CLARINEX works by blocking the action of histamine released by the immune system, thus relieving some of the important allergy symptoms. When you are exposed to an allergen, a specific type of white blood cell called the mast cell, which is located in the membrane lining the nose and sinuses, releases a chemical called histamine. Histamine attaches to its site of action called receptors on nearby blood vessels, causing them to dilate or enlarge, leading to redness, swelling, itching, and changes in the secretions.

Antihistamines block the histamine receptors, preventing these membrane changes and the resulting symptoms. Antihistamines also block histamine from stimulating nerve endings, which can cause itching and other symptoms.

Unlike some over-the-counter and prescription antihistamines, at the recommended dose, CLARINEX does not cause drowsiness, which is important for patients with active lifestyles who drive, operate equipment or machines. In clinical studies, the incidence of drowsiness with CLARINEX was similar to that of a placebo or sugar pill at the recommended dose.

To take Clarinex orally disintegrating tablet:

• Keep the tablet in its blister pack until you are ready to take the medicine. Open the package and peel back the foil from the tablet blister. Do not push a tablet through the foil or you may damage the tablet.
• Using dry hands, remove the tablet and place it on your tongue. It will begin to dissolve right away.
• Do not swallow the tablet whole. Allow it to dissolve in your mouth without chewing.
• Swallow several times as the tablet dissolves. If desired, you may drink water to help swallow the dissolved tablet.