Pharmacology Central Nervous system 28a24aad Which of the following is 100 times more potent than morphine? A Pethidine B Fentanyl C Pentazocin D Meperidine High-Yield Explanation Fentanyl is 100 times more potent than morphine. Pethidine is 1/10th as potent as morphine. Ref KD Tripathi 8th ed.