THE EFFECTS OF A NEW-GENERATION OF H-1 ANTIHISTAMINES (CETIRIZINE ANDLORATADINE) ON HISTAMINE-RELEASE AND THE BRONCHIAL RESPONSE TO HISTAMINE IN ATOPIC PATIENTS

The effects of two selective H-1 receptor blockers, cetirizine and lor atadine, in comparison with placebo, on basophil histamine release and the bronchial response to histamine were assessed. The studies were p erformed in a group of 18 patients with pollinosis and 22 with atopic asthma. Both tests were performed before and after medication. Histami ne release from isolated basophils was evaluated by Shore's method usi ng anti-IgE and pollen antigen as stimulants. The bronchial provocatio n tests were performed by Ryan's method. The results were expressed as PC(20)FEV(1). It was shown that both drugs significantly inhibited ba sophil histamine release induced by anti-IgE or specific allergen. It was also found that these drugs effectively reduced the bronchial resp onse to histamine challenge. These findings confirm the beneficial cli nical effect of a new generation of selective H-1 blockers in the trea tment of IgE-mediated allergic diseases, and also the possible role of these drugs in the therapy of atopic asthma.