In a study presented at ASCO, researchers found that the drug duloxetine (Cymbalta) can help to treat peripheral neuropathy, a painful side effect of chemotherapy using taxanes. Taxotere, the chemotherapy drug used to treat castrate resistant, advanced prostate cancer is a taxane.

Peripheral neuropathy occurs when nerves in the body’s peripheral nervous system (outside the brain and spinal cord) are damaged, in this case by the chemotherapy. The most common symptoms depend on where the damaged nerves are located, it can cause numbness and tingling in the hands and feet, pain, muscle weakness, constipation, and dizziness.

About 20% to 30% of patients who receive a taxane chemotherapy and a platinum-based chemotherapy (not used for prostate cancer) develop peripheral neuropathy. Peripheral neuropathy is a long-lasting side effect that lowers the quality of life (QOL) during and after treatment.

This reported study was small, it included 231 subjects who had high levels of pain caused by peripheral neuropathy from chemotherapy. They received either duloxetine followed by placebo (an inactive treatment) or a placebo followed by duloxetine. The dose was started low and then gradually increased to lessen the side effects of duloxetine, which include fatigue, dry mouth, sleepiness, and nausea.

The subjects then completed a survey on the amount of pain they were experiencing before the study started and then weekly during the study. Researchers learned the following information from these surveys:

• 59% of the patients given duloxetine and 39% of those given the placebo felt that they had less pain

• 30% of the patients given duloxetine and 33% of those given the placebo felt no change in pain

• 11% of the patients given duloxetine and 28% of those given the placebo felt that they had more pain

The researchers concluded that when the subjects took duloxetine, they had less pain and they were less likely to have no change or an increase in pain than when they took the placebo. The most common side effect that the subjects experienced during this study was fatigue, and it was more common for those taking duloxetine.

“Duloxetine isn’t perfect and didn’t work for every patient in our study, but it was effective for a majority of people, and this was the first randomized clinical trial to show that any drug is effective for this terrible pain,” said lead author Ellen M. Lavoie Smith, PhD, Assistant Professor in the School of Nursing at University of Michigan in Ann Arbor. “We now have a treatment that could improve the quality of life for many of our patients.”

Duloxetine is currently available to treat depression and peripheral neuropathy from diabetes. You might wish to ask your doctor about adding duloxetine to your drug list to counter peripheral neuropathy from chemotherapy.

Joel T Nowak, M.A., M.S.W.