Both of those illicit fentanyl and carfentanil are particularly perilous opioids which could bring about A fast overdose and Dying when abused, but carfentanil is more potent than fentanyl. Several doses in the anti-overdose drug naloxone (Narcan) will not be effective to reverse an overdose. Keep on examiningNasal Spray: Keep at nearly 25C; do not