M.D.s May Needlessly Deny Addicts Opiate-Based Pain Control

Inadequate control of patients’ pain has been a significant problem in most North American patient populations for decades, and one that has been difficult to remedy, despite substantial evidence that patients who use opiate pain medications for legitimate physical pain have a very low potential for developing an addiction.

The data on drug use and outcomes are somewhat conflicting, though, according to Peggy Compton, R.N., Ph.D., a professor of nursing at the University of California at Los Angeles School of Nursing. While medical use of pain medications has increased significantly since the late 1980s, data from annual surveys conducted by the Substance Abuse and Mental Health Services Administration (SAMHSA) indicate that emergency room visits attributed to those medications have either held steady or actually declined. For example, while the use of oral morphine increased nearly 60 percent between 1990 and 1998, emergency room visits connected to morphine only rose 3 percent during those years.

The medical use of fentanyl rose an astounding 1,168 percent during the same years, with a corresponding 59 percent decrease in emergency room visits attributed to the drug.

Yet other SAMHSA data indicate that the number of individuals reporting nonmedical use of opioids has risen drastically since the mid 1980s, from about 400,000 to 2.5 million in 2001, Compton noted. Young white males aged 18 to 25 are most likely to abuse opioids, according to the data. And while medical uses of opioids may not contribute to emergency room utilization, nonmedical use of opioids ranks fifth on the list of visits attributed to a medication. Visits attributed to nonmedical use of codeine actually decreased between 2000 and the first nine months of 2002, but in that same period visits attributed to hydrocodone (Vicodin, Lorcet, and other brands) rose 131 percent, while visits attributed to oxycodone (Percocet, Tylox, and OxyContin) rose an alarming 352 percent.

The difficulty in the statistics, Compton said, is determining the difference between medical and nonmedical uses and their consequences. “If you really look at the data,” Compton asserted, “it is nonmedical use that is the problem. Patients treated appropriately for control of physical pain—even those already addicted to opioids—generally do not get into trouble.”

Research has only begun to shed light on the neurological mechanisms of pain in nonaddicted patients over the last two decades, and studies of pain in patients with opioid addiction have not until recently been undertaken and have studied only small patient samples. But these initial research findings have not appeared to improve pain control.

“Despite the advances in our knowledge of pain processing, the progress has unfortunately not translated into a corresponding improvement in our ability to treat pain,” stressed Sidney Schnoll, M.D., Ph.D., medical director of health policy at Purdue Pharma and a clinical professor of internal medicine and psychiatry at the Medical College of Virginia.

“The most important thing that we have learned,” Schnoll said during his AAAP lecture, “is that pain processing has a high degree of plasticity—it is very important to understand that it is not a static system.”

In addition, he said, pain specialists now know that pain is not “hard-wired from the periphery to the brain. In fact, there are multiple channels, multiple synaptic relays, multiple feedback circuits.” And as pain moves from an acute stage to a chronic phenomenon, the physical and physiological mechanisms change, he said.

Modern approaches to pain control have begun to reflect some of this expanding knowledge base, Schnoll said. “We now aim to prevent rather than palliate pain. We now try to dose to individual needs rather than restricting a patient to low doses of opioids, and we use combinations of drugs rather than a single analgesic. We now use scheduled dosing or patient-controlled analgesia.”

These advances are also applicable to treating pain in a patient with an existing opioid addiction. Clinicians should set clear rules and expectations for both the clinician and the patient, according to Schnoll. Dosing of pain medication should be set at an appropriate level to treat the condition, and dose must be titrated as necessary.

It is important to note, he added, that patients already addicted to opioid medications are likely to require higher doses of pain medication than nonaddicted patients. This is due to the sensitization that occurs over time. Rather than making a patient less sensitive to pain, continued use of opioids tends to cause physical changes in pain pathways, which result in a hypersensitization, thus making patients more sensitive to pain.

In addition, said Jon Streltzer, M.D., a professor of psychiatry at the University of Hawaii medical school, “there is the development of tolerance and desensitization of opioid receptors in response to chronic opioid administration that has been termed ‘the cascade of cellular adaptation.’ ”

Nonetheless, he said, both acute pain and chronic or terminal pain in the opioid-dependent patient are generally manageable, but with higher opioid doses. Streltzer advocates using advances in nonopioid analgesics, such as nonsteroidal antiinflammatory medications.

“If the opioid-dependent patient does not seek other sources of opioid medications,” he stated, “pain management that eliminates the opioids can result in improvements in both pain and in function.” ▪