In Vivo Model for the Evaluation of Topical Antiallergic Medications

A novel human in vivo model of intranasal challenge with antigen is used to demonstrate the effectiveness of a topical antirelease drug. Previous experimentation has established a highly significant correlation between the physiologic response of sneezing, which occurs after insufflation of antigen into the nose of allergic individuals, and the recovery of putative mast cell mediators: histamine, tosyl arginine methyl ester (TAME)–esterase(s), and prostaglandin D2. Azatadine base, a tricyclic antihistamine, which also inhibits mediator release in vitro, applied prior to antigen administration not only reduces the clinical symptom of sneezing but simultaneously reduces the concentration of the inflammatory mediator, TAME-esterase(s), recovered from nasal washes. To our knowledge, this is the first observation that an antirelease drug can stop mediator release in vivo in the nose. (Arch Otolaryngol 1984;110:25-27)