Treatments on the Horizon
Scientists in research laboratories around the world are working feverishly toward better treatments for fibromyalgia, ones that target several symptoms at once with few side effects. As of right now, there are no medications specifically approved by the U.S. Food and Drug Administration to treat fibromyalgia.
There is hope, however, that that will change in the next few years as researchers forge ahead with their experiments on treatments for fibromyalgia. Some of these are even entering the final stages of clinical trials as this book goes to press. In any case, it appears that someday soon, fibro sufferers will have more treatment options at their disposal.
Milnacipran
Milnacipran is the first in a new class of antidepressants known as norepinephrine serotonin reuptake inhibitors (NSRIs) and is currently used as an antidepressant by 3 million people around the world. These medications work by blocking the reuptake of both norepinephrine and serotonin, neurotransmitters involved in regulating mood and pain. It's believed that people with fibromyalgia do not have enough norepinephrine and serotonin, which results in depression and chronic pain.
Fact
On average, a new drug takes twelve years to go from preclinical testing to approval. The earliest phases begin with tests done on lab animals, then testing progresses through three phases of clinical trials before reaching the review process at the FDA. Even the review process takes about two and a half years.
In phase two clinical trials by the pharmaceutical company Cypress Bioscience, Inc., fibro patients who took milnacipran experienced significant improvements in their pain and fatigue symptoms. They also reported less depression. The study also found that most patients were able to take high dosages without problems. The most common side effect was nausea, but most problems were mild or moderate in intensity.
The drug is now in phase three of clinical trials, the last phase before FDA approval. Cypress Bioscience has made it the company's goal to be the first to market a product in the United States specifically for the treatment of fibromyalgia. The company hopes to submit a new drug application to the FDA by late 2006 at the earliest.
Pyridostigmine
People who have fibromyalgia generally have low levels of human growth hormone (HGH), the lack of which causes poor health. They tend to be overweight and have low energy, impaired thinking, and mild depression. They also have poor tolerance for cold temperatures and low blood volume. Many of these symptoms of low HGH overlap with those in fibromyalgia.
But treating people with HGH is unrealistic. Although HGH does produce a positive response in most patients, treatment takes at least six months for results and currently costs about $80,000 a year, which most insurance companies won't cover. That's why some researchers are considering the use of pyridostigmine, which can influence the production of HGH during exercise. Pyridostigmine (Mestinon) is currently used to treat myasthenia gravis, an autoimmune neuromuscular disease in which the patient's muscles become weakened.
Normal healthy people secrete growth hormone during sleep and after they exercise. But a study by Robert Bennett, MD, in 2002, found that people who had fibromyalgia did not produce as much human growth hormone in response to exercise. When the subjects were tested a month later and given pyridostigmine, HGH levels increased eightfold after exercise.
Pyridostigmine is believed to work by inhibiting somatostatin, a hormone that occurs in abundance in people with fibromyalgia and inhibits growth hormone. By giving the drug to people before exercise — and thus blocking somatostatin from inhibiting growth hormone — the subjects had more growth hormone following exercise. Growth hormone is needed to regenerate tissues and repair muscles after exercise, which would definitely benefit people with fibromyalgia.
To better understand the effects of pyridostigmine, researchers at the Oregon School of Nursing Research are examining the effects of pyridostigmine on women during exercise. The study will be done over a six-month period and will measure the impact of pyridostigmine on fibro pain.
Xyrem
Sodium oxybate (Xyrem) has had a checkered history, but it is emerging as a possible treatment for fibromyalgia. Xyrem is a central nervous system depressant and a form of gamma hydroxybutyrate (GHB), a naturally occurring metabolite. In the 1980s, GHB was popular among body builders, who used it to reduce fat and build muscle. It was also abused as a recreational drug and involved in several reported incidences of date rape. After several adverse events, including death, the FDA removed GHB from store shelves.
Subsequent research by a company called Orphan Medical soon discovered that Xyrem was effective in reducing cataplexy attacks in people with narcolepsy, a sleep disorder characterized by excessive daytime sleepiness. Cataplexy is a condition in which muscles become suddenly weak or paralyzed during intense emotional reactions, such as laughter, anger, or fear.
Other researchers soon learned that Xyrem could reduce the symptoms of fibromyalgia. In studies with fibromyalgia patients, Xyrem decreased the intrusion of alpha waves during sleep and increased REM sleep. In addition, Xyrem reduced pain and fatigue in the patients. Buoyed by these findings, Orphan did a follow-up trial, which was completed in 2005. Results were not available at the time of this publication.
Because of its history of abuse and adverse events, access to Xyrem is highly restricted. At this time, the drug is available only through the Xyrem Central Pharmacy, which is run by the makers of the drug, Orphan Medical. Xyrem is a federally controlled substance approved for medical use only.
What is a double-blind placebo-controlled study?
This type of study is considered the gold standard of research, in which neither the researchers nor the subjects know who receives the treatment and who receives the placebo. The arrangement is designed to avoid bias in the research process.
High-Dose Mirapex
People who have Parkinson's disease are slowly losing a chemical in their brains called dopamine, which controls muscle function. As a result, patients typically suffer from tremors, or involuntary shaking of the limbs. In some cases, muscles become stiff and rigid, and movement becomes quite slow.
One of the drugs used to treat Parkinson's is pramipexole (Mirapex), a dopamine agonist that mimics the action of real dopamine. In addition, Mirapex is used in low doses to treat restless legs syndrome. Researchers recently learned that Mirapex may also help relieve symptoms of fibromyalgia.
A double-blind placebo-controlled study involved forty-nine patients with fibromyalgia. Those who were given pramipexole used a gradual escalating dose of Mirapex over a fourteen-week period. The dosage started at 0.25 mg the first week and ended at 4.5 mg during the final three weeks. By the end of the study, most patients in the group who took Mirapex experienced improvements in pain, fatigue, and function. The drug caused few side effects, with the most common being nausea and weight loss. More research into Mirapex and fibromyalgia are expected.
