Major
celecoxib × Warfarin
Selective COX-2 inhibitor (coxib)×Vitamin K antagonist anticoagulants
Mechanism
Celecoxib is metabolised by CYP2C9 – the same route as S-warfarin (the more active form). Enzyme competition raises INR. Celecoxib also moderately injures the gastric mucosa.
Symptoms
Gum bleeding, epistaxis, bruising without trauma, blood in urine or stool, menorrhagia. Severe cases include gastrointestinal or intracranial haemorrhage. Risk rises in patients over 65 and with prior peptic ulcer disease.
Management
The combination is acceptable when chronic NSAID therapy is needed. Check INR at 1 and 2 weeks after starting celecoxib, then monthly. PPI cover with pantoprazole is mandatory.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.