Emerging opportunities and concerns for drug discovery at serotonin 5-HT2B receptors.

5-HT(2B) receptors have been reported to play an important role at cardiac, intestinal and central levels, as well as in bone marrow formation and growth. In the last decade, 5-HT(2B) receptors have also gained much attention as new targets in therapeutics, but also as off-targets because their activation along with the inhibition of serotonin transporters plays a significant role in the pathogenesis of 5-HT induced valvulopathy. Taking this into account, the present review focuses on the new therapeutic applications of 5-HT(2B) receptor ligands as well as on the potential concerns.