Avinza™ a new once-daily pain medication reduced pain and improved overall quality of sleep in patients with chronic, moderate-to-severe osteoarthritis (OA) pain. This is according to a Phase III study published in The Journal of Pain and Symptom Management (Vol. 23, No. 4, 2002).
Once-daily Avinza is a morphine sulfate extended-release medication approved in March by the U.S. Food and Drug Administration for the relief of moderate-to-severe pain in patients requiring long term, continuous, around-the-clock opioid therapy.
In the study, researchers performed a randomized, four-week trial evaluating the safety and efficacy of Avinza, MS Contin® a controlled-release morphine sulfate medication, and placebo in 295 patients with chronic, moderate-to-severe OA pain.
These patients had failed to respond well to NSAIDs and acetaminophen treatment, or had previously received opioid therapy. They were given Avinza 30 mg. once daily in the morning or evening, MSC 15 mg. twice daily, or placebo. No dosage adjustments were allowed.
According to the WOMAC OA Index Pain Visual Analogue Scale, the AM Avinza group showed a 17% scale improvement, while the PM Avinza groups showed a 20% improvement. Those patients who received MSC twice-daily showed an 18% improvement on the pain index. These results demonstrated a statistically significant reduction in pain from baseline over the four-week study compared to placebo.
Less pain was reported in all treatment groups by week one, and further reductions in pain were evident throughout the four-week period compared to baseline. Analgesic efficacy was comparable between once-daily Avinza and twice-daily MSC.
Avinza and MSC also provided improvements in all sleep measures compared to placebo. In addition, Avinza AM demonstrated a statistically significant improvement in overall quality of sleep compared to twice-daily MSC at weeks one and four. Sleep disturbances occur in 50-70% of patients with chronic pain. The investigators evaluated overall quality of sleep, need for sleep medication, hours of sleep, difficulty falling asleep, and awakening in the morning and evening due to pain.
“Poor sleep may lead to increased pain, physical disability, and psychological disturbances that accompany chronic pain,” said lead author Jacques Caldwell, M.D., of Radiant Research in Daytona Beach, Fla. “In this study, the greatest improvements in sleep measures were experienced by patients taking Avinza QAM, and further studies are warranted.”
Adverse events, most commonly nausea and constipation, were consistent with those commonly observed with opioid therapy and generally similar among the active treatments. A total of 58 patients (20%) withdrew from the study due to adverse events. Six patients experienced a serious adverse event but only one, who was hospitalized for constipation, experienced an adverse event possibly related to Avinza.