Drug interactions
Elvitegravir / cobicistat / emtricitabine / tenofovir df + Methadone
Severity: Moderate
Elvitegravir / cobicistat / emtricitabine / tenofovir df 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
Cobicistat inhibits CYP3A4 and can raise methadone exposure, increasing the risk of sedation, respiratory depression and QT prolongation. The effect is usually modest and manageable, and methadone is not a label contraindication with this regimen.
What this interaction means in plain words
Elvitegravir / cobicistat / emtricitabine / tenofovir df 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.
Why it happens
Cobicistat inhibits CYP3A4 (and CYP2D6), which contribute to methadone metabolism.
What to do
Monitor for opioid excess such as sedation and slowed breathing, and obtain an ECG if there are other QT risk factors. Reduce the methadone dose if signs of toxicity appear.
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 Elvitegravir / cobicistat / emtricitabine / tenofovir df with Methadone?
MediHelp rates the interaction as moderate. Elvitegravir / cobicistat / emtricitabine / tenofovir df 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. Cobicistat inhibits CYP3A4 and can raise methadone exposure, increasing the risk of sedation, respiratory depression and QT prolongation. The effect is usually modest and manageable, and methadone is not a label contraindication with this regimen.
How serious is the interaction between Elvitegravir / cobicistat / emtricitabine / tenofovir df 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 opioid excess such as sedation and slowed breathing, and obtain an ECG if there are other QT risk factors. Reduce the methadone dose if signs of toxicity appear.
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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