-up

Further Inpatient Care

  • PCP-induced psychosis may be very difficult to treat, and sometimes psychotic symptoms may persist for up to 6 weeks or even longer. In such cases, transfer to a long-term psychiatric hospital may be required in some areas because of a shortage of acute psychiatric beds or managed care restrictions. Usually, managed care companies do not approve inpatient substance dependence rehabilitation at present, but an intensive outpatient program certainly may be justified for a person who uses PCP.
  • Rhabdomyolysis may require more prolonged medical hospitalization in the rare instances when this complication occurs.

Further Outpatient Care

Psychiatric follow-up care and follow-up care (if the patient is dependent) in addiction treatment usually is needed.

  • The goal of psychiatric treatment is to assess when the person can safely be weaned from an antipsychotic, if it has been needed. Generally, most patients can be weaned from antipsychotics necessitated by PCP-induced psychosis within a 6-month period.
  • Extend addiction treatment until all goals have been met and the person is working with a personal program for continued abstinence.
  • Occasionally, additional booster addiction treatment may be needed because all people with addictions have some tendency to relapse.

Inpatient & Outpatient Medications

Unlike the opiates and their antagonists, no phencyclidine antagonist is currently available.

Transfer

  • Transfer to a psychiatric unit after acute medical stabilization often is necessary. The need for this can be assessed by a psychiatric consultant.
  • Transfer to a long-term psychiatric hospital from an acute psychiatric unit may be necessary, depending on the local interactions of state hospitals and acute units.
  • Once the acute medical and psychiatric symptoms have been adequately treated, always provide patients with the opportunity to transfer to some type of chemical dependency treatment program, because the tendency of PCP users to return to the drug has been noted often in the literature.

Deterrence/Prevention

  • In all disorders of drug abuse and dependence, the earlier the intervention, the better the outcome.
  • No solid proof exists that treatment of PCP dependence in a chemical dependency program will succeed, perhaps because people tend to decrease use with age. However, encouraging a patient to begin (or resume) a substance dependence treatment program is worthwhile.

Complications

  • A number of patients who abuse hallucinogenic drugs eventually are diagnosed with another psychiatric disorder, such as depression, anxiety disorder, or schizophrenia. Whether these drugs cause these other disorders is not clear, and, in any case, multiple factors contribute to the major psychiatric syndromes. Additionally, sound evidence indicates that people who have a psychiatric disorder have a higher likelihood of abusing drugs, so this may simply be an issue of which condition is diagnosed first.
  • PCP can cause a prolonged psychosis, and users are subject to so-called flashbacks, and either or both of these may be misdiagnosed as a comorbid psychiatric condition.
  • Other longer-term complications that can arise from acute PCP intoxication include rhabdomyolysis with resulting renal disease, as well as complications of acute hypertension. Some evidence indicates that prolonged use of PCP may cause prolonged symptoms of confusion, but this is not yet clear.
  • Weak evidence supports the existence of a withdrawal syndrome. Animal studies show a withdrawal syndrome, and reports exist in the literature of prolonged users of PCP showing a dysphoria and intense craving for the drug, which have been described as a withdrawal syndrome. Abuse of PCP is not known to cause liver disease, and no evidence suggests that PCP causes a Parkinson-like syndrome such as that observed with designer drugs such as 1-methyl1-4-phenyl-1,2,3,6-tetrahydropyridine (MTPT).

Prognosis

Because 62% of people abusing PCP are aged 20-29 years, most people clearly stop using PCP once they have passed young adulthood. Thus, for most people, the long-term prognosis probably is good.

Patient Education

  • PCP is a drug that has a significant likelihood of adverse effects including psychosis, serious injuries while intoxicated, higher likelihood of arrest for disorderly conduct or assault, suicidal behavior, and possible sudden death12 . Clinicians may wish to point out these effects during drug education opportunities.
  • On average, about half of all "PCP trips" are estimated to be dysphoric in nature.
  • Often, dealers will substitute PCP for more exotic or expensive drugs such as THC (tetrahydrocannabinol).
  • Books and book chapters on PCP:
    • Hafen B, Frandsen K. Phencyclidine - Angel Dust: By any name not fit for human consumption. Hazelden Foundation, 1980
    • Carroll M. The dangerous angel. In: Snyder SH, ed. The Encyclopedia of Psychoactive Drugs. Chelsea House Publishers, 1985, ISBN: 087754753X
    • Ogelsby EW, Faber S, Faber S. Angel Dust - What everyone should know about PCP. Charing Cross Publishing Company, 1982, ISBN: 0890740666
  • For excellent patient education resources, visit eMedicine's Substance Abuse Center. Also, see eMedicine's patient education article Drug Dependence and Abuse.
  • U.S. Drug Enforcement Administration, Phencyclidine (PCP)
  • Neuroscience for Kids, PCP - Phencyclidine 
  • National Institute on Drug Abuse, PCP/Phencyclidine     

Miscellaneous

Medicolegal Pitfalls

  • A physician may have to consider involuntary hospitalization and treatment in patients using PCP, because these patients sometimes do not have the capacity to make their own treatment decisions. Always document whether the patient appears to have the medical capacity to make such decisions in a competent manner.
  • These patients, as with anyone in a delirium, can wax and wane in the severity of their symptoms and confusion. It takes time to decide if improvement will continue enough to justify release of such patients.
  • In communities in which PCP is a significant drug of abuse, police officials become very concerned about the anesthetic qualities it possesses. The usual approach to subduing someone who is acting in a violent manner is to apply just enough discomfort or pain to communicate to the person the need to cease and desist. This is nearly impossible to accomplish in someone who has sufficient PCP in his or her system to produce aggressive behavior.

