Allegra Side Effects
Generic Name: fexofenadine
Medically reviewed by Drugs.com. Last updated on July 30, 2020.
Note: This document contains side effect information about fexofenadine. Some of the dosage forms listed on this page may not apply to the brand name Allegra.
For the Consumer
Applies to fexofenadine: oral suspension, oral tablet, oral tablet disintegrating
Side effects requiring immediate medical attention
Along with its needed effects, fexofenadine (the active ingredient contained in Allegra) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur while taking fexofenadine:
- Chest tightness
- feeling of warmth, redness of the face, neck, arms and occasionally, upper chest
- large, hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
- shortness of breath, difficult or labored breathing
Side effects not requiring immediate medical attention
Some side effects of fexofenadine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.
Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Back pain
- body aches or pain
- difficulty with moving
- ear congestion
- joint pain
- loss of voice
- muscle aching or cramping
- muscle pains or stiffness
- nasal congestion
- pain in arms or legs
- pain or tenderness around eyes or cheekbones
- painful menstrual bleeding
- redness or swelling in ear
- ringing or buzzing in ears
- runny or stuffy nose
- sleepiness or unusual drowsiness
- sore throat
- stomach upset
- swollen joints
- unusual feeling of tiredness or weakness
- viral infection (such as cold and flu)
- terrifying dreams
- trouble sleeping
For Healthcare Professionals
Applies to fexofenadine: oral capsule, oral suspension, oral tablet, oral tablet disintegrating
The most commonly reported side effects included headache, drowsiness, dizziness, and nausea.[Ref]
Very common (10% or more): Vomiting (up to 12%)
Common (1% to 10%): Nausea, diarrhea, stomach discomfort[Ref]
Very common (10% or more): Headache (up to 10.3%)
Common (1% to 10%): Drowsiness, dizziness, somnolence[Ref]
Common (1% to 10%): Cough, upper respiratory tract infection, rhinorrhea
Common (1% to 10%): Back pain[Ref]
Common (1% to 10%): Dysmenorrhea[Ref]
1. Cerner Multum, Inc. "Australian Product Information." O 0
2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
3. "Product Information. Allegra (fexofenadine)." Hoechst Marion-Roussel Inc, Kansas City, MO.
Frequently asked questions
- Allegra vs Claritin: Which is more effective for allergies?
- Can I take Allegra in the morning and Zyrtec in the evening?
More about Allegra (fexofenadine)
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Images
- Drug Interactions
- Compare Alternatives
- Support Group
- En Español
- 86 Reviews
- Drug class: antihistamines
- Patient Information
- Allegra (Advanced Reading)
- Allegra (Fexofenadine Oral Suspension)
- Allegra (Fexofenadine Tablets)
Related treatment guides
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Some side effects may not be reported. You may report them to the FDA.