Claritin: What It Does and Possible Side Effects

Claritin is an over-the-counter (OTC) medication used to relieve symptoms of seasonal allergies. Claritin is the brand name for the drug loratadine. It is available for adults and children over age 2.

A benefit of Claritin is that it's a non-drowsy antihistamine, meaning it is less likely to cause you to feel sleepy compared to Benadryl and some other medications. However, some people do experience tiredness after taking Claritin.

This article discusses the uses of Claritin, as well as potential side effects and interactions.

Active Ingredient

As an antihistamine, loratadine is approved to treat allergy symptoms and hives.

Uses

Antihistamines are medications that reduce the effects of histamine, a natural chemical released by the immune system in response to a "threat." Histamine causes allergy symptoms.

Claritin is used to relieve symptoms of seasonal allergies and hives which include:

• Runny nose
• Sneezing
• Itchy eyes
• Itchy nose or throat
• Itchy rash (hives)

Claritin can help many people with allergy symptoms, but the medication may not be appropriate for certain situations:

• If you are using Claritin to treat hives, contact your healthcare provider if they do not improve within three days or if they last for more than six weeks.
• Do not use Claritin to treat hives that do not itch, are bruised or blistered, or are an unusual color.

OTC antihistamines like Claritin should not affect your blood pressure. However, allergy medicine that includes a decongestant may raise blood pressure. Talk to your healthcare provider before using these medications.

Dosage and Directions

Adults and children ages 6 and older:

• One (10 mg) tablet every 24 hours
• One (10 mg) Reditab every 24 hours

Children age 2 to 6 years old:

• One (5 mg) teaspoon every 24 hours
• One (5 mg) chewable tablet every 24 hours

Children under 2 years old:

• Talk to your child's healthcare provider.

When to Take Claritin

Since Claritin does not cause drowsiness, it can be taken at any time of day. Check the product label to see how much of a particular product you should take within 24 hours.

You can take Claritin with or without food.

Side Effects of Claritin

Some side effects may occur, depending on the individual. Following the directions provided on the medication label can reduce the risk of adverse reactions.

Possible side effects of Claritin to watch for include the following:

• Headache
• Dry mouth
• Nosebleed
• Sore throat or sores in the mouth
• Difficulty sleeping at night or falling asleep
• Nervousness
• Weakness
• Stomach pains or diarrhea
• Red, itchy eyes
  

Drowsiness

Claritin is less likely to cause drowsiness compared to some other allergy medications, but it can cause drowsiness if you take more than the recommended dose. To prevent drowsiness, always follow dosage instructions on the package or the recommendations provided by your healthcare provider. 

Is It OK to Take Claritin Every Day?

Claritin is considered a safe antihistamine that can be used every day, long term. However, there are very rare instances of liver damage that may have been caused by loratadine.

In these cases, the people who developed liver problems may have been pre-disposed to the illnesses.

Warnings and Interactions

While Claritin is available over the counter, check with your healthcare provider if you have specific health needs, such as:

• You are allergic to loratadine, or any other medications.
• You have ever had asthma, kidney, or liver disease.
• You are pregnant, plan to become pregnant, or are breastfeeding.
• You have phenylketonuria (PKU). Some rapidly dissolving tablets contain aspartame, which could be dangerous if you have this condition.

Claritin should not be taken alongside some other prescription medications, such as the antibiotic erythromycin. Speak to your pharmacist about other drugs you take before taking Claritin.

Alternatives

Other over-the-counter allergy medications that can be used in place of Claritin include:

• Allegra (fexofenadine): A non-drowsy antihistamine that works like Claritin
• Zyrtec (cetirizine): A second-generation antihistamine that works like Claritin, but can cause more drowsiness than Claritin
• Xyzal (levocetirizine): Has the same active ingredient as Zyrtec and works in the same way as Zyrtec
• Benadryl (diphenhydramine HCL): A first-generation antihistamine that can cause sedation, drowsiness, fatigue, and impaired alertness and concentration. It may be helpful when symptoms prevent you from sleeping.

First-generation antihistamines not only block histamine and muscarinic receptors but also cross the blood-brain barrier. Second-generation antihistamines, like Claritin, do not pass through the blood-brain barrier, have fewer side effects, and interact with fewer medications.

In addition to other medications, there are some natural antihistamines and alternative treatments that you can consider to treat your allergies. These include:

• Quercetin
• Vitamin C
• Stinging nettle
• Butterbur
  

There is little research on the effectiveness of these remedies for relieving allergy symptoms, so ask your healthcare provider if these therapies are safe and effective for you.

Summary

Claritin is an over-the-counter antihistamine that can ease common symptoms related to seasonal allergies and hives. It does not cause drowsiness for most people.

Formulas are available for children as well as adults. It is generally a safe medication but talk to your healthcare provider if you have special health needs or are pregnant or breastfeeding.

A Word From Verywell

There are many antihistamines available over the counter, so it can sometimes be overwhelming trying to decide which to use. Claritin (loratadine) is a good choice for many, given its non-drowsy nature and once-daily dosing. As always, it's important to check with your healthcare provider or pharmacist before starting a new medication.

— LINDSAY COOK, PHARMD, MEDICAL EXPERT BOARD