Drug interactions
Dimenhydrinate + Methadone
Severity: Moderate
Dimenhydrinate and Methadone: 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
Dimenhydrinate is a sedating antihistamine, and with methadone it increases drowsiness, psychomotor impairment and the risk of respiratory depression. Anticholinergic effects may also add to constipation and urinary retention.
What this interaction means in plain words
Dimenhydrinate and Methadone 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.
Dimenhydrinate belongs to Respiratory; Methadone belongs to Musculoskeletal.
Why it happens
Additive CNS depression from opioid agonism and central H1 antihistamine effects.
What to do
Use the lowest effective antihistamine dose and advise against driving or operating machinery. Monitor sedation and breathing, especially in elderly or opioid-naive patients.
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
Other interactions of Dimenhydrinate
Frequently asked questions
Can I take Dimenhydrinate with Methadone?
MediHelp rates the interaction as moderate. Dimenhydrinate and Methadone 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. Dimenhydrinate is a sedating antihistamine, and with methadone it increases drowsiness, psychomotor impairment and the risk of respiratory depression. Anticholinergic effects may also add to constipation and urinary retention.
How serious is the interaction between Dimenhydrinate and Methadone?
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 antihistamine dose and advise against driving or operating machinery. Monitor sedation and breathing, especially in elderly or opioid-naive patients.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
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