By Ed Susman
MINNEAPOLIS, MN -- June 14, 2007 -- Patients who suffer moderate to severe osteoarthritis pain that is bad enough to disturb sleep may find both pain relief and sound sleep from treatment with extended release morphine sulfate (Avinza), researchers suggested here at the 21st annual meeting of the Associated Professional Sleep Societies (SLEEP).
"There patients are having sleep disturbances that are as bad as people with chronic insomnia," said researcher Polly Moore, PhD, director of sleep research, California Clinical Trials, San Diego, California, United States.
When the pain killer is given to patients with documented pain from osteoarthritis in the morning when the wake up, the effects of the extended release morphine sulfate appears to make sleep easier, longer and more fulfilling.
"We were somewhat surprised how well these patients did in improving their sleep," said Dr. Moore. "When we did the polysomnography studies of these patients we were shocked at how badly they were sleeping. Their percentage of sleep efficiency was around 76% which is the same level of people who have insomnia complaints," she said.
"It was apparent from their sleep characteristics seen on polysomnography that they, as a group, were indeed experiencing significant sleep disruption due to their chronic pain for osteoarthritis, even while on their current medications," added Dr. Moore.
The researchers screened 127 individuals, finding 34 patients who fulfilled entry criteria - moderate to severe pain caused by osteoarthritis that was having a profound effect on their ability to sleep. The report discussed 31 evaluable patients who completed two polysomnography sessions.
After 14 days of therapy, Dr. Moore said that the patients improved significantly in most area. "Their sleep efficiency increased from 76.5% to 83.8%," she said. While the difference was statistically significant at the P <.05 level, she said.
Total sleep time increased from 367 minutes a night - 6 hours and 7 minutes to 402.5 minutes - 6 hours and 42.5 minutes a night (P <.05).
REM Sleep latency - the time it took patients to reach a deep sleep - decreased from 113 minutes to 62.5 minutes (P <.05).
"It is sort of counterintuitive to think that by taking an opioid medication for pain in the morning that you would have an improved sleep at night," Dr. Moore said. "However, we have learned that opioids given at night before bedtime actually tend to interfere with sleep."
"Overall, this study provides support for the clinical use of Avinza in chronic non-malignant pain patients who complain of significant difficulties with sleep. The prescribing physician should feel confident that pain control in these patients will improve nighttime sleep quality and will increase total sleep time in patients who are experiencing sleep disruption due to their chronic pain," she said.
The study indicated that the 30 mg dose of Avinza was most successful in increasing sleep efficiency, increasing total sleep time and decreasing total wake-after-sleep-onset times. Dr. Moore said the use of Avinza caused no unexpected adverse side effect.
The study was conducted by California Clinical Research for Ligand Pharmaceuticals of San Diego.
[Presentation title: Sleep Improvement in Chronic Osteoarthritis Pain Patients With Morning Dosing of Once-a-Day Extended Release Morphine Sulfate. Abstract 0925]
E-Mail this DGDispatch to a colleague
