Morphine Equivalent for Methadone 30 mg Daily
Methadone 30 mg daily is approximately equivalent to 140-180 mg of oral morphine daily, though the conversion ratio is highly variable and depends on the direction of conversion and individual patient factors.
Conversion Ratios Based on Evidence
The conversion from methadone to morphine is complex and lacks a universally accepted standard:
For switching FROM methadone TO morphine: Research suggests a ratio of approximately 1:4.7 for oral methadone to oral morphine equivalent daily dose (MEDD), which would make 30 mg methadone equivalent to approximately 141 mg morphine 1
For switching FROM morphine TO methadone: Studies indicate a ratio of approximately 1:12 (morphine to methadone) for doses in this range, which would suggest 30 mg methadone equals approximately 360 mg morphine 2
Significant variability exists: A survey of clinicians found the mean morphine equivalent for methadone 40 mg was 193 mg (±201 mg standard deviation), with a median of 160 mg, demonstrating substantial inconsistency in conversion practices 3
Critical Clinical Considerations
The direction of conversion matters significantly:
Converting FROM methadone requires higher morphine doses due to methadone's unique pharmacology, including NMDA receptor antagonism and long half-life 1
Converting TO methadone from morphine uses lower methadone doses due to incomplete cross-tolerance 2, 4
For your specific question of 30 mg methadone daily:
Using the most conservative estimate from switching FROM methadone, 30 mg methadone ≈ 140-150 mg oral morphine daily 1
This ratio (approximately 1:5) is the most clinically relevant when determining morphine equivalents for regulatory, prescribing, or safety monitoring purposes 1
Important Caveats
Methadone maintenance provides minimal analgesia for acute pain, so patients on methadone 30 mg daily for maintenance would require additional opioids (like morphine) for pain management without modifying their methadone dose 5
No fixed maximum exists: Research shows that a fixed methadone dose of 30 mg/day can be effective even for patients previously on >1200 mg morphine daily, highlighting methadone's disproportionate potency at higher dose ranges 4
Individual variability is substantial: Methadone has unpredictable pharmacokinetics with significant inter-patient variation, making any conversion ratio an approximation requiring careful titration 2, 3