Coxibs + oral anticoagulants: risk of interaction

(1) Concomitant use of a classical NSAID and a vitamin K antagonist carries a risk of bleeding. Some NSAIDs, and especially phenylbutazone, increase the INR. NSAIDs have antiplatelet effects and can cause gastrointestinal erosions and bleeding. (2) Celecoxib or rofecoxib in combination with an oral anticoagulant has been reported to increase the INR and, in some cases, to cause bleeding. The "coxibs" can also cause bleeding-prone gastrointestinal lesions. (3) If a coxib is combined with an oral anticoagulant then the INR must be watched closely.