Acetyl fentanyl, similar to the Schedule II opioid fentanyl, is a potent opioid analgesic. Recently, it has been linked to a number of overdose deaths in the United States.
Acetyl fentanyl is not a part of most illicit drug screens and may remain undetected in many cases.
Acetyl norfentanyl is a major metabolite of acetyl fentanyl, a designer drug and fentanyl analog with a potency 40 times greater than heroin and 80 times greater than morphine. In June, 2013, the Centers for Disease Control (CDC) issued a health alert for acetyl fentanyl, reporting 14 overdose deaths in Rhode Island.