Boston, Mass. (Mar. 31) - Opiate analgesic abuse is on the rise among nonmedical users, and may also be a problem among chronic pain patients, Nora Volkow, MD, the director of the National Institute on Drug Abuse in Bethesda, Maryland, declared during the keynote address Wednesday at the 24th Annual Scientific Meeting of the American Pain Society (APS) in Boston, Massachusetts.
"Physicians who treat chronic pain should recognize that even in patients who have pain, opiates can produce addiction, although it is less likely," Dr. Volkow tells CIAOMed, adding that to avoid misuse, they should give medication at the lowest effective dose. "Prescribe these medications not at the level that pain disappears, but at a relief level that is acceptable to patients and allows them to function," she suggests. "Moreover, the onus is on doctors to recognize individuals who are more vulnerable to addiction, including patients with a history of alcohol or nicotine addiction and/or a family history of drug or alcohol abuse."
Buprenorphine, which, unlike methadone can be administered in a primary care setting, may help doctors treat addiction. Buprenorphine hydrochloride (SubutexR) and the combination of buprenorphine hydrochloride and naloxone hydrochloride (SuboxoneR) tablets are designed to prevent symptoms of opiate withdrawal. It is hoped that eventually opiates will be developed that do not affect dopamine transmission, allowing treatment of chronic pain without the risk of addiction.
While there are no data on the efficacy of buprenorphine in the treatment of opiate addiction in the chronic pain population, a new large scale clinical trial is slated to begin in November 2005. Funded by National Institute on Drug Abuse (NIDA), this study is one element of a larger initiative to better understand and target abuse of prescription drugs. As part of this program, NIDA is working on the development and funding of alternative medications for the treatment of pain that do not involve opiates and/or do not affect dopamine receptors.
To date, more than 5000 physicians have been trained in the use of buprenorphine, and more than 3,300 are approved to prescribe it. Methadone must be prescribed in a drug abuse clinic, and therefore, there is a stigma associated with receiving treatment, Dr. Volkow points out.
Precautions can identify abusers
"One of the problems is that we don't know how frequent opiate addiction is in people with chronic pain, but the party line is that it is less of a problem in chronic pain than in the general population," says Roger B. Fillingham, PhD, associate professor in the division of public health services and research at the University of Florida in Gainesville. Dr. Fillingham is the chair of the APS meeting's scientific program committee.
However, "[the problem] is big enough that I believe we need to approach treatment using universal precautions, because we don't know who will have a problem with abuse/addiction or diversion," he tells CIAOMed. "We should treat everyone the same and have systems in place to assess the probability of abuse." He suggests that this would include urine screens, questionnaires, and careful assessments of pain as well as physical and psychological function.
Overall, opiate addiction on the rise
According to Dr. Volkow, new nonmedical users abusing pain and analgesic medications increased in all ages from 1965 to 2002. "In the past 5 years, there has been a steep increase in the number of people who are abusing opioids," Dr. Volkow says.
Nearly one in 10 high school seniors abused hydrocodone (Vicodin) last year, she points out, adding that "vicodin is the number-one prescription drug of abuse in teenagers." There has been a parallel increase in narcotic-related emergency department visits. "It was a surprise to me," Dr. Volkow says.
Suggesting that the increase is due to greater availability, including easier access via the Internet, she observes that "the Internet has given us increasing access to information, but at the same time it has become possible to get some of these substances that require prescriptions without them."
"Opiophobia" abates slightly, but it is still a barrier to effective pain treatment
As government researchers in the US attempt to rein in abuse, fear of opiate use by patients and prescription by physicians continues in Canada, according to a study1 presented by A. J. Clark, MD, medical director of the Calgary Health Region Chronic Pain Center in Alberta, Canada.
In 2004, 32% of Canadian physicians said the main reason they were reluctant to prescribe opioids is the potential for addiction. By contrast, 40% cited this reason in 2001. Dr. Clark tells CIAOMed that these findings likely reflect a similar situation in the US and Europe.
Overall, physician preference for prescribing weak and strong opioids as first-line therapy increased from 30% in 2001 to 51% in 2004. The use of strong opiates increased more modestly, however, from 31% in 2001 to 37% in 2004, the survey showed. "The other side of the coin is that patients are reluctant to take these medications because of concerns of addiction," Dr. Clark says, pointing out that, for this reason, a number of patients do not get appropriate treatment.
Reference:
Clark AJ, Boulanger A, Squire P, et al. Canadian pain study II: opiophobia in Canada, 2004. Presented at: 24th Annual Scientific Meeting of the American Pain Society; March 30-April 2, 2005; Boston, Massachusetts. Poster No. 740.