Which Class II opioid is commonly administered via a transdermal pouch?

Fentanyl is commonly administered via a transdermal pouch, which allows for a sustained release of medication over time through the skin. This method is particularly beneficial for providing continuous pain relief in both human and veterinary medicine, as it bypasses the gastrointestinal tract and enables steady absorption. Transdermal delivery through patches is favored for patients who may have difficulty swallowing or receive inconsistent dosing with oral administration. Fentanyl patches are designed to provide long-lasting analgesia, making them a popular choice for managing chronic pain conditions in animals, ensuring stable plasma levels without the peaks and troughs associated with other routes of administration.

Other opioids listed, such as morphine, buprenorphine, and codeine, do have forms of administration, but they are not typically given through a transdermal pouch in the same way that fentanyl is, limiting their use in situations where a constant rate of opioid delivery is required.