How much Benadryl is safe to take. What are the recommended dosages for adults and children. What are the potential risks of Benadryl overdose. How long does Benadryl stay in your system. What factors affect Benadryl metabolism.

Understanding Benadryl: An Overview of the Popular Antihistamine

Benadryl is a widely used over-the-counter antihistamine medication containing diphenhydramine as its active ingredient. It’s primarily used to combat allergy symptoms and mild cold discomfort. The Food and Drug Administration (FDA) approved Benadryl as the first antihistamine, and it has since become a household name for allergy relief.

How does Benadryl work? It counteracts the effects of histamine, a substance produced by the body in response to allergens like pollen, animal dander, or dust. By doing so, Benadryl helps alleviate symptoms such as sneezing, itchy eyes, scratchy throat, runny nose, and breathing difficulties.

Available Forms of Benadryl

• Tablets
• Liquid gels
• Chewables

Despite its widespread availability, it’s crucial to use Benadryl responsibly and follow the recommended dosage instructions to avoid potential side effects or overdose.

Safe Dosage Guidelines for Benadryl

Are you wondering about the correct Benadryl dosage? The standard dose of diphenhydramine in brand name Benadryl differs for adults and children:

• Adults: 25 mg per dose
• Children: 12.5 mg per dose (in children’s formulas)

It’s important to note that these dosages are general guidelines. Individual factors such as age, weight, and overall health can influence the appropriate dosage. Always consult with a healthcare professional or carefully read the product label before administering Benadryl, especially to children or elderly individuals.

Benadryl Elimination Time

How long does Benadryl stay in your system? For the average healthy adult, the elimination half-life of Benadryl ranges from 6.7 to 11.7 hours. This means that between 6 to 12 hours after taking Benadryl, half of the drug will be eliminated from the body. Within approximately two days, the drug should be completely cleared from the system.

Factors Affecting Benadryl Metabolism

Several factors can impact how quickly Benadryl is metabolized by the body. Understanding these factors is crucial for safe and effective use of the medication:

1. Age: Adults over 65 and children under 12 metabolize diphenhydramine more slowly, requiring lower and less frequent doses for safe use.
2. Liver Function: Since Benadryl is processed through the liver, individuals with decreased hepatic function may have difficulty safely metabolizing the drug.
3. Kidney Health: The kidneys play a role in processing toxins, so those with decreased renal function may struggle to metabolize Benadryl effectively.
4. Hydration Levels: Proper hydration is essential for efficient elimination of diphenhydramine from the system.
5. Dosage Amount: Taking more than the recommended dose can lead to prolonged metabolism and potential buildup in the body.
6. Drug Interactions: Other medications, both prescription and over-the-counter, can affect how the body processes Benadryl.
7. Body Weight and Composition: Different body types process medications at varying rates, impacting Benadryl’s effectiveness and elimination time.

Potential Side Effects of Benadryl

Even when taken as directed, Benadryl can cause various side effects. It’s important to be aware of these potential effects:

• Drowsiness or sleepiness
• Dry mouth, nose, or throat
• Dizziness
• Nausea or stomach upset
• Headaches
• Jitteriness or restlessness
• Chest tightness
• Muscle weakness
• Loss of appetite
• Constipation

When taken at the recommended dosage, Benadryl’s effects typically peak after about two hours and wear off within four hours. However, metabolites from diphenhydramine’s breakdown remain in the body, making it potentially dangerous to take another dose before the full effects have subsided.

The Dangers of Benadryl Misuse

Can Benadryl be misused? Unfortunately, yes. Some individuals may attempt to use Benadryl recreationally, seeking a “high” from its sedative effects. However, taking more than the recommended 25 mg dose can be extremely dangerous and is more likely to cause harm than produce any euphoria.

Misuse of Benadryl can occur in several ways:

• Not properly reading or following the dosage instructions
• Mixing Benadryl with alcohol or other intoxicants
• Taking excessive amounts in a single dose

Any form of misuse can lead to severe side effects or potentially life-threatening overdose situations.

Recognizing Benadryl Overdose

A Benadryl overdose can occur when an individual takes too much of the medication or combines it with other potent substances. Recognizing the signs of a Benadryl overdose is crucial for seeking timely medical intervention.

