Drug interactions
Efavirenz + Regorafenib
Severity: Major
Efavirenz and Regorafenib: 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 is an inducer of CYP3A4 and may lower regorafenib exposure while changing the ratio of its active metabolites. This may reduce antitumour efficacy and alter the toxicity profile.
What this interaction means in plain words
Efavirenz and Regorafenib 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; Regorafenib belongs to Oncology.
Why it happens
Efavirenz induces CYP3A4, accelerating regorafenib metabolism.
What to do
Avoid concomitant use and choose an antiretroviral without enzyme-inducing effects, such as an integrase inhibitor-based regimen. If unavoidable, monitor tumour response and adverse effects closely.
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 Regorafenib
Frequently asked questions
Can I take Efavirenz with Regorafenib?
MediHelp rates the interaction as major. Efavirenz and Regorafenib 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 is an inducer of CYP3A4 and may lower regorafenib exposure while changing the ratio of its active metabolites. This may reduce antitumour efficacy and alter the toxicity profile.
How serious is the interaction between Efavirenz and Regorafenib?
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 concomitant use and choose an antiretroviral without enzyme-inducing effects, such as an integrase inhibitor-based regimen. If unavoidable, monitor tumour response and adverse effects closely.
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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