Anaes · Anaesthetic adjuncts

Sufentanil

Also known as Most potent fentanyl-family opioid · High-dose cardiac-anaesthesia opioid

Sufentanil is a synthetic phenylpiperidine opioid and a full agonist at the mu-opioid receptor, and it is the MOST POTENT of the fentanyl family in clinical use — about 5 to 10 times more potent than fentanyl and roughly 500 to 1000 times more potent than morphine (Liu 2026, Zhou 2026). Two pharmacological features make it exam-critical. First, it is VERY HIGHLY LIPID-SOLUBLE — more so than fentanyl — giving it a large volume of distribution, significant tissue uptake and accumulation, a rapid onset of 1 to 3 minutes, and a longer apparent duration than fentanyl after a single bolus because of extensive redistribution (Li 2026, Ramesh 2026). Second, like fentanyl it releases NO histamine, so it preserves cardiovascular stability and is a standard high-dose opioid for cardiac anaesthesia; and it is metabolised by hepatic CYP3A4 to INACTIVE metabolites with no active metabolite, making it safe in renal failure (Lewis 2026, Voronkov 2026). Its context-sensitive half-time rises with infusion duration, though at very long infusions it may rise less steeply than fentanyl because the smaller mass dose means less peripheral compartment saturation (Li 2026). At high doses it can cause chest-wall rigidity and bradycardia, and its respiratory depression and toxicity are reversed by the competitive mu antagonist naloxone (Lewis 2026, Voronkov 2026).