Clarinex (Desloratadine) - Oral

Warning:

What Is Clarinex?

Clarinex (desloratadine) is a prescription treatment option to relieve allergy symptoms, itchiness, and hives. It's a second-generation histamine (H1) antagonist, which works by blocking histamine release in the body. Histamine is a chemical responsible for causing allergy symptoms.

Clarinex is available as a regular tablet, an easily dissolvable tablet, and as an oral syrup.

Drug Facts

Generic Name: Desloratadine

Brand Name: Clarinex

Drug Availability: Prescription

Administration Route: Oral (by mouth)

Therapeutic Classification: Second-generation histamine (H1) antagonist

Available Generically: Yes (tablets)

Controlled Substance: No

Active Ingredient: Desloratadine

Dosage Form: Tablets, oral syrup

What Is Clarinex Used For?

Clarinex is used to relieve allergy symptoms. It may also help with itchiness and hives (skin rash).

In the United States (U.S.), millions of people have allergies every year. Allergy symptoms may include sneezing, runny nose, itchiness, and rash. Allergies happen when your immune system (the body's defense system) overreacts to certain allergens (triggers). Examples of some triggers are pollen, dust mites, and pet dander.

Some people, however, experience itchiness and rashes without a trigger. This medical condition is called chronic (long-term) idiopathic urticaria (hives). Idiopathic is a term that means of unknown cause.

Fortunately, in addition to relieving allergy symptoms, the Food and Drug Administration (FDA) also approved Clarinex to treat these types of hives.

Clarinex (Desloratadine) Drug Information: A person with hives on their face and neck

Verywell / Zoe Hansen

How to Take Clarinex

Clarinex is typically taken by mouth once daily with or without food.

Clarinex has two different types of tablets: a regular tablet and an orally disintegrating tablet (ODT). The ODT is an easily dissolvable tablet. It's also called a RediTab. Once placed on the tongue, it quickly breaks apart and dissolves without any need for water. Just wait for the tablet to dissolve before swallowing.

Storage

Clarinex is a non-controlled medication. Therefore, your healthcare provider can authorize refills for up to one year from the original written date on the prescription.

When you bring Clarinex home from the pharmacy, the medication has a safe storage range between 59 degrees to 86 degrees Fahrenheit (F). As a result, room temperature will typically be an acceptable environment. Clarinex, however, is sensitive to heat. Therefore, avoid temperatures above 86 degrees F. Also, protect this medication from moisture.

If travel with Clarinex, become aware of your final destination's regulations. In general, make a copy of your Clarinex prescription and keep the medication in its original container from the pharmacy, with your name on it.

Off-Label Uses

Clarinex has some off-label uses.

In fact, experts recommend Clarinex as an effective treatment option for acute (new-onset) hives. A 2016 study also suggests that Clarinex might be a potential preventative option for people with hives from nonsteroidal anti-inflammatory drugs (NSAIDs)—like Advil (ibuprofen).

How Long Does Clarinex Take to Work?

You might start to notice Clarinex effects within one hour.

What Are the Side Effects of Clarinex?

This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the Food and Drug Administration (FDA) at fda.gov/medwatch or 800-FDA-1088.

Common Side Effects

Common side effects with Clarinex include:

Severe Side Effects

Get medical help right away if you experience a severe allergic reaction to Clarinex. Symptoms of a severe allergic reaction may include:

  • Breathing difficulties
  • Hives
  • Itchiness
  • Rash
  • Swelling

Long-Term Side Effects

Second-generation histamine (H1) antagonists—like Clarinex—have good long-term safety profiles. In fact, this class of antihistamines has little to no side effects with long-term use.

In children, there are also no differences in the safety profiles between this antihistamine class and placebo (a substance with no medicine in it).

Report Side Effects

Clarinex may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much Clarinex Should I Take?

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The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

For patients using the oral disintegrating tablet form of this medicine:

  • Make sure your hands are dry.
  • Do not push the tablet through the foil backing of the package. Instead, gently peel back the foil backing and remove the tablet.
  • Immediately place the tablet on top of the tongue.
  • The tablet will dissolve in seconds, and you may swallow it with your saliva. You do not need to drink water or other liquid to swallow the tablet.

