The Dose Makes the Poison

Among the devastating health crises of the COVID-19 pandemic has been a massive upsurge in drug-overdose deaths across the United States. Having risen less than 6 percent between 2018 and 2019, from 68,000 to 72,000, the overdose-death rate spiked by more than 29 percent between 2019 and 2020, to 93,000—and is currently on track to break the 2020 record in 2021. Why is this happening?

Noa Krawczyk is an assistant professor in the Department of Population Health at New York University’s Grossman School of Medicine and a member of NYU’s Center for Opioid Epidemiology and Policy. According to Krawczyk, there’s a complex set of elements behind these numbers. They include a proliferation of difficulties people have experienced in trying to get treatment during the pandemic; an increase in instances of people using opioids alone, on account of lockdowns and the need for social distancing; mental-health issues and other problems related to the fracturing of social networks. But the most significant factor driving the escalation in overdose deaths, Krawczyk says, is the emergence of the opioid fentanyl in illicit-drug supplies. “What's really important to keep in mind with opioids particularly is that so much of the overdose-death crisis really depends on the drug supply,” she says. “So, we might be seeing certain areas of the country with higher death rates, and it's not always due to more drug use, or particular patterns of drug use, but rather to illicit-drug supplies being contaminated with fentanyl.”

Eve Valentine: What’s causing this rise in overdose deaths?

Noa Krawczyk: Mostly, it’s been driven by illicit fentanyl, a very potent opioid—much stronger than other opioids like oxycodone or heroin. Since 2013, we’ve seen this substance infiltrate the illicit U.S. drug market—not only the opioid supply but also the supply of other drugs, such as cocaine and methamphetamines.

There are few reasons why fentanyl would have become especially dangerous during the pandemic. One is that the pandemic seriously disrupted illicit drug supplies. Many people dependent on opioids were no longer able to their usual supplier, and so ended up accessing more contaminated supplies that contained more fentanyl. So, separately from any rise in drug use, even people who were using the same quantity of drugs were more likely to encounter illicit fentanyl in their supply—and so were at greater risk of death, just because that fentanyl is so potent.

Valentine: Why are we seeing illicit drug supplies cut with more fentanyl?

Krawczyk: There are a couple of theories. One is that, because there were already disruptions to drug-supply chains in certain areas, there were lower quantities of drugs available and so more pressure to cut them with fentanyl—essentially to make them stronger. You’d need a little fentanyl where you’d need, say, a lot more heroin.

Then there’s just a really big increase in the fentanyl supply itself. We have reason to believe that we would have seen an increase in overdose deaths even without a pandemic, especially among people who weren’t even using opioids. People who are mainly cocaine or methamphetamine users—even recreational users, who only use from time to time—were much more likely to die from an overdose because of the fentanyl reaching those drug supplies.

Valentine: How do you see these developments against the broader history of the American opioid epidemic?

Krawczyk: The first phase of the epidemic started in the late 1990s, when we saw a real increase in opioid pain-reliever prescriptions. The influx of prescription opioids in the medical market very quickly led to a growth in illicit markets. By the early 2000s, we saw many, many people addicted to opioids and an increase in overdose deaths.