A consistent line of investigation proposes that
fibromyalgia is a sympathetically maintained
neuropathic pain syndrome. Dorsal root ganglia
sodium channels may play a major role in
fibromyalgia pain transmission.
Ambroxol is a secretolytic agent used in the treatment of various airway disorders. Recently, it was discovered that this compound is also an efficient
sodium channel blocker with potent anti-
neuropathic pain properties. We evaluated the add-on effect of
ambroxol to the treatment of
fibromyalgia. We studied 25 patients with
fibromyalgia.
Ambroxol was prescribed at the usual clinical dose of 30 mg PO 3 times a day × 1 month. At the beginning and at the end of the study, all participants filled out the Revised
Fibromyalgia Impact Questionnaire (FIQ-R) and the 2010 ACR diagnostic criteria including the widespread
pain index (WPI). At the end of the study, FIQ-R decreased from a baseline value of 62 ± 15 to 51 ± 19 (p = 0.013).
Pain visual analogue scale decreased from 77 ± 14 to 56 ± 30 (p = 0.018). WPI diminished from 14.6 ± 3.1 to 10.4 ± 5.3 (p = 0.001). Side effects were minor. In this pilot study, the use of
ambroxol was associated to decreased
fibromyalgia pain and improved
fibromyalgia symptoms. The open nature of our study does not allow extracting the placebo effect from the positive results. The
drug was well tolerated.
Ambroxol newly recognized pharmacological properties could theoretically interfere with
fibromyalgia pain pathways. Dose escalating-controlled studies seem warranted.