June 4, 2012 (Chicago) -- The antidepressant Cymbalta is the first drug that has been shown to relieve the nerve pain and discomfort that afflicts up to one-third of cancer patients treated with certain chemotherapy drugs, researchers report.
In a study of over 200 people who suffered from the condition known as chemotherapy-induced peripheral neuropathy, 59% of those given Cymbalta reported a decrease in pain, compared with 39% given placebo.
Chemotherapy-induced peripheral neuropathy is caused by damage to nerves, most often in the arms and legs. Besides shooting pain, symptoms include burning, tingling, numbness, problems with balance, dropping things, and cold or heat sensitivity.
"Peripheral neuropathy is a chronic, debilitating problem, with some patients enduring pain, numbness, and tingling for months, possibly years, after completion of chemotherapy," says researcher Ellen M. Lavoie Smith, PhD, an assistant professor in the School of Nursing at University of Michigan, Ann Arbor.
"Until now, we knew of nothing that was effective in treating the condition," she tells WebMD.
The drug was generally "well tolerated," Smith says. The most common side effect was mild fatigue, reported by 11% of people taking Cymbalta and 3% on placebo. Twelve patients (11%) dropped out of the study due to drug-associated side effects.
The findings were presented here at the annual meeting of the American Society of Clinical Oncology.
A Step Forward
"Many more patients are affected by peripheral neuropathy than previously thought," says Nicholas Vogelzang, MD, of the Comprehensive Cancer Centers of Nevada in Las Vegas and US Oncology. He was not part of the study.
Although Cymbalta doesn't help everyone, "it is a step forward for patients who can be debilitated by chemotherapy," he tells WebMD.
In the study, 30% of patients on Cymbalta reported no change in pain and 11% taking the drug reported an increase in pain.
Participants took one 30-milligram capsule of Cymbalta daily for one week, followed by two capsules daily (60-milligram total) for four additional weeks. The gradual dosing was important to reduce the side effects of Cymbalta, which can include fatigue, dry mouth, sleepiness, and nausea, Smith says.
Cymbalta is thought to work by changing levels of brain chemicals linked to pain and nerve function, she says.
Chemotherapy-induced peripheral neuropathy is commonly managed similarly to other types of nerve pain -- with a combination of physical therapy, complementary therapies such as massage and acupuncture, and medications that can include steroids, antidepressants, anti-epileptic drugs, topical numbing medicine, and opioids for severe pain.
Cymbalta, which is approved for the treatment of depression and painful diabetic peripheral neuropathy, costs about $150 for a month supply.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.