Benadryl is the brand name of the active drug diphenhydramine.

It belongs to the class of drugs called antihistamines.

It is commonly used to treat symptoms of allergies,common cold,andhay fever.

Close-up of Benadryl blister pack label

Getty Images /Smith Collection/Gado/ Contributor

Benadryl is an effective medicine and is easily available over-the-counter (OTC).

Taking too much Benadryl, however, can lead to an overdose.

When severe, a Benadryl overdose may cause hallucinations, seizures, coma, and even death.

It should only be used as prescribed or as directed on the drug label.

It can cross the blood-brain barrier and cause central nervous system effects.

Monitoring of vital signs may be required.

The major therapeutic goal is to control and reverse the symptoms of overdose in an individual.

Do not take more than the dose recommended on the label.

When using Benadryl, carefully read the label before taking any other OTC medicine.

Tell your healthcare provider about all medicines you are taking to avoid diphenhydramine overdose.

The FDA is aware of this challenge and warns against it.

High intake of Benadryl can lead to serious heart problems, seizures, coma, or even death.

It relieves symptoms like sneezing, a runny nose, sore throat, and watery eyes.

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2024;12(6):376. doi:10.3390/toxics12060376

MedlinePlus.Diphenhydramine.

Nishino T, Wakai S, Aoki H, Inokuchi S.Cardiac arrest due to diphenhydramine overdose.Acute Med Surg.

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DailyMed.Label: Benadryl- diphenhydramine hydrochloride tablet, film coated.

DailyMed.Label: Benadryl allergy extra strength- diphenhydramine hydrochloride tablet, film coated.

DailyMed.Label: Children Benadryl allergy- diphenhydramine hydrochloride solution.