Allegra is a medication that is very commonly used to treat Allergies. It is also known as Fexofenadine which is a selective peripheral H1-blocker or an antihistamine medication.

This medication is classified as a second-generation and it is less able to cross the blood-brain barrier. This allows for treatment without significant sedation.

Method of Action:

This medication blocks the activation of the H1 receptor, which typically occurs by histamine. The goal is for the prevention or dramatic improvement of the symptoms associated with allergies from occurring. It typically takes 30-60 minutes to take effect.


1.)  Seasonal Allergic Rhinitis
2.)  Chronic Urticaria

Side Effects

–  Headache
–  Muscle pain
–  Nausea
–  Drowsiness
–  Cramping
–  Anxiety
–  Difficulty sleeping

** – Anxiety and Difficulty sleeping are rarely seen.

Use in Pregnancy

Allegra is a category C which indicates that its use should only be done if benefits outweigh the risks.