<prompt> The most potent analgesic agent is:FentanylSufentanilRemifentanilAllentanil  <response>: Sulfentanil is 5 times more potent than Fentanyl.Alfentanil and remifentanil are faster acting and recovery is rapid. Above three drugs are congeners of Fentanyl. Ref: KD Tripathi 8th ed. 