 - Concomitant Medication: Use of prescription or over-the-counter medication that would significantly affect the course of AR, or interact with study drug, such as: Chronic use of concomitant medications such as tricyclic antidepressants, that would affect assessment of the effectiveness of the study drug; Chronic use of long- acting beta2-agonists e.g., salmeterol; Potent Cytochrome P450 subfamily enzyme 3A4 CYP3A4 inhibitors e.g., ritonavir, ketoconazole, itraconazole, clarithromycin, etc; Allergen immunotherapy for the treatment of allergies. 