- What is desloratadine, and how does it work (mechanism of action)?
- What is desloratadine used for?
- What are the side effects of desloratadine?
- What is the dosage for desloratadine?
- Which drugs or supplements interact with desloratadine?
- Is desloratadine safe to take if I'm pregnant or breastfeeding?
- What else should I know about desloratadine?
What is desloratadine, and how does it work (mechanism of action)?
Desloratadine is an oral, long-acting antihistamine that is similar chemically to loratadine (Claritin). It is used to treat the symptoms caused by histamine. Histamine is a chemical that is responsible for many of the signs and symptoms of allergic reactions, for example, swelling of the lining of the nose, sneezing, and itchy eyes. Histamine is released from histamine-storing cells (mast cells) and then attaches to other cells that have receptors for histamine. The attachment of the histamine to the receptors causes the cells to be "activated," releasing other chemicals which produce the effects that we associate with allergy. Desloratadine blocks one type of receptor for histamine (the H1 receptor) and thus prevents activation of H1 receptor-containing cells by histamine. Desloratadine does not readily enter the brain from the blood and, therefore, causes less drowsiness (sedation). It is a member of a small family of non-sedating antihistamines which includes loratadine (Claritin), cetirizine (Zyrtec), fexofenadine (Allegra), and levocetirizine (Xyzal). Desloratadine was approved by the FDA in December 2001.
What brand names are available for desloratadine?
Clarinex, Clarinex Reditabs
Is desloratadine available as a generic drug?
GENERIC AVAILABLE: Yes
Do I need a prescription for desloratadine?
Yes
What is desloratadine used for?
What are the side effects of desloratadine?
The most common side effects of desloratadine are:
- headache,
- dizziness,
- nausea,
- weakness,
- sore throat,
- dry mouth,
- muscle pain,
- painful menstruation, and
- sleepiness.
What is the dosage for desloratadine?
The recommended dose for adults and children 12 years or older is 5 mg daily.
For children 6 to 11 years of age the dose is 2.5 mg of the syrup or 2.5 mg of the RediTabs once daily.
Children 12 months to 5 years old should receive 1.25 mg of the syrup once daily and children 6 to 11 months old are treated with 1 mg of syrup once daily.
Desloratadine can be taken with or without food.

SLIDESHOW
Common Allergies: Symptoms and Signs See SlideshowWhich drugs or supplements interact with desloratadine?
Ketoconazole (Nizoral, Extina, Xolegel, Kuric), erythromycin, azithromycin (Zithromax), fluoxetine (Prozac), and cimetidine (Tagamet) increase blood levels of desloratadine by reducing the elimination of desloratadine by liver enzymes.
Is desloratadine safe to take if I'm pregnant or breastfeeding?
Desloratadine has not been studied in pregnant women.
Desloratadine passes into breast milk and should therefore be used with caution in women who are breastfeeding.
Summary
Desloratadine (Clarinex, Clarinex Reditabs) is a medication used to treat allergies and hives (chronic urticaria) in adults and children 12 years of age and older. Review side effects, drug interactions, warnings and precautions, and patient safety information prior to taking any medication.
Multimedia: Slideshows, Images & Quizzes
Related Disease Conditions
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Chronic Rhinitis and Post-Nasal Drip
Chronic rhinitis (non allergic rhinitis) causes runny nose, sneezing, nasal itching and congestion. Post-nasal drip is drainage of mucus from the sinuses into the throat. Treatment includes over-the-counter (OTC) medications.
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Hives (Urticaria)
Hives, also called urticaria, is a raised, itchy area of skin. Most often the cause of hives is unknown. Sometimes it is a sign of an allergic reaction to food or medications, but the cause of the allergy (the allergen) is unknown. Dermatographism and swelling (angioedema) may accompany hives. Treatment to get rid of hives and alleviate symptoms typically includes antihistamines.
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Allergy (Allergies)
An allergy refers to a misguided reaction by our immune system in response to bodily contact with certain foreign substances. When these allergens come in contact with the body, it causes the immune system to develop an allergic reaction in people who are allergic to it. It is estimated that 50 million North Americans are affected by allergic conditions. The parts of the body that are prone to react to allergies include the eyes, nose, lungs, skin, and stomach. Common allergic disorders include hay fever, asthma, allergic eyes, allergic eczema, hives, and allergic shock.
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Hay Fever (Allergic Rhinitis)
Hay fever (allergic rhinitis) is an irritation of the nose caused by pollen and is associated with the following allergic symptoms: nasal congestion, runny nose, sneezing, eye and nose itching, and tearing eyes. Avoidance of known allergens is the recommended treatment, but if this is not possible, antihistamines, decongestants, and nasal sprays may help alleviate symptoms.
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Eye Allergy
Eye allergy (or allergic eye disease) are typically associated with hay fever and atopic dermatitis. Medications and cosmetics may cause eye allergies. Allergic eye conditions include allergic conjunctivitis, conjunctivitis with atopic dermatitis, vernal keratoconjunctivitis, and giant papillary conjunctivitis. Dry eye, tear-duct obstruction, and conjunctivitis due to infection are frequently confused with eye allergies. Eye allergies may be treated with topical antihistamines, decongestants, topical mast-cell stabilizers, topical anti-inflammatory drugs, systemic medications, and allergy shots.
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What Is Allergic Cascade?
The allergic cascade refers to allergic reactions that happen in the body in response to allergens. A variety of immune cells and chemical messengers participate in the allergic cascade. Symptoms of the allergic cascade range from mild swelling and itching to full-blown anaphylactic shock. Allergen avoidance and medications are used to prevent or treat allergies.
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