The medication, Lyrica, known generically as pregabalin, had previously gained FDA approval to treat, among other conditions as partial seizures and neuralgia.
Lyrica posted about $1.2 billion in world-wide sales last year, and has been used by about five million patients.
Fibromyalgia, which typically affects women, leaves sufferers in chronic pain. An estimated 3 million to 6 million people in the United States are affected each year.
Lyrica side effects include mild-to-moderate dizziness and drowsiness.
While the exact cause of fibromyalgia is a medical mystery, scientists believe onset may be triggered by injury or emotional distress. Viruses that alter the way the brain perceives pain is also among the theories.
