Remifentanil onset and duration of action are best described as:

Remifentanil onset and duration of action are best described as:

• A. Onset 1 minute; peak 1 minute; duration of action 5-10 minutes.
• B. Onset 5-10 minutes; duration 60-90 minutes; peak 10 minutes.
• C. Onset 30-60 seconds; duration 2-4 hours; peak 2 minutes.
• D. Onset 2-3 minutes; duration 30-60 minutes; peak 5 minutes.

Answer: (A)

Remifentanil is an ultra-short-acting opioid that is rapidly metabolized by non-specific esterases in blood and tissues. This causes effects to begin quickly after IV administration, with onset essentially within about 1 minute and peak effect occurring around 1 minute as well. Because of the rapid breakdown, its action wears off in roughly 5–10 minutes after a bolus. This combination of very fast onset, near-immediate peak, and short duration best matches the description of onset about 1 minute, peak about 1 minute, and duration 5–10 minutes. Other options imply slower onset or much longer durations (hours), which do not align with remifentanil’s rapid metabolism and offset.

Remifentanil is an ultra-short-acting opioid that is rapidly metabolized by non-specific esterases in blood and tissues. This causes effects to begin quickly after IV administration, with onset essentially within about 1 minute and peak effect occurring around 1 minute as well. Because of the rapid breakdown, its action wears off in roughly 5–10 minutes after a bolus. This combination of very fast onset, near-immediate peak, and short duration best matches the description of onset about 1 minute, peak about 1 minute, and duration 5–10 minutes. Other options imply slower onset or much longer durations (hours), which do not align with remifentanil’s rapid metabolism and offset.