Buprenorphine is used for opioid use disorder (OUD) maintenance therapy. Its pharmacological profile that supports this use includes which combination of properties?

• A Full mu agonist and kappa antagonist; long half-life via plasma protein binding
• B Pure opioid antagonist at mu, delta, and kappa receptors; similar to naloxone
• C Partial mu agonist (high affinity, slow dissociation) and kappa antagonist; ceiling effect on respiratory depression; very high receptor affinity preventing displacement by illicit opioids ✓
• D Sigma receptor agonist with delta receptor partial agonism; bypasses mu receptor tolerance

Explanation

Buprenorphine's therapeutic profile in OUD derives from its unique combination: (1) partial agonism at mu-opioid receptors — it activates the receptor but with a ceiling effect on euphoria and respiratory depression, reducing misuse liability; (2) very high mu receptor affinity (Ki ~0.2 nM) combined with very slow receptor dissociation (t½ of receptor binding ~166 min), which prevents full agonists like heroin from displacing it and precipitating craving ('blockade'); (3) kappa antagonism, which has antidepressant and anti-dysphoric properties relevant to early recovery; and (4) its sublingual bioavailability and long plasma half-life (24–72 hours) enabling once-daily or alternate-day dosing.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

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Written and medically reviewed by the StethoPrep medical team.