R-Methadone
levomethadone
What it isThe R-enantiomer of methadone, carrying essentially all the mu opioid activity.
Why this oneRacemic methadone’s analgesia comes from this enantiomer, which is marketed alone as levomethadone in some European countries.
What limits itIt does not avoid the QT prolongation entirely, and the long variable half-life is unchanged.
FDA-approved for
- opioid use disorder / pain (enantiomer)
Off-label
- opioid use disorder and pain as levomethadone (approved in Germany)
NO BOXED WARNINGS
Principal riskIt does not avoid the QT prolongation entirely, and the long variable half-life is unchanged
Classes and tags
Clinical profile
Serotonin and MAOI
Provisional washout figures
Elevating mechanismWeak/borderline SRI
Evidence confidenceLow
InterpretationThe enantiomer that carries racemic methadone's mu activity and its reuptake inhibition.