"Overdose results in respiratory depression which is reversible with naloxone. Sudden death can also occur because of cardiac arrest or severe anaphylactic reaction. The estimated lethal dose of fentanyl in humans is 2 mg. The recommended serum concentration for analgesia is 1–2 ng/ml and for anaesthesia it is 10–20 ng/ml"
"Overdose results in respiratory depression which is reversible with naloxone. Sudden death can also occur because of cardiac arrest or severe anaphylactic reaction. The estimated lethal dose of fentanyl in humans is 2 mg. The recommended serum concentration for analgesia is 1–2 ng/ml and for anaesthesia it is 10–20 ng/ml"
https://www.emcdda.europa.eu/publications/drug-profiles/fentanyl_en
he was analgeezing out of his fucking mind