Drug interactions
Clopidogrel + Efavirenz
Severity: Moderate
Clopidogrel and Efavirenz: moderate 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
Clopidogrel is a prodrug that needs CYP2C19 and other CYP enzymes for activation. Efavirenz has variable effects on these enzymes, and the clinical significance is uncertain. Induction could theoretically increase activation and bleeding, while inhibition could reduce antiplatelet effect.
What this interaction means in plain words
Clopidogrel and Efavirenz can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Clopidogrel belongs to Cardiovascular; Efavirenz belongs to Anti Virals.
Why it happens
Efavirenz modulates CYP2B6, CYP3A4 and CYP2C19 activity, which may alter formation of clopidogrel's active metabolite; the net direction is not well established.
What to do
Avoiding the combination is not usually necessary. Monitor for bleeding or for thrombotic events in high-risk patients such as those with recent stents, and consider an alternative antiplatelet agent if concerned.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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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 Clopidogrel
Frequently asked questions
Can I take Clopidogrel with Efavirenz?
MediHelp rates the interaction as moderate. Clopidogrel and Efavirenz can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Clopidogrel is a prodrug that needs CYP2C19 and other CYP enzymes for activation. Efavirenz has variable effects on these enzymes, and the clinical significance is uncertain. Induction could theoretically increase activation and bleeding, while inhibition could reduce antiplatelet effect.
How serious is the interaction between Clopidogrel and Efavirenz?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoiding the combination is not usually necessary. Monitor for bleeding or for thrombotic events in high-risk patients such as those with recent stents, and consider an alternative antiplatelet agent if concerned.
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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