Phencyclidine (PCP)-Related Psychiatric Disorders Follow-up

• 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 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.

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

  • 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 within a personal program for continued abstinence.
  • Occasionally, additional booster addiction treatment may be needed because people with addictions have a tendency to relapse.

Unlike the opiates that have antagonists, no phencyclidine antagonist is currently available.

• 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.

• 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.

• 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 all of 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 on going 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).

• 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.

• PCP is a drug that has a significant likelihood of adverse effects. Point out these effects during drug education opportunities.
• For excellent patient education resources, visit eMedicine's Substance Abuse Center. Also, see eMedicine's patient education article Drug Dependence and Abuse.