What clinical risk arises if buprenorphine is administered to a patient already taking a full mu-opioid agonist?

• A. Severe respiratory depression
• B. Precipitated withdrawal
• C. No interaction
• D. Enhanced analgesia

Answer: (B)

Buprenorphine’s high affinity for mu-opioid receptors and its partial agonist activity mean it can displace a full mu-opioid agonist from the receptor while providing only limited receptor activation. In someone who is dependent on a full agonist, this displacement creates a sudden drop in mu-receptor signaling, producing abrupt withdrawal symptoms despite opioids being present. That’s why precipitated withdrawal is the clinical risk when buprenorphine is given to a patient on a full mu-opioid agonist. The ceiling effect of buprenorphine on respiratory depression makes severe respiratory depression less likely here, and analgesia is not enhanced—in fact, buprenorphine can blunt analgesia by displacing a full agonist.