Antidepressants Help Treat Fibromyalgia
Researchers Find Some Antidepressants May Relieve Pain of Fibromyalgia
Jan. 13, 2009 -- Certain antidepressants can be effective treatments for fibromyalgia, but it is not clear if they are good choices for long-term use, a new research analysis shows.
Fibromyalgia remains a poorly understood and hard-to-treat disorder, characterized by widespread pain with no clear cause. Other commonly reported symptoms include fatigue, sleep problems, and depressed mood.
A wide range of antidepressants may be used to treat the disorder, but only one -- Eli Lilly and Company's Cymbalta -- has been specifically approved for the condition.
The FDA approval for use in fibromyalgia patients came last June, making it just the second drug approved to treat the disorder.
Pfizer's Lyrica was the first drug approved for fibromyalgia, but it was not included in the analysis because it is not an antidepressant. It is believed to work by targeting a key pain center within the brain.
Antidepressants vs. Fibromyalgia
Researchers examined 18 studies involving 1,427 fibromyalgia patients taking different classes of antidepressants, including low doses of tricyclic and tetracyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), serotonin and noradrenaline reuptake inhibitors (SNRI), and monoamine oxidase inhibitors (MAOIs).
The researchers used a standardized model to assess the effectiveness of the medications on common fibromyalgia symptoms, including pain, sleeplessness, fatigue, and depressed mood.
Among the major findings:
- The TCA amitriptyline (Elavil, Endep), given in low doses, had the largest effect on pain, fatigue, and sleep disturbances. Little effect was recorded on depressed mood, however.
- The SNRIs Cymbalta and milnacipran, which is not yet approved for sale in the U.S., were found to have a small effect on pain, sleep disturbance, and depressed mood.
- The SSRI antidepressants Prozac and Paxil also had a small positive effect on pain and depressed mood, but no effect on fatigue and sleep.
- The MAOIs moclobemide (Aurox, Manerox) and pirlindole (Pyrazidol) had a modest effect on pain, but there was no evidence that moclobemide improved fatigue or sleeplessness.
Researcher Winfried Hauser, MD, of Germany's Saarbrucken Hospital, tells WebMD that the TCA amitriptyline and the SNRI Cymbalta are the antidepressants with the most evidence of effectiveness for the short-term treatment of fibromyalgia.
Lilly spokeswoman Sonja Popp-Stahly tells WebMD that the three company-funded Cymbalta studies included in the analysis show that the drug works in fibromyalgia patients with and without depression.
Since none of the studies in the analysis followed patients for longer than six months, the long-term effectiveness of these drugs is not clear, Hauser notes.
"Fibromyalgia is a lifelong disorder, so we definitely need to study these drugs to see if they work for long periods," he says.
Antidepressants Don't Work for All
And while antidepressants can improve fibromyalgia symptoms, they don't work for everyone.
According to Hauser, about one out of four to six patients experiences significant pain reductions of about 30% while taking an antidepressant.