Fexofenadine Dosage and Overdose, Side Effects, Generic Forms And Packaging

Fexofenadine (Allegra) is an antihistamine drug used in the treatment of hayfever and similar allergy symptoms. It was developed as a successor of and alternative to terfenadine, an antihistamine with potentially serious contraindications.
Fexofenadine, like other second and third-generation antihistamines, does not readily cross the blood-brain barrier, and so causes less drowsiness than first-generation histamine-receptor antagonists.


Fexofenadine is prescribed for the relief from physical symptoms associated with seasonal allergic rhinitis and treatment of chronic idiopathic urticaria.
It is not a therapeutic drug and does not cure but rather prevents the aggravation of rhinitis and urticaria and reduces the severity of the symptoms providing much relief from repeated sneezing, runny nose, itchy eyes and general body fatigue caused by rhinitis and urticaria.

Allegra Tablets (Fexofenadine)View Of Allegra Tablets

Fexofenadine Dosage

Chronic idiopathic urticaria: Children 6 months to < 2 years: 15 mg twice daily
Chronic idiopathic urticaria, seasonal allergic rhinitis:

  • Children 2–11 years: 30 mg twice daily
  • Children 12 years and above and Adults:60 mg twice daily or 120 mg once daily
  • Elderly: Starting dose: 60 mg once daily


Allegra is not to be taken with fruit juices as this may decrease the absorption of the drug.

Availability and Packaging

Fexofenadine is available in various brand names such as Allegra, Telfast, Fastofen, Tilfur, Vifas.Various generic forms of fexofenadine are also available. The Dosage forms are
* Suspension: 6 mg/mL (30 mL, 300 mL) [raspberry cream] * Tablet: 30 mg, 60 mg, 120 mg, 180 mg

Common Side Effects Of Fexofenadine

The common side effects include Nausea, Dizziness, Vomiting, Weakness, Drowsiness, sleepiness, Fatigue, Diarrhea, Unusual bowel movements, Headache, Aggression and Fever.

Fexofenadine Overdose

Reports of fexofenadine overdose are rare and because of this, the effects are not well established. No deaths occurred in testing on mice, at 5000 mg/kg, which is 110 times the maximum recommended dose for an adult human. Further research shows no deaths in rats at the same concentration, which equates four hundred times the recommended dose in an adult human. Research on humans ranges from a single 800 mg dose, to a twice-daily 690 mg dose for a month, with no clinically significant adverse effects, when compared to a placebo.

Further Information

Manufacturers pamphlet: Sanofi Aventis Allegra Information

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