Health Encyclopedia
Diphenhydramine overdose
Definition
This article discusses poisoning from taking a large amount (overdose) of diphenhydramine, which is found in various over-the-counter allergy and sleep medicines.
Alternative Names
Benadryl overdose; Sominex overdose; Nytol overdosePoisonous Ingredient
- Diphenhydramine
Where Found
The ingredient diphenhydramine may be found in the following products:- Benadryl
- Nytol
- Sominex
Symptoms
- Agitation
- Blurred vision due to large pupil size
- Coma
- Confusion
- Convulsions
- Delirium
- Diarrhea
- Drowsiness
- Dry cotton-like mouth
- Flushing on the face and skin
- Inability to urinate
- Incoherence (not understandable)
- Lack of sweat
- Low grade fever
- Movement problems
- Nausea
- Rapid heart rate
- Stomach pain
- Unsteadiness
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
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:
- Medicines to treat symptoms or cause vomiting
- Activated charcoal
- A nasogastric (NG) tube thru the nose into the stomach to empty the stomach (gastric lavage)
- Laxative
Outlook (Prognosis)
Recovery is very likely.
Reviewed By: Eric Perez, MD, Department of Emergency Medicine, St. Luke's-Roosevelt Hospital Center, New York, NY. Review provided by VeriMed Healthcare Network.

