Drug interactions
Deflazacort + Efavirenz
Severity: Major
Deflazacort 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
Deflazacort is activated to 21-desDFZ, which is cleared mainly by CYP3A4. Efavirenz, a moderate-to-strong CYP3A4 inducer, markedly lowers exposure to the active metabolite and may cause loss of efficacy.
What this interaction means in plain words
Deflazacort 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.
Deflazacort belongs to Miscellaneous; Efavirenz belongs to Anti Virals.
Why it happens
Induction of CYP3A4 by efavirenz increases clearance of deflazacort's active metabolite.
What to do
Avoid coadministration, as the labeling advises against moderate or strong CYP3A4 inducers. Consider an alternative antiretroviral regimen or an alternative corticosteroid.
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 Deflazacort
- Adenovirus types 4 and 7 live + Deflazacort Contraindicated
- Bcg vaccine live + Deflazacort Contraindicated
- Deflazacort + Influenza virus vaccine quadrivalent intranasal Contraindicated
- Deflazacort + Measles mumps and rubella vaccine Contraindicated
- Deflazacort + Measles mumps and rubella vaccine live Contraindicated
- Deflazacort + Measles mumps rubella and varicella vaccine live Contraindicated
Frequently asked questions
Can I take Deflazacort with Efavirenz?
MediHelp rates the interaction as major. Deflazacort 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. Deflazacort is activated to 21-desDFZ, which is cleared mainly by CYP3A4. Efavirenz, a moderate-to-strong CYP3A4 inducer, markedly lowers exposure to the active metabolite and may cause loss of efficacy.
How serious is the interaction between Deflazacort 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 coadministration, as the labeling advises against moderate or strong CYP3A4 inducers. Consider an alternative antiretroviral regimen or an alternative corticosteroid.
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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