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Allergic reaction how much benadryl: BENADRYL® Dosing Guide: Adult & Children’s Diphenhydramine Dosage

How Much Benadryl Can I Give My Dog?

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It’s fairly common for dogs to have allergies. Some breeds, like Chinese Shar-Peis, Wirehaired Fox Terriers, Golden Retrievers, Dalmatians, Boxers, and Boston Terriers, among others, are predisposed to developing allergies. But any dog breed can get an allergic reaction to something. When they do, it’s essential as a dog parent to know how to treat it naturally or possibly with Benadryl.

Though Benadryl is a human medication made for people, most veterinarians will tell you it’s safe for dogs. After all, dogs can suffer from the same allergens we do. What’s important to keep track of is proper dosage.

This article will detail how to determine Benadryl dosage for dogs, what it’s used for, and the potential side effects. We’ll also review natural alternatives that might help with your dog’s itching, sneezing, runny nose, rash, or other allergy symptoms.

What Does Benadryl Do?

Benadryl is an over-the-counter antihistamine that also goes by its generic name, diphenhydramine HCL (this is also its active ingredient). Benadryl can help alleviate allergy symptoms in both you and your dog that come from seasonal allergies, environmental allergies, food allergies, and insect bites.

According to Catherine Barnette, DVM, and Ernest Ward, DVM of VCA Hospitals, the most common sign of a dog with an allergy is itching of the skin. Skin conditions can arise in conjunction with respiratory symptoms as well. “In some cases, the symptoms involve the respiratory system, with coughing, sneezing, and/or wheezing.”

Both the brand-name Benadryl and other diphenhydramine medications typically come in tablets of 25 milligrams. Luckily, the math involved to determine the proper Benadryl dose for dogs is quite straightforward.

Benadryl Dose for Dogs

Plumb’s Veterinary Drug Handbook recommends giving a standard dosage of 25 milligrams for a 25-pound dog two to three times per day.

As a general rule of thumb, use 1 milligram per pound of your dog’s body weight. For example, a 50-pound dog would be given two 25 milligram tablets. Small dogs under 25 pounds can be given children’s liquid Benadryl.

According to Veterinaryplace.com, at the standard concentration of children’s Benadryl, “every 5 milliliters of liquid contains 12.5 milligrams of diphenhydramine and can be given at a dosage of 0.4 milliliters per pound.”

But before you break open the medicine cabinet or head to the nearest pharmacy for over-the-counter drugs, talk to your vet first to ensure you are giving your pet the right dosage. This is especially critical if your pup is on any other medications or has existing medical conditions.

There are some cases where an allergic reaction is so severe that it requires a trip to the animal hospital for a shot. In such cases, the doctor might need to directly inject the medicine into the dog’s skin so it can act quickly to treat the symptoms.

Be conservative with an antihistamine like Benadryl because an overdose isn’t unheard of. Always consult your vet beforehand as new medications (or overusing the drug) can result in fatal diphenhydramine poisoning.

Signs of Benadryl overdose include constipation, agitation, dilated pupils, seizures, and rapid heart rate. If you suspect your dog is exhibiting signs of Benadryl overdose, contact your vet ASAP or call the Pet Poison Helpline at 855-764-7661.

Side Effects of Benadryl

Will Benadryl make my dog sleepy? It could, yes. Like most over-the-counter medications, Benadryl comes with some potential side effects. Common side effects include drowsiness, dry mouth, hypersalivation, increased heart rate, difficulty breathing, high blood pressure, sedation, urinary retention, and loss of appetite.

To avoid these possible adverse reactions or a potential overdose, consult your veterinarian first to be certain you administer the correct dosage of Benadryl.

Benadryl and Dog Anxiety

We’ve answered the questions, “How much Benadryl can I give my dog?” and “Can I give my dog Benadryl for allergies?” But there are some other instances where diphenhydramine HCL is used for dogs. Here’s what you need to know.

