Sufentanil is a narcotic analgesic with a greater potency and therapeutic ratio
than its structural relative fentanyl. It appears to produce fewer cardiac effects
and less respiratory depression than fentanyl, and thus is especially useful as an
analgesic/anesthetic in open heart surgery.
Sufentanil is one of the most potent opioids; it has a rapid onset of action
after i.v. administration, and peak analgesic effect is at approximately 8min.
It is 625 times more potent than morphine and 12 times more potent than
fentanyl. However, diffusion to tissues is slower than alfentanil because,
although sufentanil is highly lipid soluble, it is also highly protein bound,
resulting in low unbound plasma fractions at body pH. It has very low
concentration of non-specific binding that may increase potential effect-site
concentrations. The speed of onset of a large dose is caused by saturation of
receptors and non-specific sites, with potential for overdose. One of its
metabolites (desmethylsufentanil) is active at the MOP receptor (10% of
sufentanil's potency).
Sufentanil (Sufenta) contains the same 4 methoxy methylsubstituent as alfentanil along with an isosteric replacementof the phenyl of the phenethyl group with a thiophene ring. The resulting compound is about 7 times morepotent than fentanyl with an immediate onset of action anda similar recovery time compared with fentanyl. Sufentanilis only available in an injectable formulation and is alsoused as an anesthetic adjunct.
