Fentanyl use among people who inject drugs in two large Pacific Northwest metropolitan areas

Background We examined fentanyl use and outcomes among people who inject drugs (PWID) in the urban Pacific Northwest (PNW). Methods We conducted secondary analysis of data from the 2022 National HIV Behavioral Surveillance PWID cycle from Portland, OR and Seattle, WA. We calculated proportions of any fentanyl, injection fentanyl, non-injection fentanyl, and street pill use. Next, we compared characteristics, behaviors, and outcomes by any fentanyl use. Finally, we estimated adjusted relative risk (aRR) of overdose outcomes associated with fentanyl use and injecting less associated with type of street pill use. Results Among 835 PWID, 76% reported fentanyl use, 47% injection fentanyl use, 68% non-injection fentanyl use, and 66% street pill use. Of those who used pills, 94% smoked them. Fentanyl use was crudely associated with age; race; housing; detainment; usual drug injected; injection frequency; syringe service programs, substance treatment, overdose, and naloxone (p<0.05). With adjustment, any fentanyl use (aRR=2.99, 95% CI: 1.55-5.76), injection fentanyl use (aRR=2.98, 95% CI: 1.43-6.19), and non-injection fentanyl use (aRR=2.12, 95% CI: 1.19-3.75) were associated with higher risk of overdose. Participants who smoked street pills were more likely to report injecting less because of pill use (aRR=1.80, 95% CI: 1.23-2.64). Conclusions Fentanyl use was highly prevalent among PWID in the urban PNW. Non-injection fentanyl use was most common and street pills were frequently administered by smoking which was associated with injecting less. All fentanyl use was associated with increased risk for overdose. There is ongoing need for access to naloxone for PWID who use fentanyl.