Symptoms of Benadryl Overdose

• Severe drowsiness
• Confusion or disorientation
• Blurred vision
• Dilated pupils
• Dry mouth and extremely dry, hot skin
• Difficulty urinating
• Agitation or hallucinations
• Seizures
• Rapid heartbeat
• Low blood pressure
• Tremors
• Nausea and vomiting

If you suspect a Benadryl overdose, it’s critical to seek emergency medical attention immediately. Overdose can lead to serious complications, including coma or even death if left untreated.

Safe Use Practices for Benadryl

To ensure safe use of Benadryl, consider the following guidelines:

1. Always read and follow the dosage instructions on the package carefully.
2. Do not exceed the recommended dose or frequency of use.
3. Avoid mixing Benadryl with alcohol or other medications without consulting a healthcare professional.
4. Be aware of potential drug interactions, especially if you’re taking other medications.
5. Do not drive or operate heavy machinery while taking Benadryl, as it can cause drowsiness.
6. If symptoms persist or worsen, consult a healthcare provider.
7. Store Benadryl out of reach of children and in a cool, dry place.

By adhering to these practices, you can maximize the benefits of Benadryl while minimizing potential risks.

Alternatives to Benadryl for Allergy Relief

While Benadryl is effective for many people, some individuals may seek alternatives due to side effects or personal preferences. Several other options are available for managing allergy symptoms:

Other Over-the-Counter Antihistamines

• Cetirizine (Zyrtec)
• Loratadine (Claritin)
• Fexofenadine (Allegra)

These newer generation antihistamines often cause less drowsiness compared to Benadryl.

Natural Remedies

• Nasal irrigation with saline solution
• Local honey consumption
• Butterbur supplements
• Quercetin-rich foods

While some natural remedies show promise, it’s important to consult with a healthcare provider before trying any new treatment, especially if you have existing health conditions or are taking other medications.

Lifestyle Changes

• Using air purifiers
• Regularly cleaning bedding and carpets
• Keeping windows closed during high pollen days
• Showering after spending time outdoors

These measures can help reduce exposure to allergens and minimize symptoms without medication.

When considering alternatives to Benadryl, it’s crucial to discuss options with a healthcare professional to determine the most suitable approach for your specific allergy symptoms and overall health condition.

Understanding Benadryl’s Impact on Different Age Groups

The effects and safe usage of Benadryl can vary significantly across different age groups. Let’s explore how Benadryl impacts children, adults, and the elderly:

Benadryl Use in Children

Is Benadryl safe for children? While Benadryl can be used in children, extra caution is necessary:

• Not recommended for infants under 2 years old without doctor’s advice
• Children’s formulas contain lower doses (typically 12.5 mg)
• May cause paradoxical excitation in some children
• Should not be used as a sleep aid for children

Parents should always consult a pediatrician before giving Benadryl to children, especially for extended use.

Benadryl Use in Adults

For healthy adults, standard dosing guidelines typically apply:

• 25 mg per dose
• No more than 300 mg in 24 hours
• Effects usually last 4-6 hours

Adults should be aware of potential drowsiness and avoid tasks requiring alertness after taking Benadryl.

Benadryl Use in the Elderly

Older adults may be more sensitive to Benadryl’s effects:

• Increased risk of side effects like confusion and urinary retention
• May exacerbate existing conditions like glaucoma or enlarged prostate
• Potential for drug interactions with other medications common in older adults

Elderly individuals should consult their healthcare provider before using Benadryl, as alternative antihistamines may be safer.

Long-Term Effects of Regular Benadryl Use

While Benadryl is generally safe for short-term use, regular long-term use may lead to certain health concerns:

Potential Risks of Chronic Benadryl Use

• Tolerance development, requiring higher doses for the same effect
• Increased risk of dementia in older adults with prolonged use
• Possible impact on cognitive function and memory
• Dry mouth and associated dental problems
• Chronic constipation

It’s important to note that Benadryl is intended for short-term relief of allergy symptoms. If you find yourself needing to use Benadryl regularly for extended periods, consult with a healthcare provider to explore underlying causes and alternative treatments.

