Will Your Fibromyalgia Med Work?
The chances that a medication will effectively reduce your fibromyalgia symptoms are usually less than 50 percent and quite often the drug will produce intolerable side effects. Given these odds, the trial and error process is a difficult road for fibromaylgia patients to take. However, a recent study by researchers in the United Kingdom may help. They evaluated the data from four clinical trials involving Lyrica (pregabalin) for the treatment of fibromyalgia to look for an easy measurement that might help predict early on if a drug is drug is worth sticking with.*
The researchers wondered if a significant change in pain intensity could predict whether a person also reaped improvements in sleep, mood, quality of life, and physical function. Pain intensity is a simple measure because it is just the difference in pain scores after eight weeks on Lyrica compared to each patient’s pain score before starting the drug. But how much does the pain intensity have to improve in order for the drug to be considered a successful therapy? To answer this question, the researchers divided the clinical trial information obtained on 2,757 fibromyalgia participants into the following five groups:
- Substantial benefit – greater than 50 percent reduction in pain intensity
- Moderate benefit – between 30 and 50 percent reduction
- Minimal benefit – between 15 and 30 percent reduction
- Marginal benefit – between 0 and 15 percent reduction
- Worse – pain intensity was made worse by the drug
Out of the 2,757 participants, 689 of them received a placebo (sugar pill) and the remainder received Lyrica at various doses (150 mg to 600 mg per day), with the average dose being around 450 mg/day. One third of the patients (899) withdrew before the trials ended and were not included in the analysis for determining how the reduction in pain intensity might predict a favorable response. This left 1,858 patients included in the analysis, and the number of patients fitting into each of the five groups were:
- 510 patient – Substantial benefit
- 390 patients – Moderate benefit
- 304 patients – Minimal benefit
- 366 patients – Marginal benefit
- 288 patients – Worsening of symptoms during trial
Oddly, the study authors did not indicate which of the above patients were taking Lyrica and which were taking the placebo. The same holds true for the 899 patients who withdrew before the end of the trial—Was it due to drug side effects or because they were taking the placebo? This information could possibly have been withheld since the data was provided by Pfizer, the manufacturer of Lyrica. Putting these questions aside, the study authors were able to use reduction in pain intensity as a predictor of who responded to Lyrica.
Fibromyalgia patients who achieved a substantial or moderate benefit based on pain intensity scores were the ones who showed significant improvements in all other symptom measures. In addition, lost time from work was significantly reduced for patients in these two categories (substantial or moderate benefit).
“Pain intensity reduction is a simple and effective predictor of those patients who should continue treatment, and those who should discontinue and try an alternative therapy,” write the study authors. “In our sample in fibromyalgia, this means that two-thirds would have to seek another treatment.”
Too often, patients stay on a drug for months hoping it will eventually improve their symptoms. This study shows that if your pain intensity does not improve by at least 30 percent within two months, it’s time to talk to your doctor about trying something else.
* Moore RA, et al. PAIN March 25 [Epub ahead of print] 2010.