Which two opioids are known to be thousands of times more potent than morphine?

Fentanyl and Carfentanil are indeed known to be thousands of times more potent than morphine, making this the correct answer. Fentanyl is a synthetic opioid that is approximately 50 to 100 times more potent than morphine. This potent analgesic is commonly used for severe pain management, particularly in anesthesia and in patients with chronic pain who are tolerant to other opioids.

Carfentanil, which is used primarily as a tranquilizer for large animals, is even more potent than fentanyl, estimated to be around 100 times more potent than fentanyl and 10,000 times stronger than morphine. This incredibly high potency poses significant risks if used improperly, leading to potentially fatal respiratory depression, especially in humans.

In contrast, the other options consist of opioids that are not nearly as potent as morphine. Hydrocodone and Oxycodone, while effective pain medications, are much less potent than morphine. Codeine is also significantly weaker, and Methadone, although a strong opioid, does not reach the extreme potency levels of fentanyl or carfentanil. Buprenorphine is a partial agonist, making it less potent on a per milligram basis than full agonists