Safer Alternatives for Long-Term Allergy Management

For those requiring long-term allergy management, consider these options:

• Newer generation antihistamines (e.g., Zyrtec, Claritin)
• Nasal corticosteroid sprays
• Allergy shots (immunotherapy)
• Lifestyle modifications to reduce allergen exposure

A allergist or immunologist can help develop a comprehensive, long-term allergy management plan tailored to your specific needs.

Benadryl Interactions with Other Substances

Understanding how Benadryl interacts with other substances is crucial for safe use. Let’s explore some common interactions:

Benadryl and Alcohol

Combining Benadryl with alcohol can be dangerous. Both substances have a depressant effect on the central nervous system, potentially leading to:

• Increased drowsiness and dizziness
• Impaired motor coordination
• Decreased alertness
• Increased risk of accidents

It’s strongly advised to avoid alcohol consumption when taking Benadryl.

Benadryl and Other Medications

Benadryl can interact with various medications, including:

• Other antihistamines
• Antidepressants
• Anti-anxiety medications
• Muscle relaxants
• Some Parkinson’s disease medications

Always inform your healthcare provider about all medications you’re taking, including over-the-counter drugs and supplements, to avoid potential interactions.

Benadryl and Caffeine

Some people may use caffeine to counteract the drowsiness caused by Benadryl. However, this combination can lead to:

• Increased jitteriness or anxiety
• Irregular heartbeat
• Difficulty sleeping

It’s generally better to avoid combining these substances and instead choose a non-drowsy antihistamine if alertness is required.

By understanding these interactions, you can make more informed decisions about using Benadryl safely and effectively. Always consult with a healthcare professional if you have concerns about how Benadryl might interact with other substances you use.

Getting High on Benadryl: How Much Is Safe?

Benadryl is a brand name over-the-counter antihistamine medication. Histamine is a substance produced by the body in response to the presence of allergens like pollen, animal hair, or dust. Histamine release underlies certain symptoms like sneezing, itchy eyes, scratchy feelings in the nose or throat, runny nose, and difficulty breathing. Antihistamines like Benadryl combat the actions of histamine. Some people may also take Benadryl to reduce similar symptoms when they have a cold. Diphenhydramine is the main ingredient in this drug, and the substance can be found in other over-the-counter medications, too.¹

Although Benadryl is sold without a prescription, the drug can cause drowsiness and sedation. Misuse of the medication may occur because people do not properly read the directions, mix it with alcohol or other intoxicants, or take too much of it at once. Any form of misuse can be dangerous and may result in severe side effects or an overdose. ¹

Just like with a prescription drug, it is important to follow the instructions on the package and only take Benadryl in recommended doses for a short period of time.

What Is Benadryl? How Is It Taken Safely?

Benadryl was the first antihistamine to receive approval from the Food and Drug Administration (FDA). The brand name was acquired by Johnson & Johnson in 2007 and the medication remains a widely-used treatment for allergies and mild cold symptoms.¹

Since the medication has been available for several decades, safe dosage and elimination time are well understood. Benadryl is available in a variety of formulations, including tablets, liquid gels, and chewables. The standard dose of diphenhydramine in brand name Benadryl is 25 mg per dose for adults and 12.5 mg per dose in children’s formulas. For the average healthy adult, elimination half-life ranges from 6.7 to 11.7 hours.² So between 6 to 12 hours after taking Benadryl, half the drug will be eliminated from the body. Within two days, the drug will be completely gone from the body.

Several factors impact how quickly Benadryl is metabolized, including: 3

• Age: Adults over 65 years old and children younger than 12 years old metabolize diphenhydramine more slowly, so lower doses less often are safer.³
• Liver problems: Since the active ingredient in Benadryl is processed through the liver, anyone with decreased hepatic function will have difficulty safely consuming this drug.
• Kidney problems: The kidneys help to process toxins by passing them out through the bladder. People who have decreased renal function may have a tough time metabolizing Benadryl. Urinary pH can also impact how the body processes diphenhydramine.
• Hydration: People who do not drink sufficient water may struggle to eliminate diphenhydramine from their system.
• Low vs. high dose: Even healthy adults who take more than the recommended dose of Benadryl will experience consequences, such as taking longer to metabolize the drug. Taking the recommended dose of Benadryl for longer than recommended may also lead to tolerance as the drug builds up in the body, and that also might increase the medication’s elimination time.
• Other medications: Taking prescription drugs, or other over the counter drugs, along with Benadryl may change how the body metabolizes all the substances together.
• Body weight/mass: Different body types process different amounts of medication at different rates. This is true for prescription drugs, recreational substances like alcohol, and over the counter drugs like Benadryl.

