SAN ANTONIO, Nov. 17 /PRNewswire/ -- A clinical study unveiled today at the American College of Rheumatology Annual Scientific Meeting in San Diego shows that a drug now used to help patients with the sleep disorder narcolepsy can be useful at treating fibromyalgia syndrome patients, as well.
Researchers from The University of Texas Health Science Center at San Antonio and the Oregon Health Sciences University in Portland reported that sodium oxybate, currently approved for the treatment of cataplexy in patients with narcolepsy, significantly improved patients’ self-reported perceptions of their own pain and enhanced the quality of their sleep. At the higher dosage, the drug also reduced patients’ tenderness during examinations in the doctor’s office.
“No medication is currently approved by the United States Food and Drug Administration for the treatment of fibromyalgia; physicians treat the disorder with medications officially approved for other purposes,” said the study’s lead researcher, I. Jon Russell, M.D., Ph.D., associate professor of medicine at the Health Science Center in San Antonio. “This study suggests that sodium oxybate is a novel option of therapy for physicians and patients coping with fibromyalgia. We need to examine it in greater detail.”
Fibromyalgia, a common clinical condition marked by widespread body pain, a form of body tenderness, fatigue, morning stiffness, and disrupted sleep, affects 1 in 50 Americans, mostly women, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases. The relationship of fibromyalgia body pain to the insomnia of fibromyalgia is not well defined.
Dr. Russell and his colleagues, Drs. Robert M. Bennett in Portland and Joel E. Michalek in San Antonio, conducted a randomized, double-blind, placebo-controlled, multicenter clinical trial. The centers randomized 188 fibromyalgia syndrome patients to receive active treatment with one of two doses of sodium oxybate or with a placebo. One active treatment group took 4.5 grams of sodium oxybate per night, while a second group took 6 grams per night. The sodium oxybate was administered at night in two oral doses. The trial lasted eight weeks.
Before they began to take the study medication, all of the study participants were withdrawn from other medications used to treat their fibromyalgia symptoms. Of the 147 patients who completed the trial, 51 took 4.5 grams per day, 44 took 6 grams per day and 52 took a placebo.
“We saw significant clinical benefit with both doses of sodium oxybate compared with placebo,” Dr. Russell said. “The patients’ self-reported pain and their perceptions of how well they slept improved among both dosage groups. The tenderness found during in-office examinations was significantly improved with the 6 gram dose.”
The medication caused nausea and dizziness in a few cases, effects that increased with increasing the dosage of sodium oxybate, but no unexpected adverse events were reported, Dr. Russell said.
Sodium oxybate is marketed as Xyrem(R) in the U.S. by Orphan Medical, a subsidiary of Jazz Pharmaceuticals, which funded the study.
Read news from the UT Health Science Center at http://www.uthscsa.edu/hscnews/newsrelease.asp .
Contact: Lucie Portela (210) 567-2570 or Natalie Gutierrez (210) 567-6814
University of Texas
CONTACT: Lucie Portela, +1-210-567-2570, or Natalie Gutierrez,+1-210-567-6814, both for University of Texas
