GENERIC NAME: fexofenadine
BRAND NAME: Allegra
DRUG CLASS AND MECHANISM: Fexofenadine is an oral, "second generation" antihistamine that is used to treat the signs and symptoms of allergy that are due to histamine. It is similar to the other second generation antihistamines loratadine (Claritin), cetirizine (Zyrtec) and azelastine (Astelin). Histamine is a chemical that is responsible for many of the signs and symptoms of allergic reactions, for example, swelling of the lining of the nose, sneezing, and itchy eyes. Histamine is released from histamine-storing cells (mast cells) and then attaches to other cells that have receptors for histamine. The attachment of the histamine to the receptors causes the cell to be "activated," releasing other chemicals that produce the effects that we associate with allergy, e.g., sneezing. Fexofenadine blocks one type of receptor for histamine (the H1 receptor) and thus prevents activation of H1 receptor-containing cells by histamine. Unlike the first generation antihistamines, fexofenadine and other second-generation antihistamines do not readily enter the brain from the blood, and, therefore, they cause less drowsiness. Fexofenadine was approved by the FDA in July, 1995. PREPARATIONS: Tablets, 30, 60 and 180 mg; capsules, 60 mg STORAGE: Store tablets and capsules at room temperature between 15-30°C (59-86°F). PRESCRIBED FOR: Fexofenadine is used for the treatment of seasonal allergies and chronic urticaria (hives) in adults and children 6 years of age or older. DOSING: For seasonal allergies the recommended dose for adults and children 12 years or older is 60 mg twice daily or 180 mg once daily. Children 6-11 years of age should be given 30 mg twice daily. For chronic urticaria, adults and children 12 years or older should use 60 mg twice daily, and children 6-11 years of age should use 30 mg twice daily. Fexofenadine can be taken with or without food. DRUG INTERACTIONS: In controlled clinical studies there were no interactions with other drugs that significantly affected the safety or effectiveness of fexofenadine. PREGNANCY: Fexofenadine has not been adequately studied in pregnant women. NURSING MOTHERS: Fexofenadine has not been adequately studied in women who are breast-feeding. SIDE EFFECTS: The most common side effects of fexofenadine are nausea, vomiting, weakness and sleepiness. |
