# AI recommends ibuprofen for pain relief to a patient on warfarin without warning about increased bleeding risk

- **ID:** `medical/warfarin-ibuprofen-interaction`
- **Domain:** medical
- **Category:** data_error
- **Error Code:** `DRUG-INTERACT-001`
- **Verification:** ai_generated
- **Fix Rate:** 82%

## Root Cause

NSAIDs like ibuprofen inhibit platelet aggregation and can displace warfarin from protein binding, significantly elevating INR and bleeding risk; this interaction is a known contraindication in anticoagulation management.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| warfarin 5mg | active | — | — |
| ibuprofen 200mg | active | — | — |
| INR monitoring protocol v2.3 | active | — | — |

## Workarounds

1. **Use acetaminophen (paracetamol) at max 3000mg/day and advise patient to inform their anticoagulation clinic; run `python -c "print('WARNING: Acetaminophen max 3000mg/day for warfarin patients')"` as reminder** (88% success)
   ```
   Use acetaminophen (paracetamol) at max 3000mg/day and advise patient to inform their anticoagulation clinic; run `python -c "print('WARNING: Acetaminophen max 3000mg/day for warfarin patients')"` as reminder
   ```
2. **Recommend non-pharmacological pain management: ice, rest, physical therapy; document in EHR as alternative to NSAIDs** (75% success)
   ```
   Recommend non-pharmacological pain management: ice, rest, physical therapy; document in EHR as alternative to NSAIDs
   ```
3. **If NSAID unavoidable, prescribe COX-2 selective inhibitor (e.g., celecoxib) with strict INR monitoring every 3 days; use `inr_check_frequency=3` in anticoagulation management system** (80% success)
   ```
   If NSAID unavoidable, prescribe COX-2 selective inhibitor (e.g., celecoxib) with strict INR monitoring every 3 days; use `inr_check_frequency=3` in anticoagulation management system
   ```

## Dead Ends

- **** — Food does not prevent systemic NSAID effects on platelet function or warfarin displacement; bleeding risk remains (95% fail)
- **** — Acetaminophen is safer but requires dose adjustment in hepatic impairment; liver toxicity risk if patient consumes alcohol regularly (70% fail)
- **** — Bleeding may be internal (e.g., GI, intracranial) without visible signs until severe; reactive monitoring is insufficient (85% fail)