Which statement best describes alfentanil metabolism?

Which statement best describes alfentanil metabolism?

• A. Metabolized via CYP450.
• B. Not metabolized and excreted unchanged.
• C. Metabolized to an active metabolite by hepatic conjugation.
• D. Eliminated primarily by kidney filtration.

Answer: (A)

Alfentanil is cleared primarily by the liver through oxidation mediated by cytochrome P450 enzymes, especially CYP3A4. This hepatic metabolism converts it to an inactive metabolite (noralfentanil), which is then excreted. Because the drug is rapidly inactivated by CYP450 enzymes, its effect is short-lived. The other ideas don’t fit because alfentanil is not left unmetabolized to be excreted unchanged, it does not primarily rely on hepatic conjugation to produce an active metabolite, and its major elimination is not by kidney filtration but by hepatic metabolism with renal excretion of the metabolites.

Alfentanil is cleared primarily by the liver through oxidation mediated by cytochrome P450 enzymes, especially CYP3A4. This hepatic metabolism converts it to an inactive metabolite (noralfentanil), which is then excreted. Because the drug is rapidly inactivated by CYP450 enzymes, its effect is short-lived. The other ideas don’t fit because alfentanil is not left unmetabolized to be excreted unchanged, it does not primarily rely on hepatic conjugation to produce an active metabolite, and its major elimination is not by kidney filtration but by hepatic metabolism with renal excretion of the metabolites.