Pregabalin Improves Pain and Fatigue Symptoms in Patients With Fibromyalgia
February 10, 2003
By Emma Hitt, Ph.D.
Pregabalin appears to be effective and safe in treating patients with fibromyalgia, according to new clinical trial findings. It may also appear to improve sleep quality, fatigue, and increase quality of life, research suggests. Leslie Crofford, M.D., from the University of Michigan, Ann Arbor, and colleagues presented their findings here Tuesday at the American College of Rheumatology (ACR) 66th Annual Scientific Meeting.
Patients with fibromyalgia experience chronic musculoskeletal pain, fatigue, and sleep disturbances. "There are no approved therapies, and treatments that are used often do not provide adequate relief, " Dr. Crofford and colleagues note.
According to Dr. Crofford, the mechanism of action of pregabalin is "not completely understood," but it binds to calcium channels, modulating calcium influx, which results in analgesic, anxiolytic, and anticonvulsant activity.
In a study sponsored by Pfizer, Inc., researchers evaluated the efficacy and safety of pregabalin up to 450 mg/day (150 mg three times daily) for reducing pain and associated symptoms in patients with fibromyalgia.
A total of 529 patients were randomized to receive 150, 300, or 450 mg/day of pregabalin or placebo during the second of six required visits.
Compared with those receiving placebo, patients treated with pregabalin 450 mg/day showed significant improvement in their endpoint mean pain score (-0.93; P<.001), and they were more likely to experience a 50% reduction in pain from baseline (P=.003), the researchers report.
Patients receiving 300 and 450 mg/day pregabalin also experienced reduced fatigue and improved sleep quality compared with those receiving 150 mg/day pregabalin or placebo.
Forty-eight patients (9%) withdrew due to adverse events, and 44 patients (8%) withdrew due to lack of efficacy. The most common adverse events were dizziness and somnolence, the authors note.
"Treatments for fibromyalgia are limited," Dr. Crofford told Medscape, "and pregabalin represents another treatment option compared to tricyclic antidepressants and serotonin reuptake inhibitors, which have also been shown to be useful in smaller studies," she said.
According to Dr. Crofford, within the next year, an application will be filed for approval for neuropathic pain and anxiety indications in the U.S. and in Europe, and "then there will have to be other studies with respect to fibromyalgia," she said.
"This is a very important study with robust results over a long follow-up," session moderator Laurence Bradley, PhD, from the University of Alabama, Birmingham, told Medscape. "Most of the studies for fibromyalgia pain have produced very modest results," he added.
Also presented at the session were three studies on the efficacy and safety of cyclobenzaprine, tizanidine, and methylphenidate in patients with fibromyalgia. Another study suggested that multinutrient supplementation had no effect on fibromyalgia symptoms.
ACR 66th Annual Meeting: Abstract 1653. Presented Oct. 29, 2002.
Source: Medscape. Reviewed by Gary D. Vogin, MD