The clinical safety of H₁‐receptor antagonists: An EAACI position paper*

Antihistamines, or HI-antagonists, despite their pronounced unwanted effects, were the first efficacious drugs to be used for the symptomatic relief of allergic diseases.In recent years, pharmacologic research has produced a new generation of antihistamines, the so-called newer or secondgeneration antihistamines, with high potency and minimal sedative effects as compared to the older or classical antihistamines.Recently, the newer antihistamines have become the focus of medical scientific interest for two reasons.Firstly, many of these drugs have been claimed to have additional antiallergic properties, and, secondly, there are several reports of possible cardiotoxic effects and carcinogenicity.In particular, the safety issue is of central importance because of the widespread use of antihistamines in current medical practice.Furthermore, since antihistamines are used to treat non-life-threatening disorders, their risk/benefit ratio must be carefully evaluated (1).