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Tetrahydrozoline poisoning

Tetrahydrozoline is a form of a medicine called imidazoline, which is found in over-the-counter eye drops and nasal sprays. Tetrahydrozoline poisoning occurs when someone accidentally or intentionally swallows this product.

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 a local poison control center at 1-800-222-1222.

Poisonous Ingredient

  • Tetrahydrozoline

Where Found

Tetrahydrozoline is sold under the following brand names:

Note: This list may not be all-inclusive.


Symptoms may include:

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

The following information is helpful for emergency assistance:

  • The patient's age, weight, and condition
  • The name of the product (ingredients and strengths if known)
  • The time it was swallowed
  • The amount swallowed

However, DO NOT delay calling for help if this information is not immediately available.

Poison Control What to Expect at the Emergency Room

In the United States, call 1-800-222-1222 to speak with a local poison control center number. This 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.

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 as appropriate. The person may receive:

  • Activated charcoal
  • Airway support, including oxygen, breathing tube through the mouth (intubation),and ventilator (breathing machine)
  • Blood and urine tests
  • Chest x-ray
  • EKG (electrocardiogram, or heart tracing)
  • Fluids through the vein (intravenous or IV)
  • Laxative
  • Medicines to treat symptoms

Survival past 24 hours is usually a good sign that the person will recover.

Review Date: 1/23/2015
Reviewed By: Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
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