The two illicit fentanyl and carfentanil are really risky opioids that will result in A fast overdose and Demise when abused, but carfentanil is a lot more powerful than fentanyl. Several doses of the anti-overdose drug naloxone (Narcan) will not be effective to reverse an overdose. Continue examiningNEONATAL OPIOID WITHDRAWAL SYNDROME: Prolonged u