Which opioid agonist is metabolized by plasma cholinesterases?

The opioid agonist that is metabolized by plasma cholinesterases is Remifentanil. This particular drug is unique among the listed options due to its rapid metabolism, which occurs through hydrolysis by non-specific plasma esterases, specifically plasma cholinesterases. As a result, Remifentanil has a very short duration of action, making it ideal for situations where quick recovery from anesthesia is desired, such as in outpatient settings or procedures requiring brief periods of analgesia.

This characteristic sets Remifentanil apart from other opioids provided in the question. For example, Sufentanil, Alfentanil, and Fentanyl undergo hepatic metabolism and have longer half-lives when compared to Remifentanil. The quick breakdown of Remifentanil allows for precise control over analgesia, making it a critical agent in anesthesia practices. It reflects the pharmacokinetic principles relevant to the use of opioids in medical procedures.