Description and General Information

Fexofenadine is typically found in the medications Allegra, Telfast, Fastofen and Tilfur. It is an antihistamine that is used in the treatment of hayfever and other allergic reactions. Fexofenadine does not easily traverse the blood-brain barrier, and subsequently will not induce sleepiness. It is indicated for the general relief of red, itchy, or watery eyes; runny nose; sneezing; itching of the throat or on the roof of the mouth. It may be taken by adults and children over the age of two years old. It may also be prescribed for the relief of symptoms associated with urticaria which produces hives and red, itchy elevated portions of the skin. It functions by obstructing the unpleasant effects of histamine which is essentially a substance that triggers allergic reactions within the body.

Fexofenadine is available in a tablet and as a liquid and will be taken orally. It may be swallowed in the case of the tablet with water no more than two times daily. Fexofenadine should not be taken with fruit juices such as orange, grapefruit, or apple juice as the acidic content may interfere with the effectiveness of the pill. It should be taken at the same time(s) daily. Additionally, ensure that you are taking it as prescribed. Have the doctor or pharmacist clarify any thing that is not clear in relation to the dosage instructions. It is important to take it exactly as it has been prescribed to avoid any unnecessary complications.

It will reduce the symptoms experienced as a result of seasonal allergic rhinitis and urticaria but will not cure either condition. Therefore, you will need to take it even when symptoms are no longer apparent. Lengthening the period between doses may cause allergic symptoms to return. Always shake the liquid thoroughly before using it to promote a more consistent mixture.

Inform your doctor of certain pre-existing conditions like kidney disease and pregnancy. Be certain to let your doctor know what medications you are currently taking, if any, to avoid any unexpected reactions. Antacids that contain magnesium or aluminium will need to be taken a few hours before or a few hours after taking the medication.


Children between the ages of 2–11 years will be required to take 30 mg twice daily

Children 12 years and older (including adults) will be prescribed 60 mg twice daily or 180 mg once per day.

Patients with chronic idiopathic urticaria who are children between the ages of 6 months to 2 years will need to take 15 mg twice daily.

For the elderly the starting dose will be 60 mg once daily. This amount will be altered based on renal function i.e. possible kidney damage.

The medications will be available in these two forms

  1. Suspension in the amount 6 mg/mL (30 mL, 300 mL) (raspberry cream)
  2. Tablet in the amount 30 mg, 60 mg, 180 mg

Side effects will include

  • Drowsiness/sleepiness
  • Headache
  • Nausea
  • Abnormal bowel movements
  • Dizziness
  • Vomiting
  • Weakness
  • Fatigue
  • Diarrhea

In Case of Overdose

Overdose with this drug is a rare occurrence, consequently the effects of possible overdose are not well documented. When tested on laboratory mice none died because of excessive exposure, specifically when given 5000 mg/kg, of the drug. This amount is 110 times the amount recommended for human consumption. The amount used in laboratory tested rats would actually be the equivalent of an individual taken 400 times the recommended dosage. When testing was done on humans with excessive dosages no additional adverse reactions occurred.

Drug Interactions

If fexofenadine is taken in conjunction with fluoxetine it may trigger drowsiness.