Antidepressant Cymbalta Might Tame Post-Chemotherapy Pain
The antidepressant Cymbalta® (duloxetine) appears to reduce the numbness and tingling associated with taxane or platinum-based chemotherapy, according to the results of a study presented at the 2012 annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago, Illinois.
Peripheral neuropathy refers to numbness and tingling of the extremities (hands and feet) and is caused by damage to the nerves between the extremities and the central nervous system (CNS). Some chemotherapy drugs can cause peripheral neuropathy. Because the condition can have a lasting impact on day-to-day life, researchers continue to search for ways to mitigate this pain.
Cymbalta is a serotonin-norepinephrine reuptake inhibitor (SNRI) that works by increasing the amounts of serotonin and norepinephrine, natural substances in the brain that help maintain mental balance and stop the movement of pain signals in the brain.
To evaluate the effect of Cymbalta on pain from chemotherapy-induced peripheral neuropathy, researchers conducted a randomized, double-blind study that included 220 patients who were predominantly survivors of breast and gastrointestinal cancers and who had peripheral neuropathy induced by paclitaxel or oxaliplatin. Patients were randomized to receive Cymbalta or placebo. Cymbalta dosing started at 30 mg daily for the first week and then increased to 60 mg daily for 4 weeks.
Over the course of treatment, pain scores fell in both groups, but significantly more so in the Cymbalta group. Scores on the Brief Pain Inventory-Short Form fell by a mean of 1.09 points in the Cymbalta group compared with 0.33 in the placebo group. More patients in the Cymbalta group reported a reduction in pain—59 percent, compared to 38 percent in the placebo group. Approximately one-third of patients in the Cymbalta group reported a clinically significant 30 percent or greater reduction in pain scores, compared to 17 percent of placebo-treated patients. Furthermore, 21 percent of patients in the Cymbalta group reported that their pain was cut in half, compared to 9 percent in the placebo group.
What’s more—the impact of pain on daily life appeared to improve. The interference scores (indicating impact on activity, mood, walking, work, relationships, sleep, and enjoyment of life) declined significantly more in the Cymbalta group.
The drug appeared well tolerated. The most common side effect was fatigue.
The researchers concluded that pain from chemotherapy-induced peripheral neuropathy fell significantly with the use of Cymbalta and noted that it is the first drug to have been shown to work against chronic neuropathy in a clinical trial. While some other drugs, such as gabapentin, have been shown to be helpful with neuropathy, they are associated with somnolence—or severe drowsiness. Since Cymbalta is not associated with drowsiness, it could prove helpful for those suffering from neuropathy.
Smith EML, et al. CALGB 170601: A phase III double blind trial of duloxetine to treat painful chemotherapy-induced peripheral neuropathy (CIPN). Presented at the 2012 annual meeting of the American Society of Clinical Oncology, June 1-5, 2012, Chicago, IL. Abstract CRA9013.
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