FIBROMYALGIA

Fibromyalgia is a common, often overlooked, clinical syndrome in general practice. It can be associated with considerable disability.

Patients with fibromyalgia often have other chronic conditions. Careful clinical evaluation and management of aggravating factors can therefore be beneficial.

WHAT IS FIBROMYALGIA

Fibromyalgia is a disorder characterized by widespread musculoskeletal pain accompanied by fatigue, sleep, memory and mood issues. it is believe that fibromyalgia amplifies painful sensations by affecting the way your brain processes pain signals.

Fibromyalgia is a debilitating and often unrecognised syndrome. It affects 2% of the population with a peak incidence in middle-aged women. Despite an incomplete understanding of its pathogenesis, there is increasing evidence for mechanism-based management approaches to this syndrome.

The syndrome is characterised by its hallmark features of widespread somatic pain and deep tissue tenderness, which result from sensitisation of neural pain pathways.There are also variable combinations of fatigue, sleep disturbance, cognitive dysfunction and psychological distress. These symptoms occur despite the absence of objective abnormalities on clinical assessment.

Diagnosis

Given the multidimensional nature of fibromyalgia, including its association with other chronic medical disorders, clinical assessment in time-poor general practice can be challenging. The condition should be considered as a diagnostic possibility in all cases of persistent, significant musculoskeletal pain, fatigue or sleep disturbance, particularly when such symptoms seem out of proportion to the severity of any background chronic illness. Examination for deep tissue tenderness, which was required by the old criteria, is now avoided. Investigations are only needed to exclude treatable comorbidities and potential differential diagnoses, such as thyroid dysfunction.

Management 

Antidepressants

Low-dose amitriptyline has traditionally been the first-line drug for treating pain and sleep disturbance in fibromyalgia. Tolerance development and weight gain limit the use of amitriptyline, but in a small subgroup it can be very useful in the long term.

Milnacipran inhibits the reuptake of serotonin and noradrenaline (norepinephrine). It has been approved in Australia for the treatment of fibromyalgia rather than depression. The recommended dose is 100 mg daily in divided doses.

Antiepileptic drugs

The concentrations of the pain facilitatory neurotransmitters glutamate and substance P in the central nervous system are elevated in fibromyalgia. They are the targets of pregabalin and gabapentin, which have potential pain modulatory, physiological-sleep-promoting and anxiolytic actions. 

Drugs such as codeine, fentanyl and oxycodone, are contraindicated because of poor clinical response and increased risk of opioid-induced hyperalgesia. There is no trial evidence of efficacy for paracetamol used alone and there is weak evidence that non-steroidal anti-inflammatory drugs are ineffective.