Does making naloxone available to reverse potentially fatal overdoses have the unintended effect of making people more likely to use opiates?
Two researchers – Jennifer Doleac of the University of Virginia, and Anita Mukherjee of the University of Wisconsin—compared time periods before and after a number of naloxone access laws took effect. That includes making naloxone available in pharmacies without a prescription, and making those who prescribe or administer the drug immune from prosecution.
Doleac and Mukherjee – who are economists, not public health experts – wondered if reducing the risk of a fatal overdose make people more likely to use opioids.
After naloxone-access laws take effect, they found, arrests related to the possession and sale of opioids went up, as did opioid-related ER visits. They also found no reduction in the death rate. In the Midwest, they found that new naloxone laws were followed by a 14 percent increase in opioid overdose deaths.
Doleac said the researchers’ finding represents what is sometimes called a “moral hazard.” That means “anytime you make something less dangerous, people are going to do more of it,” she told the Atlantic Monthly. In a similar example, researchers found that giving teenagers free condoms led to more teen pregnancies.
Other public health officials have expressed concern that Doleac and Mukherjee’s results could cause cities and states to reconsider a strategy that has become one of the most widely used harm reduction strategies in response to the opioid epidemic.
Other studies comparing naloxone availability to overdose death rates have reached different conclusions. . A 2012 Massachusetts study found a reduction in opioid-overdose death rates in communities where people were given nasal-naloxone rescue kits. Another study arrived at similar findings, and one other study found no evidence of “compensatory” drug use risk behavior among heroin users after receiving take-home naloxone.
Baltimore Health Commissioner Leana Wen, who has supported expanding access to naloxone, noted that changing the naloxone laws does not necessarily mean people were able to instantly obtain it more easily. “[Doleac and Mukherjee’s] study assumes that passage of these laws lead immediately to everyone having easy access to naloxone when they need it, when this is not the case,” she told the Atlantic.
“The Massachusetts study shows that actual naloxone distribution shows a decrease in mortality. This is consistent with what we see in Baltimore, where over 1,600 lives have been saved as a result of our naloxone distribution program.”
While Baltimore didn’t see a reduction in opioid-related mortality, the death rate might have been even higher without the life-saving drug, Wen said.
Some critics contend that Doleac and Mukherjee’s study confused correlation with causation. “The first problem is that they seem to be making the big mistake of assuming that correlation equals causation,” said Jermaine Jones, a Columbia University neurobiologist whose study found naloxone didn’t increase heroin use. “This misinterpretation of data is one of the first things we are taught in psychology,” Jones told the Atlantic.
But Doleac pointed out that public health experts and economists approach research differently. Economists often make “causal inferences,” sometimes employing statistical methods to narrow the field of possible explanations, and drawing conclusions about cause and effect.
“Public-health people believe things that are not randomized are correlative,” says Craig Garthwaite, a health economist at Northwestern University, told the Atlantic. “But [economists] have developed tools to make causal claims from non-randomized data.”
Doleac and Mukerjee’s article has not yet been reviewed by their peers. In the economist’s typical modus operandi, it’s considered a “working paper,” to be shared with colleagues, who can then raise questions and make suggestions. The two researchers said they plan to submit their paper to an economics journal after they complete that part of the process.