Emerging pharmacological strategies for the treatment of fibromyalgia

Abstract

Fibromyalgia (FM) has been described as a chronic clinical condition related to multisensory hypersensitivity presenting with a complex of symptoms dominated by chronic widespread pain associated with the existence of a range of co-morbidities, such as fatigue, sleep disturbance, cognitive impairment, anxiety and depression. Current treatments include drugs that target serotonin and noradrenaline levels within the central nervous system, e.g., tricyclic antidepressants, serotonin noradrenaline reuptake inhibitors, and voltage-gated calcium channel subunit ligands, e.g., gabapentin and pregabalin. Investigation of a range of novel targets, such as melatoninergic, cannabinoid, dopamine, NMDA, angiotensin, orexin and opioid receptors, and ion channels, in addition revisiting bioamine modulation and subunits has provided efficacy outcomes that improve the health status of patients with FM. Nevertheless, modest and limited efficacy is often observed reflecting the heterogeneity of FM with existence of subpopulations of patients, the contribution of peripheral and central components to the pathophysiology, and the extensive range of accompanying co-morbidities. The complexity and multidimensional nature of FM is emphasized by the diversity of pharmacological targets gaining interest. Clues to underlying mechanisms which offer themselves as novel and potential targets for new medications are being provided by advances in the understanding of the pathophysiology of FM.

Keywords: Fibromyalgia, Chronic pain, Fatigue, Central sensitization, NMDA receptors, Melatonin receptors, Gabapentanoids

Core tip: Fibromyalgia (FM) is a multidimensional chronic pain condition that current therapies provide modest and limited efficacy due to the heterogeneity of the condition, contribution of peripheral and central components to the pathophysiology, and a range of co-morbidities. Drugs acting on novel and existing targets, such as melatoninergic, cannabinoid, dopamine, NMDA, angiotensin, orexin and opioid receptors, ion channels, bioamine processes and subunits have provided efficacy outcomes that improve the health status of patients with FM. An understanding of the pathophysiology of FM is providing potential targets for new medications.