An Food and Drug Administration advisory committee has voted 8 to 6 in favor of expanding Eli Lilly’s antidepressant drug duloxetine (Cymbalta) indication to include the treatment of chronic pain.

The drug, which is approved to treat depression, diabetic nephropathy and fibromyalgia, will compete with Tylenol, aspirin and other anti-inflammatory drugs if the FDA approves broadening the indication to include low back pain.

The drug was used by 2.8 million patients with 14.6 million prescriptions last year, according to an F.D.A. staff report.
While the committee approved the drug’s effectiveness for lower back pain, it recommended against expanding the indication to include osteoarthritis of the knee.

There was some debate whether data from the clinical trials presented by Lilly provided adequate evidence of efficacy for the management of chronic low back pain.

Thomas Boyer, MD, from University of Arizona College of Medicine, Tucson, said 2 trials presented by Lilly were in conflict, with one showing positive results and the other showing negative results for treatment of osteoarthritis.

A penal member said that the studies presented by Lilly were done mostly in whites and left out minorities. "There is ample evidence to suggest that certain minority populations do not follow the same patterns as a Caucasian population, and so by giving this a vote of yes, we would be saying it's fine for everyone and [I] don't believe that's been shown," said Charles Rohde, MD, from Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.

Although duloxetine is known to be hepatotoxic, most drugs are also, and the panel was not too concerned about the drug’s safety.

Dr. Sidney M. Wolfe, a consumer representative on the panel and director of the health research group at the nonprofit group Public Citizen, said the agency should “move slowly, if at all,” to expand approved uses of the drug.