Drug interactions
Idelalisib + Methadone
Severity: Major
Idelalisib and Methadone: major 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
Idelalisib strongly inhibits CYP3A and can substantially raise methadone concentrations. This may cause excessive sedation, respiratory depression and QT prolongation.
What this interaction means in plain words
Idelalisib and Methadone can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Idelalisib belongs to Oncology; Methadone belongs to Musculoskeletal.
Why it happens
Strong CYP3A inhibition by idelalisib reduces methadone metabolic clearance.
What to do
Avoid if possible; otherwise monitor for sedation, respiratory depression and QTc changes and reduce the methadone dose as needed. Re-adjust the dose when idelalisib is stopped.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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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 Idelalisib
- Alfuzosin + Idelalisib Contraindicated
- Cisapride + Idelalisib Contraindicated
- Dihydroergotamine + Idelalisib Contraindicated
- Dronedarone + Idelalisib Contraindicated
- Eletriptan + Idelalisib Contraindicated
- Eplerenone + Idelalisib Contraindicated
Frequently asked questions
Can I take Idelalisib with Methadone?
MediHelp rates the interaction as major. Idelalisib and Methadone can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Idelalisib strongly inhibits CYP3A and can substantially raise methadone concentrations. This may cause excessive sedation, respiratory depression and QT prolongation.
How serious is the interaction between Idelalisib and Methadone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid if possible; otherwise monitor for sedation, respiratory depression and QTc changes and reduce the methadone dose as needed. Re-adjust the dose when idelalisib is stopped.
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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