Research presented at the 2006 American College of Rheumatology Scientific Meeting points to significant, extended pain relief for many FM patients with the drug pregabalin (Lyrica®).
A series of large clinical trials at the University of Kentucky, Lexington, indicates the drug pregabalin (Lyrica®) - already approved in the U.S. to treat nerve pain and seizures - is also an effective pain relief therapy for many Fibromyalgia patients, with generally mild to moderate side-effects.
Further, the researchers report, their latest 6-1/2 month placebo controlled, double blinded study indicated that for a significant proportion of the FM patients the drug's therapeutic benefit endured for an extended period of time.
As Crofford, et al. explained in presenting their findings* to the annual American College of Rheumatology meeting in Washington, DC, November 10-15, 2006:
In Phase One, 1,051 Fibromyalgia patients received daily does of Pregabalin for 6 weeks. These patients had been diagnosed with FM for an average of 7.8 years, all had "washed out" other forbidden medications from their systems, and measured their baseline pain severity at an average of 78 on the 100-point Visual Analog Scale (VAS). This overall study cohort was 93 percent female and 88 percent white, with an average age of 50 years.
The patients received daily doses of either 300, 450, or 600 mg, depending on which proved best given tracking of the individual's pain control/medication tolerance.
At the end of the six-week program, 63 percent (663 of the 1,051) reported a reduction in pain severity of more than 50 percent - and assessed their pain as either "much improved" or "very much improved." But how much of this was owing to a common phenomenon - the "placebo effect," reflecting patients' belief that the therapy is working? And would the drug's pain relieving effect endure for an extended period? A second phase was designed to help answer these questions.
In Phase Two, which lasted 6-1/2 months (26 weeks), 556 of the patients who had reported pain reduction of more than 50 percent were randomly assigned to receive either the optimal dose of pregabalin they'd received in Phase One, or a daily placebo (fake) dose. The assignment was "double-blinded," which means neither the patients nor the researchers who worked with them knew during Phase Two which patients were taking pregabalin and which the fake dose.
Then the researchers conducted ongoing VAS pain severity scoring, to determine the extent to which patients in the pregabalin and placebo groups maintained their initial pain improvement over time. They defined "loss of therapeutic response" as an increase of 30 percent vs. the patient's final Phase One VAS score - "or subjective worsening of FM symptoms" - for two consecutive weekly visits.
Overall, at the end of Phase Two, the group receiving pregabalin was much more likely than the group receiving fake doses (68 percent versus 39 percent) to retain a significant positive improvement in FM pain compared with the pre-Phase One baseline.
The most common "adverse effects" noted among the 1,051 patients who received pregabalin during Phase One were somnolence/sleepiness (22 percent of participants) and dizziness (35 percent) - both "mostly mild to moderate in intensity."
And during the 6-1/2 month double blinded trial, the only adverse effects that were more common among the patients receiving pregabalin than those receiving placebo doses were sinusitis (5 percent of the pregabalin patients, 3 percent of the placebo patients) and arthralgia/joint pain and anxiety (5 percent of the pregabalin patients, 2 percent of the placebo patients).
Although two of the 1,501 participants died during the study, their deaths were not considered associated with the treatment.
* See an abstract of the presentation - "A Six-month, Double-blind, Placebo-controlled, Durability of Effect Study of Pregabalin for Pain Associated with Fibromyalgia," by L.J. Crofford, et al., at http://www.immunesupport.com/library/showarticle.cfm/id/7521