Effect of Terfenadine on Substance P and Vasoactive Intestinal Polypeptide Concentrations in Nasal Secretions from Patients with Nasal Allergy

— Before terfenadine treatment, the mean substance P and vasoactive intestinal polypeptide (VIP) concentrations in nasal secretions from nasal allergy patients tended to be higher than the values of healthy subjects. During terfenadine treatment, the mean substance P concentrations in nasal secretions from patients allergic to house dust or pollen were significantly decreased to 62 and 39% of the initial values, respectively. The mean VIP concentrations in nasal secretions from the house dust allergy patients and the pollen allergy patients were significantly decreased to 52 and 18% of the initial values, respectively. Plasma substance P and VIP concentrations were not affected by nasal allergic symptom and terfenadine treatment.