People with fibromyalgia who haven’t responded well to other treatments  have another option since 2008, when duloxetine HCl (Cymbalta) became the second fibromyalgia drug to be approved by the Food and Drug Administration (FDA) based on data from approximately 1,400 patients in five drug studies.

In clinical trials for patients with fibromyalgia, Cymbalta significantly eased pain. Those who were treated with 60 mg or 120 mg of the fibromyalgia drug daily experienced greater reductions in the severity of their pain one week after starting medication compared to those taking placebo. After three months, patients treated with Cymbalta showed significant reduction in pain as well as improvement in Patient's Global Impression of Improvement (PGI-I) scores – based on a questionnaire designed to measure how the patient has felt overall since beginning to take the medication – compared with patients taking placebo.

Cymbalta is the first in a class of medications called serotonin-norepinephrine reuptake inhibitors proven to reduce pain in people with fibromyalgia. Although its precise mechanism for pain relief is not well understood, experts believe it increases the activity of two naturally occurring substances, serotonin and norepinephrine, in the brain and spinal cord. The substances are believed to mediate mood and regulate pain perception.

Fibromyalgia is the second pain indication for Cymbalta. Previously, Duloxetine HCl received approval for diabetic peripheral neuropathic pain. It is also approved for the treatment of major depressive disorder and generalized anxiety disorder. 

In 2007, the anti-seizure medication pregablin (Lyrica) became the first FDA-approved fibromyalgia drug.