Remifentanil is metabolized primarily by which mechanism?

Remifentanil is metabolized primarily by which mechanism?

• A. Kidneys
• B. Liver
• C. Hoffman elimination
• D. Nonspecific esterases

Answer: (D)

Remifentanil is cleared by rapid hydrolysis through nonspecific esterases present in blood and tissues. This enzymatic breakdown cleaves an ester bond to yield inactive metabolites, so the drug is inactivated quickly regardless of how long it’s infused. Because this pathway is not dependent on liver enzymes or renal excretion, remifentanil maintains a very short and predictable duration of action even with prolonged infusions, and its clearance is relatively unaffected by hepatic or renal impairment. The Hoffmann elimination pathway, which is a nonenzymatic chemical degradation seen with some neuromuscular blockers, does not apply to remifentanil.

Remifentanil is cleared by rapid hydrolysis through nonspecific esterases present in blood and tissues. This enzymatic breakdown cleaves an ester bond to yield inactive metabolites, so the drug is inactivated quickly regardless of how long it’s infused. Because this pathway is not dependent on liver enzymes or renal excretion, remifentanil maintains a very short and predictable duration of action even with prolonged infusions, and its clearance is relatively unaffected by hepatic or renal impairment. The Hoffmann elimination pathway, which is a nonenzymatic chemical degradation seen with some neuromuscular blockers, does not apply to remifentanil.