Pharmacological treatment of allergies

According to recent literature, the "anti-allergy" properties of antihistamines are linked to their antagonistic ability on receptor H1. In the majority of experimental models the immediate allergic responses is followed by a late phase. Especially at the pulmonary level, the presence of a late response after an allergic provocation is considered to correlate with the severity of asthma. The reference anti-allergy drugs, such as the inhaled corticosteroids or the cromones, without anti H1 activity, inhibit this late pulmonary response. Azelastine, ketotifen and cetirizine, three substances that are antagonistic to the anti-H1 receptor reduce the late pulmonary response. In addition, these three substances have other "anti-allergy" characteristics. Azelastine inhibits production of superoxide by the pulmonary neutrophils and eosinophils after PAF provocation in animals. Cetirizine significantly inhibits eosinophil infiltration in the bronchoalveolar lavage liquid in asthmatics with a late allergic bronchospasm. The presence of anti-histaminic and anti-allergy characteristics on the same molecule may perhaps convey a supplementary therapeutic benefit in the treatment of allergic symptoms.