Drug interactions
Efavirenz + Propafenone
Severity: Major
Efavirenz and Propafenone: 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
Both drugs can prolong the QT interval, raising the risk of ventricular arrhythmia. Efavirenz may also alter propafenone concentrations through enzyme induction, which can reduce antiarrhythmic efficacy.
What this interaction means in plain words
Efavirenz and Propafenone 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.
Efavirenz belongs to Anti Virals; Propafenone belongs to Cardiovascular.
Why it happens
Additive QT prolongation and efavirenz-mediated induction of CYP3A4 (and effects on CYP2D6/1A2 pathways) altering propafenone metabolism.
What to do
Avoid if an alternative is available. If combined, monitor ECG, keep potassium and magnesium normal, and watch for loss of antiarrhythmic control.
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 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 Propafenone
- Dofetilide + Propafenone Contraindicated
- Dronedarone + Propafenone Contraindicated
- Nilotinib + Propafenone Contraindicated
- Nirmatrelvir / ritonavir + Propafenone Contraindicated
- Nirmatrelvir + Propafenone Contraindicated
- Pimozide + Propafenone Contraindicated
Frequently asked questions
Can I take Efavirenz with Propafenone?
MediHelp rates the interaction as major. Efavirenz and Propafenone 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. Both drugs can prolong the QT interval, raising the risk of ventricular arrhythmia. Efavirenz may also alter propafenone concentrations through enzyme induction, which can reduce antiarrhythmic efficacy.
How serious is the interaction between Efavirenz and Propafenone?
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 an alternative is available. If combined, monitor ECG, keep potassium and magnesium normal, and watch for loss of antiarrhythmic control.
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.
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