Drug interactions
Methadone + Orphenadrine
Severity: Moderate
Methadone and Orphenadrine: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Orphenadrine is an anticholinergic muscle relaxant with sedative effects, and combining it with an opioid may increase drowsiness, confusion and respiratory depression. Anticholinergic effects such as constipation and urinary retention may also be worsened.
What this interaction means in plain words
Methadone and Orphenadrine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Additive CNS depression and anticholinergic effects.
What to do
Use the lowest effective doses and monitor for sedation and respiratory depression. Avoid in older adults where possible.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Methadone
- Alvimopan + Methadone Contraindicated
- Calcium / magnesium / potassium / sodium oxybates + Methadone Contraindicated
- Droperidol + Methadone Contraindicated
- Ibutilide + Methadone Contraindicated
- Isocarboxazid + Methadone Contraindicated
- Lefamulin + Methadone Contraindicated
Frequently asked questions
Can I take Methadone with Orphenadrine?
MediHelp rates the interaction as moderate. Methadone and Orphenadrine can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Orphenadrine is an anticholinergic muscle relaxant with sedative effects, and combining it with an opioid may increase drowsiness, confusion and respiratory depression. Anticholinergic effects such as constipation and urinary retention may also be worsened.
How serious is the interaction between Methadone and Orphenadrine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lowest effective doses and monitor for sedation and respiratory depression. Avoid in older adults where possible.
What other medicines interact with Methadone?
MediHelp also lists interactions of Methadone with, for example, Alvimopan, Calcium / magnesium / potassium / sodium oxybates, Droperidol. The full list is on the Methadone page.
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