Results from a pilot clinical study published in the journal Clinical Rheumatology showed that ambroxol may help manage pain in fibromyalgia patients.
Ambroxol is mainly known as a mucolytic and expectorant agent. It has been used for decades in the treatment of various airway disorders, helping to restore the normal clearance mechanisms of the respiratory tract.
Previous studies have shown that ambroxol has the capacity to block the response of sodium channels, which are responsible for the transmission of pain sensations caused by nerve damage or dysfunction (neuropathic pain). The drug was shown to be 13 times more potent compared to other known calcium channel blockers, such as benzocaine, Xylocaine (lidocaine), and Mexitil (mexiletine).
It’s been previously suggested that fibromyalgia could have a neuropathic nature. Indeed, a study performed by researchers from Mexico found that some patients with fibromyalgia presented a mutation on a sodium channel gene associated with neuropathic pain signals. These findings support the hypothesis that sodium channel blocker agents might have a therapeutic potential for this medical condition.
The authors of the study, “Ambroxol for fibromyalgia: one group pretest-posttest open-label pilot study,” tried to identify the add-on benefits of ambroxol to standard fibromyalgia treatment regimens.
A total of 25 patients with fibromyalgia were given Ambroxol 30 mg, three times a day, for one month. At the beginning and at the end of the study, all participants filled several questionnaires related to disease severity, pain signs, quality of life, and mental health.
By the end of the study, patients showed an overall improvement in many fibromyalgia symptoms. According to the Revised Fibromyalgia Impact Questionnaire (FIQ-R) answers, the group improved from a 62 value at the beginning of the study to a value of 51. Also, the pain visual analog scale decreased from 77 to 56, and Widespread Pain Index (WPI) decreased from a score of 14.6 to 10.4.
“In this pilot study, the use of a sodium channel blocker ambroxol was associated not only to decreased fibromyalgia pain but also to improvement in other bothersome fibromyalgia features such as sleep disturbances, stiffness, and dysautonomia [dysfunction of the autonomous nervous system] symptoms,” the researchers wrote.
During the trial, no major adverse side effects were reported, suggesting that the use of ambroxol in combination with other fibromyalgia therapies is safe and well tolerated.
Despite the positive results obtained, however, additional studies are needed to fully grasp the beneficial effects of ambroxol for fibromyalgia patients. Clinical studies with an untreated control group to assess the placebo effect, and designed to assess dose and treatment-associated effects, should be performed.