Claritin vs. Benadryl: Similarities and Differences

Karen Berger, PharmD
·10 min read

Medically reviewed by Erika Prouty, PharmD

The effective treatment of allergies is based on the identification of the existing allergy, such as hay fever, and the severity of its symptoms.

For many people with allergies, the use of an antihistamine medication is part of a holistic approach to treating and managing allergy symptoms.

Antihistamines are available in the form of pills or liquids that you can take by mouth, as well as other formulations such as nasal sprays or eye drops.

Examples of common antihistamines include Claritin (loratadine) and Benadryl (diphenhydramine), over-the-counter (OTC) medications that treat allergy symptoms such as sneezing, watery eyes, and itching.

Though both drugs can help control allergy symptoms and are generally viewed by healthcare providers as similar, potential users should understand their notable differences, including that Claritin tends to cause less drowsiness than Benadryl.

This article will provide an in-depth comparison of Claritin versus Benadryl, emphasizing their respective uses, side effects, dosing requirements, and more.

<p>Getty Images / UCG</p>

Getty Images / UCG

Understanding Antihistamines

OTC antihistamines can treat allergy symptoms. Because they are available OTC, you do not need a prescription.

When you have allergies, your immune system reacts to substances (also called allergens) that are usually not harmful under normal circumstances.

But when you have allergies, the immune response overreacts and releases chemicals such as histamines, which cause allergy symptoms.

How They Work

Antihistamines work by blocking the effects of histamines, which help with symptoms such as:

First- vs. Second-Generation Antihistamines

Benadryl and Claritin are antihistamines.

Benadryl contains the active ingredient diphenhydramine. It is a first-generation antihistamine.

First-generation antihistamines were the first group of antihistamines developed.

However, because of the way they work, they cause more problematic side effects like extreme drowsiness and impaired thinking. First-generation antihistamines, like Benadryl, are known to cross the blood-brain barrier.

This means that even when taken at a standard dose, these medications can cause extreme drowsiness and affect driving and brain functions like thinking and memory.

Unisom PM Pain Nighttime Sleep Aid and Pain Reliever (doxylamine) is an example of a commonly used first-generation antihistamine.

Claritin contains the active ingredient loratadine. It is a second-generation antihistamine.

Second-generation antihistamines are newer antihistamines that tend to cause less drowsiness. They are sometimes referred to as non-sedating antihistamines.

Besides Claritin, some other examples of second-generation antihistamines include:

Statistics on Allergies

If you experience allergies, you are not alone.

Data from the Centers for Disease Control and Prevention (CDC) and the National Center for Health Statistics (NCHS) found that about 33% of adults and 25% of children in the United States have some type of allergy, such as:

  • Seasonal allergies (when the immune system reacts to outdoor triggers like mold or pollen)

  • Eczema (a skin condition that causes itching and inflammation)

  • Food allergies (when the immune system reacts to a particular food or foods)

What Is Claritin?

Claritin, which contains the active ingredient loratadine, is an orally administered (taken by mouth) second-generation antihistamine.

Claritin works by blocking histamine, a substance that causes allergy symptoms.

The ingredient loratadine is also available as a generic alternative to the brand-name Claritin.

Uses

Claritin can treat:

  • Symptoms of allergic rhinitis (allergies; also known as hay fever), including symptoms of seasonal allergies or perennial allergies (allergies that occur year-round and can be triggered by things like dust mites or pet dander)

  • Hives

Forms of Administration

Claritin is available in the following forms:

  • Tablets

  • Dissolving tablets

  • Chewable tablets

  • Capsules

  • Liquid

Off-Label Uses

Claritin can also be taken off-label (i.e., using a drug for a purpose that the U.S. Food and Drug Administration has not approved it for) to prevent symptoms in people who have both exercise-induced asthma and allergies.

The ingredient in Claritin, loratadine, can also be found in combination products such as Alavert D-12 or Claritin-D, which contain loratadine and pseudoephedrine (PSE, a nasal decongestant that relieves a stuffy nose).

What Is Benadryl?

Benadryl, which contains diphenhydramine, is a first-generation antihistamine.

Benadryl works by blocking histamine, a substance that causes allergy symptoms.

The ingredient diphenhydramine is also available as a generic alternative to the brand-name Benadryl.

Uses

Benadryl can treat:

  • Allergy symptoms

  • Common cold symptoms

  • Allergic reactions

  • Cough

Off-Label Uses

Benadryl is sometimes taken off-label for the following:

Forms of Administration

Benadryl is available in the following forms of oral administration:

  • Tablets

  • Chewable tablets

  • Capsules

  • Liquid

Benadryl is also available in injectable and topical formulations. The injectable formulations are available by prescription.

The ingredient in Benadryl, diphenhydramine, can also be found in various combination products such as:

  • Advil PM (diphenhydramine/ibuprofen)

  • Theraflu Nighttime Severe Cold and Cough (acetaminophen/diphenhydramine/phenylephrine)

Dosing Guidelines

Dosing will depend on various factors, such as age and formulation. Always read labels carefully to check the proper dosage before taking Claritin or Benadryl.

Check with a healthcare provider or pharmacist if you have any questions about dosing.

When using a liquid formulation, always measure with a medication-measuring device.

Because multiple medication formulations are available, we will provide a few common examples.

Claritin

Common dosing volumes include the following:

  • The usual dose for children 2–5 years old is 5 milligrams (mg) by mouth once daily.

  • The usual dose for adults and children ages 6 years and older is 10 mg by mouth daily.

Benadryl

Because Benadryl has many potential uses, dosing can vary.

