SB 204741 is a selective antagonist for the 5-HT2B receptor, commonly used in pharmacological research to study serotonin receptor subtypes. It is particularly valuable in investigations related to cardiac fibrosis, as activation of 5-HT2B receptors has been linked to heart valve proliferation and fibrotic tissue growth. Researchers use SB 204741 to block these receptors and assess the downstream effects in cellular and animal models, helping to clarify the role of 5-HT2B in disease progression.

It has also been employed in neuroscience studies to differentiate the functions of 5-HT2 receptor subtypes, especially in behavioral and neurochemical experiments involving mood regulation, anxiety, and depression. Due to its selectivity, SB 204741 allows scientists to isolate 5-HT2B-mediated responses from those of closely related receptors like 5-HT2A and 5-HT2C.

Additionally, this compound serves as a tool in drug development, especially in evaluating the safety profile of new pharmaceuticals that may unintentionally activate 5-HT2B receptors—a concern linked to valvulopathy. By co-administering SB 204741, researchers can determine if observed cardiac effects are mediated through this specific pathway.