Due to its side effect of drowsiness, some pet parents use Benadryl as a mild sedative for anxious dogs in overwhelming situations like vet visits, car rides, fireworks, or thunderstorms. The Merck Veterinary Manual states that Benadryl may relieve symptoms of mild-to-moderate anxiety in dogs, especially during travel.

If you have a pooch with anxiety, you might also want to consider a natural calming supplement. Calming hemp-based chews, for example, can help make stressful situations less of an anxiety-inducing process. Look for a dog supplement that has soothing active ingredients such as chamomile, ginger root, passion flower, and hemp oil. These ingredients work together to curb your dog’s anxiety by creating a calming effect.

Natural Alternatives to Benadryl

If you’re uncomfortable giving your dog Benadryl for their seasonal allergies, environmental allergies, insect bites, hives, general itchiness, there are a handful of natural alternatives.

Colostrum

There are a number of natural allergy support supplements that support your dog’s health and immune system and give them support with environmental, food, skin and seasonal allergies. These kinds of supplements contain an ingredient called colostrum, an antibody-rich fluid that comes from mammary glands.

DVMs Steve Marsden, Shawn Messonnier, and Cheryl Yuill of VCA Hospitals found that this pre-milk superfood not only helps with  allergies, but it can also help with dental problems like gingivitis, and even food intolerances. Their research also suggests that colostrum is great for a healthy immune system and can help fight bacteria, fungi, and viruses.

In addition to colostrum, many allergy support supplements for dogs contain turmeric for its anti-inflammatory and antioxidant properties. Fish oil also does wonders for dry, itchy skin and it’s a common ingredient in allergy support chews as well.

Ultimately, it can’t hurt to give your pet a high-quality, well-rounded colostrum and turmeric-based allergy support chew as they do more than just help with symptoms of allergies. A supplemental chew that can help with allergies may help keep their immune system in tip-top shape for overall health.

The Bottom Line on Benadryl for Dogs

There are plenty of options out there for dogs suffering from allergies. Though Benadryl (or any other brand of diphenhydramine HCL) isn’t the be-all and end-all for relieving allergy symptoms, it can be an effective option for dog health as long as you consult your vet and give your dog the recommended dosage.

To learn more about supporting your pet’s allergies the natural way, check out PetHonesty’s delicious and health-conscious supplements with all the allergy-fighting ingredients your dog needs to live well.

What They Are and How to Manage Them

Benadryl (diphenhydramine) is used for allergies and allergic reactions, as well as common cold symptoms. Benadryl can cause mild or serious side effects, which are described below.

Benadryl is available as a prescription and an over-the-counter (OTC) medication. It helps reduce symptoms of hay fever (nasal allergies), other allergies, and colds. Examples include a runny nose and sneezing.

This drug is also used to treat certain allergic reactions, such as swelling and hives. For these purposes, the OTC version of Benadryl can be used by adults and children ages 6 years and older.

Benadryl comes in many different forms. Some you take by mouth, such as tablets or liquid solutions. Others you apply to your skin, such as creams or gels.

Typically, you’ll take Benadryl as a short-term treatment for your symptoms. Once your symptoms ease, your doctor will likely recommend that you stop taking Benadryl.

For more information about Benadryl, see this in-depth article.

Some people may have mild or serious side effects during their Benadryl treatment. Examples of a few of Benadryl’s more commonly reported side effects include:

  • sleepiness
  • dizziness*
  • headache
  • blurry vision*
  • low blood pressure

* To learn more about this side effect, see the “Side effects explained” section below.

Examples of mild side effects that have been reported with Benadryl include:

  • sleepiness
  • dizziness*
  • headache
  • low blood pressure
  • constipation
  • dry mouth or nose
  • blurry vision*

* To learn more about this side effect, see the “Side effects explained” section below.

In most cases, these side effects should be temporary. And some may be easily managed, too. But if you have any symptoms that are ongoing or that bother you, talk with your doctor or pharmacist. And don’t stop using Benadryl unless your doctor recommends it.

