President Obama has committed to sign the Comprehensive Addiction and Recovery Act, which includes among its provisions new policies to reduce inappropriate prescribing of prescription opioids such as Oxycontin and Vicodin. Given the ongoing epidemic of addiction and death caused by opioid painkillers, this seems like sensible public-health policy, but some critics charge that tighter prescribing rules simply cause prescription opioid users to switch to heroin, thereby feeding a second opioid epidemic. The prestigious New England Journal of Medicine recently published the first systematic analysis of this terrifying possibility.
Wilson Compton of the National Institute on Drug Abuse, who led the analysis, discovered that the timing of the prescription opioid and heroin epidemics is not consistent with the simple narrative that increased controls on the former instigated use of the latter. Heroin use and heroin-related emergency-room visits and hospitalizations were rising for years before the 2009-2011 period in which controls of prescription opioids expanded — for example, by strengthening of state prescription-monitoring programs, crackdowns on pill mills and the introduction of an abuse-deterrent formulation of Oxycontin.
Compton and colleagues also noted that fatal heroin overdoses began rising in 2007 — prior to the initiation of tighter opioid prescribing practices — and have not showed any consistent relationship with prescription opioid overdoses since. Heroin deaths rose from 2011 to 2012, when prescription opioid deaths had their only year-on-year drop, but they kept rising the next year, when prescription deaths were flat and have kept increasing since the time that prescription opioid deaths began rising again.
If controls on prescription opioids are not driving the heroin epidemic, what caused this drug to reemerge? Compton and colleagues point to the establishment of heroin markets that expanded access to a cheaper, more potent opioid that appealed to people addicted to prescription painkillers. This is highly plausible, given evidence that Mexican heroin traffickers made special efforts to expand into communities with established prescription opioid problems.
Compton also points out that “addiction to pharmaceutical opioids drives many people to seek new sources whether there are any controls in place or not.” As users become tolerant to the effects of opioids, they often consume an increasing amount of the drug until they simply cannot afford to purchase the dozens of pills they want each day from legal or illegal sources. Heroin, which once may have seemed unthinkable, thus becomes attractive because of its affordability.
Compton does not deny that some people, particularly those who are already using some heroin in addition to pharmaceutical opioids, might increase their heroin use if their doctors cut them off their prescription, and indeed studies of people being treated for heroin addiction document that such patients exist. But consider this analogy: If you live in Hawaii, most of the tourists you meet will have arrived by airplane, but it does not follow that most of the world’s tourists who board airplanes are going to Hawaii.
By the same token, studies of the select sample of people being treated for established heroin addiction by definition will never capture data on the far larger number of people who responded to reduced access to pharmaceutical opioids by ceasing use of those drugs. Nor will such studies make apparent an even more important group of beneficiaries of more careful opioid prescribing rules: the individuals in the future who will not be inappropriately prescribed opioids in the first place.
Keith Humphreys is a professor of psychiatry and mental-health-policy director at Stanford University.