The antidepressant drug duloxetine, brand name Cymbalta, has recently been approved by the US Food and Drug Administration (FDA) to treat certain chronic pain conditions. A new study, conducted at the University of Michigan Comprehensive Cancer Centers, has found that the drug may also help with the relief of joint and muscle pain associated with breast cancer treatments by aromatase inhibitors.
Cymbalta May Relieve Joint and Muscle Pain from Aromatase Inhibitors
According to the National Cancer Institute, aromatase inhibitors (AI’s) can help block the growth of estrogen-sensitive tumors by lowering the amount of hormone produced, not from the ovaries but from other body tissues. Currently, there are three AI’s approved by the FDA: anastrazole (Arimidex), exemestane (Aromasin), and letrozole (Femara).
About half of the women who take aromatase inhibitors experience aches and pains in their joints and muscles that cannot be adequately relieved by general painkillers. Unfortunately, this causes as many as 20% of women to stop use the drug.
“Since women typically take these drugs for five years, it is important that the side effects not interfere too much with their quality of life,” said study author N. Lynn Henry MD PhD, an assistant professor of internal medicine at U-M Medical School.
Henry and colleagues evaluated 29 patients being treated with AI’s who were experiencing pain during treatment. After taking Cymbalta, nearly three-fourths of the women reported that their pain had decreased by at least 30%. After eight weeks of treatment, average pain scores declined 61%.
However, one in five patients did stop taking Cymbalta due to side effects, which can include fatigue, blurred vision, dry mouth, nausea, gastrointestinal problems such as constipation or diarrhea, and agitation or irritability.
Dr. Henry, who presented the data at the 33rd Annual San Antonio Breast Cancer Symposium, plans to further review Cymbalta’s effect on AI pain relief by comparing the drug to a placebo. She is also doing research on pain perception to better understand why women develop pain.
Note about funding: The study was supported by an Investigator Initiated Grant from Lilly Pharmaceuticals