Treatment of fibromyalgia: a changing of the guard

Serotonergic Neurotransmission System Modulator, Vortioxetine, and Dopaminergic D2/D3 Receptor Agonist, Ropinirole, Attenuate Fibromyalgia-Like Symptoms in Mice

Fibromyalgia is a disease characterized by lowered pain threshold, mood disorders, and decreased muscular strength. It results from a complex dysfunction of the nervous system and due to unknown etiology, its diagnosis, treatment, and prevention are a serious challenge for contemporary medicine. Impaired serotonergic and dopaminergic neurotransmission are regarded as key factors contributing to fibromyalgia. The present research assessed the effect of serotonergic and dopaminergic system modulators (vortioxetine and ropinirole, respectively) on the pain threshold, depressive-like behavior, anxiety, and motor functions of mice with fibromyalgia-like symptoms induced by subcutaneous reserpine (0.25 mg/kg). By depleting serotonin and dopamine in the mouse brain, reserpine induced symptoms of human fibromyalgia. Intraperitoneal administration of vortioxetine and ropinirole at the dose of 10 mg/kg alleviated tactile allodynia. At 5 and 10 mg/kg ropinirole showed antidepressant-like properties, while vortioxetine had anxiolytic-like properties. None of these drugs influenced muscle strength but reserpine reduced locomotor activity of mice. Concluding, in the mouse model of fibromyalgia vortioxetine and ropinirole markedly reduced pain. These drugs affected emotional processes of mice in a distinct manner. Hence, these two repurposed drugs should be considered as potential drug candidates for fibromyalgia. The selection of a specific drug should depend on patient’s key symptoms.

Fibromyalgia: presentation and management with a focus on pharmacological treatment

Fibromyalgia is a condition with widespread muscle pain. Prevalence studies showed that 2% to 7% of the population have fibromyalgia, which affects approximately one million Canadians. Fibromyalgia is most common in women, but it also involves men and children. As with most chronic illnesses, the causes of fibromyalgia are unknown. However, recent research supports underlying abnormalities in the central nervous system, which supports fibromyalgia as a chronic disease state and valid clinical entity. Pain is the primary symptom, often accompanied by overwhelming fatigue, sleep dysfunction and cognitive impairment. In 1990, the American College of Rheumatology developed diagnostic criteria for the diagnosis of fibromyalgia. Lifestyle changes, including pacing of activities and aerobic exercise, are very important in managing fibromyalgia symptoms. Emotional and behavioural therapy can also be helpful. Controlled trials of antidepressants, gabapentinoids, tramadol, zopiclone and sodium oxybate have shown effectiveness in fibromyalgia patients. Pregabalin and duloxetine were recently approved in the United States. Effective management of fibromyalgia is complex and requires a multidisciplinary treatment approach. Response and tolerance of different therapeutic interventions vary from patient to patient. Recent advances in the pathophysiology of fibromyalgia offer hope for new and improved therapies in the management of this disabling condition.

Novel pharmacotherapy for fibromyalgia

Fibromyalgia is a common disorder that is characterized by chronic widespread pain, tenderness to light palpation, fatigue and sleep disturbances. The present lack of a well-accepted model of the disorder has hampered progress towards adequate treatment. A review of potential models to explain the pathophysiology underlying its primary symptom (i.e., chronic widespread pain) lends insight on the therapeutic potential of novel therapies. Following this, a mechanistic evaluation of those medications that are under consideration for the treatment of the disorder is offered. Adequate treatment will be likely to involve the identification of biologic subgroups within the greater fibromyalgia construct. Key insights from basic research are the basis for increased optimism for effective relief among patients and clinicians.