John: Hello, I'm John Hilton, editor in the Cochrane Editorial and Methods department. The Cochrane Pain, Palliative and Supportive Care Group is producing a series of reviews on drugs for the treatment of people with fibromyalgia. One of these, published in March 2018, examines the effects of a class of antidepressants called serotonine noradrenaline reuptake inhibitors. In this podcast, one of the co-authors, Brian Walitt, from the National Institute of Nursing Research in the USA, describes the findings.

Brian: Fibromyalgia is a common condition of pain and fatigue, whose nature is not understood. Some patients are given antidepressants to try help manage it and, in the United States, the serotonin noradrenaline reuptake inhibitors (SNRIs) duloxetine and milnacipran have been approved by the US Food and Drug Administration (FDA) for this use. However, in Europe these same medications have not been approved by the FDA’s equivalent, the European Medicines Agencies, for fibromyalgia management.
In light of this difference in the interpretation of the evidence, our review seeks to clarify the benefits and harms of SRNIs for adults with fibromyalgia.
We searched for placebo controlled randomised trials and found 18, with a total of just over 7900 patients, but we rated the quality of the evidence as low to very low. The shortest trial followed the participants for 6 weeks, while the longest lasted 27 weeks. Daily dosages of duloextine ranged between 30 and 120 mg, while the doses of milnacipran ranged between 100 and 200 mg.
In the trials, persons who took SNRIs were compared with others who took placebo, which is a dummy medication made to look and taste like the real one. We found no difference between persons taking SNRIs or placebo in acheiving a clinically relevant improvement in pain relief of 50% or greater. Those who took SNRIs did report more frequently than those taking placebo that the global impression of their health was much or very much improved and that they had pain relief of 30% or greater. But SNRIs provided no clinically relevant benefits in improving health-related quality of life, or reducing fatigue or sleep problems, and the dropouts due to side effects were higher in the SNRI group than the placebo group.
On average, the potential benefits of SNRIs in fibromyalgia were outweighed by their potential harms, although a minority of people with fibromyalgia do experience substantial symptom relief without clinically relevant adverse events with duloxetine or milnacipran.“

John: If you would like to read about the different effects of duloxetine, milnaciprane and desvenlafaxine on fibromyalgia symptoms in detail, or to look in more depth at the review as a whole, you can find it online at Cochrane Library dot com with a search for 'SNRIs for fibromyalgia'. While a simple search for 'drugs and fibromyalgia' will pick up all the reviews in this series.

Hello, I'm John Hilton, editor in the Cochrane Editorial and Methods department.