Methapyrilene hydrochloride overdose

Definition

Methapyrilene hydrochloride is an uncommon antihistamine found in cold or flu medicines.

Poisonous Ingredient

• Methapyrilene hydrochloride

Where Found

Methapyrilene hydrochloride is found in older antihistamine medications. It was removed from the market in 1979 because it was found to contribute to cancer after long-term use.

Symptoms

• Bladder and kidneys
  • Difficulty urinating
• Eyes, ears, nose, and throat
  • Dilated pupils
  • Vision abnormalities (blurry vision)
  • Dry mouth
• Skin
  • Flushed skin (red)
  • Dry skin
• Heart and blood
  • Rapid heartbeat
  • Low blood pressure
  • Convulsions
• Nervous system
  • Excitation
  • Agitation
  • Drowsiness
  • Nervousness
  • Hallucinations
  • Disorientation
  • Delirium
  • Coma
  • Unsteadiness
  • Tremor

Home Treatment

Do not make the person throw up. Seek emergency medical care immediately.

Before Calling Emergency

Determine the following information:

• Patient's age, weight, and condition
• Name of the product (ingredients and strengths, if known)
• Time it was swallowed
• Amount swallowed

Poison Control, or a local emergency number

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 U.S. 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.

What to expect at the emergency room

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

• Fluids by IV
• Activated charcoal
• A nasogastric (NG) tube thru the nose into the stomach to empty the stomach (gastric lavage)
• Blood test to determine salicylates or acetaminophen in the blood (Note: Cold and flu medications frequently contain these ingredients. Anyone who has taken an overdose is at risk from poisoning from these ingredients, too.)  
• Medicines to treat symptoms
• Medicine (antidote) to reverse the effect of the poison

Expectations (prognosis)

If the patient survives the first 24 hours, survival is likely. Few patients actually die from an antihistamine overdose.