Tramadol for management of fibromyalgia pain and symptoms: Systematic review

Fibromyalgia is a heterogeneous condition that appears to be associated with physiological and biochemical disturbances of pain modulation, and that consequently affects numerous other facets of life. Tramadol is currently being explored as an option to manage fibromyalgia pain and other symptoms because of its inhibitory activity of reuptake of neurotransmitters, but its safety and efficacy have not yet been established in these patients.

To evaluate the effectiveness and safety of tramadol on the management of symptoms of the syndrome.

We searched CENTRAL, MEDLINE, EMBASE, LILACS, Opengrey, ClinicalTrials.gov and WHO-ICTRP for randomised controlled trials analysing the association between tramadol used for fibromyalgia either single-agent or in combination with other drugs. Two reviewers independently extracted data and assessed risk of bias using the Cochrane risk-of-bias tool for all included studies. Quality of the evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE).

Four RCTs comprising 459 patients were included. Tramadol-either as a single-agent or in combination with an antidepressant or analgesic-had a positive effect on pain. Tramadol combined with analgesic showed improved quality of life over placebo as measured by the Fibromyalgia Impact Questionnaire at 91 days. However, this difference did not hold for tramadol as a single agent against placebo. The evidence in these articles was rated "low" using the GRADE approach. No serious adverse events were reported. No improvement in depression and quality of sleep were observed.

This systematic review found a dearth of clinical trials on tramadol in patients with fibromyalgia. Although the combination of monoamine and opioid mechanism of tramadol has shown positive effects for fibromyalgia, the available evidence is not sufficient to support or refute the use of tramadol in clinical practice for pain or symptom management. Protocol registration number in the PROSPERO database: CRD42017062139.