Last month I wrote about the possibility that naloxone – the only opioid overdose antidote – may no longer work because of carfentanil-laced street drugs. Although the absolute number of carfentanil-laced fentanyl samples seized between 2023-4 was very small, the trend was anything but.
Fig.1 (Left) The number of seized carfentanil-laced fentanyl began to soar beginning in 2013. (Right) The trend is regionalized, at least for now. Source: MMWR
Given the small number of samples, it is reasonable to wonder whether the trend was simply a blip or the beginning of a dangerous trend. Given the following news story from KSL.com, I lean toward the latter. Police seized enough carfentanil to kill roughly 200,000 people.
Carfentanil is really deadly
It's an understatement to claim that it doesn't take much carfentanil to kill a person. Since it's about 10,000 times more potent than morphine (and 100 times that of fentanyl) the estimated lethal dose is 100 micrograms (0.1 mg). It is difficult even to see 100 micrograms of anything. To put this in perspective, consider a grain of rice weighs about 0.3 grams (300,000 micrograms). In other words, a lethal dose of carfentanil weighs 0.033% of a grain of rice; virtually invisible.
Fig. 2 Lethal doses of heroin, fentanyl, and carfentanil. Can you even see the carfentanil? image Credit: Thermo Fisher Scientific – Portable and Handheld Raman Spectroscopy
The magnitude of the seizure
The arrests followed the seizure of 20 grams of illicit carfentanil by Homeland Security. How they detected it is anyone's guess. It's not like it was some huge, suspicious package. Quite the opposite. Here are some common items that weigh about 20 grams.
- A slice of bread
- Four paperclips
- A large strawberry
- A ballpoint pen
- 10 US quarters
It would seem that Homeland Security must have had some prior knowledge of what was found inside a bedroom in Provo, Utah. Virtually anything coming from Amazon weighs more than 20 grams.
B-b-b-b-baby, you ain't seen nothing yet
It's not just Utah. Not even close. Just in the past month, there have been multiple news stories about carfentanil, including these:
- A sharp rise in carfentanil-related overdoses in Ohio
- The first carfentanil-related death in Hawaii
- A public safety alert was issued in Montana
- Carfentanil samples detected in Buffalo, triggering a safety alert
- Large shipment seized from Puerto Rico to Staten Island (NYC)
- Sharp rise in carfentanil deaths in Illinois
- Enough fentanyl to kill 2.5 million people seized on Long Island
Bottom line - carfentanil may erase recent "progress" in reducing OD deaths. If there was any.
The CDC reported a modest decline in drug overdose deaths between 2023-24, but this may not indicate a true reversal of the crisis. It could reflect an artifact of the COVID-era surge in drug use. Why?
Fig. 3 shows the 2023-24 decline, but the red hatched line extends the pre-pandemic trend, suggesting this drop may simply reflect a return to the expected trajectory rather than real progress. This is a visual estimate, not a mathematical projection, and the true trajectory is unknowable.
Fig. 3. Overdose deaths spiked during COVID-19 but have since declined. It is impossible to tell whether the decline is real or simply reflects the COVID surge. The red-hatched line estimates the number of deaths in the absence of the pandemic.
What is certain is that the 720% surge in carfentanil detections poses a serious threat. If this trend continues, overdose deaths will spike again, possibly severely.
Don't underestimate this new monster. Carfentanil makes fentanyl look like cotton candy.
Josh Bloom
Director of Chemical and Pharmaceutical Science
Dr. Josh Bloom, the Director of Chemical and Pharmaceutical Science, comes from the world of drug discovery, where he did research for more than 20 years. He holds a Ph.D. in chemistry.
