A-381393 is a selective antagonist of the P2X3 receptor, a purinergic ion channel involved in sensory neuron signaling, particularly in pain transmission. It is primarily used in neuroscience and pharmacology research to study the role of P2X3 receptors in conditions such as chronic pain, migraine, visceral hypersensitivity, and overactive bladder disorders. By blocking P2X3 activation, it enables investigation of ATP-mediated signaling pathways, contributing to insights into pain mechanisms and the development of novel analgesics for peripheral and central nervous system-related pain disorders.