Although Benadryl is sold over the counter without a prescription, the active ingredient is potent and has an impact on the body. In addition to eliminating symptoms of allergies or a cold, it also interacts with other organ systems.

Even when taken as directed, Benadryl can cause side effects which include: 4

• Drowsiness or sleepiness.
• Dry mouth.
• Dryness in the nose or throat.
• Dizziness.
• Nausea or stomach upset.
• Headaches.
• Jitteriness or restlessness.
• Tightness in the chest.
• Muscle weakness.
• Loss of appetite.
• Constipation.

When the recommended amount is consumed, effects peak after about two hours. Within four hours, most effects of the medication wear off. There are still metabolites from diphenhydramine’s breakdown in the body, so taking another dose of Benadryl before the full effects wear off may be dangerous.⁵

Additionally, some people take more than the recommended amount because they want to get high. Benadryl produces mild sedative effects, and in larger amounts, that can feel like intoxication.

However, taking more than 25 mg can be extremely dangerous and is more likely to cause harm than produce any euphoria. ⁵

Benadryl Overdose

Too much Benadryl can lead to an overdose and taking the drug with other potent substances can increase the risk of overdose.

For example, taking other antihistamines that contain diphenhydramine can lead to an overdose. Substances like alcohol or benzodiazepines (e.g., Valium, Xanax, Klonopin, etc.) may dangerously increase Benadryl’s sedative effects.

Muscle relaxants, sedative-hypnotic sleep medications like Ambien, tranquilizers, opioids, and other prescription drugs that are central nervous system (CNS) depressants can also adversely interact with Benadryl. In addition, some types of antidepressants called monoamine oxidase inhibitors (MAOIs) do not mix with antihistamines like Benadryl.³

Symptoms of a Benadryl overdose include: 6

• Enlarged pupils.
• Very dry eyes.
• Blurry vision.
• Ringing in the ears (tinnitus).
• Low blood pressure.
• Rapid heart rate.
• Agitation, rapid mood swings, or restlessness.
• Confusion.
• Seizures.
• Delirium.
• Intense, sudden depression.
• Extreme drowsiness.
• Passing out or falling asleep.
• Nervousness or paranoia.
• Physical tremors.
• Unsteady gait, loss of balance, or inability to walk.
• Dry, red skin.
• Nausea or vomiting.
• Inability to urinate.

Attempting to Get High on Benadryl Can Be Extremely Dangerous

Benadryl is not effective as an intoxicant.Taking more than the recommended dose is more likely to lead to an overdose and uncomfortable side effects rather than euphoria. More than 500 mg, which is more than 40 times the recommended dose, may lead to a state of delirium, hallucinations, and other overdose symptoms. Anecdotal evidence about diphenhydramine highs indicates that the effects are more often uncomfortable and unsettling instead of enjoyable.

Attempts at getting high on Benadryl may be indicative of larger issues with addiction or substance abuse. Because Benadryl is easy to acquire, it may be the first drug abused by an adolescent, or it could be a drug abused after struggling with other substances. Regardless, it is important to get help ending substance abuse.

There are many risks in taking Benadryl long term, or mixing it with another drug or medication. If you have been abusing the prescribed dosage for Benadryl, it’s important to be informed about other potential signs that could lead to addiction.

If you or someone you love is struggling with substance abuse issues and are unsure of where to turn, call us today at . River Oaks, one of American Addiction Centers’ Florida rehab centers, is ready to help you overcome addiction and find long-term recovery. Call us today at to learn more about addiction treatment near you.

You aren’t alone. You deserve to get help.

We are here to help you get sober and learn how to stay that way. Retreat to the sunny climate near Tampa, Florida for a stay at the gold standard of treatment facilities. At River Oaks, we offer customized care plans to help you on your recovery journey at our beautiful Hillsborough County campus.

What is the max dose of diphenhydramine for adults?

Medically reviewed by Carmen Pope, BPharm. Last updated on Oct 4, 2021.

