The US Food and Drug Administration (FDA) gave approval Eli Lilly’s Cymbalta (duloxetine HCl) for the management of fibromyalgia, a chronic widespread pain disorder.

Cymbalta is the first serotonin- norepinephrine reuptake inhibitor with proven efficacy for reducing pain in patients with fibromyalgia. The fibromyalgia indication represents the second FDA-approved use for Cymbalta for a pain disorder, demonstrating the medication's analgesic effect.

The cause of fibromyalgia remains unknown; however, scientists believe it may be related to some combination of changes in brain and spinal cord chemistry, genetics and stress. Some researchers believe fibromyalgia is a disorder of increased sensitivity to pain. Although the way Cymbalta works in people is not fully known, medical experts believe it increases the activity of two naturally occurring substances called serotonin and norepinephrine. These substances aid communication in many areas of the brain and spinal cord that affect emotion. Research also suggests that these substances are part of the body's natural pain-suppressing system.

Fibromyalgia is estimated to affect two per cent of the US population - approximately 5 million people - the majority of those diagnosed being women. The disorder is characterized by chronic widespread pain and tenderness. Some patients may have additional symptoms. Although there is no known cure for fibromyalgia, some physicians recommend a comprehensive care plan that can include education, medication, and lifestyle changes to help manage the symptoms of the disorder.

The approval marks the fourth disorder that the FDA has approved for Cymbalta. In addition to fibromyalgia, Cymbalta is approved for the management of diabetic peripheral neuropathic pain (DPNP) and the treatment of major depressive disorder and generalized anxiety disorder, all in adults age 18 years and older.