Because we are comparing Claritin and Benadryl, we will focus on OTC Benadryl dosing for allergies:

  • The usual adult dosage is 25–50 mg by mouth every four to six hours as needed (no more than 300 mg daily).

  • The usual dose for children 6–12 years old is 12.5–25 mg orally every four to six hours as needed (no more than 150 mg daily).

  • Because of possible side effects such as drowsiness and dizziness, which can lead to falls, older adults should check with a healthcare provider before using Benadryl. If a healthcare provider recommends using Benadryl, they may suggest a lower dosage.

How Quickly Will They Work?

A dose of Claritin starts to work within one to three hours. It reaches its maximum effect at around eight to 12 hours and lasts 24 hours. This is why it only needs to be taken once daily.

Benadryl works faster but only lasts for a short time. A dose of Benadryl starts working within 15–30 minutes. It reaches its maximum effect in two to four hours.

However, because it only lasts for a short time in the body, it must be taken more frequently, generally every four to six hours, as needed.

Safe Use Guidance

Here are some tips for taking Claritin or Benadryl safely:

  • Do not drink alcohol while taking Claritin or Benadryl. It can worsen side effects such as drowsiness and dizziness.

  • While taking an antihistamine, do not drive until you know how the medication affects you. Benadryl, especially, can cause significant drowsiness. Certain medications can also have this effect, such as anxiety medications or medications that help you sleep, so avoid this combination. Ask your healthcare provider or pharmacist about drug interactions before taking Claritin or Benadryl.

  • If you are pregnant or breastfeeding, consult your healthcare provider before taking any new medication. Also, check with your healthcare provider if you have any medical conditions, such as liver or kidney problems, glaucoma, an enlarged prostate, or breathing problems,

  • Store your medication out of sight and out of reach of children and pets.

  • Follow dosage instructions closely and do not take more medication than recommended.

  • In case of overdose, call 911 or call Poison Control at 1-800-222-1222.

Side Effects

Claritin

Common side effects of Claritin may include:

  • Headache

  • Dry mouth

  • Nosebleed

  • Sore throat

  • Mouth sores

  • Having trouble falling or staying asleep

  • Feeling nervous

  • Weakness

  • Stomach problems like stomach pain or diarrhea

Benadryl

Common side effects of Benadryl may include:

  • Dryness of the mouth, nose, and/or throat

  • Drowsiness and dizziness

  • Stomach problems like nausea, vomiting, and constipation

  • Decreased appetite

  • Chest congestion

  • Headache

  • Weak muscles

  • Feeling nervous

  • Excitement (more so in children)

Efficacy

When deciding on a medication, there are several factors to consider, such as age, symptoms, and other medical conditions or potential drug interactions.

For example, a 67-year-old male truck driver with an enlarged prostate would be safer taking Claritin because it is less likely to cause extreme drowsiness and less likely to affect his prostate.

On the other hand, a young child with an allergic reaction may be better suited to take Benadryl because it works faster.

Some individuals prefer taking a non-sedating antihistamine like Claritin daily to prevent allergies but may take Benadryl at night occasionally.

Check with a healthcare provider to determine which medication is best for you in various situations, including for daily use or a more acute allergic reaction.

That said, let's take a look at some guidelines.

The American Academy of Otolaryngology-Head and Neck Surgery (AAO–HNS) clinical practice guidelines for adults and children with allergic rhinitis have some specific recommendations in this area:

  • Nasal steroid sprays, such as Flonase (fluticasone), are strongly recommended because they are effective and safe. They help with symptoms like stuffy or runny nose, sneezing, and itching.

  • In terms of oral antihistamines, the guidelines recommend second-generation antihistamines (such as Claritin) because they are less sedating than first-generation antihistamines. The guidelines note that antihistamines are less effective than nasal steroids but can relieve mild to moderate symptoms such as sneezing and itching.

Alternative Treatment Options

Aside from taking Claritin or Benadryl (and possibly a nasal steroid spray), you can visit an allergist who can help you identify your triggers and find ways to avoid them.

You can also ask about other non-medicinal methods you can try to reduce allergy symptoms, such as:

  • Rinsing nasal passages using a neti pot or nasal saline rinse

  • Monitoring weather reports for pollen and mold counts and staying inside when necessary

  • Closing doors and windows at home and keeping car windows closed

  • Taking a shower immediately after coming in from outside, washing your hair and body thoroughly, and putting on clean clothes

  • Wearing a mask when working outdoors

  • Using an air purifier, especially in the bedroom

  • Making sure carpets are regularly vacuumed during the height of allergy season and asking someone to help you with this task if it irritates your allergies

Summary

Claritin (loratadine) and Benadryl (diphenhydramine) are antihistamines that treat allergy symptoms such as runny nose, sneezing, and itchy and watery eyes.

Though similar, they do have notable differences.

For example, though both medicines can cause side effects, Benadryl is more likely to cause side effects like extreme drowsiness.

Benadryl is also more likely to interact with certain medications or medical conditions.

You can talk with a healthcare provider for more information and medical advice on Claritin and Benadryl to determine which medication is appropriate.

Frequently Asked Questions

How do I store Claritin or Benadryl?

Store Claritin or Benadryl at room temperature (68–77 degrees F), away from direct light, heat, and moisture. Do not store it in the bathroom. Keep out of reach and out of sight of children and pets.

Follow any other storage directions on the package label for the specific product you are using.

Can I measure liquid Claritin or Benadryl with a kitchen teaspoon?

No.

You should use the enclosed measuring device or ask your pharmacist for a medication-measuring device, such as an oral syringe.

Using household spoons is not safe because they are not uniform in size, which could easily result in an overdose.

Ask your pharmacist for help if you are unsure how to use a measuring device.

Read the original article on Verywell Health.