County health officials say acetylfentanyl is five times or more stronger than heroin.
County health officials say acetylfentanyl is "five times or more stronger than heroin." tlorna/Shutterstock

King County health officials are warning the public against using cocaine after two women died on Capitol Hill from cocaine containing acetylfentanyl, a powerful synthetic opiate.

From the county (emphasis mine):

"Cocaine users need to be aware that acetylfentanyl-laced cocaine can kill quickly when snorted or injected. There is no way to know whether cocaine is laced with acetylfentanyl, so the best prevention is to avoid use of cocaine altogether," said Dr. Jeff Duchin, Health Officer for Public Health—Seattle & King County.

The last known acetylfentanyl death in King County was in 2015. Acetylfentanyl is not the same as the more commonly known fentanyl. Acetylfentanyl is 5 times or more stronger than heroin and stronger than prescription fentanyl. Acetylfentanyl is not prescribed but is synthesized in clandestine laboratories. The opioid antaganost naloxone (Narcan) can help to reverse an overdose from acetylfentanyl, but higher doses may be needed compared to heroin.

Capitol Hill Seattle Blog reported yesterday on two women found dead of apparent cocaine overdoses inside an apartment on 12th Avenue. The women had reportedly been dead for about two days when they were found. A representative from the Medical Examiner's office confirmed today that the women referenced in the county's warning about acetylfentanyl were found on Capitol Hill.