Drug interactions
Apalutamide + Efavirenz
Severity: Major
Apalutamide and Efavirenz: major interaction.
Last updated Sources: US FDA label
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
Apalutamide is a strong CYP3A4 inducer and may lower efavirenz levels, risking loss of HIV suppression. Efavirenz, also an inducer, may reduce apalutamide exposure, although the net effect on activity is less clear.
What this interaction means in plain words
Apalutamide and Efavirenz 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.
Apalutamide belongs to Endocrine; Efavirenz belongs to Anti Virals.
Why it happens
Mutual induction of CYP3A4 (and other enzymes) by both drugs increases clearance of each.
What to do
Avoid the combination if possible. If it is necessary, monitor HIV viral load and consider efavirenz concentrations, and watch for reduced apalutamide effect.
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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References
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 Apalutamide
- Apalutamide + Cabotegravir Contraindicated
- Apalutamide + Cobicistat Contraindicated
- Apalutamide + Doravirine Contraindicated
- Apalutamide + Elbasvir / grazoprevir Contraindicated
- Apalutamide + Ensitrelvir Contraindicated
- Apalutamide + Fostemsavir Contraindicated
Frequently asked questions
Can I take Apalutamide with Efavirenz?
MediHelp rates the interaction as major. Apalutamide and Efavirenz 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. Apalutamide is a strong CYP3A4 inducer and may lower efavirenz levels, risking loss of HIV suppression. Efavirenz, also an inducer, may reduce apalutamide exposure, although the net effect on activity is less clear.
How serious is the interaction between Apalutamide and Efavirenz?
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 if possible. If it is necessary, monitor HIV viral load and consider efavirenz concentrations, and watch for reduced apalutamide effect.
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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