I took two 50mg capsules thinking they were 25mg each (that is I took 100mg instead of 50mg) and it was the only thing that put me into a nice 6 hour sleep which I have not had for weeks! If it is acceptable I will try to take this to finally get some good sleep!

The maximum oral dose of diphenhydramine for adults is generally reported as 100mg for a single dose or no more than 300mg in 24 hours, but this can vary depending on what condition diphenhydramine is being used for, the salt of diphenhydramine used (there are two salts available in the United States, diphenhydramine citrate and diphenhydramine chloride), the age of the person, how much diphenhydramine they have tolerated before, and if they are on any interacting medications. Taking too much diphenhydramine can be fatal.

Diphenhydramine is one of the most abused medications in the United States and a 2016 study found that diphenhydramine overdosage accounted for 3.2% of all overdosage deaths in the United States and ranked among the top 15 drugs most frequently involved in drug overdose deaths in the United States. Most diphenhydramine intoxication/overdose cases occur in children ages 6 years or younger. Children who have taken or been given more than 7.5mg/kg of diphenhydramine should be taken to a healthcare facility for observation because they require medical supervision and management. Diphenhydramine overdose or intoxication can be either accidental or intentional.

What is the maximum dose of diphenhydramine for sleep?

When used as a sleep aid the maximum recommended dosage is 76mg for diphenhydramine citrate or 50mg for diphenhydramine hydrochloride. Although diphenhydramine is commonly used for sleeping it is not recommended because it prevents the brain from achieving restorative deep REM sleep and tends to cause anxiety or a “hangover” effect, which causes a person to feel drowsy the next day. Alternatives, such as zolpidem, are preferred as a sleep aid.

Taking diphenhydramine as a sleep aid for more than 7 to 10 nights is not recommended, because you will gain tolerance to it.

Diphenhydramine should never be given to children to help them sleep and is best not given to children younger than 12 years of age without the direction of a physician. Use in children under 6 years old should be avoided. Long-acting tablets or capsules should never be given to children.

What are the symptoms of diphenhydramine overdose or toxicity?

Diphenhydramine can be harmful in large amounts. Symptoms of a diphenhydramine overdose include:

• Blurred vision
• Confusion
• Dry mouth
• Dry skin
• Drowsiness
• Hallucinations (seeing or hearing things that aren’t there)
• Heart rhythm disturbances such as QT prolongation
• Nausea and/or vomiting
• Nervousness
• Psychosis
• Seizures
• Sleepiness
• Tremor
• Unsteadiness.

Recovery from a diphenhydramine overdose is likely if the person survives the first 24 hours but in some people, serious heart rhythm disturbances may occur, which can cause death.

What medicines contain diphenhydramine?

Diphenhydramine may be found in many medicines, sometimes in combination with other ingredients such as acetaminophen or ibuprofen, for example:

• Advil PM
• Aleve PM
• Bayer PM
• Benadryl
• Dimetapp
• Ivarest
• Nytol
• Sominex
• Tylenol PM
• Unisom.

What brands contain diphenhydramine hydrochloride and diphenhydramine citrate?

Common brands containing diphenhydramine and the salt they contain include:

• Advil PM (diphenhydramine citrate)
• Aleve PM (diphenhydramine hydrochloride)
• Bayer PM (diphenhydramine citrate)
• Benadryl (diphenhydramine hydrochloride)
• Dimetapp (diphenhydramine hydrochloride)
• Ivarest (diphenhydramine hydrochloride)
• Sominex (diphenhydramine hydrochloride)
• Tylenol PM (diphenhydramine hydrochloride)
• Unisom (diphenhydramine hydrochloride).

References

• Diphenhydramine overdose Mt Sinai.https://www.mountsinai.org/health-library/poison/diphenhydramine-overdose
• Huynh DA, Abbas M, Dabaja A. Diphenhydramine Toxicity. [Updated 2021 May 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557578/
• Zhang D, Tashiro M, Shibuya K, Okamura N, Funaki Y, Yoshikawa T, Kato M, Yanai K. Next-day residual sedative effect after nighttime administration of an over-the-counter antihistamine sleep aid, diphenhydramine, measured by positron emission tomography. J Clin Psychopharmacol. 2010 Dec;30(6):694-701. doi: 10.1097/jcp.0b013e3181fa8526. PMID: 21105284.
• Katayose Y, Aritake S, Kitamura S, Enomoto M, Hida A, Takahashi K, Mishima K. Carryover effect on next-day sleepiness and psychomotor performance of nighttime administered antihistaminic drugs: a randomized controlled trial. Hum Psychopharmacol. 2012 Jul;27(4):428-36. doi: 10.1002/hup.2244. PMID: 22806823.

