According to Volkow, one of the initiatives they are pushing to do with their sister agencies, SAMHSA and the Office of National Drug Control Policy, is the education of physician specialists about the dangers of narcotic analgesics and proper management of pain. Many specialists believe that if an opioid analgesic is given for pain, the patient is not going to become addicted.
"That is what they teach you in medical school," Volkow said. "That's true if they give you the opioid analgesic for a very short period of time, such as one week. The problem starts when an opioid analgesic is given for a chronic condition such as back pain. Anywhere from 5% to 7% of people prescribed opioid analgesics for chronic pain are going to become addicted. So there is this false belief that you are not going to become addicted if you have pain, and that has led some physicians to prescribe opiates much more than they should."
On the other hand, Volkow said, we have also been hearing for many years about patients with severe pain who never get the proper medications and as a result suffer a lot of handicaps. To help, NIDA is promoting the development of compounds that have analgesic properties yet are not addictive.
Non-Addictive Pain Treatments
Frank Vocci, Ph.D., NIDA's director of the Division of Pharmacotherapies and Medical Consequences of Drug Abuse, told Psychiatric Times that NIDA is looking at drugs that are cannabinoid agonists. Cannabinoids diminish responses to painful stimuli. There are two types of cannabinoid receptors, according to Vocci: CB1 receptors are found in the brain, while CB2 receptors are found primarily in peripheral tissues with immune functions. Through the research of medicinal chemist Alexandros Makriyannis, Ph.D., of Northeastern University, NIDA is exploring whether CB2 receptor agonists may hold the promise for medical treatment of pain without central nervous system effects. The research is still in the preclinical stage.
There is another project with a drug called resiniferatoxin (RTX) that has been shown to be effective for treatment of severe pain in several animal models, Vocci said. "Hopefully, we will have clinical studies in 2005. We are in the final stages of discussing this with the [U.S. Food and Drug Administration]. A package has been sent to them, and we are going to have a conference with them about this," he added. The medications will be tested in terminal cancer patients for whom opiate analgesics no longer provide pain relief.
The lead researcher on that study is expected to be Andrew Mannes, M.D., anesthesiologist at NIH's Warren Grant Magnuson Clinical Center.
For individuals suffering from chronic pain, who have become addicted to opioid analgesics, NIDA is evaluating alternative medications.
