The approval makes Cymbalta the first and only FDA-approved drug to treat the disorder, known as diabetic peripheral neuropathic pain. The condition affects up to 5 million people in the U.S. and is a complication of diabetes and may cause burning, stabbing, or shooting pain as a result of nerve damage thought to be caused by high blood sugar levels.
It's the second FDA approval within a month for Cymbalta, which was approved on Aug. 3 as a treatment for major depression in adults.
Antidepressant Eases Diabetic Pain
Both studies showed that Cymbalta significantly reduced overall pain compared with a placebo (sugar pill). More than half of those treated with Cymbalta (58%) reported at least a 30% reduction in pain compared with nearly a third (34%) of those treated with the placebo.
The studies also showed that the 60-milligram-per-day dose of the drug was better tolerated and caused fewer side effects than a higher, 120-milligram-per-day dose of the drug, although both doses were safe and effective.
Researchers found participants reported improvement in pain symptoms as early as in the first week of treatment. Cymbalta also reduced nighttime pain, which is common in people with diabetic neuropathy and often causes sleeping problems.
Researchers say Cymbalta does not reverse or treat the underlying nerve damage caused by the condition. But they believe the drug eases the pain caused by this condition by increasing levels of two chemicals in the brain (serotonin and norepinephrine) that are thought to regulate people's emotions and sensitivity to pain. Increasing these chemicals is thought to improve a person's ability to regulate and tolerate pain.
In clinical trials of Cymbalta for diabetes-related pain, the most common side effects were nausea, sleepiness, dizziness, constipation, dry mouth, increased sweating, decreased appetite, and fatigue. Most people were not bothered enough by side effects to stop taking Cymbalta.
Cymbalta is made by Eli Lilly and Co., which is also a WebMD sponsor.