Benadryl may cause mild side effects other than the ones listed above. For more information, talk with your doctor or pharmacist.

Note: The Food and Drug Administration (FDA) tracks side effects of medications. If you’d like to notify the FDA about a side effect you’ve had with Benadryl, visit MedWatch.

Serious side effects that have been reported with Benadryl include:

  • changes in blood cell levels, such as a decreased red blood cell level
  • heart rhythm problems, including a condition called long QT syndrome
  • seizures
  • hallucinations (seeing or hearing something that’s not really there)
  • memory loss or dementia*
  • feeling confused
  • allergic reaction*†
  • fast heartbeat*

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after using Benadryl. But it’s not clear whether this side effect occurred in studies.

If you develop serious side effects while taking Benadryl, call your doctor right away. If the side effects seem life threatening or if you think you’re having a medical emergency, immediately call 911 or your local emergency number.

The side effects of Benadryl in children are generally similar to the drug’s side effects in adults. But it’s also possible for this medication to cause hyperactivity and excitability in children.

Benadryl typically shouldn’t be used in children younger than 6 years because they can have more serious side effects from the drug. This includes seizures and a fast heartbeat.

The over-the-counter forms of Benadryl are only approved for children 6 years and older, as well as adults. If your child is younger than 6 years, talk with their doctor about whether Benadryl is safe for them.

Get answers to some frequently asked questions about Benadryl’s side effects.

Are there any long-term side effects of Benadryl?

Yes, there are. Some long-term side effects that Benadryl may cause include:

  • dementia
  • memory problems
  • anxiety
  • dependence or withdrawal symptoms, such as psychosis, when you stop taking Benadryl

Benadryl is recommended only as a short-term treatment for people with symptoms of allergies or other conditions that the drug treats. If you take Benadryl long term, you may develop long-term side effects of the medication.

Which side effects you experience can determine how long your side effects last. For example, if you feel sleepy, this side effect may last a few hours or until the medication is no longer in your body. But other side effects can be longer lasting.

Talk with your doctor about your Benadryl use and which other medications may be better for your condition.

Do seniors have a higher risk of side effects from Benadryl?

Yes, older adults (ages 65 years and older) likely have a higher risk of side effects from Benadryl than younger adults. This is because their bodies may get rid of the drug more slowly.

Older adults may have more side effects from Benadryl, including sleepiness, dizziness, or heart problems. Sleepiness and dizziness can increase the risk of falling, which can be very serious.

If you’re an older adult interested in taking Benadryl, talk with your doctor. They may recommend that you take a lower dose of Benadryl to reduce your risk of side effects. Or they may suggest that you take a different medication to treat your allergy or cold symptoms.

Can Benadryl be used in babies or toddlers? If so, what are the possible side effects?

Over-the-counter forms of Benadryl shouldn’t be used in babies or toddlers. This is because children younger than 6 years old have an increased risk of side effects from Benadryl.

Children can have the same side effects of Benadryl as adults, such as dizziness or drowsiness. But Benadryl can also cause more serious side effects in children, such as a fast heartbeat or seizures. The drug may also cause children to become more excitable or hyperactive.

You should never use Benadryl to help your child fall asleep. This can be very dangerous.

Due to these risks, you shouldn’t give Benadryl to your baby or toddler without the direction of their doctor. If your child has symptoms of an allergy or cold, talk with their doctor about the best way to treat those symptoms.

Does my risk of side effects from Benadryl vary, depending on the dose (such as 25 mg or 50 mg)?

Yes, your risk of side effects can vary, depending on the dose of Benadryl you take.

A higher dose of Benadryl can increase the risk of side effects. So you’re more at risk of side effects from taking 50 milligrams (mg) of Benadryl than from taking 25 mg.

If you have concerns about side effects from your dose of Benadryl, talk with your doctor.

Does Benadryl cause diarrhea?

