Is the shift from injecting to smoking fentanyl contributing to lower overdose deaths?
Over the past few years, there are indications of a growing trend among opioid users towards smoking rather than injecting fentanyl. Can this explain part of why overdose deaths have declined over the past 12 months?
Overdose deaths are declining
You can track overdose death rates in near real-time on this CDC dashboard. Around February of 2022, overdose death rates started to flatten and then began to fall in September of 2023. This is wonderful news!
We are, of course, still near record highs. Even with the decline, overdose deaths remain 400% higher than 20 years ago—but any progress is welcome after so many years of ever-higher numbers.
There are a handful of theories about why overdose rates are falling. German Lopez offered one explanation in The New York Times Morning newsletter:
“Opioids, including fentanyl, have already reached every corner of the country; they have few places left to spread. The Covid pandemic is over, taking with it the chaos and isolation that led to more overdoses. The drug users most likely to die have already done so. More people have rejected opioid use. And the remaining users have learned how to use fentanyl more safely.”
NPR reported on the trend last week, quoting an opioid user:
"Some of us have learned to deal with the overdoses a lot better," said Kevin Donaldson, who uses fentanyl and xylazine on the street in Burlington, Vermont.
According to Donaldson, many people using fentanyl now carry naloxone, a medication that reverses most opioid overdoses. He said his friends also use street drugs with others nearby, ready to offer aid and support when overdoses occur.
NPR also quoted Brad Finegood, who does opioid crisis response work in Seattle:
"We've almost tripled the amount of naloxone out in the community," said Finegood. He noted that one survey in the Seattle area found 85 percent of high-risk drug users now carry the overdose-reversal medication.
All of these theories seem plausible, particularly the end of the COVID era surge and the increase in naloxone (Narcan) distribution to reverse overdoses that are in progress. People have also speculated that many years of reduced opioid prescribing by doctors could finally be making an impact or that younger people are starting to avoid opioids after witnessing the destruction in the previous generation. Theories abound.
And there’s another possibility that could be part of the story: the shift from injecting to smoking fentanyl and meth.
Does smoking fentanyl lead to fewer overdoses?
Anecdotal evidence shows that fentanyl users generally believe smoking is less likely (though still extremely likely) to lead to overdoses, and most experts would likely share that assumption. While this isn’t a hypothesis that is likely to be tested experimentally and there are no real-time national data sources tracking rates of smoking vs injecting fentanyl and meth, there is clear a trend towards smoking.
The CDC reported that by the second half of 2022, smoking overtook injection as the primary route of ingestion for overdose deaths, a sign of increasing prevalence. A study examining the longer term trend of smoking opioids found that it gradually became more common between 2000 and 2021. Another paper focusing on San Francisco demonstrated similar results.
A third study across California found that in early 2023, 59% of participants were only smoking fentanyl. Even more importantly, participants who only smoked were 40% less likely to have overdosed. This suggests that smoking may be substantially safer, though it’s important to remember that there could be significant self-selection here: people who are more cautious about their dosing might also choose to smoke rather than inject.
The most detailed recent trend data may come from this San Diego study. It shows a large reduction in the percent of people injecting fentanyl, heroin, and meth between Oct 2020 and April 2023. The number of people in their study who only smoke jumped from 0% to 34%. That’s a huge shift in behavior in a short time period.
We don’t know if national trends proceeded at the same rate or with the same timing as they did in San Diego. But it’s worth comparing this chart to the overdose trend line of deaths in the first chart. Between April 2022 and April 2023, the percent of people only smoking opioids and meth in this study increased by 22%. This coincides with the period when overdose deaths flattened out nationally. If smoking is indeed 40% (or even 20%) less likely to cause a fatal overdose, this shift could explain some of the recent reduction in deaths.
Another way this question could be examined is through analysis of data on overall use of opioids vs overdose trends: has opioid use gone down as overdoses have declined or has use stayed steady but fewer people are dying? I haven’t been able to find good data to look at this question.
Pulling back and taking a look at the bigger picture, it’s fair to ask if the trend towards smoking rather than injecting is a good thing. For now, I would say “probably,” with the caveat that smoking may feel easier and more accessible to new users, potentially drawing in people who would have been too nervous to inject. And, of course, smoking fentanyl, even if somewhat safer, is not a solution for anyone in the grips of opioid addiction. For that, we need better medications to eliminate cravings and more access to the medications already on the market, like buprenorphine.
A big thank you to Dr. Julia Zur at NIDA for pointing me to much of the research referenced above!