Non-H-1-receptor effects of antihistamines

Visit any international allergy meeting and you will soon learn that there are a plethora of very potent and effective histamine H-1-receptor antagoni sts, or antihistamines as they are more often called. Thus, in order to mak e any particular antihistamine stand out therapeutically or commercially fr om the others, additional properties, e.g. antiinflammatory properties, are often claimed. But are these claims valid and, if so, are the 'additional properties' clinically relevant? This document will review the evidence beh ind some of the 'additional properties' of antihistamines and lay the basis for discussion of their relevance.