No, you shouldn’t have diarrhea from taking Benadryl. In fact, Benadryl can cause constipation.

Some other medications used to treat allergy symptoms, such as Allegra Allergy (fexofenadine), may cause diarrhea.

If you have diarrhea while taking Benadryl, talk with your doctor about what may be causing it.

Learn more about some of the side effects Benadryl may cause.

Fast heartbeat

A fast heartbeat is a common side effect of Benadryl. In rare cases, it can become serious.

Symptoms of a fast heartbeat may include:

  • feeling like your heart is racing
  • dizziness
  • shortness of breath
What might help

If you have symptoms of a fast heartbeat while taking Benadryl, talk with your doctor. They may recommend that you take a lower dose of the medication to treat your symptoms. Or they may recommend a different medication for you.

Blurry vision

Benadryl works by drying out your body, which may result in blurry vision. This is a more common side effect of Benadryl.

What might help

If you have blurry vision from taking Benadryl, talk with your doctor or pharmacist. They can recommend ways to decrease this side effect. They may also suggest a different medication to treat your symptoms.

Until your vision has cleared, you shouldn’t drive a car or operate other machinery.

Memory loss or dementia

Taking Benadryl may cause memory loss or dementia. Although rare, this side effect may be more common in older adults or people who’ve taken the drug long term. Symptoms can include:

  • trouble speaking or finding the right words to say
  • problems with short-term memory
  • trouble concentrating
What might help

If you’re experiencing memory loss or dementia while taking Benadryl, talk with your doctor. They’ll likely suggest that you stop taking Benadryl. They’ll also look for the cause of your memory loss or dementia so that they can recommend the right treatment for you.

Dizziness

Dizziness is a common side effect of Benadryl. This side effect can be serious.

Until you know how Benadryl will affect you, you shouldn’t drive a car or operate other machinery after taking the drug. If it causes you to feel dizzy, avoid doing either activity until the effects of the medication have worn off.

In addition, dizziness may lead to an increased risk of falling for older adults. Falls can be very dangerous for people who are older.

What might help

If you have dizziness from taking Benadryl, talk with your doctor. They’ll recommend that you don’t drive a car or operate other machinery while you’re dizzy.

In addition, they may suggest a different medication for your symptoms, one that doesn’t make you dizzy.

Allergic reaction

Like most drugs, Benadryl can cause an allergic reaction in some people. But it’s not clear whether this side effect occurred in studies.

Symptoms can be mild or serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe
What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They can suggest treatments to manage your symptoms.

If your doctor confirms that you had a mild allergic reaction to Benadryl, they’ll decide if you should continue using it.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms that you had a serious allergic reaction to Benadryl, they may have you switch to a different treatment.

Keeping track of side effects

During your Benadryl treatment, consider keeping notes about any side effects you’re having. Then, you can share this information with your doctor. This is especially helpful to do when you first start taking new drugs or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of drug you were taking when you had the side effect
  • how soon after starting that dose you experienced it
  • the specific symptoms of the side effect
  • how it affected your daily activities
  • any other medications you were also taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Benadryl affects you. And your doctor can use this information to adjust your treatment plan if needed.

Benadryl may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before you take Benadryl. The list below includes factors to consider.

Dementia. Benadryl may cause dementia, as well as worsen symptoms of dementia, in a person with this condition. If you have dementia, talk with your doctor before you take Benadryl. Your doctor may recommend that you take a different medication instead.

Allergic reaction. If you’ve had an allergic reaction to Benadryl or any of its ingredients, you shouldn’t take it. Ask your doctor what other medications are better options for you.

Heart problems or high blood pressure. Benadryl can increase your heart rate and may cause more serious heart-related side effects, such as heart rhythm problems. If you already have heart disease, taking Benadryl can make your condition worse. Talk with your doctor about whether it’s safe for you to take Benadryl.

