Standard treatment: the role of antihistamines.

Histamine-1 (H1) antihistamines are the first-line drug for the treatment of urticaria. Major progress has been achieved in recent years both in the understanding of their ligands, the H1-histamine receptors, and therefore in the mechanisms of their pharmacologic effects, as well as in the development of safer antihistamines with low or no sedating effects and no interactions on the level of potassium channels leading to QT-prolongations and interactions on the level of cytochrome P450 isoenzymes. This development has brought antihistamines very close to the ideal antihistamines that are desired by clinicians to treat most types of urticaria in patients who have to take these drugs for a long time.