Basics about medications approved for use in FM

Pregabalin (Lyrica)

The FDA approved Lyrica, made by Pfizer, Inc., in June 2007 as the first prescription medication for the treatment of FM. Very simply, Lyrica is thought to work by changing the effect of GABA (gamma amino butyric acid), often referred to as a "calming" neurotransmitter/brain chemical.

Structurally, it is related to Pfizer's first antiepileptic drug, gabapentin (Neurontin), which came on the market in 1983. Lyrica is found to be more potent and effective at lower doses than gabapentin (Neurontin). Its primary uses in FM are for pain relief and improvement of fatigue and sleep.

An "informal" review of several internet drug information sources show that patients' experiences with Lyrica varied widely, from stating that it caused many difficult side effects, rapid weight gain, and the drug was found to be very expensive, to praising it as the best treatment they've used to date. The average of the patient/user ratings placed Lyrica at slightly beyond the halfway point on the scale used. This information is meant to provide a general idea in how a random group of patients responded to this treatment—it is strictly subjective and not a medical interpretation.

Lyrica is also used to treat diabetic nerve pain, nerve pain after shingles and partial onset seizures in adults with epilepsy.

The most common side effects are weight gain, swelling of hands and feet, and may worsen "fibro fog" in some patients. In some clinical trials, dizziness and somnolence were the most frequently reported adverse events. Many of these side effects were echoed in the above-mentioned patient/user reviews.

It is important to report any unusual reactions to the prescribing physician, as some of these could be serious and warrant discontinuation of treatment—such as loss of coordination, uncontrolled movements, unusual fatigue, difficulty speaking or changes with vision.

Some patients have experienced depression, changes in their mood or have had suicidal thoughts. As a result, effective April 2009, Lyrica and Neurontin (along with other antiepileptic drugs) were required by the FDA to include a warning about the increased risk of suicidal thoughts or actions on their product labels.

Duloxetine (Cymbalta)

In June 2008, Cymbalta, manufactured by the Lilly Co., was approved by the FDA for use in FM, to help reduce pain and improve function. Cymbalta belongs to a class of medications called selective SNRIs (serotonin and norepinephrine reuptake inhibitors). It works by increasing the activity of these two neurotransmitters which are found to be deficient in FM.

By adjusting in how the brain and spinal cord respond to painful stimuli (which is part of the nociception system/how pain is sensed), is how it is thought to provide an analgesic effect.

Cymbalta is also indicated for the treatment of major depressive disorder, generalized anxiety disorder, management of diabetic peripheral neuropathic pain, and more recently, it was approved for the management of chronic musculoskeletal pain, including chronic osteoarthritis pain and chronic low back pain.

Though Cymbalta is suggested for a wide range of problems, it still should be approached as a potent treatment with a dual mechanism. A thorough assessment should be made of the patient's personal and/or family history of psychiatric problems (e.g. bipolar/manic-depressive disorders) as this drug may worsen or uncover these.

It is also very important to review all medications used by the patients (including over-the-counter products and supplements) in order to prevent serious interactions since one-fourth of all prescribed medications are metabolized by the same enzyme (CYP2D6).

These medications include other selective serotonin reuptake inhibitors (SSRI's), tricylic antidepressants (TCA's), beta-blockers, opiates, antiarrhythmics, migraine headache treatments, and various plant substances.

For their own safety, patients need to communicate with their doctors in an honest, open manner, and not withhold any information about what else they might be using on their own (including alcohol), and use medications exactly as prescribed.

In the event of adverse effects, patients need to inform their doctors about these problems and not make changes on their own.

NCBI warning for medication-induced suicidal tendencies. The National Center for Biotechnology Information (NCBI, a branch of the National Institutes of Health (NIH)) has posted an important warning about the potential risk of suicidal tendencies in some patients while using certain antidepressants, including, but not limited to, duloxetine (Cymbalta).

The NCBI advises that "all" patients should be informed about this risk and the early signs/symptoms associated with this risk. Family members or caregivers should know the same, so they can recognize warning signs. The reason for extra precautions, according to NCBI, is because people's mental health can change unexpectedly, even in individuals who do not have mental illness, but are using duloxetine to treat other conditions. This appears to happen, more often, at the beginning of treatment and/or when the dose is increased or decreased; therefore, their recommendation is that patients be closely monitored during these times. NCBI lists the following symptoms as potential warning signs of suicidal tendencies which need to be immediately reported to the doctor: "new or worsening depression; thinking about harming or killing yourself, or planning or trying to do so; extreme worry; agitation; panic attacks; difficulty falling asleep or staying asleep; aggressive or hostile behavior; irritability; acting without thinking; severe restlessness; frenzied abnormal excitement; or any other unusual changes in behavior."

Milnacipran (Savella) 

Savella was approved by the FDA in January 2009 as yet another FM-appropriate treatment. It is made by Forest Laboratories Inc., and falls into the same class of medications as Cymbalta.

However, its mechanism focuses on boosting norepinephrine levels more so than serotonin ones.

Its overall ability to reduce pain has been reported by several sources as being only "marginal."

Two of its more frequent side effects are increase in blood pressure and nausea.

According to the NCBI, milnacipran is currently not used in the U.S. to treat depression. The NCBI has issued the same warnings for milnacipran as for duloxetine regarding potential changes in mood and/or risk of suicidal thoughts and tendencies.