Pregabalin for Fibromyalgia
Benefits vs. Side Effects
Pregabalin (Lyrica) has been on the U.S. market since 2005 and was approved by the Food and Drug Administration (FDA) for treating fibromyalgia in 2007. While physicians who are less experienced with managing fibromyalgia pain may eagerly prescribe pregabalin because of the large-scale clinical trial data to substantiate its use, patients’ concerns about side effects are valid.
Most physicians tend to follow the standard dosing regimen approved by the FDA for pregabalin, which may not be optimal for you. Researchers offer information about pregabalin’s ability to treat fibromyalgia, commonly reported side effects, and practical tips on how to get the most relief with the least amount of side effects.
Effectiveness for Fibro
What are the odds that pregabalin will improve your fibromyalgia symptoms? In general, a one-third reduction in symptoms is viewed as providing clinically meaningful relief. It’s a degree of improvement that patients would clearly notice. In the real world of managing fibromyalgia symptoms, three or more medications are combined in hopes that each one gives a patient 15-20 percent symptom improvement. Yet, the FDA does not allow this strategy for documenting the effectiveness of a drug, so keep this in mind.
While the statistics look impressive, 33 percent of the patients taking a placebo (sugar pill) also indicated a one-third improvement in pain.1 So the chances that pregabalin alone will significantly reduce your symptoms are between 10 and 20 percent. Stating it another way, less than one out of five fibromyalgia patients will achieve significant relief from their symptoms while using pregabalin as a “monotherapy.”
The trial statistics blend the data from over 2,000 fibromyalgia patients who were only allowed to take pregabalin. The range in response to this drug varies substantially, with some patients claiming, “I got my life back” to others stating, “It did nothing for me but produce intolerable side effects.” Given the diversity in response to pregabalin, it still may be worth a try, even if you have to take a lower dose to avoid side effects.
Common Side Effects
Most of pregabalin’s side effects are dose-dependent, meaning that the more you take the greater your chances of getting a particular side effect.2
“The most common reasons for discontinuing pregabalin are sleepiness and weight gain,” says Kenneth Miller, M.D., of Danbury, CT. “The side effects of blurred vision occur in less than 10 percent of patients and usually resolves with continued use of pregabalin.” Should patients encounter this side effect, they need to notify their doctor and have routine eye exams as a precautionary measure. “Dry mouth and constipation occur more often at the higher doses,” adds Miller. The cause of these two side effects is unknown.
Even if weight gain tends to plateau off after four months, this side effect is highly variable.3 The average weight gain per month for patients at the 300 mg/day dose could be as high as 4.5 percent of a person’s body weight. “I have seen patients gain 10-15 pounds during the first 3-4 months,” says Miller. “If a patient gains more than this, I would advise them to discontinue the drug. There are no safe appetite suppressants, so patients need to monitor their calories and try to increase physical activity if their pain improves.”
“Patients who get edema (fluid retention) can try taking a mild diuretic,” says Miller. In fact, Lesley Arnold, M.D., of Cincinnati, OH, says she starts patients with an over-the-counter diuretic, such as pamabrom (in Pamprin), but she has had mixed results. “It’s the active ingredient in the PMS drugs and you can find it sold separately in the diet section of the drugstore,” says Arnold. “If a patient is having a good response to pregabalin and wants to continue on this med but they are uncomfortable with the fluid retention, diuretics are worth a try.”
Practical Advice
What other treatment strategies, besides those offered above by Drs. Miller and Arnold, might help you reap the most benefits from pregabalin with minimal side effects? I. Jon Russell, M.D., Ph.D., of San Antonio, TX, suggests that patients take pregabalin at bedtime to minimize dizziness and use the sedating side effect to help with sleep. However, if you only take pregabalin at night, will you get enough pain relief during the day and can this approach minimize any of the other common daytime side effects?
“I have many patients that get an entire day of symptom relief when they just take pregabalin at bedtime,” says Kevin Hackshaw, M.D., now at the University of Texas in Austin. “I would say there is a 50 percent chance that this strategy will be effective.” He adds that predominant nighttime dosing leads to less daytime side effects for the other problems listed in the table.
