Benadryl is an antihistamine medication that can be used to treat allergy or cold symptoms. It has a sedating effect and can interact with other medications. As such, it can be dangerous when overdosed on alone or when combined with other substances, which can require urgent medical care.
- Benadryl is an antihistamine that can be bought over the counter to treat allergy and cold symptoms.
- Benadryl can be safe in recommended doses, but taking too much can result in a dangerous or even fatal overdose.
- Benadryl overdose may require emergency treatment to prevent severe or life-threatening consequences.
Can you overdose on Benadryl?
Yes, you can overdose on Benadryl if you take more than recommended or use Benadryl alongside certain other medications or substances.
Benadryl (diphenhydramine) is an antihistamine used to treat symptoms related to allergies or the common cold. It can be used safely to manage these symptoms, although side effects often occur, such as sedation and drowsiness. If it is misused or taken alongside other medications or illicit substances, overdose is possible, which may have severe consequences. [1][2]
This might occur intentionally, such as among those who wish to harm themselves or attempt suicide. Unintentional overdose might be related to confusion around dosing recommendations or if using Benadryl alongside other substances.
Data from the National Poison Data System (NPDS) details over 45,000 cases of pediatric Benadryl overdoses from 2014 to 2023. Of these, 90% required hospital treatment and 20% were admitted to critical care. This report indicates that the majority of these cases involved suicidal intent. [3]
What is the maximum dose for Benadryl?
Benadryl is available in a range of products, including 25 mg tablets, 50 mg tablets, and oral liquid solution for children containing 12.5 mg per 5mL.
- Children over 12 and adults can take a maximum dose of 50 mg.
- Children aged 6-12 can take a maximum dose of 25 mg.
- Children under 6 should not take Benadryl unless directed by a doctor.
Doses can be taken once every four to six hours, and no more than six times in 24 hours.
Older adults or people with a history of heart conditions, hypertension, asthma, and eye problems may need to take a reduced dose or find alternative medications, as Benadryl may exacerbate these conditions and cause health risks. [4]
Benadryl overdose symptoms
Benadryl overdose can range from mild to severe, depending on various circumstances and the dosage administered. Mild to moderate overdose symptoms include: [2][4]
- Confusion
- Shaking
- Slight increase in body temperature
- Changes in heart rate
- Agitation
- Restlessness
- Flushed skin
Severe symptoms of Benadryl overdose may require urgent medical attention and can include: [2][4]
- Severe agitation or restlessnessÂ
- Delirium
- Uncontrollable shaking
- Hyperthermia
- Blurred vision
- Urinary retention
- Extreme change in heart rate
- Hallucinations
- Trouble walking
- Balance impairments
- Difficulty with speech
- Trouble breathing or swallowing
- Seizures
- Signs of rhabdomyolysis, such as pain and weakness in the muscles, and dark urine
Anticholinergic toxidrome
Anticholinergic toxidrome refers to a clinical syndrome that occurs when anticholinergic substances, such as Benadryl, that cause the blocking of the neurotransmitter acetylcholine, are taken in excess. This leads to potentially severe symptoms that require medical treatment. [2][5]
The following mnemonics describe the commonly seen symptoms of anticholinergic toxidrome: [5]
- ‘Red as a beet’: flushed skin
- ‘Dry as a bone’: dry mouth
- ‘Blind as a bat’: blurred vision, dilated pupils
- ‘Mad as a hatter’: delirium, confusion, hallucinations
- ‘Full as a flask’: difficulty urinating
Monoamine oxidase inhibitors (MAOIs) can significantly increase the risk of anticholinergic toxidrome if used alongside Benadryl. Other anticholinergic substances can also increase this risk, including tricyclic antidepressants, some antipsychotics, Parkinson’s medications, antispasmodics, and other antihistamines. [4]
Is a Benadryl overdose fatal?
A Benadryl overdose could be fatal, particularly if it is taken alongside other substances. For example, taken with other CNS depressants, Benadryl could cause oversedation and respiratory depression. In the case of anticholinergic toxidrome caused by multiple substance ingestion, fatal complications may occur, including severe issues with breathing and cardiac function. [2][4]
Benadryl overdose alone, without other substances, is less likely to be fatal, although severe and potentially life-threatening cardiac effects can occur. If a Benadryl overdose is recognized quickly and urgent medical care is provided, the individual is likely to recover completely. [2]
Real risks to the Benadryl TikTok Challenge
Social media challenges have become widely prevalent among TikTok users in recent years and can range from harmless to more dangerous challenges, such as those that involve the ingestion of household cleaning products or large quantities of medications or substances.Â
One such challenge is the Benadryl TikTok Challenge, in which people (often children and adolescents) are encouraged to ingest as many Benadryl tablets as they can. This challenge resulted in dangerous consequences, with many young people presenting to emergency care, some of whom lost their lives. [6]
What to do if someone overdoses on Benadryl
If you see someone who has overdosed on Benadryl or a Benadryl overdose is suspected, call Poison Control at 1-800-222-1222 for advice. If it is an emergency, call 911 for immediate medical attention, such as if the individual is unconscious, having trouble breathing, or is experiencing seizures or delirium.Â
If possible, collect information for medical professionals, such as the amount and time of Benadryl administration and any other substances taken.Â
Emergency treatment and how to manage Benadryl toxicity
Medical attention should be provided as quickly as possible, as this can improve the outcome and success of treatment. An initial assessment will be required to determine the severity of the overdose, including checking vital signs and heart functioning. [4][5]
If Benadryl was ingested within the last hour, activated charcoal can be administered, as this can help delay absorption. [4]
There is no specific antidote for Benadryl overdose, and treatment will involve managing the presenting symptoms. Benzodiazepines can be administered to manage agitation and seizures. Symptoms related to heart function or sodium channel blockade may be managed with magnesium sulfate, vasopressors, and sodium bicarbonate. Physostigmine can be administered to manage anticholinergic toxidrome. [2][4]
The individual will be closely monitored throughout these treatments.
Signs of Benadryl misuse and addiction risk
Because of its effects, some people might misuse and become addicted to Benadryl. Signs of this might include:
- Visiting multiple pharmacies to purchase the medication
- Empty boxes or blister packs in their home
- Taking increasing amounts of Benadryl in order to produce the same effect
- Using Benadryl with other substancesÂ
- Changes in mood and behavior
Abusing Benadryl increases the risk of overdose.
Prevention: How to use Benadryl safely
To prevent a Benadryl overdose, only take the medication in the exact dose and at the same frequency as it has been prescribed or as advised on the label.Â
Before taking Benadryl, it may be advisable to discuss any preexisting conditions with a physician to ensure that Benadryl is safe for you. People with a history of conditions relating to breathing, eyesight, or urinating might be unsuitable to use Benadryl.
Do not drink alcohol or use illicit substances while taking Benadryl, and discuss with a doctor the safety of using other medications alongside Benadryl before administering the medications.Â
Do not drive or operate heavy machinery while using Benadryl, as drowsiness can occur.
Store the medication in a secure location where it is inaccessible to children.
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