Drug interactions
Efavirenz + Quinine
Severity: Major
Efavirenz and Quinine: 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, increasing the risk of ventricular arrhythmia. Efavirenz may also lower quinine exposure through CYP3A4 induction, which could reduce antimalarial efficacy.
What this interaction means in plain words
Efavirenz and Quinine 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; Quinine belongs to Anti Parasitic.
Why it happens
Additive QT prolongation and efavirenz-mediated induction of CYP3A4 metabolism of quinine.
What to do
Use an alternative antimalarial if possible. If quinine is required, obtain an ECG, correct electrolytes, and monitor for treatment failure.
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 Quinine
- Arsenic trioxide + Quinine Contraindicated
- Dofetilide + Quinine Contraindicated
- Dronedarone + Quinine Contraindicated
- Ibutilide + Quinine Contraindicated
- Mefloquine + Quinine Contraindicated
- Nilotinib + Quinine Contraindicated
Frequently asked questions
Can I take Efavirenz with Quinine?
MediHelp rates the interaction as major. Efavirenz and Quinine 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, increasing the risk of ventricular arrhythmia. Efavirenz may also lower quinine exposure through CYP3A4 induction, which could reduce antimalarial efficacy.
How serious is the interaction between Efavirenz and Quinine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use an alternative antimalarial if possible. If quinine is required, obtain an ECG, correct electrolytes, and monitor for treatment failure.
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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