Fentanyl is which of the following in relation to morphine potency?

• A. It is twice as potent as morphine.
• B. It is half as potent as morphine.
• C. It is equally potent to morphine.
• D. It has no analgesic effect.

Answer: (A)

Potency is about how much drug you need to achieve the same effect. Fentanyl is a synthetic opioid that requires far smaller doses than morphine to produce analgesia; in practice it’s many times more potent than morphine. The option stating it is twice as potent best conveys this relationship: it shows fentanyl has greater potency than morphine, which is the key idea. The other statements—being half as potent, equally potent, or having no analgesic effect—don’t fit because they imply less potency, the same potency, or no effect, which aren’t true.