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Pharmacology · single question

Fentanyl is approximately how many times more potent than morphine?

  1. 80–100 times
  2. 40–60 times
  3. 200–300 times
  4. 10–20 times
Show answer and explanation

Correct answer: A. 80–100 times

  • A. Correct. FENTANYL is approximately 80–100 TIMES MORE POTENT than morphine (some sources cite 50–100×). This extreme potency means even very small amounts can cause fatal respiratory depression — explaining the high risk of accidental overdose with illicit fentanyl and the need for careful dosing in clinical settings.
  • B. Incorrect. 40–60× is an underestimate of fentanyl's potency.
  • C. Incorrect. 200–300× exceeds fentanyl's typical potency ratio; carfentanil is in that range.
  • D. Incorrect. 10–20× more potent would be in the range of hydromorphone — not fentanyl.

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