Using this strategy, blurry vision and dry mouth shouldn’t bother you during sleep. Also, edema (especially swelling in the legs) ought to be lessened because you are not on your feet when the higher dose of pregabalin is in your system. If you take the brunt of pregabalin at night, your GI system gets a rest from the drug during the daytime, making constipation problems less likely.
Even if you find nightly dosing of pregabalin helpful, Hackshaw says, “It is more often effective for fibromyalgia as an all-day medication.” But how do you get around the daytime side effects? He places his patients on 25 mg in the morning, 25 mg in the late afternoon, and then anywhere from 100 to 150 mg at bedtime. “You don’t have to take the 150 mg dosage two times a day to get relief from pregabalin.”
Sometimes Hackshaw writes two prescriptions, one for 25 mg capsules of pregabalin to be taken twice daily, and a separate script for 150 mg capsules to be taken at bedtime. This method may be the most convenient for patients and is usually covered by insurance companies, but it requires patients to pay for two copays. This method is more costly, but now that pregabalin is available as a generic, it may be doable.
“A way to get around the issue of two copays is to write just one prescription for 25 mg caps,” says Hackshaw. “For example, I write the script for one 25 mg cap in the morning, one 25 mg cap in the afternoon, and six 25 mg caps at bedtime. Insurance companies usually approve prescriptions written in this manner. The advantage of this prescription is that the patient only pays one copay because the copay is dependent on the different dosages of pregabalin and independent of the number of capsules being dispensed.”
Certainly, the above dosing strategy in which the brunt of pregabalin is taken at bedtime with small booster doses during the day, is bound to minimize side effects. It also makes plenty of sense given that studies show the drug enhances the quality of sleep, possibly by increasing the sedating brain chemical, GABA.4,5
In addition to boosting sleep-promoting GABA, brain imaging studies show that pregabalin reduces glutamate, an excitatory transmitter that disrupts sleep and is linked to enhanced fibromyalgia pain.6 So, why is this dosing method of pregabalin not generally publicized? Pfizer is required to adhere to the FDA-approved dosing schedules (e.g., 150 to 225 mg twice daily).
Real World Dosing
If you tried pregabalin but the side effects prevented you from reaching the recommended daily dose of 300 to 450 mg, you may be a typical fibromyalgia patient.
Daniel Arkfeld, M.D., and his team at the University of Southern California, evaluated a series of 126 fibromyalgia patients who were treated with pregabalin in clinical practice.7 He wanted to determine how many tolerated the recommended dose of 300 to 450 mg pregabalin per day.
Unlike the fibromyalgia patients in the treatment trials for pregabalin, these patients were likely taking several other medications. Many also had other medical conditions, so they represented the average patient with fibromyalgia.
Out of the 126 patients, 113 were at least able to tolerate pregabalin. However, the average dose achieved with continued therapy was only 150 mg/day, and this was also the most frequently used dose. Only seven patients were able to tolerate the FDA approved dose of 300 mg/day and one patient was able to handle the higher recommended dose of 450 mg per day.
If you cannot tolerate pregabalin or find it beneficial at half the recommended dose, you can be assured that your response to this medication is quite normal. As with many medications prescribed for fibromyalgia, higher doses generally don’t offer more benefits.
1. Barrett J, et al. Myopain – 7th World Congress, Washington D.C., Abstract, 2007.
2. Mease PJ, et al. J Rheumatol, 35(3):502-14, 2008.
3. Frame B, et al. J Pharmacokinet Pharmacodyn 34(6):753-70, 2007.
4. Hindmarch I, et al. Sleep 28(2):187-93, 2005.
5. Roth T, et al. Arthritis Care Res 64(4):597-606, 2012.
6. Harris RE, et al. Anesthesiology 119(6):1453-64, 2013.
7. Arkfeld DG, et al. American College of Rheumatology Meeting San Francisco, 2008.