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Near death from a novel synthetic opioid labeled U-47700: emergence of a new opioid class.

  • Author(s): Schneir, Aaron;
  • Metushi, Imir G;
  • Sloane, Christian;
  • Benaron, David J;
  • Fitzgerald, Robert L
  • et al.


In the last decade there has been a worldwide surge in the recreational abuse of novel psychoactive substances, particularly amphetamine derivatives and synthetic cannabinoids. Synthetic opioids such as AH-7921, MT-45, and U-47700, with structures distinct from those ever used therapeutically or described recreationally, have also recently emerged.

Case details

We report a patient who suffered respiratory failure and depressed level of consciousness after recreationally using a novel synthetic opioid labeled U-47700. A single dose of naloxone administered by paramedics completely reversed his opioid poisoning. Comprehensive laboratory analysis confirmed the presence of a novel synthetic opioid and excluded other drugs. The drug used appeared to have caused a false positive benzodiazepine result on the initial urine drugs of abuse panel.


The case we describe of toxicity from the synthetic opioid labeled U-47700 highlights the emerging trend of novel synthetic opioid abuse.

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