Terfenadine acid metabolite

• Antihistamines
• ATC:R06AX26

• Allegra
• Carboxyterfenadine
• Fexofenadine hydrochloride
• Fexofendine
• Terfenadine acid metabolite
• Terfenadine carboxylate
• Terfenadine-COOH

• Allegra-D (Fexofenadine hydrochloride + Pseudoephedrine hydrochloride)

C₃₂H₃₉NO₄

http://www.rxlist.com/cgi/generic/fexofen.htm

Terfenadine_acid_metabolite FDA

S. H. Kawai et al., J. Org. Chem. 59, 2620 (1994)

501.656 g/mol

142.5 ^oC

Slightly soluble

Solid

6.759

Oral tablets; Capsules

For management of Seasonal allergic rhinitis

Fexofenadine is a second-generation, long lasting H1-receptor antagonist (antihistamine) which has a selective and peripheral H1-antagonist action. Histamine is a chemical that causes many of the signs that are part of allergic reactions, for example, swelling of tissues. Histamine is released from histamine-storing cells (mast cells) and 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 which produce the effects that we associate with allergy. Fexofenadine blocks one type of receptor for histamine (the H1 receptor) and thus prevents activation of cells by histamine. Unlike most other antihistamines, Fexofenadine does not enter the brain from the blood and, therefore, does not cause drowsiness. Fexofenadine lacks the cardiotoxic potential, since it does not block the potassium channel involved in repolarization of cardiac cells.

33%

Side effects include dizziness, drowsiness, and dry mouth.

Patients taking ALLEGRA tablets should receive the following information:

ALLEGRA tablets are prescribed for the relief of symptoms of seasonal allergic rhinitis or for the relief of symptoms of chronic idiopathic urticaria (hives). Patients should be instructed to take ALLEGRA only as prescribed. Do not exceed the recommended dose. If any untoward effects occur while taking ALLEGRA, discontinue use and consult the doctor.

The product should not be used by patients who are hypersensitive to it or to any of its ingredients.

Patients should be told that this product should be used in pregnancy or lactation only if the potential benefit justifies the potential risk to the fetus or nursing infant.

Patients should be advised to take the tablet with water. Patients should also be advised to store the medication in a tightly closed container in a cool, dry place, away from children.

Humans and other mammals