Deadly risk of residues in smoking devices

Like smoking fentanyl becoming more common than injections, users face increasing risks from residues in smoking equipment.

Now that smoking has overtaken injecting as the most common method of ingesting fentanyl, researchers at the University of California, San Francisco (UCSF) have found an increased risk of fatal overdose due to residues accumulating in smoking equipment.

Researchers found that people both shared and accidentally ingested fentanyl resin, potentially increasing the risk of overdose. This is particularly concerning for people who use the equipment to smoke other drugs, such as methamphetamine, and have not developed a tolerance to opioids such as fentanyl.

“The risk of overdose when sharing smoking devices containing fentanyl resin can be viewed as analogous to the risk of sharing injection paraphernalia and transmitting HIV,” said Daniel Ciccarone, MD, MPH, Justine Miner Professor of Addiction Medicine at the University of California, San Francisco at the Faculty of Family & Community Medicine, who is the first author of the paper. “To address this new risk, harm reduction-based and culturally responsive education campaigns must be rapidly accelerated.”

Article published today (May 22, 2024) in a scientific journal PLOS ONEwas the first to state that fentanyl resin may be a leading cause of overdoses.

Fentanyl smoking is on the rise locally and nationally

In 2023, San Francisco saw a record 806 deaths, 653 of them from fentanyl. Nationwide, fentanyl-related deaths decreased slightly in 2023, from 76,226 to 74,702; however, they remain high and the number of fatal overdoses of psychostimulants, including methamphetamine and cocaine, is increasing.

In recent years, consistent with national trends, fewer people in San Francisco were injecting fentanyl and more were smoking. However, the beliefs and behaviors associated with this development are not yet well understood.

To conduct the study, researchers followed people in their own settings in 2022, conducting face-to-face interviews with 34 participants who were recruited through syringe management programs. They asked about participants’ progress in substance use, as well as their patterns of use, experiences with overdoses, and changes they had observed in the local drug supply. Interviews were supplemented with daily field notes, videotaped smoking sequences, and photos of drugs and equipment.

Scientists have observed that fentanyl is extremely cheap, costing as little as $10 per gram; and most people smoked it with foil, although glass bulbs, bongs, and dabbing devices were also popular. The quality of fentanyl varied and people had no visible method to determine it. However, participants were able to assess the potency after inhalation and developed techniques to adjust the dose. Several participants reported frequent use, up to one or more grams per day.

Shared equipment poses serious risks

It was both the difficulty of injecting and the fear of overdose that motivated people to start smoking fentanyl. Smoking was also more social, with people sharing equipment, drugs and information. The researchers were surprised to find that it prompted participants to reflect on the changing risk environment for people with different opioid tolerances and to develop strategies to protect others.

Early in the fieldwork, researchers observed an interaction in which a random person tried to borrow a glass pipe from a participant, who adamantly refused. The participant explained that the pipe was made of fentanyl and he did not want to share it with someone who only used methamphetamine. Smoked fentanyl and methamphetamine residues look similar, and the equipment used often overlaps.

“The risk of overdose occurs when there is a potential discrepancy between the potency of the residual drug and the recipient’s tolerance,” Ciccarone explained.

Although some participants took precautions to prevent others from using smoking equipment and overdosing on the residue, the shared culture of smoking continues to pose an increased risk, especially given high rates of consumption.

“This underscores the need for data that can inform harm reduction education that incorporates and responds to the insights of people who use opioids,” Ciccarone said. “Steering, increasing awareness of ingested doses, and testing the tolerance of recipients of leftovers are potentially viable interventions that merit further study.”

Reference: “Innovation and Adaptation: The Rise of a Fentanyl Smoking Culture in San Francisco” May 22, 2024, PLOS ONE.
DOI: 10.1371/journal.pone.0303403