The promise of substance P inhibitors in fibromyalgia

The fibromyalgia syndrome (FMS) is a chronic pain disorder that exhibits elevated levels of cerebrospinal fluid (CSF) substance P (SP). Because SP is known to influence the normal process of pain perception, there is reason to address its role in the pain of FMS. The discovery and characterization of the SP receptor (neurokinin-1 receptor, NK1r) for the action of SP have disclosed new opportunities to understand a wide variety of conditions that are mediated, at least in part, by SP. Knowledge about the receptor prompted an aggressive search for agonists and antagonists that might be useful in mimicking (modeling) or in treating the relevant conditions. This article will draw heavily from the descriptions of the pioneers in the field, as they have summarized their years of careful study; it will then briefly summarize the results of a study designed to examine the response of FMS patients to an NK1 antagonist; and finally, it will attempt to forecast some ways in which this technology may be used in the future to more effectively manage FMS.