Drug interactions
Efavirenz + Levoketoconazole
Severity: Moderate
Efavirenz and Levoketoconazole: 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
Levoketoconazole inhibits CYP3A4 and may raise efavirenz levels, though efavirenz is metabolized by several pathways including CYP2B6. Efavirenz may in turn reduce levoketoconazole exposure, possibly lessening its cortisol-lowering effect. Levoketoconazole also prolongs the QT interval, and efavirenz may add to this.
What this interaction means in plain words
Efavirenz and Levoketoconazole 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; Levoketoconazole belongs to Endocrine.
Why it happens
Levoketoconazole inhibits CYP3A4 while efavirenz induces CYP3A4; additive QT effects are also possible.
What to do
Monitor for efavirenz CNS adverse effects, cortisol control and ECG. Correct electrolytes and consider an alternative if the QTc lengthens.
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 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 Levoketoconazole
- Alfuzosin + Levoketoconazole Contraindicated
- Alprazolam + Levoketoconazole Contraindicated
- Amiodarone + Levoketoconazole Contraindicated
- Avanafil + Levoketoconazole Contraindicated
- Cisapride + Levoketoconazole Contraindicated
- Clarithromycin + Levoketoconazole Contraindicated
Frequently asked questions
Can I take Efavirenz with Levoketoconazole?
MediHelp rates the interaction as moderate. Efavirenz and Levoketoconazole 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. Levoketoconazole inhibits CYP3A4 and may raise efavirenz levels, though efavirenz is metabolized by several pathways including CYP2B6. Efavirenz may in turn reduce levoketoconazole exposure, possibly lessening its cortisol-lowering effect. Levoketoconazole also prolongs the QT interval, and efavirenz may add to this.
How serious is the interaction between Efavirenz and Levoketoconazole?
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 efavirenz CNS adverse effects, cortisol control and ECG. Correct electrolytes and consider an alternative if the QTc lengthens.
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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