An FDA advisory committee will meet today to review whether the antidepressant Cymbalta should be used as a treatment for chronic pain, despite risks that include liver damage and skin disease.
Drugmaker Eli Lilly is seeking an indication for use in treatment of chronic pain, including pain related to arthritis and chronic low back pain.
In briefing documents posted on Tuesday, FDA reviewers said four
studies found Cymbalta worked better than the placebo at easing pain, but they questioned one crucial aspect of Eli Lilly's study design, and pointed to a number of major safety concerns associated with Cymbalta.
Earlier this year, the agency took Lilly to task for making false and misleading claims in Cymbalta marketing materials, overstating efficacy of the drug against pain and minimizing its risks.
If the FDA approves Lilly's current application, it would "likely result in a substantial increase in the prescribing of the product in the general population given the large number of Americans suffering from these types of chronic pain conditions," wrote Dr. Bob Rappaport, director of the FDA's Division of Anesthesia and Analgesia Products in the briefing documents.
Many physicians say the decision likely won't change their prescribing habits, but an approval could expand insurance coverage.
"Insurance reimbursement of an antidepressant for pain will help patients who couldn't get access to the meds due to restrictive formularies and so may expand coverage that way," said Dr. Joan M. Von Feldt, a pain specialist at the University of Pennsylvania, in an e- mail.
Von Feldt added that many doctors are pleased to have non-narcotic options for chronic pain treatment, especially with the troubling trend of prescription opioid addiction.
Some, however, don't see the need for the alternative.
Dr. Nortin Hadler, an arthritis specialist at the University of North Carolina Chapel Hill, called the potential approval "a marketing ploy."
"The marketing of Cymbalta as an analgesic is an example of data torturing," he said. "I do not prescribe it for [pain]."
Dr. Randy Wexler, a primary care physician at Ohio State University, agreed.
"I do not prescribe this unless a patient comes to me already on it," Wexler said. "There are other, and in my opinion safer, medications which are also generic that can be used."
Few seemed concerned about the potential side effects.
"Any medication with the potential to treat pain has potential side effects," said Dr. John Messmer of Pennsylvania State University, "but the risks of hepatotoxicity and Stevens-Johnson syndrome are so low as to be not worthy of mention."
Von Feldt added that all medications have side effects, and "some patients may have more susceptibilities to some side effects than to others."
Cymbalta, a serotonin-norepinephrine reuptake inhibitor, was originally approved to treat depression, and its indications were subsequently extended to include fibromyalgia, anxiety, and pain associated with diabetic neuropathy.
Prescriptions for the drug increased from five million in 2005 to more than 14 million in 2009, a threefold increase, according to another FDA reviewer, Rajdeep Gill. The majority of prescriptions are for depression, but at least 14 percent are already for off-label use in pain treatment, he said.