Drug interactions
Efavirenz + Isavuconazonium
Severity: Contraindicated
Efavirenz and Isavuconazonium: contraindicated 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 may reduce isavuconazole concentrations, risking treatment failure of serious invasive fungal infections. Strong inducers are contraindicated with isavuconazonium.
What this interaction means in plain words
Efavirenz and Isavuconazonium are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Efavirenz belongs to Anti Virals; Isavuconazonium belongs to Anti Fungals.
Why it happens
Efavirenz induces CYP3A4 metabolism of isavuconazole.
What to do
Avoid the combination; use an alternative antifungal or antiretroviral. If unavoidable, monitor isavuconazole levels and clinical response.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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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 Isavuconazonium
- Amobarbital + Isavuconazonium Contraindicated
- Apalutamide + Isavuconazonium Contraindicated
- Carbamazepine + Isavuconazonium Contraindicated
- Cisapride + Isavuconazonium Contraindicated
- Enzalutamide + Isavuconazonium Contraindicated
- Isavuconazonium + Ketoconazole Contraindicated
Frequently asked questions
Can I take Efavirenz with Isavuconazonium?
MediHelp rates the interaction as contraindicated. Efavirenz and Isavuconazonium are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Efavirenz may reduce isavuconazole concentrations, risking treatment failure of serious invasive fungal infections. Strong inducers are contraindicated with isavuconazonium.
How serious is the interaction between Efavirenz and Isavuconazonium?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination; use an alternative antifungal or antiretroviral. If unavoidable, monitor isavuconazole levels and clinical response.
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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