H4 Receptor Antagonists and Their Potential Therapeutic Applications

The histamine H 4 receptor shows generally restricted expression in immune cells and has been shown to mediate histamine induced-chemotaxis, suggesting that it may play a role in inflammation. This has led to the discovery and characterization of histamine H 4 receptor antagonists from multiple chemical scaffolds. These antagonists have shown efficacy in numerous preclinical models of inflammation, further supporting the critical role of the histamine H 4 receptor in inflammatory diseases, including rheumatoid arthritis, asthma, pruritis and inflammatory pain. The first histamine H 4 receptor antagonists have entered into clinical trials and data are expected soon to establish the importance of targeting this receptor as a novel therapeutic in inflammation. This review focuses on the histamine H 4 receptor antagonists that have been identified to date.