Critical Pharmacodynamic Warning
ibuprofen weakly inhibits the 2C9 metabolic pathway.
When patients take ibuprofen concurrently with drugs metabolized by 2C9, the risk of adverse effects may significantly increase. This interaction affects drug clearance and systemic exposure, potentially leading to toxicity or reduced therapeutic efficacy.
Clinical Impact: As a weak inhibitor, ibuprofen can alter the metabolism of substrate drugs, requiring careful monitoring and potential dose adjustments.
Clinical Overview for ibuprofen
This page outlines known interaction pathways involving ibuprofen, focusing primarily on its profile as a Weak inhibitor affecting the 2C9 pathway.
Enzyme Interaction Profile
ibuprofen demonstrates weak inhibitor potency against 2C9. This level of inhibition causes ≥1.25-fold but <2-fold increase in AUC of substrate drugs.
Inhibitor
A substance that slows down or prevents an enzyme from metabolizing a drug. Inhibitors can lead to increased drug concentrations in the body, potentially causing toxicity or enhanced therapeutic effects.
Clinical Example: ibuprofen weakly inhibits 2C9Inducer
A substance that speeds up enzyme activity, causing drugs to be cleared from the body faster. Inducers can reduce drug effectiveness by lowering concentrations below therapeutic levels.
Interaction Details
| Drug Name | ibuprofen |
| Affected Enzyme | 2C9 |
| Inhibitor Strength | Weak inhibitor Low Severity |
| Inducers | No inducers listed |
| Inhibitors | quercetin |
Clinical Recommendations
Generally safe for co-administration. Routine monitoring recommended.
- Therapeutic drug levels
- Adverse effect monitoring
- Clinical response assessment
- Consider dose reduction
- Evaluate alternative therapies
- Adjust based on response
Quick Facts
10206
2C9
Enzyme Inhibition
Low Severity
Clinical Significance
Minor clinical significance. Routine monitoring sufficient.
Information Sources
- FDA Drug Interaction Database
- Clinical Pharmacology Guidelines
- Pharmaceutical Labeling Information
- Published Clinical Studies
Last updated: June 15, 2026