White-brown powder containing metonitazene

A white-brown powder containing the potent opioid ‘metonitazene’ may be sold as ketamine or heroin. Metonitazene is a potent synthetic opioid Opioids are central nervous system depressants that produce effects including pain relief, sedation and respiratory depression (where breathing slows or stops). Respiratory depression often appears more quickly with potent synthetic opioids (PSOs), increasing the risk of life-threatening