Hydroxyzine is an antihistamine available only with a prescription. It is used to treat symptoms of allergies and motion sickness.
Hydroxyzine 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 has overdosed, 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
Hydroxyzine can be harmful in large amounts.
Where Found
Hydroxyzine is found in medicines with these names:
- Durrax
- Rezine
- Vistaril
Other medicines may also contain hydroxyzine.
Symptoms
Dilated pupils are the classic symptom of a hydroxyzine overdose. Below are other symptoms of a hydroxyzine overdose in different parts of the body.
AIRWAYS AND LUNGS
BLADDER AND KIDNEYS
EYES, EARS, NOSE, THROAT, AND MOUTH
- Blurred vision
- Dry mouth
- Enlarged pupils
- Dry eyes
- Ringing in the ears
HEART AND BLOOD
- Rapid heartbeat
- Low blood pressure
- Pounding heartbeat (palpitations)
NERVOUS SYSTEM
- Agitation
- Coma (decreased level of consciousness and lack of responsiveness)
- Seizures
- Delirium
- Depression
- Disorientation
- Dizziness
- Drowsiness
- Hallucinations (seeing or hearing things that aren't there)
- Nervousness
- Sleeping difficulties
- Tremor
- Uncoordinated movement
- Unsteadiness
SKIN
- Dry, red, or flushed skin
STOMACH AND INTESTINES
- Nausea
- Vomiting
Before Calling Emergency
Have this information ready:
- Person's age, weight, and condition
- Name of the product (ingredients and strength, if known)
- Time it was swallowed
- Amount swallowed
- If the medicine was prescribed for the person
Poison Control
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. 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.
You can also get online poison help now at Poisonhelp.org. Just enter the product, poison, or medicine to get expert help.
What to Expect at the Emergency Room
Take the container to the hospital with you, if possible.
Your health care provider will measure and monitor your vital signs, including temperature, pulse, breathing rate, and blood pressure.
Tests that may done include:
- Blood and urine tests
- Chest x-ray
- Electrocardiogram (ECG)
- Fluids through a vein (by IV)
- Medicines to treat symptoms
- Activated charcoal
- Laxative
- Breathing support, including a tube through the mouth into the lungs and connected to a breathing machine (ventilator)
Outlook (Prognosis)
Recovery is likely if the person survives the first 24 hours. Complications such as pneumonia, muscle damage from lying on a hard surface for a prolonged period of time, or brain damage from lack of oxygen may cause permanent disability. Few people actually die from an antihistamine overdose, unless they have serious heart rhythm disturbances or breathing problems.
Keep all medicines in child-proof bottles and out of reach of children.
Alternative Names
Vistaril overdose
Images
References
Aronson JK. Anticholinergic drugs. In: Aronson JK, ed. Meyler's Side Effects of Drugs. 16th ed. Waltham, MA: Elsevier; 2016:534-539.
Hoppe JA, Monte AA. Anticholinergics. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 140.
Meehan TJ. Care of the poisoned patient. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 135.
Nelson LS, Calello DP. Acute poisoning. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 96.
Review Date 10/14/2025
Updated by: Jesse Borke, MD, CPE, FAAEM, FACEP, Attending Physician at Kaiser Permanente, Orange County, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
