Pharmacologic Treatment of OUD — Buprenorphine, Methadone, Naltrexone
Module 3 of 11 · 45 min
MAT mechanisms, induction protocols, perioperative considerations for the CRNA encountering MAT-treated patients.
Learning objectives
- •Compare buprenorphine, methadone, naltrexone mechanisms + indications
- •Recognize precipitated withdrawal + how to avoid it
- •Manage perioperative analgesia for MAT-treated patients
- •Identify which patients are candidates for which agent
The three MAT options
Buprenorphine: partial mu agonist (high affinity, low intrinsic activity); ceiling on respiratory depression. Sublingual films/tabs; long-acting injectables (Sublocade, Brixadi). Suboxone = bup + naloxone (naloxone bypasses if injected, deters diversion). Methadone: full mu agonist; only dispensed by federally-licensed OTPs (Opioid Treatment Programs). Long half-life (24-36h) → daily dosing → stable plasma levels. Naltrexone: pure antagonist; oral (poor adherence) or monthly IM (Vivitrol). Requires patient already detoxed (7-10 days off opioids) before starting.
Buprenorphine induction + precipitated withdrawal
Bup's high mu affinity displaces full agonists from receptors → if patient still has full agonist on board, this triggers acute withdrawal (precipitated withdrawal — severe, lasts 8-24h). Standard induction: wait until COWS (Clinical Opioid Withdrawal Scale) ≥ 8 (mild-moderate withdrawal), then 2-4 mg test dose, titrate to 12-16 mg over 24-72h. Microdosing strategies (Bernese method) allow induction without withdrawal — used for patients on long-acting opioids or fentanyl.
Perioperative — the CRNA's challenge
Patients on buprenorphine present a paradox: their mu receptors are partially occupied + you cannot displace easily with standard opioids. Multiple approaches: (1) Continue buprenorphine perioperatively + use full opioid agonists at higher doses + multimodal (regional, ketamine, NSAID, acetaminophen, dexmedetomidine). (2) Hold bup 24-72h preop + use full agonists. (3) Convert to methadone perioperatively. Modern consensus (Anesthesiology 2019): CONTINUE buprenorphine for most surgeries; use multimodal aggressively. Patients on methadone: continue perioperatively, supplement with additional opioids as needed (their tolerance is real). Naltrexone: hold 72h (oral) or 30 days (Vivitrol) preop if opioid analgesia anticipated.
Counseling + plan
Discuss with patient PREOP: their MAT is therapy, not addiction itself; perioperative pain is treatable; they should expect higher opioid doses + close monitoring. Engage their SUD provider in the plan. Document the plan. Avoid surprises postop.
References
- · ASAM Practice Guideline OUD 2020
- · Anesthesiology 2019 (Buprenorphine Perioperative)
- · SAMHSA TIP 63