Benadryl Overdose Symptoms & Treatment

Benadryl is an over-the-counter (OTC) medication that, when abused or taken at high doses, can lead to overdose. Those experiencing Benadryl addiction have options for recovery support.
Evidence Based
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What is Benadryl (Diphenhydramine)?

Benadryl is a brand name FDA approved over-the-counter medication. Benadryl’s active ingredient is diphenhydramine, which is classified as an antihistamine. The intended use of Benadryl (diphenhydramine) is in the alleviation of symptoms related to allergies and the common cold, including:

  • Rash
  • itching
  • Watery eyes
  • Itchy eyes/nose/throat
  • Runny nose
  • Sneezing

How Does Benadryl Work?

When an individual experiences an allergic reaction or a common cold, the body releases the compounds Histamine and Acetylcholine into the body. When these two compounds successfully bind with receptors, the symptoms listed above can occur in response. Diphenhydramine works as a Anticholinergics by blocking receptors for histamine and acetylcholine, which can eliminate or decrease symptoms associated with allergies or a cold. 

Benadryl Side Effects

A side effect is a reaction to a medication that is not intended and is generally seen as undesirable. As with many medications, Benadryl can produce unwanted side effects. When taken in the correct dose, side effects from Benadryl are typically mild to moderate. 

Common side effects of Benadryl:

  • Sedation, tiredness, and/or sleepiness
  • dizziness
  • constipation
  • disturbed coordination
  • drying and thickening of oral and other respiratory secretions
  • Difficulty urinating

Less common side effects of Benadryl:

  • Changes in heart rate
  • confusion
  • nervousness
  • irritability
  • blurred vision
  • tremor
  • sweating
  • loss of appetite
  • erectile dysfunction
  • Nausea

Is Benadryl Addictive?

Benadryl taken at high doses beyond the recommended amount can cause changes in perception such as hallucination, changes in vision, and mood. These effects can be sought after as a “high,” which can lead to abuse of the medication. When an individual takes high doses of Benadryl frequently, there is a risk for diphenhydramine addiction. To have significant impairment or distress to a substance, the Diagnostic Statistical Manual used by medical professionals looks at tolerance, withdrawal, increased use, loss of control, and functioning decline. 

Additionally, due to Benadryl’s sedating side effect, research conducted in the United States is showing increased use of antihistamines as sleep aids. Although Benadryl has not been shown to be physically addictive, its use can become psychologically addictive. Individuals who rely on Benadryl for sleep have been shown to get less restful sleep.

Symptoms of Benadryl addiction: 

  • Tolerance — A need for increased amounts of Benadryl to achieve intoxication or  diminished effect with continued use of the same amount of Benadryl
  • Withdrawal — Experiencing withdrawal symptoms such as insomnia, irritability, and physical discomfort
  • Increased Use — Benadryl  is often taken in larger amounts than the individual intended 
  • Loss of Control — The individual is persistently unsuccessful in efforts to cut down on Benadryl’s use
  • Loss of Time — A lot of time is spent in activities necessary to obtain, use, and recover from the effects of Benadryl abuse
  • Functioning Decline — Important social, occupational, or recreational activities are given up or reduced because of Benadryl abuse 

Symptoms of Benadryl Overdose

An overdose is a serious medical condition that occurs when an individual receives too much of a substance. Overdoses can be fatal if immediate medical attention is not sought. Benadryl (Diphenhydramine) can lead to an overdose when taken in large amounts. Symptoms of Benadryl overdose include the following:

  • Inability to urinate
  • Blurred vision
  • Dry mouth
  • Enlarged pupils
  • Very dry eyes
  • Ringing in the ears
  • Low blood pressure
  • Rapid heartbeat
  • Agitation
  • Seizures
  • Delirium
  • Depression
  • Drowsiness
  • Hallucinations (seeing or hearing things that aren't there)
  • Increased sleepiness
  • Nervousness
  • Tremor
  • Nausea
  • Vomiting

If you believe you are experiencing or witnessing an overdose, visit your local emergency room or contact your local poison control center. 

Symptoms of Benadryl Overdose in Toddlers

Benadryl and other antihistamine products are not safe or effective in children younger than six years. Therefore, the use of the medication should only be done with a prescription from a licensed medical provider. When storing antihistamines, it is important to keep them out of the reach of children. 

Symptoms of antihistamine overdose in toddlers include the following:

  • Seizures
  • Cardiac Arrhythmias
  • Tremors
  • Extreme Drowsiness
  • Dry Eyes
  • Dry Mouth
  • Dry red skin

If you believe your child is experiencing a drug overdose, visit your local emergency room or contact your local poison control center. 

Treatment for Benadryl Addiction

The first step to all addiction recovery is to recognize there is a problem and evaluate what resources and supports are needed to overcome it. Often a good first step is to talk to your primary health care provider about your concerns and explore what level of care is right.


When a substance is taken for long enough at a high enough dosage, quickly stopping use without medical and emotional support can be dangerous. Detoxification/rehabilitation sites can assist you at safely withdrawing from Benadryl. 

Individual Mental Health and Substance Abuse Counseling 

Individual counseling is a meeting between yourself and a licensed mental health therapist. These meetings are used to assist you in understanding triggers for substance use, exploring strategies to decrease or stop substance abuse, and identify strengths you can use moving forward.

Group Therapy 

Group therapy is a form of treatment in which a group of individuals with a common issue, such as substance abuse, meet regularly under the guidance of a trained facilitator. Group therapy can assist the individual in finding support, discussing issues in a less judgemental space, and gaining insight from other members.   

Peer Support Groups (i.e., Narcotics Anonymous) 

Peer support groups such as NA are meetings led by community members that encourage honest introspection. 

Assisting Medication 

There are now several medications on the market particularly designed to assist with substance abuse and dependence. Some work as Agonist treatment blocking the receptors in the brain that would allow for a high. Other medications may assist in treating other psychological disorders exacerbating addition such as depression or anxiety. These medications are only FDA approved for alcohol and opioid use disorders.

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Omudhome Ogbru, PharmD. Diphenhydramine, (Benadryl), Antihistamine, Side Effects, Dosing, Uses. 30 Aug. 2017,

“Diphenhydramine: MedlinePlus Drug Information.” MedlinePlus, U.S. National Library of Medicine, 15 Aug. 2018,

Treatment, Center for Substance Abuse. “Exhibit 2-6, DSM-IV-TR Criteria for Substance Abuse and Substance Dependence - Managing Chronic Pain in Adults With or in Recovery From Substance Use Disorders - NCBI Bookshelf.” Managing Chronic Pain in Adults With or in Recovery From Substance Use Disorders., U.S. National Library of Medicine, 1 Jan. 1970,

American Psychiatric Association. (2013). Anxiety Disorders. In Diagnostic and statistical manual of mental disorders (5th ed.)

Borke, Jesse. “Diphenhydramine Overdose.” Mount Sinai Health System,

Trouble Sleeping? Experts Say Skip Antihistamines.

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Updated on: October 15, 2020
Addiction Group Staff
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Medically Reviewed
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Annamarie Coy,
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