Health Information

Chlorpromazine overdose

Chlorpromazine overdose


Chlorpromazine is a prescription medication used to treat psychotic disorders. It may also be used for other reasons, such as preventing nausea and vomiting.

Chlorpromazine overdose occurs when someone accidentally or intentionally takes more than the normal or recommended amount of this medication. Use of this medication may also alter the metabolism and effect of other drugs.

This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local emergency number (such as 911) or the National Poison Control Center at 1-800-222-1222.


I Would Like to Learn About:

  • Poisonous Ingredient


  • Where Found

    • Thorazine
    • Largactil

    Note: This list may not be all-inclusive.

  • Symptoms

    Airways and lungs:

    • No breathing
    • Rapid breathing

    Shallow breathing

    • Bladder and kidneys:
    • Urinary hesitancy
    • Inability to urinate

    Eyes, ears, nose, mouth, and throat:

    • Blurred vision
    • Difficulty swallowing
    • Drooling
    • Dry mouth
    • Stuffy nose
    • Ulcers on the gums, tongue, or in the throat
    • Yellow eyes

    Heart and blood:

    • High or severely low blood pressure
    • Rapid, irregular heartbeat

    Muscles, bones, and joints:

    • Muscle spasms
    • Stiff muscles in neck or back

    Nervous system:

    • Coma
    • Confusion
    • Convulsions
    • Drowsiness
    • Fainting
    • Fever
    • Hallucinations (rare)
    • Irritability
    • Low body temperature
    • Tremor
    • Uncoordinated movement
    • Weakness

    Reproductive system:

    • Change in female menstrual pattern


    • Bluish skin color
    • Rash

    Stomach and intestines:

    • Constipation
    • Loss of appetite
    • Nausea
  • Home Care

    Seek immediate medical help. Do NOT make a person throw up unless told to do so by poison control or a health care professional.

  • Before Calling Emergency

    Determine the following information:

    • Patient's age, weight, and condition
    • The name of the product (ingredients and strengths, if known)
    • When it was swallowed
    • The amount swallowed
    • If the medication was prescribed for the patient
  • Poison Control What to Expect at the Emergency Room

    The National Poison Control Center (1-800-222-1222) can be called from anywhere in the United States. This national hotline number will let you talk to experts in poisoning. They will give you further instructions.

    This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.

    Take the container with you to the hospital, if possible.

    See: National Poison Control Center

  • The health care provider will measure and monitor the patient's vital signs, including temperature, pulse, breathing rate, and blood pressure. Symptoms will be treated as appropriate. The patient may receive:

    • Activated charcoal
    • Blood and urine tests
    • Chest x-ray
    • EKG (electrocardiogram), or heart tracing
    • Breathing support
    • Intravenous (through the vein) fluids
    • Laxatives
    • Medication to treat symptoms
    • Tube through the mouth into the stomach to wash out the stomach (gastric lavage)
  • Outlook (Prognosis)

    Recovery depends on the amount of damage. Survival past 2 days is usually a good sign. The most serious side effects are usually due to damage to the heart. If heart damage can be stabilized, recovery is likely. Some neurologic symptoms may be lifelong.

  • Prevention

    Keep all medications in child-proof bottles and out of the reach of children.

Related Information



Nockowitz RA, Rund DA. Psychotropic medications. In: Tintinalli JE, Kelen GD, Stapczynski JS, Ma OJ, Cline DM, eds. Emergency Medicine: A Comprehensive Study Guide. 6th ed. New York, NY: McGraw-Hill; 2004:chap 290.

Levine M, Burns MJ. Antipsychotic Agents. In: Shannon MW, Borron SW, Burns MJ, eds. Haddad and Winchester's Clinical Management of Poisoning and Drug Overdose. 4th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 38.

Velez LI, Feng S-Y. Anticholinergics. In: Marx JA, ed. Rosen's Emergency Medicine - Concepts and Clinical Practice. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2013:chap 150.


Review Date: 10/16/2013  

Reviewed By: Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

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