Buprenorphine
Buprenex · Belbuca · Suboxone (with naloxone)
Partial μ-agonist / κ-antagonist
High-affinity PARTIAL μ-agonist — binds tightly and is hard to displace with naloxone or other opioids. Ceiling on respiratory depression; blunts the effect of full agonists.
Indications
- •Opioid use disorder maintenance
- •Chronic pain
- •Moderate acute pain
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Analgesia (parenteral) | 0.3 mg IV/IM q6–8h | — |
| OUD maintenance | Sublingual, individualized | — |
Pharmacokinetics
Onset ~15 min IV; long duration 6–8 h+ (high receptor affinity).
Hemodynamic effects
Minimal.
Respiratory effects
Ceiling effect; high receptor affinity complicates acute opioid analgesia.
Side effects
- !Respiratory depression (ceiling)
- !Sedation
- !Blunts effect of co-administered full agonists
Contraindications
- ×—
Reversal / antidote
Naloxone (higher doses needed due to tight receptor binding)
Clinical pearls
- ★Perioperative management of buprenorphine-maintained patients is a board topic — modern guidance often CONTINUES it perioperatively plus multimodal + short-acting full agonists.
- ★Its high μ-affinity blunts other opioids — plan regional/multimodal analgesia.
Other drugs in Narcotics & Analgesics
- Fentanyl
μ-opioid receptor agonist. ~100× potency of morphine.
- Remifentanil
μ-opioid agonist. Ester linkage hydrolyzed by nonspecific tissue + plasma esterases — no organ-dependent clearance.
- Morphine
μ-opioid receptor agonist. Active metabolite morphine-6-glucuronide (M6G) is analgesic and renally cleared — accumulates in renal failure → prolonged sedation/respiratory depression. Causes histamine release.
- Hydromorphone
μ-opioid agonist ~5–7× more potent than morphine. No clinically significant active metabolites → safer than morphine in renal failure. Less histamine release.
- Sufentanil
Most potent opioid in common clinical use — ~1000× morphine, ~10× fentanyl. High lipid solubility.
- Alfentanil
μ-opioid agonist ~1/5–1/10 the potency of fentanyl but FASTEST onset of the family — low pKa means a high non-ionized fraction at physiologic pH.
- Meperidine
μ-opioid agonist ~1/10 morphine, plus κ-agonism (anti-shivering). Active metabolite normeperidine is renally cleared, proconvulsant, and neurotoxic.
Suggested reading
- •Stoelting & Hines, Pharmacology & Physiology in Anesthetic Practice, 6e
- •Miller's Anesthesia, 9e
- •FDA package insert