Liver problems. Benadryl is removed from your body through your liver. If your liver isn’t working properly, it may take your body longer to remove the medication. This can increase your risk of side effects. If you have any liver conditions, tell your doctor before taking Benadryl.

Kidney, bladder, or prostate problems. Benadryl may decrease the amount of urine that you make. If you have kidney or bladder problems, you may already produce a decreased amount of urine. If you have prostate problems, you may have urinary retention (not being able to fully empty your bladder). These conditions may worsen due to Benadryl. If you have kidney, bladder, or prostate problems, talk with your doctor before you take this drug.

Respiratory conditions, including asthma. Benadryl works by drying out your nose and mouth, which decreases symptoms of an allergy or a cold. This can make mucus in your nose or mouth thicker. If you have trouble breathing, thickened mucus can make it even harder for you to breathe. Before you start taking Benadryl, talk with your doctor if you have any respiratory conditions.

Certain eye conditions. Benadryl may increase pressure in your eyes. If you already have a condition that increases eye pressure, taking Benadryl may worsen your condition. An example of this type of condition is glaucoma. Talk with your doctor to see if it’s safe for you to take Benadryl with your eye condition.

Alcohol use and Benadryl

You shouldn’t drink alcohol while you’re taking Benadryl. Alcohol can increase your risk of drowsiness or dizziness. It may also cause more serious side effects, such as trouble breathing or slowed breathing.

If you drink alcohol, talk with your doctor about other medications you can take to treat your cold or allergy symptoms.

Pregnancy and breastfeeding while taking Benadryl

It’s usually safe to take Benadryl during pregnancy. Benadryl doesn’t seem to increase the risk of fetal harm.

And taking small doses of Benadryl for a short time may be safe while breastfeeding.

But Benadryl does pass into breast milk, and it can also decrease milk supply.

If you’re breastfeeding and you take high doses of Benadryl, it may increase your child’s risk of side effects. This is also the case if you take the drug long term.

High doses or long-term use of Benadryl may also reduce your supply of breast milk.

If you’re pregnant or planning to become pregnant, talk with your doctor about the safety of Benadryl treatment during pregnancy. Also talk with your doctor about this if you’re breastfeeding or planning to breastfeed.

Most side effects of Benadryl are mild, and some people may not have any side effects at all from it. In some rare cases, the drug can cause serious side effects.

Before you take Benadryl, be sure to talk with your doctor about whether the drug is safe for you. Some questions that you may wish to ask about Benadryl’s side effects include:

  • How can I decrease my risk of side effects from Benadryl?
  • How long can I take Benadryl for my condition without increasing my risk of side effects?
  • If I have serious side effects from taking Benadryl, what other medications can I use instead?

To get information on different conditions and tips for improving your health, subscribe to any of Healthline’s newsletters. You may also want to check out the online communities at Bezzy. It’s a place where people with certain conditions can find support and connect with others.

Q:

Do other medications that I’m taking increase my risk of side effects from Benadryl?

Anonymous

A:

Yes, they may. When taking Benadryl with certain medications, your risk of side effects is increased. Examples of such medications include:

  • anticholinergics, such as Ditropan XL (oxybutynin)
  • antidepressants, such as Celexa (citalopram) and Zoloft (sertraline)
  • benzodiazepines, such as Xanax (alprazolam) and Ativan (lorazepam)
  • opioids, such as Zohydro (hydrocodone) and Roxicodone (oxycodone)

Before taking Benadryl, talk with your doctor or pharmacist. Based on other medications you may be taking, they can tell you whether your risk of side effects will increase from taking Benadryl.

The Healthline Pharmacist TeamAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.

Can Benadryl be given to a dog with an allergic reaction?

Benadryl is an excellent remedy for dogs with mild to moderate allergies. Seasonal allergies, food allergies, environmental allergies, and allergic reactions to snake and insect bites are most likely to respond to Benadryl.

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.