For patients using the syrup form of this medicine: Use a calibrated measuring dropper or syringe to measure the direct dose for your child based on your doctor's instructions. Do not use a regular teaspoon. If you are unsure about how much of the syrup to give to your child, ask your doctor or pharmacist.

  • For oral dosage form (oral disintegrating tablets):
    • For symptoms of chronic hives:
      • Adults and children 12 years of age and older—5 milligrams (mg) once a day.
      • Children 6 to 11 years of age—2.5 mg once a day.
      • Children 4 to 6 years of age—Use and dose must be determined by your doctor.
      • Children and infants up to 4 years of age—Use is not recommended .
    • For symptoms of hay fever:
      • Adults and children 12 years of age and older—5 mg once a day.
      • Children 6 to 11 years of age—2.5 mg once a day.
      • Children 4 to 6 years of age—Use and dose must be determined by your doctor.
      • Children and infants up to 4 years of age—Use is not recommended .
  • For oral dosage form (tablets):
    • For symptoms of chronic hives:
      • Adults and children 12 years of age and older—5 mg once a day.
      • Children 4 to 12 years of age—Use and dose must be determined by your doctor.
      • Children and infants up to 4 years of age—Use is not recommended .
    • For symptoms of hay fever:
      • Adults and children 12 years of age and older—5 mg once a day.
      • Children 4 to 12 years of age—Use and dose must be determined by your doctor.
      • Children and infants up to 4 years of age—Use is not recommended .
  • For oral dosage form (syrup):
    • For symptoms of chronic hives:
      • Adults and children 12 years of age and older—2 teaspoonfuls (5 milligrams [mg] in 10 milliliters [mL]) once a day.
      • Children 6 to 11 years of age—1 teaspoonful (2.5 mg in 5 mL) once a day
      • Children 4 to 5 years of age—½ teaspoonful (1.25 mg in 2.5 mL) once a day
      • Children and infants up to 4 years of age—Use is not recommended .
    • For symptoms of hay fever:
      • Adults and children 12 years of age and older—2 teaspoonfuls (5 milligrams [mg] in 10 milliliters [mL]) once a day.
      • Children 6 to 11 years of age—1 teaspoonful (2.5 mg in 5 mL) once a day
      • Children 4 to 5 years of age—½ teaspoonful (1.25 mg in 2.5 mL) once a day
      • Children and infants up to 4 years of age—Use is not recommended .

Modifications

Your healthcare provider might slightly modify (change) your Clarinex treatment under the following situations:

People with kidney or liver problems: If you have kidney or liver impairment, your healthcare provider may need to adjust your dose.

Pregnant people: There is limited safety and effectiveness data about Clarinex in pregnant people. If you have any concerns, talk with your healthcare provider to weigh the benefits and risks of taking Clarinex during your pregnancy.

Nursing people: Experts expect low amounts of Clarinex in breast milk. As a result, experts believe that Clarinex is unlikely to cause negative effects on the nursing baby or milk production. Combining Clarinex with a decongestant—like Sudafed (pseudoephedrine), however, might negatively affect milk production.

Children: There is no safety and effectiveness information for Clarinex in children younger than 6 months.

Older adults: Some people over 65 may have medical conditions, such as liver and kidney impairment. Therefore, caution with Clarinex is recommended.

Missed Dose

If you accidentally forgot your Clarinex dose, take it as soon as you remember. If it's already close to your next scheduled dose, then skip the missed dose and take the following dose at your next scheduled time. Don't try to double up to make up for the missed dose.

Overdose: What Happens If I Take Too Much Clarinex?

Daily high Clarinex doses of 45 45 milligrams (mg) for 10 days did not result in any side effects. If you accidentally take too much Clarinex, however, you might experience some drowsiness.

If you suspect you're experiencing life-threatening side effects, seek immediate medical attention.

What Happens If I Overdose on Clarinex?

If you think you or someone else may have overdosed on Clarinex, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking Clarinex, call 911 immediately.

