For mild to moderate pain, which opioids are recommended?

• A. Morphine
• B. Butorphanol or Buprenorphine
• C. Fentanyl
• D. Methadone

Answer: (B)

For mild to moderate pain, you want an opioid that provides enough relief without the higher risk of side effects seen with stronger mu agonists. Butorphanol and buprenorphine fit this balance because they are not full mu agonists. Butorphanol acts as a kappa agonist with mu antagonism/partial agonism, offering analgesia with a lower risk of respiratory depression and a shorter, controllable duration—useful for lighter pain or shorter procedures. Buprenorphine is a partial mu agonist with high receptor affinity and a long duration of action, giving sustained analgesia with a relatively safer respiratory profile and practicality for ongoing mild-to-moderate pain management.

In contrast, morphine and fentanyl are potent, full mu agonists that provide stronger analgesia but come with higher risks of respiratory depression, sedation, and other dose-related effects, making them more suited to moderate-to-severe pain or intraoperative scenarios. Methadone is long-acting and has unique properties (like NMDA antagonism) that make it valuable for certain chronic or neuropathic pain cases, but it’s not typically the first choice for mild to moderate pain.

So, for mild to moderate pain, butorphanol or buprenorphine are the preferred opioid options.