Both of those illicit fentanyl and carfentanil are particularly perilous opioids that will cause a quick overdose and Demise when abused, but carfentanil is much more strong than fentanyl. A number of doses of the anti-overdose drug naloxone (Narcan) will not be effective to reverse an overdose. Go on looking throughFentanyl OD or W/D!!! Unsure, re