A review of loratadine in the treatment of patients with allergic bronchial asthma.

Patients with seasonal or allergic bronchial asthma experience an immediate allergic response caused by allergen-specific immunoglobulin E-mediated histamine release. The release of histamine and other chemical mediators may trigger airway hyperresponsiveness and exaggerated bronchoconstriction, characteristic features of allergic bronchial asthma. Traditional antihistamines have demonstrated only moderate activity of short duration against this disease. In contrast, loratadine, a potent, nonsedating, histamine-1-receptor antagonist with activity in seasonal and perennial allergic rhinitis, has demonstrated effective control of asthma symptoms, improved pulmonary function, and long duration of action in patients with allergic bronchial asthma. This review summarizes preclinical evidence for the antiallergic activity of loratadine and the results of clinical studies with oral loratadine in patients with allergic bronchial asthma.