TRPV1 antagonists: the challenges for therapeutic targeting.

The capsaicin receptor TRPV1 (transient receptor potential cation channel, subfamily V, member 1) is a polymodal nociceptor whose expression is upregulated in several painful disorders. At present, potent small molecule TRPV1 antagonists are undergoing clinical trials in patients with chronic pain. Clinical development of TRPV1 antagonists is, however, facing new challenges. Many drug candidates evoke a febrile reaction that varies among patients. We speculate that TRPV1 gene polymorphism might be an underlying cause of the inter-subject variability in pain sensation and response to TRPV1 antagonists. This newly understood and yet to be fully validated aspect of pain suggests that pain management based on regulating the TRPV1 receptor might require a personalized approach for effective clinical outcome. Here, we provide our perspectives on current progress in targeting TRPV1.