Chlorpromazine overdose

Definition

Chlorpromazine is a prescription medicine used to treat psychotic disorders. It may also be used to prevent nausea and vomiting, and for other reasons.

This medicine may also change the metabolism and the effect of other drugs.

Chlorpromazine overdose occurs when someone takes more than the normal or recommended amount of this medicine. This can be by accident or on purpose.

This article is for information only. DO NOT use it to treat or manage an actual overdose. If you or someone you are with overdoses, call the local emergency number (such as 911), or the local poison control center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States.

Poisonous Ingredient

Chlorpromazine can be poisonous in large amounts.

Where Found

Chlorpromazine is found in chlorpromazine hydrochloride.

Other medicines may also contain chlorpromazine.

Symptoms

Below are symptoms of a chlorpromazine overdose in different parts of the body.

AIRWAYS AND LUNGS

• No breathing
• Rapid breathing
• Shallow breathing

BLADDER AND KIDNEYS

• Inability to urinate
• Weak urine stream

EYES, EARS, NOSE, MOUTH, AND THROAT

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

HEART AND BLOOD

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

MUSCLES, BONES AND JOINTS

• Muscle spasms
• Rapid, involuntary movements of the face (chewing, blinking, grimaces, and tongue movements)
• Stiff muscles in the neck or back

NERVOUS SYSTEM

• Drowsiness, coma
• Confusion, hallucinations (rare)
• Convulsions
• Fainting
• Fever
• Inability to sit still
• Irritability
• Low body temperature
• Tremor
• Weakness, uncoordinated movements

REPRODUCTIVE SYSTEM

• Change in female menstrual pattern

SKIN

• Bluish skin color
• Hot skin
• Rash

STOMACH AND INTESTINES

• Constipation
• Loss of appetite
• Nausea

Home Care

Seek medical help right away. DO NOT make a person throw up unless poison control or a health care provider tells you to do so.

Before Calling Emergency

Have this information ready:

• Person's age, weight, and condition
• The name of the medicine and strength, if known
• When it was swallowed
• The amount swallowed
• If the medicine was prescribed for the person

Poison Control

Your local control poison center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States. This national hotline 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.

What to Expect at the Emergency Room

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

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

• Breathing support, including oxygen and a tube through the mouth into the lungs and breathing machine (ventilator)
• Blood and urine tests
• Chest x-ray
• CT scan (computerized axial tomography or advanced brain imaging)
• ECG (electrocardiogram, or heart tracing)
• Intravenous fluids (through a vein)
• Laxative
• Medicine to reverse the effects of the drug and treat symptoms

Outlook (Prognosis)

Chlorpromazine is fairly safe. Most likely, an overdose will only cause drowsiness and some side effects such as uncontrolled movements of the lips, eyes, head, and neck for a short time. These movements may continue if they are not treated quickly and correctly.

In rare cases, an overdose can cause more serious symptoms. Nervous system symptoms may be permanent. The most serious side effects are usually due to damage to the heart. If heart damage can be stabilized, recovery is likely. Life threatening heart rhythm disturbances may be difficult to treat, and may result in death. Survival past 2 days is usually a good sign.

References

Aronson JK. Chlorpromazine. In: Aronson JK, ed. Meyler's Side Effects of Drugs. 16th ed. Waltham, MA: Elsevier; 2016:274-275.

Skolnik AB, Monas J. Antipsychotics. In: Walls RM, Hockberger RS, Gausche-Hill M, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier; 2018:chap 155.