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Medical Disclaimer

Quick Answer: How much Benadryl is safe for a dog?

According to the Merck Veterinary Manual, the safe dosage is 2-4 milligrams per kilogram of body weight, or 0. 9 to 1.8 milligrams per pound. This amount can be administered two to three times a day, depending on your dog’s symptoms.

Benadryl is commonly used to treat itching in dogs caused by skin allergies and also reduces many other allergy symptoms, including: hives. Edema and inflammation. Redness.

With proper pet safety instructions, proper dosage, and guidance from your veterinarian, yes, Benadryl can be safe for dogs. With all medications, please observe your dog’s behavior during the first medication trial. Before proceeding, make sure your dog is not reacting abnormally to the medication.

Benadryl may cause severe drowsiness, dry mouth or urinary retention in the dog, and potentially cause gastrointestinal disturbances such as diarrhea and/or vomiting.

According to the Merck Veterinary Manual, the safe dosage is 2-4 milligrams per kilogram of body weight, or 0.9 to 1.8 milligrams per pound. This amount can be administered two to three times a day, depending on your dog’s symptoms.

This medicine will work quickly, in about 1-2 hours, and this should be followed by an improvement in clinical signs.

Oatmeal is an age old remedy for dry, itchy skin that is safe to use on our dog friends too! In fact, most hypoallergenic dog shampoos contain oatmeal as an active ingredient that soothes and fights irritation. Start by grinding plain oatmeal into a powder to sprinkle in your dog’s warm bath.

When dog scratches get out of hand, it’s often the result of food allergies or environmental factors, including mold and pollen. Dogs can also develop a skin irritation called contact dermatitis when in contact with substances such as pesticides or soaps. Boredom or anxiety.

The standard dose of oral Benadryl for dogs is 1 mg per pound of body weight 2-3 times daily. Most diphenhydramine tablets have a 25mg dose, which is about the size of a 25-pound dog. But the safest way to give the correct dose is to ask your veterinarian.

Never give your dog too much Benadryl – an overdose is possible. Abuse of the drug can lead to fatal diphenhydramine poisoning, so always consult your veterinarian if you are unsure of the correct dosage. Signs of an overdose include constipation, agitation, dilated pupils, seizures, and rapid heartbeat.

Diphenhydramine-only Benadryl is a human drug that can also be used as an additional labeling drug for dogs. It is very important to check the ingredients on the label as some strains contain additional ingredients such as phenylephrine that may be harmful to your pet.

You can give your dog Benadryl (diphenhydramine) 2-3 times a day at a rate of 1 mg per pound of body weight. For example, a 12-pound dog may receive 12 mg, which is equal to one child’s dose of Benadryl or ½ an adult’s dose. A 50 lb dog will need 50mg or two of adult Benadryl. Benadryl may cause drowsiness.

Benadryl begins to work in 15-30 minutes, and its maximum effect occurs in 2-4 hours. The adult dose for sedation is 25 to 50 milligrams.

It is true that Benadryl can relieve symptoms in some dogs, but the sedative effects are mild and not as pronounced in dogs as they are in humans. Thus, in general, Benadryl does not usually help dogs struggling with anxiety or phobias.

Antihistamines. Diphenhydramine (Benadryl®), cetirizine (Zyrtec®), and loratadine (Claritin®) are commonly antihistamines that relieve allergy symptoms or counter allergic reactions. Antihistamines are generally safe, but they can cause drowsiness in some dogs and hyperactivity in others.

Is expired Benadryl safe?

If a medicine is past its expiration date, throw it away and replace it with a new product, Benadryl says. However, according to The Allergy Clinic.

The expiration date on medicine vials is the last date the manufacturer is prepared to guarantee safety and efficacy. After the expiration date, nothing happens for the drug to lose its effectiveness, explains the Harvard Medical School Family Health Guide. Many medicines, especially those kept in unopened original containers, can remain effective for many years after the expiration date.