NEW YORK (Reuters Health) - Among chronic pain patients who have been prescribed opioid drugs such as OxyContin or Percocet by primary care physicians, nearly 4 percent abuse these drugs, according to the results of a large study conducted in Wisconsin.
The findings also suggest that these patients commonly exhibit "aberrant drug behavior," such as requesting early refills or purposely oversedating themselves.
Dr. Michael F. Fleming, at the University of Wisconsin in Madison, and his associates point out that a large number of patients have severe, incapacitating pain that cannot be controlled without daily opioid therapy. The researchers investigated substance abuse disorders in this patient population.
In the study, sponsored by the National Institute on Drug Abuse, Fleming's group recruited and interviewed 801 patients from 235 primary care practices. The subjects all had chronic non-cancer pain and used opioids daily for at least 3 months.
The average age was 49 years old and the average duration of chronic pain was 16 years. Nearly half had degenerative arthritis and chronic low back pain. Other common conditions were migraine headaches, fibromyalgia and neurological pain.
The opioids most frequently prescribed were oxycodone preparations, such as OxyContin, making up nearly 60 percent of the prescriptions; followed by hydrocodone, which is commonly combined with acetaminophen in compounds such as Vicodin; and morphine.
Thirty patients (3.8 percent) met the clinical criteria for opioid use disorder, compared with a rate of 0.9 percent reported in the general population, the researchers report in The Journal of Pain.
The most significant predictor of abuse was aberrant drug behavior, including deliberate oversedation, feeling intoxicated by the medication, using opioids for reasons other than pain, and raising the dose without authorization.
Fleming's group cautions that these types of behaviors could also be caused by inadequate levels of medication, untreated psychiatric illness or stressful life situations.
Although the frequency of opioid abuse is of concern, Fleming and his colleagues still "support the use of opioids for the treatment of chronic pain by primary care providers."
They point out that "considering the potential benefit to improving the lives of patients with chronic pain, a 3.8-percent rate of opioid addiction is a small risk compared with the alternative of continuous pain and suffering."
SOURCE: The Journal of Pain, July 2007.
