Drug interactions
Crofelemer + Efavirenz
Severity: Minor
Crofelemer and Efavirenz: minor 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
Crofelemer may inhibit CYP3A4 in the gut, but it is minimally absorbed, so a clinically meaningful rise in efavirenz levels is unlikely.
What this interaction means in plain words
Crofelemer and Efavirenz have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Crofelemer belongs to Gastrointestinal Tract; Efavirenz belongs to Anti Virals.
Why it happens
Possible intestinal CYP3A4 inhibition by crofelemer with negligible systemic exposure.
What to do
No dose adjustment is required; monitor for efavirenz adverse effects if symptoms arise.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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 Crofelemer
- Crofelemer + Ergotamine Moderate
- Alfuzosin + Crofelemer Minor
- Amiodarone + Crofelemer Minor
- Apixaban + Crofelemer Minor
- Aprepitant + Crofelemer Minor
- Armodafinil + Crofelemer Minor
Frequently asked questions
Can I take Crofelemer with Efavirenz?
MediHelp rates the interaction as minor. Crofelemer and Efavirenz have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Crofelemer may inhibit CYP3A4 in the gut, but it is minimally absorbed, so a clinically meaningful rise in efavirenz levels is unlikely.
How serious is the interaction between Crofelemer and Efavirenz?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No dose adjustment is required; monitor for efavirenz adverse effects if symptoms arise.
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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