Detailed dosage guidelines and administration information for Allegra (fexofenadine hydrochloride). Includes dose adjustments, warnings and precautions. Allegra is a non-drowsy antihistamine for allergy relief. Here’s our guide for dosing Allegra for kids and adults, and what to do if you miss a dose or take too much. Overview: Fexofenadine is an antihistamine that is taken to help treat allergy symptoms, such as a runny nose, itchy or watery eyes, sneezing, or an itchy nose or throat. Common side effects may. Allegra (fexofenadine) is a non-drowsy antihistamine used for seasonal allergic rhinitis and chronic idiopathic urticaria. Compared with first-generation agents, it has minimal CNS penetration and is less sedating, making it suitable for daytime use and tasks that require alertness. While some other oral antihistamines may cause you to be drowsy, Allegra® won't. Fexofenadine, the active ingredient in Allegra ®, provides non-drowsy allergy relief with 0% brain interference, relieving allergy symptoms like sneezing, runny nose and itchy eyes. It is a common over-the-counter medication available under many brand names (including Allegra), as well as a generic drug. [11] Therapeutically, fexofenadine is a selective peripheral H 1 blocker. Fexofenadine (Allegra) is an antihistamine that treats and prevents allergy symptoms. It blocks histamine to reduce your symptoms. What is Allegra? Allegra (fexofenadine) is an antihistamine used to treat allergy symptoms, including sneezing, itching, watery eyes, and a runny nose in adults and children. Want fast, non-drowsy allergy relief? Allegra helps relieve your toughest allergy symptoms, without the drowsy effect, empowering you to live life fully*, everyday. The Scottsdale pool bar you've been looking for. Allegra offers the ultimate pool party Scottsdale experience with cabanas, cocktails & skyline views.