The use of opioids in fibromyalgia.

Fibromyalgia syndrome (FMS) is a chronic disorder of widespread pain with high personal and societal burdens. Although targeted pharmacotherapies have become available in recent years, it remains a challenging condition to treat. Despite no randomized controlled trials addressing the short- or long-term use of opioids in FMS, their use remains prevalent. In this article we discuss the role of opioids and other analgesics in the management of FMS, with particular focus on problems associated with their use. We review aspects of the pathophysiology of FMS and consider how specific factors may contribute to the lack of efficacy of opioids in this condition. Finally, we discuss drugs with combined opioid and anti-opioid action and their roles in FMS. There is insufficient evidence to recommend the routine use of opioids in FMS. As well as having a significant adverse effect profile, their inefficacy may be due to their inability to target the pathophysiologic processes involved in this central sensitization syndrome.