[The effect of loratadine on skin and bronchial reactivity and histamine liberation from basophils in patients with atopic asthma and allergic rhinitis].

The effect of the therapy with Loratadine on skin and bronchial reactivity to histamine and on a specific histamine release from isolated basophils of allergic patients was assessed. The studies were carried out on a 34 patients (23 with pollen rhinitis and 11 with a mild bronchial asthma). The effect loratadine versus placebo on the skin reactivity to histamine was measured in patients suffering from pollen rhinitis. Outside the pollen season in 12 patients from the above group a histamine release from isolated basophils was evaluated by Shore method, using a-IgE and pollen allergen as liberators, before and after 4 days therapy with loratadine. In the group of the 11 asthmatic patients the effect of the single dose of 10 mg Loratadine on spirometric parameters and on a bronchial response to histamine was studied. The Bronchial Provocation Test with histamine was performed by the Ryan's method. The results were expressed as PC20 FEV1. It was shown that loratadine statistically significant limited of the skin reactivity to histamine and specific histamine release from basophils. The one tablet of Loratadine have not changed of spirometric parameters in the patients with mild asthma, but statistically significant reduced their bronchial response to histamine.