Fibromyalgia, an incurable illness that causes stiffness, fatigue, muscle aches and sleep disturbances, affects about 10 million Americans, mostly women. The underlying cause is unknown and current treatments include pain medication, stretching, exercise, sleep management and psychological support.

The study of 14 women with fibromyalgia and 10 women without the disease found dextromethorphan appears to temporarily reduce the intensity of "wind-up," a cascading pain response to minor, repetitive physical touch, which is symptom of the syndrome.

The study appears in the May issue of the Journal of Pain.

One Piece of the Mosaic

The Florida study did not establish guidelines for clinical use of dextromethorphan. However, the findings do suggest it may eventually provide an option for treating fibromyalgia and other conditions that cause heightened pain sensitivity, the researchers said.

"I think it's one piece of the mosaic. We currently have no single therapy in chronic pain that has a big effect.

"So what this really means for chronic pain patients is that they need to use a whole host of different interventions to decrease the pain they have. And in this, dextromethorphan may have a role in the future," study principal author and rheumatology expert Dr. Roland Staud, an associate professor of medicine, said in a prepared statement.

However, he cautioned that fibromyalgia patients should not self-medicate by taking cough syrups that contain dextromethorphan.

10 Million Americans, Mostly Women

Fibromyalgia, an incurable illness that causes stiffness, fatigue, muscle aches and sleep disturbances, affects about 10 million Americans, mostly women.

The underlying cause is unknown and current treatments include pain medication, stretching, exercise, sleep management and psychological support.

More information: The Arthritis Foundation has more about fibromyalgia.