Used to help manage depression, anxiety disorder and diabetic nerve pain, Cymbalta can now be taken for fibromyalgia.

Last month the U.S. Food and Drug Administration (FDA) approved this use of the drug, made by Indianapolis-based Eli Lilly and Company.

“The approval of Cymbalta is important because it provides physicians and patients … a new treatment option shown to help reduce pain and improve functioning in this difficult-to-treat disorder,” said Madelaine Wohlreich, M.D., medical advisor and research physician at Lilly, in a press release.

According to the U.S. Centers for Disease Control (CDC), fibromyalgia affects 2 percent of the population, or an estimated 5 million people.

Cymbalta’s approval comes on the heels of two 3-month clinical trials involving 874 fibro patients.

The studies found that:

  • “Significant improvement in pain for [those patients taking Cymbalta and not the placebo] was observed in the first week of each study.”

  • “51 percent and 55 percent of patients on Cymbalta had a [clinically significant] 30 percent improvement on the Brief Pain Inventory (BPI) at endpoint.”

    (The BPI is a 24-hour average pain scale that measures the severity of pain for a patient.)

And yet, Cymbalta’s approval has drawn criticism from some corners — but not because of the drug itself.

As the CreakyJoints team discusses in this week’s podcast (Show 52 – Fibromyalgia: Seth and Dr. Laurie dive in), many physicians refuse to acknowledge fibromyalgia.

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“A lot of doctors deny the existence of fibromyalgia,” said Dr. Marcia Angell, former editor-in-chief of the New England Journal of Medicine, to Indianapolis Star reporter John Russell. “It certainly cannot be reproducibly diagnosed because so many of the criteria are subjective.

“So you have a subjective diagnosis and a subjective outcome. You don’t know whether the treatment has worked or not.”

Thus, these “non-believing” physicians discount or ignore their patients’ pain — and whether it is improving or worsening.

Forget them, says Lynne Matallana, president of the National Fibromyalgia Association and a fibro patient.

“The FDA approval of Cymbalta for the management of fibromyalgia is another important step in the efforts to ensure that people with fibromyalgia will have the availability of effective medications to help reduce the chronic, widespread pain of this life-altering disorder,” she said in Lilly’s press release.

So, how does the drug work? Researchers aren’t quite sure.

Lilly offers that some “medical experts believe [taking Cymbalta] increases the activity of two naturally occurring substances called serotonin and norepinephrine. These substances aid communication in many areas of the brain and spinal cord … [and research] suggests that these substances are part of the body’s natural pain-suppressing system.”

Reestablishing that pain suppression system is Cymbalta’s goal, said Dr. Michael Robinson, a Lilly psychiatrist and associate medical director of Cymbalta.

“All pain travels through the body and into the brain,” Robinson told Russell. “In order for someone to experience pain, it’s perceived by the brain. Cymbalta is a medication that works [to stop the pain’s perception].”

Cymbalta is currently approved to treat four disorders in the U.S. and a fifth — stress urinary incontinence — in Europe (marketed under the name Yentreve).

CDC estimates for Fibromayalgia    Source: Click on the chart above to enlarge it.  

Some in the media have speculated Cymbalta cannot be effective across illness categories.

But this ignores our medicine cabinets now, says Russell. “The practice of using one pill for numerous ailments has a long history. Aspirin, for example, has become the workhorse of the medicine chest, used by millions of people for such diverse needs as reducing inflammation, treating a fever, relieving pain and preventing heart trouble,” he said.

Important to remember above all is that Cymbalta is an antidepressant — and should not be used for juvenile patients. “Like all antidepressants, the drug has a black-box warning that it may increase the risk of suicide in people younger than 25,” Russell reports.

Lilly itself warns, “Antidepressants can increase suicidal thoughts and behaviors in children, adolescents, and young adults.” As such, Cymbalta is approved only for adults 18 and older. points out the reported side effects from four pooled studies: “The most commonly observed adverse events in Cymbalta-treated patients with fibromyalgia (greater than or equal to 5 percent and at least twice placebo) were nausea (29 percent), dry mouth (18 percent), constipation (15 percent), decreased appetite (11 percent), sleepiness (11 percent), increased sweating (7 percent) and agitation (6 percent). In the placebo-controlled clinical trials, the overall discontinuation rates due to adverse events for Cymbalta vs. placebo were 20 percent and 12 percent, respectively.”

To read a press release from Lilly, a article on the announcement, the CDC’s fibromyalgia overview page, or John Russell’s Indianapolis Star article on the uses of Cymbalta, click on the links below:

Article References
Lilly Press Release: FDA Approves Cymbalta for the Management of Fibromyalgia, site accessed on 07/28/08 FDA Approves Cymbalta For The Management Of Fibromyalgia, site accessed on 07/28/08

CDC: Arthritis – Types – Fibromyalgia, site accessed on 07/28/08

Cymbalta: One drug, many uses. Good idea?, site accessed on 07/28/08