Opioid intoxications involving butyrfentanyl, 4-fluorobutyrfentanyl, and fentanyl from the Swedish STRIDA project

Abstract

Typical and potentially life-threatening opioid toxicity was seen in acute intoxications involving butyrfentanyl, 4F-butyrfentanyl, and fentanyl. The incorrect labelling of butyrfentanyl NPS products which instead mainly contained fentanyl is alarming, given the narrow range between a safe and a lethal dose for opioids.