Fexofenadine

Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Jul 27, 2022

Side Effects


Allegra Side Effects

Common side effects of Allegra are listed below. Tell your doctor if they are severe or do not go away in a few days.

  • Headache
  • Dizziness
  • Drowsiness
  • Tiredness 
  • Nausea, vomiting, diarrhea, upset stomach
  • Cough
  • Pain in the arms and legs
  • Menstrual cramps and pain

Some of the side effects of Allegra are more serious. Contact your healthcare provider right away or seek medical help immediately if you experience any of the following side effects:

  • Hives, rash, itching (allergic reaction to Allegra)
  • Difficulty breathing or swallowing
  • Swelling of the throat, tongue, lips, face, eyes, hands, lower legs, ankles, or feet

The above list may not include all the potential side effects of Allegra. Tell your doctor if you have any unusual side effects or if the side effects do not get better over time. You can also report unusual side effects to the Food and Drug Administration at 1-800-FDA-1088.

Allegra Overdose: In case of a known or suspected overdose of Allegra, contact your doctor immediately or call the local poison control center or provincial poison control center in your area. You can also call the national poison control center at 1-800-222-1222. If a person has collapsed, cannot breathe, or has had a seizure, call 911. Symptoms of an Allegra overdose may include dry mouth, dizziness, and drowsiness. 

Source: FDA