A randomised controlled trial comparing duloxetine and acetyl L-carnitine in fibromyalgic patients: preliminary data

Fibromyalgia syndrome (FMS) is a chronic disorder characterised by widespread musculoskeletal pain, troubled sleep, disturbed mood, and fatigue. Recently published reviews have demonstrated that it is influenced by various psychological aspects, and antidepressants are now considered the treatment of choice for most patients. The aim of this randomised controlled trial was to compare the effects of duloxetine and acetyl L-carnitine on pain, depression, anxiety and well-being in FMS patients.

Sixty-five female outpatients with FMS diagnosed by a rheumatologist were recruited between January 2011 and May 2012, and randomised to receive duloxetine 60 mg/day or acetyl L-carnitine 1500 mg/day (500 mg t.i.d.). Drug efficacy and side effects were assessed by the same psychiatrist at baseline, and four and 12 weeks later.

Both drugs led to a general clinical improvement, with positive effects on pain and depressive symptoms; but neither induced a significant improvement in anxiety. Both drugs had a positive effect on the physical component of the quality of life, but only duloxetine improved the psychological component.

Although they need to be confirmed by further studies, these preliminary findings confirm the efficacy of duloxetine, and suggest that acetyl L-carnitine is also efficacious in improving depressive symptoms, pain, and the quality of life of FMS patients.