2B Determined: The Future of the Serotonin Receptor 2B in Drug Discovery.

The cardiotoxicity associated with -ethyl-dexfenfluramine (norDF) and related agonists of the serotonin receptor 2B (5-HT) has solidified the receptor's place as an "antitarget" in drug discovery. Conversely, a growing body of evidence has highlighted the utility of 5-HT antagonists for the treatment of pulmonary arterial hypertension (PAH), valvular heart disease (VHD), and related cardiopathies. In this Perspective, we summarize the link between the clinical failure of fenfluramine-phentermine (fen-phen) and the subsequent research on the role of 5-HT in disease progression, as well as the development of drug-like and receptor subtype-selective 5-HT antagonists.