Drug interactions
Efavirenz + Pretomanid
Severity: Major
Efavirenz and Pretomanid: 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
Efavirenz markedly lowers pretomanid exposure, risking reduced antimycobacterial effect, and both drugs may be hepatotoxic. This risks treatment failure of drug-resistant tuberculosis and added liver injury.
What this interaction means in plain words
Efavirenz and Pretomanid 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; Pretomanid belongs to Anti Bacterial.
Why it happens
CYP3A4 induction accelerates pretomanid metabolism, with additive hepatotoxic potential.
What to do
Avoid the combination and use an alternative antiretroviral such as dolutegravir-based therapy. Monitor liver function if both are used.
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 Pretomanid
Frequently asked questions
Can I take Efavirenz with Pretomanid?
MediHelp rates the interaction as major. Efavirenz and Pretomanid 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 markedly lowers pretomanid exposure, risking reduced antimycobacterial effect, and both drugs may be hepatotoxic. This risks treatment failure of drug-resistant tuberculosis and added liver injury.
How serious is the interaction between Efavirenz and Pretomanid?
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 the combination and use an alternative antiretroviral such as dolutegravir-based therapy. Monitor liver function if both are used.
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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