The Rise and Fall of Fentanyl Analogs in Overdose Deaths, 2016–2018

Of the 70,237 U.S. drug overdose deaths in 2017, about two thirds involved opioids, and since 2013 deaths involving illicitly made fentanyl had climbed sharply. Fentanyl analogs — chemically similar drugs of widely varying potency, mostly sold illicitly — can only be found with specific postmortem toxicology tests. In 2016–2017, deaths involving them, especially carfentanil, rose in 10 states, often together with fentanyl.

CDC funded 32 states and Washington, D.C., to expand toxicology testing and record detailed data on opioid overdose deaths through its State Unintentional Drug Overdose Reporting System (SUDORS) — 12 states from July 2016, the rest from July 2017. Tracking the exact drugs matters, because potency, dose, purity and what they're mixed with vary enormously.

Ten states, July 2016 – December 2018

Of 26,104 opioid overdose deaths, 5,083 (19.5%) involved at least one fentanyl analog. More than 15 different analogs turned up, sometimes several in one death.

By December 2018, deaths with carfentanil, furanylfentanyl, cyclopropylfentanyl or acrylfentanyl were down to fewer than five each — while deaths with fentanyl rose 25.8%, from 3,086 in July–December 2016 to 3,881 in July–December 2018.

Deaths with fentanyl and the five most common analogs, 10 SUDORS states. CDC

Twenty-eight states and D.C., July – December 2018

At least one analog was found in 2,824 (19.4%) of 14,571 opioid overdose deaths. Fentanyl itself was in 73.9%.

Apart from acetylfentanyl, every analog appeared in under 5% of deaths.

What it means

The fall in deaths from carfentanil, furanylfentanyl, acrylfentanyl and cyclopropylfentanyl helped drive the decline in opioid overdose deaths seen in 25 states in 2018 — even as fentanyl deaths rose. That suggests the illicit market was shifting from analogs to fentanyl itself. The rise of acetylfentanyl needs caution: it may be a by-product or contaminant of illicit fentanyl rather than something sold on purpose.

Analogs could return. In 2019, an Ohio county reported a sharp rise in carfentanil deaths, and Ontario, Canada, issued an alert about increasing carfentanil overdoses. Timely toxicology surveillance is essential to catch such shifts and respond to a fast-changing drug market.

Sources

Based on O'Donnell J, Gladden RM, Goldberger BA, Mattson CL, Kariisa M, "Notes from the Field: Opioid-Involved Overdose Deaths with Fentanyl or Fentanyl Analogs Detected — 28 States and the District of Columbia, July 2016–December 2018," MMWR Morbidity and Mortality Weekly Report volume 69, number 10, Centers for Disease Control and Prevention; a work of the United States government in the public domain.