Allegra (fexofenadine) Side Effects, Dosing, Interactions, and Efficacy | Omudhome Ogbru, PharmD | RxEconsult

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Allegra (fexofenadine) Uses, Side Effects, Dosing, Interactions, and Efficacy Category: Allergies by - November 13, 2011 | Views: 9866 | Likes: 0 | Comment: 0  


Allegra for allergies

Brand Name: Allegra
Generic Name: fexofenadine

Medication class: Antihistamine
Manufacturer: Sanofi-Aventis
Approval date: July, 1996

What is Allegra and how does it work?

Allegra is an antihistamine that works by blocking histamine H1 receptors. Histamine is a chemical that is released when the body senses an allergen (foreign substance) and is responsible for allergic symptoms (watery eyes, sneezing, runny nose, itchy eyes). By blocking the action of histamine Allegra prevents allergic symptoms. Allegra is a non-sedating antihistamine when used at recommended doses. What does Allegra treat?

  • Symptoms of seasonal allergies (hay fever) or other respiratory allergies such as sneezing, running nose, itchy nose and/or throat and itchy or watery eyes.

  • Chronic (long term) itching and hives (urticaria).

How effective is Allegra?

  • In studies spanning 2 weeks, 15, 30 and 60 mg of Allegra reduced allergy symptoms in pediatric patients (between 6 and 11 years old) better than placebo. The 60 mg dose did not exhibit any additional benefit over the 30 mg dose.

  • In a clinical study of pediatric patients (between 6 months to 5 years) of age with allergic reactions, Allegra 15 mg and 30 mg was well tolerated as compared to placebo.

  • Allegra 60 mg taken twice daily administered to patients (between 12 and 68 years old) over 2 weeks significantly reduced sneezing, runny and itchy nose, itchy palate and throat, and itchy, watery and red eyes better than placebo.

  • Allegra 180 mg, administered once daily to patients (12 to 65 years old) over a 2-week period considerably reduced symptoms of seasonal allergies (sneezing, runny and itchy nose, itchy palate and throat, and itchy, watery and red eyes) better than placebo.

  • In a 4-week study, Allegra doses of 20, 60, 120, 240 mg twice daily were better than placebo in reducing chronic itching and wheals. The maximum benefit was achieved with the 60 mg twice daily dose.

What are interesting facts about Allegra?

  • Allegra provides 12-24 hour relief from indoor and outdoor allergies.

  • It is a non-sedating antihistamine.

  • It is available over the counter.

  • It is available for children 2 years and older.

How is Allegra dosed and administered?

Allegra is available as tablets or liquid for oral administration.

  • Children (2 years and older): 30 mg (1 teaspoonful) of Children’s Allegra every 12 hours.

  • Adults and Children (12 years and older): 60 mg every 12 hours or 180 mg every 24 hours.

What are the side effects of Allegra?

Common: Drowsiness, dizziness, fatigue, headache, back pain, diarrhea, stomach upset, muscle aches, runny nose, coughing and fever.

Serious: Serious allergic reactions to Allegra.

Allegra drug interactions

  • Erythromycin and ketoconazole: Erythromycin and ketoconazole lead to increased blood levels of Allegra. This may increase occurrence of Allegra adverse effects.

  • Antacids containing aluminum and magnesium (e.g., Maalox): Antacids that contain magnesium or aluminum decrease the absorption of Allegra, potentially reducing the effect of Allegra.

  • Do not administer with grapefruit juice because grapefruit juice decreases the absorption of Allegra.


 Allegra FDA prescribing information and Allegra drug facts label.

Also Read

Grastek (Timothy Grass Pollen Allergen Extract) Cost, Dosage, Side Effects

Review of Medications For Hives (Urticaria) Treatment

Rare Allergic Drug Reactions

Antihistamines for Allergies 


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