Precautions

Drug Content Provided and Reviewed by IBM Micromedex®

If your symptoms do not improve within a few days or if they become worse, check with your doctor.

This medicine may cause some people to become drowsy, dizzy, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert.

What Are Reasons I Shouldn't Take Clarinex?

Before taking Clarinex, talk with your healthcare provider if the following applies to you.

  • Severe allergic reaction: If you have a severe allergic reaction to Clarinex or its components (ingredients), then Clarinex isn't an ideal option for you.
  • Kidney or liver problems: If you have kidney or liver impairment, your healthcare provider may need to adjust your Clarinex dose.
  • Pregnant people: There is limited safety and effectiveness information about Clarinex in pregnant people.
  • Nursing people: Clarinex is unlikely to have negative effects on the nursing baby or milk production. If possible, however, avoid combining Clarinex with pseudoephedrine. On the other hand, this combination might have adverse effects on milk production.
  • Children: Clarinex has no safety and effectiveness data in children younger than 6 months.
  • Older adults: In older adults with medical conditions—like kidney and liver impairment-Clarinex should be taken with caution.

What Other Medications Interact With Clarinex?

Use caution when taking Clarinex with the following medications:

  • Cimetidine: Tagamet (cimetidine) is a histamine (H2) blocker and a treatment option for heartburn. It may also lead to high levels of Clarinex in the body, and these increased levels might raise the chances of side effects.
  • CYP3A4 inhibitors: CYP3A4 is a protein in the liver that breaks down medications—like Clarinex. CYP3A4-inhibiting medications—like the erythromycin antibiotic—can also block the CYP3A4 protein from working. This can lead to high levels of Clarinex in the body, which might raise the likelihood of side effects.
  • Fluoxetine: Prozac (fluoxetine) is a selective serotonin reuptake inhibitor (SSRI) commonly used to treat depression. This medication is linked to high amounts of Clarinex in the body, and high Clarinex levels might raise the risk of side effects.

For more detailed information about drug interactions with Clarinex, talk with your pharmacist or healthcare provider.

What Medications Are Similar?

There are many medications available to relieve allergy symptoms. Since Clarinex is a second-generation histamine (H1) antagonist, the following medications are most similar to Clarinex.

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

There are few studies that compare these different second-generation H1 antagonist medications. However, Xyzal and Zyrtec have the highest potency—with a moderate risk of sleepiness or drowsiness compared to the other medications in this class.

Except for Clarinex, all of the medications in this class are available as convenient over-the-counter (OTC) options. While insurance doesn't typically cover OTC products, it might cover Clarinex, which is a prescription medication.

Clarinex is also the only medication in the class approved to relieve allergy symptoms and treat chronic idiopathic hives. Additionally, Clarinex is the only medication in the class approved for children as young as 6 months.

Frequently Asked Questions

  • Where is Clarinex available?

    Clarinex is available as a prescription from your healthcare provider. Many local retail pharmacies carry Clarinex. If necessary, pharmacy staff can usually order this medication for you.

  • How much does Clarinex cost?

    Clarinex is a prescription. Without insurance, it tends to be more expensive than other over-the-counter medications in its class. However, since it has a generic version, this will help with the cost.

  • What if Clarinex doesn't work for me?

    If Clarinex doesn't work for you, switching to another medication in its class might work. Talk with your pharmacist or healthcare provider about your symptoms. For example, if you have mainly allergy symptoms of the nose, then a steroid nasal spray might be a better option.

How Can I Stay Healthy While Taking Clarinex?

Allergy season can be a miserable time for many people, and living with chronic idiopathic hives can also be frustrating.

Taking Clarinex or other allergy-relieving medications may help. If you have allergy symptoms, avoiding exposure to triggers may also help. For example, avoid contact with pets if you're allergic to pet dander. You can also wear a mask or sunglasses outdoors to limit your exposure to allergens.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Ross Phan, PharmD, BCACP, BCGP, BCPS
Ross is a writer for Verywell with years of experience practicing pharmacy in various settings. She is also a board-certified clinical pharmacist and the founder of Off Script Consults.