Due to the recent intensified occurrence of allergic diseases, antihistamines have become extremely popular. Antihistamines inhibits action of histamine via binding with histamine receptors (H1, H2, H3 i H4) localized among others  on smooth muscle, endothelium cells, hepatocytes, basophils, eosynophils, neutrophils, central nervous system cells, on thymus, spleen, small intestine, colon and limphocytes T.

Drugs including loratadine, belong to the group of antihistamines, is a second generation drug. It competes with free histamine in binding with the H1 receptor and is mainly used in the course of seasonal or chronic allergic rhinitis or chronic, including idiopathic, urticaria. Apart from its antihistaminic effect, loratadine is characterized by anti-inflammatory influence achieved by inhibiting the synthesis of pro-inflammatory mediators. The application of loratadine rarely results in undesirable effects and a convenient form of the pharmaceutic makes loratadine widely recommended by doctors. Pharmacokinetic and pharmacodynamic parameters, as well as the results of conducted and published clinical studies, indicate that drugs containing loratadine are  safe and effective.