For mild allergic reactions, you can consult your veterinarian about home treatment with Benadryl (make sure there are no other ingredients added to Benadryl). The dose of Benadryl is usually 1mg per pound of your dog’s body weight (so a 50lb dog would receive 50mg of Benadryl).

So a simple and practical dose is 1mg of Benadryl per pound of your dog’s weight taken 2-3 times a day. For example, a 10-pound dog may receive a dose of 10 mg in the morning, afternoon, and evening.

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

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.

Edema occurs 30 minutes to several hours after exposure. The veterinarian often gives dogs with this reaction injections of antihistamines. If left untreated, the swelling will disappear in a day or two. Another reaction that we see 6–24 hours after exposure to an antigen is urticaria.

If your pet’s face looks swollen or crooked, contact your veterinarian immediately. Just like humans, dogs can be allergic to chemicals, foods, plants, spider stings, bee stings, medications, or vaccines (although this is rare).

Benadryl Liquid for Children can be used in small dogs at the same dosage. Avoid Adult Liquid Benadryl Blend as it often contains alcohol, which is toxic to dogs. As with any flavored human medication, always test inactive ingredients for xylitol, a sweetener that is extremely toxic to dogs.

Official response. The general dose of Benadryl (diphenhydramine) is 2 to 4 mg/kg up to three times a day. If your dog weighs 25 pounds (11.3 kg), the dose of Benadryl will be 22.6 to 45.2 mg up to three times a day. Benadryl tablets are available in 25 and 50 mg dosages.

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.

Quick-acting allergy medicines such as diphenhydramine (Benadryl) can help reduce swelling and itching after an insect bite.

Histamines cause upper respiratory allergy in humans, while cytokines (not histamines) cause pruritus in dogs. In allergic dogs, antihistamines do not control the cytokines (signaling proteins) that cause inflammation and itching.

Can dogs overdose on Benadryl? Yes, a dog can ingest or receive a dangerous dose of Benadryl. Fortunately, when treated promptly by a veterinarian, Benadryl toxicity usually produces excellent results in healthy animals.

How long does Benadryl take to work (and why)? –

Last updated: December 2, 2022 / author
Sandeep Bhandari

/ Fact verified / 4 minutes

Exact answer: up to 1 hour

Benadryl or diphenhydramine is a first-generation antihistamine primarily used to treat symptoms of allergies, colds, or hay fever. Symptoms may include sneezing, itching, watery eyes, and a runny nose. It can also be used to treat insomnia, Parkinson’s tremors, and nausea.

Health

Test your knowledge on health-related topics

1 / 10

Which organ is responsible for producing insulin in the body?

Liver

Pancreas

Stomach

Kidneys

2 / 10

The thick, oily, dark liquid that forms when tobacco is burned is called ___________.

Tar

Nicotine

carbon

Coal

3 / 10

What is the recommended daily intake of fiber for an adult?

10 grams

20 grams

30 grams

40 grams

4 / 10

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5 / 10

What is the role of carbohydrates in our diet?

Provide energy

Build muscle

Help digestion

Regulate body temperature

6 / 10

What is the main cause of type 2 diabetes?

Heredity

Poor diet

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Stress

7 / 10

How much physical activity is recommended for adults per week?

30 minutes

1 hour

2 hours

3 hours

8 / 10

What is the main cause of a cold?

Bacteria

virus

Allergies

None of the above

9 / 10

Which of the following is NOT a symptom of a cold?

Sore throat

Runny nose

Indigestion

Cough

10 / 10

What is the best way to improve sleep quality?

Maintaining a consistent sleep schedule

Regular exercise

Avoiding caffeine before bed

All of the above

Your score

Totals

1

9000 2 Diphenhydramine also has local anesthetic properties, which is useful for patients suffering from allergies caused by the use other commonly used anesthetics. However, this is not a drug use label. Benadryl can also cause allergic reactions in some people. In such a case, the use of Benadryl should be avoided.

How long does Benadryl take to work?

