Drug interactions
Efavirenz + Ponesimod
Severity: Moderate
Efavirenz and Ponesimod: 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
Efavirenz can prolong the QT interval and ponesimod can affect cardiac conduction, so combined use may add to arrhythmia risk. Efavirenz is also a CYP3A4/UGT inducer that could modestly lower ponesimod exposure.
What this interaction means in plain words
Efavirenz and Ponesimod 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.
Efavirenz belongs to Anti Virals; Ponesimod belongs to Central Nervous System.
Why it happens
Possible additive cardiac effects (QT prolongation and bradyarrhythmia) plus enzyme induction by efavirenz; the clinical significance is not well established.
What to do
Obtain a baseline ECG and correct potassium and magnesium before starting. Monitor heart rate and ECG, and reassess ponesimod response if used long term.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Efavirenz and Ponesimod, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Efavirenz
- Cobimetinib + Efavirenz Contraindicated
- Dienogest / estradiol valerate + Efavirenz Contraindicated
- Dihydroergotamine intranasal + Efavirenz Contraindicated
- Dihydroergotamine + Efavirenz Contraindicated
- Doravirine + Efavirenz Contraindicated
- Efavirenz + Elbasvir / grazoprevir Contraindicated
Other interactions of Ponesimod
- Fingolimod + Ponesimod Contraindicated
- Ponesimod + Siponimod Contraindicated
- Amiodarone + Ponesimod Major
- Amisulpride + Ponesimod Major
- Anagrelide + Ponesimod Major
- Anti-thymocyte + Ponesimod Major
Frequently asked questions
Can I take Efavirenz with Ponesimod?
MediHelp rates the interaction as moderate. Efavirenz and Ponesimod 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. Efavirenz can prolong the QT interval and ponesimod can affect cardiac conduction, so combined use may add to arrhythmia risk. Efavirenz is also a CYP3A4/UGT inducer that could modestly lower ponesimod exposure.
How serious is the interaction between Efavirenz and Ponesimod?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG and correct potassium and magnesium before starting. Monitor heart rate and ECG, and reassess ponesimod response if used long term.
What other medicines interact with Efavirenz?
MediHelp also lists interactions of Efavirenz with, for example, Cobimetinib, Dienogest / estradiol valerate, Dihydroergotamine intranasal. The full list is on the Efavirenz page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
