fexofenadine (Allegra, Mucinex Allergy)

What is fexofenadine, and how does it work (mechanism of action)?

Fexofenadine is an oral, "second generation" antihistamine that is used to treat the signs and symptoms of allergy and hives. It is similar to the other second generation antihistamines loratadine (Claritin), cetirizine (Zyrtec) and azelastine (Astelin).

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 that produce the effects that we associate with allergy (for example, sneezing). Fexofenadine blocks one type of receptor for histamine (the H1 receptor) and thus prevents activation of H1 receptor-containing cells by histamine. Unlike the first generation antihistamines, fexofenadine and other second-generation antihistamines do not readily enter the brain from the blood. Therefore, they cause less drowsiness and are called non-sedating antihistamines. Fexofenadine was approved by the FDA in July 1995.

What brand names are available for fexofenadine?

Allegra, Allegra Allergy, Children's Allegra, Allergy 24-HR, Mucinex Allergy

Is fexofenadine available as a generic drug?


Do I need a prescription for fexofenadine?

No, yes (suspension)

What are the uses for fexofenadine?

Fexofenadine is used for the treatment of seasonal allergies in patients 2 years of age and older and chronic urticaria (hives, itching) in patients 6 months of age and older.

What are the side effects of fexofenadine?

The most common side effects of fexofenadine are:

Other important side effects include:


Common Allergies: Symptoms and Signs See Slideshow

What is the dosage for fexofenadine?

For seasonal allergies and urticaria the recommended dose for adults and children 12 years of age or older is 60 mg twice daily or 180 mg once daily.

Which drugs or supplements interact with fexofenadine?

Aluminum containing antacids (for example, Maalox) reduced the absorption of fexofenadine when administered 15 minutes apart. Therefore, aluminum containing antacids and fexofenadine should not be administered together. Fruit juices (apple, orange, grapefruit) may reduce the absorption of fexofenadine. Fexofenadine should only be administered with water.

Is fexofenadine safe to take if I'm pregnant or breastfeeding?

Fexofenadine has not been adequately studied in pregnant women.

Fexofenadine has not been adequately studied in women who are breastfeeding.

What else should I know about fexofenadine?

What preparations of fexofenadine are available?

Tablets: 30, 60 and 180 mg. Suspension: 30 mg/5 ml.

Children 2-11 years of age should be given 30 mg twice daily for seasonal allergies or urticaria.

Children 6 months to 2 years old should receive 15 mg twice daily for urticaria.

The suspension is used for children less than 6 years old.

How should I keep fexofenadine stored?

Tablets and suspension should be stored at room temperature between 20 C - 25 C (68 F - 77 F).


Fexofenadine (Allegra, Mucinex Allergy) is a medication prescribed for the treatment of allergy and hives. Side effects, drug interactions, and pregnancy safety should be reviewed prior to taking this medication.

Treatment & Diagnosis

Medications & Supplements

Prevention & Wellness

Subscribe to MedicineNet's Allergy and Asthma Newsletter

By clicking "Submit," I agree to the MedicineNet Terms and Conditions and Privacy Policy. I also agree to receive emails from MedicineNet and I understand that I may opt out of MedicineNet subscriptions at any time.

Health Solutions From Our Sponsors

FDA Logo

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

See more info: fexofenadine on RxList

FDA Prescribing Information