The FDA has now approved Cymbalta (duloxetine) to treat chronic musculoskeletal pain, including discomfort from osteoarthritis and chronic lower back pain.
"Up to three quarters of the population experience chronic pain at some time in their lives," said Janet Woodcock, M.D., director of FDA's Center for Drug Evaluation and Research. "This approval means that many of those people now have another treatment option."
Since its initial approval in 2004, about 30 million patients in the United States have used Cymbalta. Thus far Cymbalta, manufactured by Eli Lilly and Co., has received FDA approval for six different indications, three of which are pain-related:
- Major depressive disorder in 2004
- Diabetic peripheral neuropathy in 2004
- Generalized anxiety disorder in 2007
- Maintenance treatment of major depression in 2007
- Fibromyalgia in 2008
- Chronic musculoskeletal pain in 2010
Cymbalta is classified as an antidepressant in a group of drugs called selective serotonin and norepinephrine reuptake inhibitors (SNRIs). SNRIs work by inhibiting the reuptake (reabsorption) of the neurotransmitters serotonin and norepinephrine, which results in increased concentrations of serotonin and norepinephrine in the brain. Both serotonin and norepinephrine are known to play an important part in mood and appear to also play a significant role in many types of pain.
The FDA assessed the efficacy of Cymbalta in chronic low back pain and osteoarthritis in four double-blind, placebo-controlled, randomized clinical trials. At the end of the study period, patients taking Cymbalta had a significantly greater pain reduction compared with placebo.
The most common side effects reported with Cymbalta include nausea, dry mouth, insomnia, drowsiness, constipation, fatigue, and dizziness.
