Fibromyalgia: Psychiatric drugs target CNS-linked symptoms
Repeated pain signals in the periphery may sensitize spinal cord neurons, resulting in amplified and prolonged signals traveling to the brain
Other medications, such as the first-line agent amitriptyline, have shown beneficial effects in fibromyalgia but are not FDA-approved for this indication (Table 4).27-32
Choosing medications. When prescribing one of the FDA-approved medications to treat fibromyalgia, consider their benefits and side effects.
Pregabalin may be a beneficial first choice for patients who report pain and sleep as major issues. Although the medication’s label recommends starting with twice-daily dosing, patients might better tolerate an initial dose of 50 to 75 mg in the evening, with the morning dose added later. Pregabalin can be useful in patients taking multiple medications because of its renal clearance, resulting in low risk of interactions with drugs metabolized by liver enzymes. It also can be useful in patients who have not tolerated antidepressants in the past or in whom antidepressants are contraindicated.
If a patient has a history of depression or discontinuing medications because of sedating side effects, an antidepressant such as duloxetine or milnacipran may be more successful than starting with pregabalin. In general, if a patient does not respond to one of these SNRIs, moving on to the other might help. Milnacipran’s more selective effect on norepinephrine could be beneficial for some patients, especially those with excessive fatigue. Others, especially those with a high level of anxiety, might respond better to a more balanced SNRI such as duloxetine.
Table 4
Off-label medications shown to benefit patients with fibromyalgia
| Drug | Comment |
|---|---|
| Amitriptyline27,28 | Considered first-line because of studies supporting its use, low cost, and wide availability; may be associated with more side effects than newer medications |
| Gabapentin29 | Possible alternative to pregabalin but may not be as well tolerated |
| Tramadol30 | May help with breakthrough pain; use with extreme caution in patients taking antidepressants because of serotonin syndrome risk |
| Fluoxetine31 | Dosages of 40 to 60 mg/d may help patients who do not tolerate SNRIs |
| Venlafaxine32 | Dosages of 150 to 225 mg/d may be an alternative to other SNRIs |
| SNRIs: serotonin/norepinephrine reuptake inhibitors | |
CASE CONTINUED: Not as hopeless
Ms. D’s primary care physician confirms your presumptive diagnosis of fibromyalgia. He prescribes a trial of amitriptyline, which she does not tolerate well because of sedation and weight gain. At her next psychiatric visit, she tells you she remains very frustrated about her physical symptoms and reports that her doctor “has given up on me.”
You discuss what a fibromyalgia diagnosis means to her and educate her about the syndrome. You refer her to a colleague who does CBT with chronic pain patients and start her on a low dose of duloxetine (30 mg once daily) to minimize side effects. You discuss possible side effects and that she may need a higher dose to notice improvement in her pain. She seems receptive to starting a graded exercise program, and you encourage her to reduce physical and emotional stress in her life.
- Arthritis Foundation. Fibromyalgia. www.arthritis.org/disease-center.php?disease_id=10.
- National Fibromyalgia Association. www.fmaware.org.
- Self-management program for patients with fibromyalgia, cosponsored by the National Fibromyalgia Association and Eli Lilly and Company. www.knowfibro.com.
- Amitriptyline • Elavil, Endep
- Cyclobenzaprine • Flexeril
- Duloxetine • Cymbalta
- Fluoxetine • Prozac
- Gabapentin • Neurontin
- Milnacipran • Savella
- Pregabalin • Lyrica
- Tramadol • Ultram, Ultracet
- Venlafaxine • Effexor, Effexor XR
Dr. Stanford receives grant/research support from Eli Lilly and Company, Pfizer, Cypress Bioscience, and Allergan.