Benadryl works quickly and may take up to an hour to achieve maximum effect. It is taken orally in the form of tablets, which allows it to be easily distributed in the body. You may notice effects within 20-30 minutes, although it should continue to work for about four to six hours.

Benadryl primarily works by neutralizing h2 (histamine 1) receptors present on airway smooth muscle and other cells such as vascular endothelial cells, gastrointestinal (GIT), cardiac tissue, immune cells, uterus and central nervous system neurons. nervous system. nervous system (CNS) of your body. As a result, Benadryl may make you dizzy. Other side effects of the medication may include heart palpitations and dry mouth.

Total:

effect Elapsed time
soft 20-30 min.
maximum 1 hour

Benadryl can also be taken in the form of injections when the oral form is not practical. In this form, it has a fast-acting mechanism. When used at night before bed, the dose of Benadryl should not exceed 50 mg. For the elderly, a lower dose is preferred to avoid subsequent side effects.

Why does Benadryl work fast?

Benadryl antagonizes the h2 receptors in your body and acts as an inverse h2 receptor agonist. It reduces the symptoms of an allergic reaction by reversing the effect of histamine on your capillaries.

The h2 receptor is also similar to muscarinic receptors, due to which Benadryl also acts as an antimuscarinic agent that can be used to treat parkinsonism. It also blocks intracellular sodium channels in your body, resulting in local anesthetic properties.

There are also other medicines that can interact with Benadryl, decreasing or increasing its effect, or manipulating how long the medicine lasts. You may consult your doctor if you are taking other medications or want to control the effect and mode of action of Benadryl. Alcohol has also been shown to increase the sedative effects of Benadryl, so alcohol intake should be controlled while taking the medication.

A few tips to enhance the effect of Benadryl:

  1. It can be taken before or after meals.
  2. Take exactly as directed by your doctor. Do not exceed recommended.
  3. If you are using it to treat motion sickness or related symptoms, take Benadryl at least 30 minutes before exposure to movement. Take doses either before meals or at night before bed for best effect.
  4. It should not be used in children under the age of twelve to induce sleep. It should not be used in infants at all and should be kept away, especially from premature babies. In children, Benadryl can cause many side effects. Therefore, check with your doctor before allowing your child to use Benadryl.
  5. If you use Benadryl for a long period of time, take care of your oral hygiene.
  6. If you experience symptoms such as hallucinations, palpitations, drowsiness, muscle tremors, vomiting, or diarrhea, seek emergency medical attention.
  7. Use of Benadryl during pregnancy should be avoided as there are no adequate studies in pregnant women. Consult your doctor before starting medication.

If you are between the ages of 18 and 60, you may experience the side effects of Benadryl, such as drowsiness, low blood pressure, headache, rapid heartbeat, incoordination, abdominal discomfort, and thick mucus in the nostrils. . Not suitable for breastfeeding women and the elderly.

It is also not suitable for people with respiratory conditions such as narrow angle glaucoma, asthma, peptic ulcers, intestinal obstruction or heart disease, high thyroid levels, enlarged prostate or constricted bladder. An overdose of Benadryl can cause hallucinations, convulsions, and can also be fatal.

Conclusion

Benadryl will take 15 to 30 minutes to work, but you may experience its peak effect in about an hour. A dose of 25 to 50 milligrams has been suggested for its sedative effect. If you experience any health problems while taking Benadryl, see your doctor as soon as possible. It is best to keep Benadryl away from pregnant women, the elderly, and children until directed by a doctor. There are herbal remedies that have the same effect as antihistamines. Instead, you can use these remedies to avoid the side effects of Benadryl.

Recommendations

  1. https://nyaspubs.onlinelibrary.wiley.com/doi/abs/10.1111/j.1749-6632.1950.tb39907.x
  2. https://www.jacionline.org /article/0021 -8707(46)

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Sandeep Bhandari

Sandeep Bhandari is the founder of ExactlyHowLong.com.

I am a professional full-time blogger, internet marketer and trainer.