serious Illness medication ServiceS

Addiction Medicine in Serious Illness: Chapter 1 - Traditional Initiation Therapies for MOUD — Methadone vs Buprenorphine

Patients with opioid use disorder who need medical care—especially for acute pain, or during serious illness and hospice care—require careful coordination between addiction treatment and symptom management. MOUD decisions are more complex in serious illness: goals of care, oral intake limits, drug interactions, altered pharmacokinetics, and the priority of comfort can affect whether and how methadone or buprenorphine are continued, adjusted, or temporarily bridged. This post compares the two main MOUD options, methadone and buprenorphine, summarizes initiation approaches and practical pros/cons, and highlights how each affects acute symptom management.

11/2/20253 min read

Introduction

Medication for opioid use disorder (MOUD) centers on two established options: methadone and buprenorphine. Both reduce mortality and improve outcomes but differ in pharmacology, delivery, dosing, advantages/limitations, and implications for acute pain and symptom management. This concise guide covers formulations, initiation approaches, pros/cons, coordination needs, and acute‑pain considerations for clinicians and programs.

Formulations & pharmacology

  • Methadone: oral solution/tablets dispensed through OTPs; full mu‑opioid agonist with a long, variable half‑life.

  • Buprenorphine: sublingual/buccal films, tablets, depot injections, and implants; partial mu‑agonist with high receptor affinity and ceiling effect for respiratory depression.

Traditional Initiation & dosing

  • Methadone (OTP): start low, commonly 10–30 mg/day, with a maximum day 1 dose of 50 mg, and titrate cautiously with close monitoring for accumulation. Stabilization doses often range widely (40–120+ mg/day).

  • Buprenorphine: traditional start when mild–moderate withdrawal is present (e.g., 4-8 mg SL, titrate to 8–24 mg/day).

Advantages and disadvantages

  • Methadone

    • Pros: Effective for high-tolerance patients, with a strong analgesic effect.

    • Cons: limited to OTPs when used for MOUD (access barriers), QTc prolongation risk, drug interactions, and regulatory burden.

  • Buprenorphine

    • Pros: office‑based access, lower overdose risk, multiple formulations.

    • Cons: high receptor affinity can complicate adjunctive opioid analgesia; incorrect initiation can precipitate withdrawal.

Acute pain and symptom management complexities

  • General: Continue MOUD when possible; expect altered analgesic responses due to tolerance or changes in receptor dynamics.

  • On methadone: high tolerance often requires larger supplemental full‑agonist doses; monitor for sedation and QTc effects.

  • On buprenorphine: high receptor affinity can blunt full‑agonist analgesia. Strategies include continuing buprenorphine with aggressive multimodal analgesia, dividing/shortening buprenorphine dosing interval, using higher‑dose short‑acting opioids, IV buprenorphine for breakthrough, or, rarely, transitioning off buprenorphine under specialist guidance.

  • Maximize nonopioid therapies: acetaminophen, NSAIDs, gabapentinoids, regional techniques, ketamine, clonidine, etc.

Note on methadone prescribing in hospice

Hospice providers generally cannot initiate methadone for opioid use disorder (MOUD) outside of an OTP, and many hospice clinicians avoid using once‑daily methadone as an MOUD strategy. When methadone is used in hospice for pain (not MOUD), it must be prescribed and dosed as an analgesic—typically with divided (split) dosing (e.g., every 8–12 hours) rather than a single daily dose. Coordinate with the patient’s OTP or addiction specialist if MOUD is ongoing; document the indication (pain vs MOUD), monitor QTc, and communicate dose/schedule changes clearly at transitions of care.

Note on buprenorphine/naloxone (Suboxone)

Suboxone combines buprenorphine with naloxone to deter injection. Naloxone has negligible oral or sublingual bioavailability, so when Suboxone is taken as intended (sublingually), the naloxone component does not reach levels that precipitate withdrawal. Clinically, this means Suboxone can be continued while using traditional full‑agonist opioids as short‑term adjuvants for acute symptom management—though higher supplemental opioid doses or alternative strategies may be required due to buprenorphine’s high receptor affinity.

Bottom line

Methadone and buprenorphine are both essential MOUD tools; initiation choice depends on patient tolerance, access, clinical goals, and setting. Acute pain in patients on MOUD requires proactive coordination, multimodal strategies, and early involvement of addiction/pain specialists.

References

  1. SAMHSA. TIP 63: Medications for Opioid Use Disorder — Treatment Improvement Protocol (2020). Substance Abuse and Mental Health Services Administration. https://store.samhsa.gov/product/tip-63-medications-for-opioid-use-disorder/full-report

  2. WHO. Guidelines for the Psychosocially Assisted Pharmacological Treatment of Opioid Dependence (2009). World Health Organization. https://www.who.int/publications/i/item/9789241547543

  3. National Institute for Health and Care Excellence (NICE). Drug misuse in over 16s: prevention, treatment and recovery. NICE guideline [NG64], 2017 (updates on buprenorphine/methadone). https://www.nice.org.uk/guidance/ng64

  4. American Society of Addiction Medicine (ASAM). National Practice Guideline for the Use of Medications in the Treatment of Addiction Involving Opioid Use (2020). https://www.asam.org/quality-practice/guidelines-and-consensus-docs

  5. FDA. Information on Buprenorphine (Suboxone) and Naloxone Combination Products — Prescribing Information and Safety. https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=021429