Substance use - phencyclidine (PCP)

PCP is a mind-altering drug. This means it acts on your brain (central nervous system) and changes your mood, behavior, and the way you relate to the world around you. Scientists think it blocks the normal actions of certain brain chemicals.

PCP is in a class of drugs called hallucinogens. These are substances that cause hallucinations. These are things that you see, hear, or feel while awake that appear to be real, but instead have been created by the mind.

PCP is also known as a dissociative drug. It causes you to feel separated from your body and surroundings. Using PCP may make you feel:

• You are floating and disconnected from reality.
• Joy (euphoria, or "rush") and less inhibition, similar to being drunk on alcohol.
• Your sense of thinking is extremely clear, and that you have superhuman strength and aren't afraid of anything.

How fast you feel the effects of PCP depends on how you use it:

• Shooting up. Through a vein, PCP's effects start within 2 to 5 minutes.
• Smoked. The effects begin within 2 to 5 minutes, peaking at 15 to 30 minutes.
• Swallowed. In pill form or mixed with food or drinks, PCP's effects usually start within 30 minutes. The effects tend to peak in about 2 to 5 hours.

PCP can also have unpleasant effects:

• Low to moderate doses can cause numbness throughout your body and loss of coordination.
• Large doses may cause you to be very suspicious and not trust others. You might even hear voices that are not there. As a result, you may act strangely or become aggressive and violent.

PCP's other harmful effects include:

• It can increase heart rate, blood pressure, breathing rate, and body temperature. At high doses, PCP can have an opposite and dangerous effect on these functions.
• Because of the pain-killing (analgesic) properties of PCP, if you get seriously injured, you might not feel pain.
• Using PCP for a long time can cause memory loss, thinking problems, and problems talking clearly, such as slurring words or stuttering.
• Mood problems, such as depression or anxiety can develop. This can lead to suicide attempts.
• A very large dose, usually from taking PCP by mouth, may cause kidney failure, heart arrhythmias, muscle rigidity, seizures, or death.

People who use PCP can get psychologically addicted to it. This means their mind is dependent on PCP. They are not able to control their use of it and they need PCP to get through daily life.

Addiction can lead to tolerance. Tolerance means you need more and more PCP to get the same high. If you try to stop using, you may have reactions. These are called withdrawal symptoms, and may include:

• Feeling fear, unease, and worry (anxiety)
• Feeling stirred up, excited, tense, confused, or irritable (agitation), having hallucinations
• Physical reactions may include muscle breakdown or twitching, weight loss, increased body temperature, or seizures.

Treatment begins with recognizing there is a problem. Once you decide you want to do something about your PCP use, the next step is to get help and support.

Treatment programs use behavior change techniques through counseling (talk therapy). The aim is to help you understand your behaviors and why you use PCP. Involving family and friends during counseling can help support you and keep you from going back to using (relapsing).

If you have severe withdrawal symptoms, you may need to stay at a live-in treatment program. There, your health and safety can be monitored as you recover. Medicines may be used to treat withdrawal symptoms.

At this time, there is no medicine that can help reduce the use of PCP by blocking its effects. But scientists are researching such medicines.

As you recover, focus on the following to help prevent relapse:

• Keep going to your treatment sessions.
• Find new activities and goals to replace the ones that involved your PCP use.
• Spend more time with family and friends with whom you lost touch while you were using. Consider not seeing friends who are still using PCP.
• Exercise and eat healthy foods. Taking care of your body helps it heal from the harmful effects of PCP. You will feel better, too.
• Avoid triggers. These can be people you used PCP with. Triggers can also be places, things, or emotions that can make you want to use it again.

Resources that may help you on your road to recovery include:

• Partnership for drug-Free Kids -- drugfree.org
• LifeRing -- www.lifering.org
• SMART Recovery -- www.smartrecovery.org
• Narcotics Anonymous -- www.na.org

Your workplace employee assistance program (EAP) is also a good resource.

Contact your health care provider if you or someone you know is addicted to PCP and needs help stopping. Also contact your provider if you are having withdrawal symptoms that concern you.

If you are thinking about hurting yourself or others, call or text 988 or chat 988lifeline.org. You can also call 1-800-273-8255 (1-800-273-TALK). The 988 Suicide and Crisis Lifeline provides free and confidential support 24/7, anytime day or night.

You can also call 911 or the local emergency number or go to the hospital emergency room. DO NOT delay.

If someone you know has attempted suicide, call 911 or the local emergency number right away. DO NOT leave the person alone, even after you have called for help.

PCP; Substance abuse - phencyclidine; Drug abuse - phencyclidine; Drug use - phencyclidine

Barrett W, Iwanicki JL. THC and hallucinogens. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 145.

Kowalchuk A, Reed BC. Substance use disorders. In: Rakel RE, Rakel DP, eds. Textbook of Family Medicine. 9th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 50.

National Institute on Drug Abuse website. Psychedelic and dissociative drugs. nida.nih.gov/research-topics/psychedelic-dissociative-drugs. Updated April 2023. Accessed June 13, 2024.

Weiss RD, Liebschutz JM. Drug use disorders. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 365.

Updated by: Fred K. Berger, MD, addiction and forensic psychiatrist, Scripps Memorial Hospital, La Jolla, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.