What to Know About Claritin (Loratadine)

An Over-the-Counter Antihistamine for Allergy Symptoms

Claritin (loratadine) is a popular over-the-counter (OTC) antihistamine used for treating allergy symptoms, such as runny nose, itchy or watery eyes, and sneezing. It can also be used for treating itchy skin reactions and urticaria (hives).

The medication blocks the actions of histamine, a substance that can be released by the immune system in response to harmless particles, such as pollen or mold. Histamine plays a major role in promoting nasal allergy symptoms, such as mucus, swelling, and itching.

Claritin comes in tablets, quick-dissolve tablets, chewable tablets, liquid-filled capsules, and a syrup. There are generic options, as well as another OTC brand of loratadine named Alavert.

Claritin package

Uses

Claritin is approved for treating allergic rhinitis (nasal inflammation) due to seasonal allergies or perennial allergies (occuring year round) in adults and children ages 6 months and older.

It can be used to help improve or prevent the following allergy symptoms:

  • Runny nose
  • Sneezing
  • Itchy, watery eyes
  • Itchy nose or throat
  • Itchiness or irritation from skin reactions, such as urticaria

Before Taking

Your doctor will ask you about your symptoms and may do a blood or skin test to identify or confirm that allergies are causing your symptoms. Common allergens include pollen (from trees, grasses, weeds), mold, dust mites, pets (cats, dogs), and pests (cockroaches, mice).

If the allergens are identified, you may be able to do some environmental interventions, such as mold remediation or pest control, to minimize exposure and eliminate symptoms without taking medications (or doing so for an extended period of time). If that proves insufficient, Claritin may be considered.

Because of how they work, first-generation antihistamines such as Benadryl typically cause drowsiness and carry risks for those with certain conditions, such as heart problems or glaucoma, or risk factors for dementia. Claritin and other second-generation antihistamines target histamine receptors more directly, reducing or eliminating these concerns (why they are typically considered first-line treatments).

Your doctor can help you evaluate if Claritin may be the best second-generation antihistamine for you or if another brand may be a better fit in your case. For example, while most people do not experience drowsiness while taking Claritin, this side effect can occur. If you experience this or are concerned about drowsiness, Allegra (fexofenadine) may be a preferred option.

Talk to your doctor about all medications, supplements, and vitamins that you currently take. While some drugs pose minor interaction risks, others may outright contraindicate use or prompt careful consideration as to whether the pros of treatment outweigh the cons in your case.

Precautions and Contraindications

While some people find that taking Claritin (without a decongestant) can be useful in treating their allergies on a daily basis, Claritin-D should not be taken for more than a few days. Claritin-D when taken regularly can raise blood pressure and can make nasal symptoms paradoxically worse.

Certain medical circumstances can make taking Claritin risky or even prohibit its use, including:

  • Allergic reactions: Do not take Claritin if you have ever had an allergic reaction to loratadine or any of the inactive ingredients. Those who are allergic or sensitive to gelatin should avoid the quick-dissolve tablets and the liquid-filled capsules.
  • Pregnancy: While studies suggest that use of antihistamines during pregnancy is not linked to birth defects, there is a lack of adequate and well-controlled human studies and more research is needed. Your doctor can help you evaluate whether or not you should take Claritin.
  • Nursing: Antihistamines may be transferred to the infant in breastmilk and may not recommended while breastfeeding. Your doctor can help you evaluate whether or not to take Claritin.
  • Phenylketonuria (PKU): The chewable tablets contain aspartame that is dangerous for those with the inherited metabolic disorder PKU.

Combination Products

Claritin-D is a combined product with both loratadine and pseudoephedrine, a decongestant that can interact with several medications and raise the risk of side effects. Consult your doctor if you plan to take a combination product, especially if you are taking any other drugs.

Other Treatment Options

There are a variety of second-generation OTC antihistamines. Some include:

  • Allegra (fexofenadine)
  • Zyrtec (cetirizine)
  • Xyzal (levocetirizine)

A common prescription brand of second-generation antihistamines is Clarinex (desloratadine).

Other OTC first-generation antihistamines that come with more side effects and risks, include

  • Ala-Hist IR (dexbrompheniramine)
  • Chlor-Trimeton, Aller-Chlor (chlorpheniramine)
  • Tavist, Dayhist Allergy (clemastine)

If antihistamines are not effectively managing your nasal allergy symptoms, your doctor may recommend another medication or combination therapy, such as an antihistamine along with a leukotriene modifier. Leukotriene modifiers, including prescription Singulair (montelukast), target molecules called leukotrienes that contribute to mucus and airway inflammation.

Your doctor may also discuss alternate treatments, such as immunotherapy (allergy shots or tablets).

Dosage

The standard dosage of Claritin for adults and children age 6 and older is 10 milligrams (mg) taken once daily or 5 mg taken up to twice daily.

The standard dosages of Claritin are as follows:

Type Dosage Max Amount Per 24 hours
Claritin tablets 10 mg  One tablet 
Claritin Liqui-Gels 10 mg One capsule 
Claritin 12-Hour RediTabs and 12-hour RediTabs for Juniors 5 mg One quick-dissolve tablet every 12 hours for a total max of two tablets 
Claritin 24-Hour RediTabs and 24-hour RediTabs for Juniors 10 mg One quick-dissolve tablet
Claritin Chewables and Children's Claritin Chewables  10 mg One chewable tablet
Children's Claritin syrup  5 mg per teaspoon/5 milliliter (mL) 2 teaspoons/10 mL

All listed dosages are according to the drug manufacturer. Check the product label and talk to your doctor to make sure you are taking the right dose for you.

For children age 12 months to five years old, the dose is 1/2 teaspoonful (1.25 mg in 2.5 mL) once daily. And for children age six months to 11 months of age, the dose is 2 mL (1 mg) once daily. 

Modifications

Your doctor may recommend a lower dose of Claritin, such as 10 mg every other day, if you have liver or kidney impairment since you may not clear antihistamines as efficiently, which puts you at a greater risk of toxicity.

How to Take and Store

You can take Claritin with or without food.

Take a missed dose as soon as possible unless it is almost time for the next dose, in which case you should just skip the dose you missed.

Follow guidelines for maximum doses per 24 hours. Taking more than the recommended dose may increase the risk of side effects and lead to an overdose.

If you accidentally take more of this medication than the recommended daily dosage, call Poison Control (800-222-1222) or seek urgent medical attention.

Store Claritin in a dry place at room temperature (ideally between 68 to 77 degrees F). As with all medications, keep it out of reach of children.

Do not use this medication if the safety seal is open or torn. Take the quick-dissolve tablets immediately after opening individual blisters.

Side Effects

Loratadine is typically well-tolerated and most side effects are mild, but it can lead to serious side effects such as a life-threatening allergic reaction called anaphylaxis in some instances.

Common

Common side effects of Claritin include:

Contact your doctor if any of these side effects are severe or don't get better over time.

Severe

If you experience any of the following serious side effects or symptoms of an allergic reaction while taking Claritin, seek urgent medical attention:

  • Nervousness
  • Wheezing
  • Difficulty Breathing
  • Fast heartbeat
  • Hoarseness
  • Swelling of the eyes, face, lips, or tongue
  • Drooling
  • Rash
  • Hives
  • Excessive restlessness
  • Abdominal pain
  • Difficulty speaking
  • Malaise

Warnings and Interactions

Some medications may interfere with loratadine blood concentrations and make Claritin more potent. These medications include:

Do not take Claritin at the same time as other antihistamines or any other oral allergy medications unless advised to do so by your physician. You may take intranasal corticosteroids sprays and allergy eye drops while also taking Claritin.

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