Chlorpheniramine—Sulfur Dioxide Interactions on Lung and Nasal Function in Allergic Adolescents

Abstract

Thirteen allergic adolescent subjects without clinical asthma but with exercise-induced bronchoconstriction participated in this study. In a double-blind protocol, they were given placebo, 4 mg, or 12 mg chlorpheniramine at bedtime the evening before exposure to 1 ppm sulfur dioxide (SO₂) during moderate exercise. Pulmonary function (forced expiratory volume in 1 second and total respiratory resistance) and nasal work of breathing were measured before and after exposure. Chlorpheniramine did not alter the statistically significant changes in pulmonary function seen after SO₂ exposure. However, 12 mg chlorpheniramine did block the SO₂-induced increase in the nasal work of breathing. It is concluded that treatment with an H₁ blocking antihistamine does not affect the mechanisms underlying SO₂-induced bronchoconstriction, although it does inhibit SO₂-induced nasal function changes.