Search

To evaluate the effect of cetirizine hydrochloride on substance P release in allergic rhinitis, we performed a single-blind placebo-controlled study of 14 patients with perennial allergic rhinitis (7 treated with cetirizine and 7 with placebo). After an initial nasal allergen challenge with lavages, the subjects received treatment with placebo or cetirizine hydrochloride (10 mg by mouth daily) for 1 week, followed by the second nasal allergen challenge with lavages. The levels of albumin, histamine, and substance P in nasal lavages before and after allergen challenge were quantified by enzyme-linked immunosorbent assay. Pretreatment of subjects with cetirizine reduced the level of substance P induced by antigen challenge, but did not significantly reduce levels of histamine. These results suggest that cetirizine may reduce nasal neurogenic inflammation by modulating the release of substance Pin allergic rhinitis. [ABSTRACT FROM AUTHOR]