Drug interactions
Atazanavir + Methadone
Severity: Moderate
Atazanavir 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
Atazanavir inhibits CYP3A4 and may modestly raise methadone concentrations, but studies showed small changes. Atazanavir itself can prolong the PR interval and slightly the QT interval, which is relevant in patients on high-dose methadone.
What this interaction means in plain words
Atazanavir 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.
Atazanavir belongs to Anti Virals; Methadone belongs to Musculoskeletal.
Why it happens
Inhibition of CYP3A4-mediated methadone metabolism by atazanavir, with additive effects on cardiac conduction.
What to do
Monitor for sedation and respiratory depression after starting atazanavir, and obtain an ECG if the patient is on a high methadone dose. Adjust the methadone dose clinically.
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 Atazanavir
- Alfuzosin + Atazanavir Contraindicated
- Atazanavir + Avanafil Contraindicated
- Atazanavir + Dronedarone Contraindicated
- Atazanavir + Eletriptan Contraindicated
- Atazanavir + Eplerenone Contraindicated
- Atazanavir + Ergotamine Contraindicated
Frequently asked questions
Can I take Atazanavir with Methadone?
MediHelp rates the interaction as moderate. Atazanavir 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. Atazanavir inhibits CYP3A4 and may modestly raise methadone concentrations, but studies showed small changes. Atazanavir itself can prolong the PR interval and slightly the QT interval, which is relevant in patients on high-dose methadone.
How serious is the interaction between Atazanavir 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: Monitor for sedation and respiratory depression after starting atazanavir, and obtain an ECG if the patient is on a high methadone dose. Adjust the methadone dose clinically.
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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