Fibromyalgia, Drugs OK'd to Manage Pain (cont.)

Approved Drugs

People with fibromyalgia have typically turned to pain medicines, antidepressants, muscle relaxants, and sleep medicines. In June 2007, Lyrica (pregabalin) became the first FDA-approved drug for specifically treating fibromyalgia; a year later, in June 2008, Cymbalta (duloxetine hydrochloride) became the second.

Both Lyrica and Cymbalta reduce pain and improve function in people with fibromyalgia. While those with fibromyalgia have been shown to experience pain differently from other people, the mechanism by which these drugs produce their effects is unknown. There is some data suggesting that these drugs affect the release of neurotransmitters in the brain. Neurotransmitters are chemicals that transmit signals from one neuron to another. Treatment with Lyrica or Cymbalta reduces the level of pain experienced by some people with fibromyalgia.

Lyrica, marketed by Pfizer Inc., was previously approved to treat seizures, as well as pain from damaged nerves that can happen in people with diabetes (diabetic peripheral neuropathy) and in those who develop pain following the rash of shingles. Side effects of Lyrica including sleepiness, dizziness, blurry vision, weight gain, trouble concentrating, swelling of the hands and feet, and dry mouth. Allergic reactions, although rare, can occur.

Cymbalta, marketed by Eli Lilly and Co., was previously approved to treat depression, anxiety, and diabetic peripheral neuropathy. Cymbalta's side effects include nausea, dry mouth, sleepiness, constipation, decreased appetite, and increased sweating. Like some other antidepressants, Cymbalta may increase the risk of suicidal thinking and behavior in people who take the drug for depression. Some people with fibromyalgia also experience depression.

Studies of both drugs showed that a substantial number of people with fibromyalgia received good pain relief, but there were others who didn't benefit.

Lyrica and Cymbalta are approved for use in adults 18 years and older. The drug manufacturers have agreed to study their drugs in children with fibromyalgia and in breastfeeding women.