Last week, the U.S. Surgeon General, Vivek Murthy, sent a personal letter to more than 2.3 million health care practitioners and public health leaders, seeking their help to address the prescription opioid crisis. He called on physicians to educate themselves in appropriate prescribing of opioids, to screen patients for opioid use disorders and refer them to treatment if necessary, and to set the right example in talking about addiction as a medical illness and not a moral failing. The Surgeon General’s letter is an important acknowledgement of both medicine’s responsibility to lead the country out of the current opioid crisis, and the mistakes that medicine and the healthcare system made in the past, which helped bring us to this point.
Medicine is not perfect. Guidelines and practices that make sense at one point in time, often based on the best available evidence and theory, are frequently reversed when better data emerge—and sometimes only after patients have been harmed. A recent analysis of articles in the New England Journal of Medicine from 2001 to 2010 identified 146 reversals of recommended medical practice during that decade alone. The increased aggressiveness in treating moderate acute and chronic forms of pain using opioids during the 1990s, abetted by heavy marketing of these drugs, will undoubtedly go down in history as another of those failed strategies, whose reversal we are now seeing in revised pain management guidelines such as those released by the CDC this past March.
Although the exact numbers are not known, the majority of people with opioid use disorders are not pain patients and did not start that way. However, overprescribing of opioids in clinical settings made these drugs available in large quantities for diversion and misuse; and there is growing evidence that treating certain kinds of pain (both acute and chronic) with opioids can have the unintended effect of worsening it for some patients. Recent studies are shedding new light on why using opioids to kill pain in the short term can have the paradoxical effect of actually intensifying and prolonging pain—an effect known as opioid-induced hyperalgesia. For example, a recent study using a rat model of chronic nerve pain found that morphine significantly enhanced sensitivity to pain following injury and prolonged the pain of the injury well beyond the point at which the tissues had healed; the priming of glial cells in the spine by inflammation may be why. The risk of hyperalgesia is another reason, besides addiction risk, that the CDC is now counseling less reliance on opioids for management of chronic pain except in cancer pain and palliative care.
It is particularly tragic that these lessons about opioids—both their addictiveness and their ability to actually increase pain—were learned as much as a century and a half ago but were forgotten or ignored. In the late 19th and early 20th century, widespread sale and medicinal use of opioids like morphine, heroin, and opium (as well as other widely misused pharmaceuticals like cocaine) led to increased misuse and addiction. Early drug policies in America, like the Harrison Narcotics Tax Act of 1914, were designed to address this problem by restricting and regulating the sale and prescribing of habit-forming substances. What is not as widely known is that increased pain sensitivity as a result of opioid dependency, then called “morphia,” was also described in the medical literature as early as 1870.
Given what we are now learning about opioids’ paradoxical effects, one has to wonder whether overtreatment with opioids might have contributed to the rise in chronic pain in America instead of just treating it. Without better epidemiological data on pain trends over time, it is only possible to speculate. The United States consumes the vast majority of the world’s opioid medications, and pain prevalence in the United States is higher than in most other developed countries. The rise in opioid prescribing, especially since pain was declared the “fifth vital sign” in 1996 (the same year OxyContin was approved), paralleled a rise in diagnoses for common forms of pain including chronic low back pain. But it is hard to disentangle these trends from other contributing variables like increased obesity in the U.S. population, which can also increase pain, as well as the increased survival from chronic diseases that produce pain. Future research will need to closely examine these questions.
In any case, people with chronic pain are real victims of these shifting tides of medical practice, and we cannot forget about these patients in our haste to end the opioid misuse crisis. Health organizations are now taking steps to revise how we diagnose and manage pain in this country, but as yet, medicine has little to offer chronic pain patients in place of opioids. Many patients with chronic pain are understandably concerned that the only medications that give them some relief are less and less available to them, and they complain of being stigmatized as “addicts” because of the almost inevitable physical dependence that comes with long-term opioid treatment, which is frequently confused with addiction. Physicians must understand that dependence on opioids is not the same as addiction; and the potential dangers of restricting opioid medications on which patients are physically dependent could be devastating in the current drug landscape, where counterfeit pain pills made with the very potent opioid medication fentanyl are causing overdoses and claiming many lives.
The Surgeon General’s letter is a call for physicians to assume greater responsibility in addressing the opioid crisis. Responsibly addressing pain includes treating existing pain patients with sensitivity and care, understanding the difficult nuances of opioid tolerance and physical dependence and their distinctness from opioid use disorders including addiction, and following appropriate strategies for addressing hyperalgesia. It is also incumbent on researchers in our field to redouble our efforts to search for new pain medications (and non-drug treatments) that have less misuse and dependence liability. Similarly, insurance and health care providers need to cover and offer evidence-based alternatives to the management of chronic pain even when they are more costly than opioid medications. Safe and effective pain management needs to be a top priority for researchers and for the health care system.