Key takeaways
Nasonex (mometasone) and Allegra (fexofenadine) are both used to treat allergy symptoms, but they work in different ways and belong to different medication classes. Nasonex is a corticosteroid nasal spray that reduces inflammation and swelling in the nose, while Allegra is an oral antihistamine that blocks histamine to relieve symptoms like itchiness and runny nose. Nasonex is available both over-the-counter and by prescription, whereas Allegra is only available over-the-counter. Nasonex can take 1 to 2 weeks to show full effects, but Allegra starts working in about 2 hours. Nasonex is used for both short-term and long-term treatment, including nasal polyps, while Allegra is used for short-term relief of allergy symptoms and hives. Common side effects of Nasonex include headache and nosebleeds, whereas Allegra can cause headache and dry mouth.
