Neue H1-Antihistaminika im Vergleich

New H 1 antihistamines like cetirizine, levocetirizine, loratadine, desloratadine, fexofenadine and mizolastine are highly selective H 1 receptor antagonists and possess partly fewer sedative side effects than the older members of this class of drugs. Desloratadine shows the highest affinity for H 1 receptors, a relatively long adherence to H 1 receptors and a strong insurmountable antagonism. Suppression of inflammation mediators, dependent and not dependent on H 1 receptors, is an important component of the therapeutic actions and of different strength for the new H 1 antihistamines. Pharmacokinetic properties are important for the duration of action, for the dose regimen if the elimination organs are disturbed and for drug interactions. In decreased renal function, e.g. the doses of cetirizine and levocetirizine have to be adjusted. In SAR and PAR the new H 1 antagonists have been used successfully, activity against nasal obstruction of desloratadine being superior to that of loratadine, fexofenadine and cetirizine. The new H 1 antihistamines show a low rate of side effects and are safe. Sedation is a rare undesired effect, but still different for the new H 1 antihistamines. The profile of action and side effects of desloratadine justifies the assignment of this drug to a 3rd generation of antihistamines.