Special Concerns

  • Some physicians suggest warning the patient and family about the possibility of later psychiatric disorders so that they can catch symptoms early. On the other hand, others recommend against such a warning because most people have no such complications. Until a better understanding of the reason(s) for any higher likelihood of a comorbid psychiatric diagnosis is developed, the decision about whether to discuss this issue or not is best left to the discretion of the individual clinician.
  • Consider addiction to, or abuse of, other drugs as possible causative agents for the signs and symptoms observed in a person with a chemical abuse or dependence history. This is especially true with PCP, which is sometimes sprinkled or sprayed on other intoxicants, such as marijuana.
 
Acknowledgments

The authors would like to acknowledge Indiana University School of Medicine, William Niles Wishard Memorial Hospital, and Larue D. Carter Memorial Hospital for their support of the faculty involved in the preparation of this eMedicine article.



More on Phencyclidine (PCP)-Related Psychiatric Disorders

Overview: Phencyclidine (PCP)-Related Psychiatric Disorders
Differential Diagnoses & Workup: Phencyclidine (PCP)-Related Psychiatric Disorders
Treatment & Medication: Phencyclidine (PCP)-Related Psychiatric Disorders
Follow-up: Phencyclidine (PCP)-Related Psychiatric Disorders
Multimedia: Phencyclidine (PCP)-Related Psychiatric Disorders
References
Further Reading
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Further Reading

Gorelick DA, Balster RL. Phencyclidine (PCP). Back to Psychopharmacology - The Fourth Generation of Progress

Pinchot JT, Schmetzer AD. Phencyclidine bibliography, for AAAP - Resource Site for the PGY-5 Curriculum Project, July 2001

Books and book chapters on PCP:

Hafen B, Frandsen K. Phencyclidine - Angel Dust: By any name not fit for human consumption. Hazelden Foundation, 1980.

Carroll M. The dangerous angel. In: Snyder SH, ed. The Encyclopedia of Psychoactive Drugs. Chelsea House Publishers, 1985, ISBN: 087754753X

Ogelsby EW, Faber S, Faber S. Angel Dust - What everyone should know about PCP. Charing Cross Publishing Company, 1982, ISBN: 0890740666

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Keywords

phencyclidine-related psychiatric disorders, PCP, angel dust, crystal, hog, krystal joint, KJ, mintweed, rocket fuel, delta-9-tetrahydrocannabinol, THC, N -methyl-D-aspartate, NMDA, lysergic acid diethylamide, LSD, substance-induced psychosis, 1-(phenylcyclidine) piperidine

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Contributor Information and Disclosures

Author

Alan D Schmetzer, MD, Professor, Vice-Chair for Education, and Director of Residency Training in General and Addiction Psychiatry, Department of Psychiatry, Indiana University School of Medicine
Alan D Schmetzer, MD is a member of the following medical societies: American Academy of Addiction Psychiatry, American Academy of Clinical Psychiatrists, American Academy of Psychiatry and the Law, American College of Physician Executives, American Medical Association, American Neuropsychiatric Association, American Psychiatric Association, and Association for Convulsive Therapy
Disclosure: Nothing to disclose.

Coauthor(s)

Roland McGrath, MD, Chairman, Professor, Department of Emergency Medicine, Indiana University School of Medicine
Roland McGrath, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

David R Diaz, MD, Assistant Professor of Clinical Psychiatry, Indiana University School of Medicine; Attending Psychiatrist, Adult Service, Larue D Carter Memorial Hospital; Medical Staff Member, Clarian Health Partners
David R Diaz, MD is a member of the following medical societies: American Psychiatric Association, Indiana Psychiatric Society, and Indiana State Medical Association
Disclosure: Nothing to disclose.

Medical Editor

Barry I Liskow, MD, Professor of Psychiatry, Vice Chairman, Psychiatry Department, Director, Psychiatric Residency Program, University of Kansas School of Medicine; Director, Psychiatric Outpatient Clinic, The University of Kansas Medical Center
Barry I Liskow, MD is a member of the following medical societies: American Academy of Clinical Psychiatrists, American Academy of Psychiatrists in Alcoholism and Addictions, American Medical Association, American Psychiatric Association, and Research Society on Alcoholism
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Iqbal Ahmed, MBBS, Professor, Department of Psychiatry, John A Burns School of Medicine, University of Hawaii
Iqbal Ahmed, MBBS is a member of the following medical societies: Academy of Psychosomatic Medicine, American Association for Geriatric Psychiatry, American Neuropsychiatric Association, and American Psychiatric Association
Disclosure: Nothing to disclose.

CME Editor

Harold H Harsch, MD, Program Director of Geropsychiatry, Department of Geriatrics/Gerontology, Associate Professor, Department of Psychiatry and Department of Medicine, Froedtert Hospital, Medical College of Wisconsin
Harold H Harsch, MD is a member of the following medical societies: American Psychiatric Association
Disclosure: lilly Honoraria Speaking and teaching; Forest Labs Honoraria Speaking and teaching; AstraZeneca Honoraria Speaking and teaching; Pfizer Grant/research funds Speaking and teaching; Northstar Grant/research funds Research; Novartis Grant/research funds research; Pfizer  Speaking and teaching; Sanofi-avetis Grant/research funds research; Otsuke Grant/research funds reseach; GlaxoSmithKline Grant/research funds research

Chief Editor

Stephen Soreff, MD, President of Education Initiatives, Nottingham, NH; Faculty, Metropolitan College of Boston University, Boston, MA
Stephen Soreff, MD is a member of the following medical societies: American College of Mental Health Administration and American Psychosomatic Society
Disclosure: Nothing to disclose.

 
 
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