Breaking Health News, August 3, 2005

Fibromyalgia Pain Helped with Parkinson's Medication

A medication used to treat Parkinson's disease appears to significantly reduce pain in severely ill fibromyalgia patients, according to a study reported in the medical journal Arthritis and Rheumatism.

Fibromyalgia is a syndrome that strikes 3.7 million Americans over the age of 18. Women have the disorder at a rate seven times that of men, according to the National Institutes of Health (NIH).

The syndrome includes symptoms ranging from chronic and diffuse pain throughout the body to fatigue and depression. There is no cure for the ailment, and many sufferers take a variety of medications to treat their symptoms.

Fibromyalgia, also called fibrositis, is a chronic, widespread pain in muscles and soft tissues surrounding the joints throughout the body, and is accompanied by fatigue.

Although its symptoms are similar to other joint diseases, such as arthritis, fibromyalgia is actually a form of soft tissue or muscular rheumatism that causes pain in the muscles and soft tissues.

Fibromyalgia is one of several pain syndromes included in the classification of musculoskeletal pain syndrome (MSPS), or pain amplification syndrome.

According to the American College of Rheumatology (ACR), persons with fibromyalgia may need a consultation with a rheumatologist to determine the cause of multiple rheumatic symptoms and to exclude other potentially progressive rheumatic diseases.

However, the ACR states that fibromyalgia can generally be treated by a primary care physician.

Findings Hopeful for Hard-to-Treat Patients

Almost half the patients who took Parkinson's medication pramipexole, which stimulates dopamine production in the brain, reported a 50 percent drop in pain, compared to only 14 percent of those who took a placebo (inactive substance).

The study participants were taking an average of more than two medications each, including narcotics, and most were disabled.

"This appears to be a novel medicine with remarkable safety that decreases fibromyalgia pain more effectively than any other single agent," says study co-author Dr. Andrew J. Holman, a rheumatologist at the University of Washington.

Because of this reliance on medication, Dr. Holman and his colleagues let participants remain on their other medications throughout the 14-week trial, which they admitted was a limitation of the study.

Dr. Holman says, however, that by permitting people to take their regular medications, at doses they had maintained for at least six weeks before beginning the study, he was able to mimic real-life situations and reach patients who were seriously ill with fibromyalgia.

However, Florida rheumatologist Dr. Roland Staud says the overlap of medicines makes it hard to assess what caused the pain reduction.

"Does the drug affect the pain itself, or does it affect the effectiveness of the medicines they're already on?" he asks.

For the study, 57 women and three men were randomly selected to receive in a 2-to-1 ratio either pramipexole or a placebo for 14 weeks.

The dosage was increased weekly, starting at 0.25 milligrams, until patients received the optimal dose of 4.5 milligrams for the last three weeks of the study. The graduated dose schedule avoided unnecessary side effects, Dr. Holman explains.

At the end of the three and a half months, 49 people remained in the study. Of those who had taken pramipexole, 42 percent reported at least a 50 percent drop in pain, as did 14 percent of those who had taken the placebo.

Treatment Success Was Significant

Overall, 82 percent of the patients taking the medication noted some improvement in pain, compared to 57 percent of the placebo group. Side effects of the medication included weight loss and nausea, although the latter was reported by many in the placebo group as well.

Dr. Holman says that the medication, which stimulates dopamine production by binding to dopamine receptor sites in the brain, appears to reduce "the inappropriately active" sensory nerve responses that cause fibromyalgia patients to feel pain.

In Parkinson's patients, the medication helps reduce tremors; it is also commonly used to treat restless leg syndrome.

"While this is an interesting study, it is very preliminary, and the results need to be replicated in other studies," Dr. Staud remarks.

Always consult your physician for more information.

Online Resources

(These links are provided for the education and convenience of our Neighbors. AAMC is not responsible for the content of Internet sites.)

American College of Rheumatology

American Fibromyalgia Syndrome Association

Arthritis and Rheumatism

Centers for Disease Control and Prevention (CDC)

Fibromyalgia Network

Institute of Medicine

National Fibromyalgia Association

National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)

National Library of Medicine

NIH on Fibromyalgia

Sign up for our Email Newsletter AAMC Neighbors News

For Email Marketing you can trust

Defining Fibromyalgia

The causes of fibromyalgia are unknown, but there are probably a number of factors involved, according to the National Institutes of Health (NIH).

Many people associate the development of fibromyalgia with a physically or emotionally stressful or traumatic event, such as an automobile accident.

Some connect it to repetitive injuries. Others link it to an illness. People with rheumatoid arthritis and other autoimmune diseases, such as lupus, are particularly likely to develop fibromyalgia.

For others, fibromyalgia seems to occur spontaneously.

Many researchers are examining other causes, including problems with how the central nervous system (the brain and spinal cord) processes pain, the NIH states.

Some scientists speculate that a person's genes may regulate the way his or her body processes painful stimuli. According to this theory, people with fibromyalgia may have a gene or genes that cause them to react strongly to stimuli that most people would not perceive as painful. However, those genes have not been identified.

Research shows that people with fibromyalgia typically see many physicians before receiving the diagnosis.

One reason for this may be that pain and fatigue, the main symptoms of fibromyalgia, overlap with many other conditions. Therefore, physicians often have to rule out other potential causes of these symptoms before making a diagnosis of fibromyalgia.

Another reason is that there are currently no diagnostic lab tests for fibromyalgia; standard laboratory tests fail to reveal a physiologic reason for pain.

A physician familiar with fibromyalgia, however, can make a diagnosis based on two criteria established by the American College of Rheumatology (ACR): a history of widespread pain lasting more than three months and the presence of tender points, the NIH states.

Pain is considered to be widespread when it affects all four quadrants of the body; that is, you must have pain in both your right and left sides as well as above and below the waist to be diagnosed with fibromyalgia.

The ACR also has designated 18 sites on the body as possible tender points. For a fibromyalgia diagnosis, a person must have 11 or more tender points.

One of these predesignated sites is considered a true tender point only if the person feels pain upon the application of 4 kilograms (8.8 pounds) of pressure to the site. People who have fibromyalgia certainly may feel pain at other sites, too, but those 18 standard possible sites on the body are the criteria used for classification.

Always consult your physician for a diagnosis.