Antidepressant Lessens Chemo-Related Pain
Cymbalta shows positive effect on neuropathy in clinical trial
The Cymbalta patients were also twice as likely to have a 50 percent decrease in pain scores versus the placebo users, and overall they reported improvements in their daily functioning and quality of life.
It is not clear how the antidepressant helps with nerve-related pain, but it is thought to act on certain brain chemicals involved in transmitting pain signals.
The findings are encouraging, Stubblefield said. But, like Smith, he pointed out that not everyone responds to Cymbalta. "This doesn't mean I'll be putting all my patients on it," he said.
There are other treatments for chemo-related pain -- although they have not yet been shown to work in rigorous clinical trials. One option, Stubblefield said, is Lyrica (pregabalin), which is another drug approved to treat other forms of nerve-damage-related pain.
Stubblefield said Lyrica tends to have fewer side effects than Cymbalta, and at least some patients may be able to tolerate it better. Cymbalta's side effects include fatigue, insomnia and nausea, which were reported by 5 percent to 7 percent of patients in the current study.
On the other hand, Stubblefield said, if a patient with nerve pain is also feeling depressed, it makes sense to try Cymbalta first.
There's also cost. Cymbalta is not yet available as a generic, and runs close to $200 a month. It is scheduled to lose patent protection at the end of 2013, so cheaper versions may become available.
Smith said there are still many questions to sort out: How well can patients tolerate Cymbalta over a longer term? Does the drug help nerve pain in patients who are still on chemo?
"We anticipate that it would help," Smith said. "But to what degree? Would it be enough to make a difference in their lives?"
As better treatments are helping more cancer patients survive, chronic peripheral neuropathy is emerging as one of the most difficult side effects of the treatments, said Dr. Sandra Swain, president of the American Society of Clinical Oncology.
Even minor actions, like picking up your keys, become difficult, Swain said. "It really affects your everyday living," she said.
Swain said the bottom line for patients is that "this drug may actually work, and it's something you can discuss with your doctor."
Still, Swain added, more research is needed -- not only into Cymbalta, but into other treatments for chemo-related pain.
Eli Lilly, the company that makes Cymbalta, provided the drug for the study. The work was funded by government and non-profit grants, and none of the researchers reported financial ties to Eli Lilly.