Which analgesic would be best for postoperative pain management in a patient who is taking fluoxetine (Prozac)?

Which analgesic would be best for postoperative pain management in a patient who is taking fluoxetine (Prozac)?

• A. Oxycodone plus aspirin
• B. Hydrocodone with acetaminophen
• C. Codeine with acetaminophen
• D. Hydromorphone

Answer: (D)

When fluoxetine is in the system, it strongly inhibits the enzyme CYP2D6. Many opioid analgesics depend on this enzyme to become their more potent active forms. Codeine, hydrocodone, and oxycodone all rely at least in part on CYP2D6 for part of their analgesic effect, so their pain relief can be reduced or unpredictable in someone taking fluoxetine. Some options also carry a higher risk of interaction through serotonergic effects with SSRIs, which is a consideration for drugs like tramadol. Hydromorphone, on the other hand, does not require CYP2D6 activation to be effective and has minimal serotonergic activity, so it provides reliable postoperative pain control without the interaction concerns posed by fluoxetine. That makes it the best choice among the listed options.

When fluoxetine is in the system, it strongly inhibits the enzyme CYP2D6. Many opioid analgesics depend on this enzyme to become their more potent active forms. Codeine, hydrocodone, and oxycodone all rely at least in part on CYP2D6 for part of their analgesic effect, so their pain relief can be reduced or unpredictable in someone taking fluoxetine. Some options also carry a higher risk of interaction through serotonergic effects with SSRIs, which is a consideration for drugs like tramadol. Hydromorphone, on the other hand, does not require CYP2D6 activation to be effective and has minimal serotonergic activity, so it provides reliable postoperative pain control without the interaction concerns posed by fluoxetine. That makes it the best choice among the listed options.