Drug interactions
Efavirenz + Parecoxib
Severity: Minor
Efavirenz and Parecoxib: 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
The legacy direction of this interaction is questionable, since efavirenz is more typically an inducer than an inhibitor of CYP2C9. The effect on parecoxib's active metabolite valdecoxib is not well characterized.
What this interaction means in plain words
Efavirenz and Parecoxib have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Mechanism is not firmly established; effects on CYP2C9 metabolism of valdecoxib are possible but uncertain.
What to do
No routine adjustment is needed; monitor analgesic response and adverse effects such as GI or renal events.
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
Frequently asked questions
Can I take Efavirenz with Parecoxib?
MediHelp rates the interaction as minor. Efavirenz and Parecoxib have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. The legacy direction of this interaction is questionable, since efavirenz is more typically an inducer than an inhibitor of CYP2C9. The effect on parecoxib's active metabolite valdecoxib is not well characterized.
How serious is the interaction between Efavirenz and Parecoxib?
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 routine adjustment is needed; monitor analgesic response and adverse effects such as GI or renal events.
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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