Off-label use of Opioids to treat Fibromyalgia Prevalent, Report McGill Researchers

A recently published study by McGill University researchers (Fitzcharles MA, Ste-Marie PA, Gamsa A, Ware MA, Shir Y) titled, Opioid Use, Misuse, and Abuse in Patients Labeled as Fibromyalgia, underscores the need for confirmatory tests for fibromyalgia and more effective pain treatments.

Fibromyalgia, a condition associated with nervous system dysregulation, is currently a clinical diagnosis based on signs and symptoms.  Like many other diseases and conditions, there is no confirmatory test.

In this study, 457 patients labeled with fibromyalgia in primary care were re-examined by a rheumatologist, but only 66 percent were diagnosed by the specialist. The authors stated that taking into account the new revised criteria for a diagnosis of fibromyalgia, which incorporate symptoms other than pain as components of fibromyalgia, some patients with predominant mood or psychiatric disorder and less prominent physical symptoms may be misclassified as having fibromyalgia.

Even though mood disorder is the strongest associated comorbidity with fibromyalgia, prominent mental illness can masquerade as a pain syndrome and should be recognized. Depression is most often a consequence of inadequately controlled pain.

According to the study, of the 155 people who had been misdiagnosed as having fibromyalgia, 65 of them had a current serious mental health/psychiatric problem – although the authors did not specify either the DSM diagnosis or the severity.

Of the remaining fibromyalgia patients twelve or 3 percent were considered to have drug seeking behaviors.

At entry, 144 (32%) of all patients were on daily opioid medication, with strong opioids such as oxycodone being used by 105 and weak opioids such as tramadol and codeine used by 39. However, of the 302 fibromyalgia patients remaining upon re-examination, 60 were taking strong opioids and 30 weak opioids.

The actual prevalence of opioid use by fibromyalgia patients is largely unknown according to the authors. Another study reported that use of any analgesic other than NSAIDS (medications such as aspirin, ibuprofen and naproxen used primarily to treat inflammation, mild to moderate pain) in 52% of patients.

Although opioids are not approved for use in fibromyalgia (hence this is considered off-label use of drug), the FDA has approved three prescription drugs for pain management in fibromyalgia:

  • Lyrica (preglabin – an anti-seizure drug),
  • Cymbalta (duloxetine hydrochloride- an antidepressant) and
  • Savella (milnacipran HCl – an anti-depressant). The anti-depressants are not prescribed for depression however and are generally prescribed in much lower doses than for depression. According to the FDA, studies of these drugs show that a substantial number of people with fibromyalgia received good pain relief, but there were others who don’t benefit.

However there are very few studies of opiod use in fibromyalgia other than for tramadol.

In this study, the authors (Fitzcharles MA, Ste-Marie PA, Gamsa A, Ware MA, Shir Y) stated that opioid use was more commonly associated with lower education, unemployment, disability payments, current unstable psychiatric disorder, a history of substance abuse, and previous suicide attempts, but did not break out the differences between the two final groups of patients.

According to the Agency for Healthcare Research and Quality, an estimated 12.1 million women age 18 and older reported suffering from chronic pain in 2008 as a result of underlying medical conditions such as chronic fatigue syndrome, endometriosis, fibromyalgia and vulvodynia. Of these women, only 8.7 million reported receiving treatment that year at a total cost of $12.9 billion.

Adrienne Dwello, the guide for the site for fibromyalgia and chronic fatigue syndrome, recently asked patients to comment on their experiences with opioids and garnered 92 comments.

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