Warfarin: Monitoring of INR values should be done when etoricoxib treatment is initiated or changed particularly in the first few days, in patients receiving warfarin or similar agents.
Rifampin: Co-administration with rifampin may cause decrease in etoricoxib plasma area under the curve (AUC).
Methotrexate: Monitoring for methotrexate-related toxicity should be considered when etoricoxib at doses greater than 90 mg daily and methotrexate are administered concomitantly.
Angiotensin Converting Enzyme (ACE) inhibitors: COX-2 selective inhibitors may diminish the antihypertensive effect of ACE inhibitors.
Lithium: COX-2 selective inhibitors may increase plasma lithium levels.
Aspirin: etoricoxib can be used concomitantly with low dose aspirin for cardiovascular prophylaxis. However, it may result in an increased rate of GI ulceration or other complications compared to use of etoricoxib alone.
Oral contraceptives: Increase in ethinyl estradiol (EE) concentration is reported when concomitantly used with etoricoxib.
Antacids and ketoconazole (a potent inhibitor of CYP3A4) reportedly did not have clinically important effects on the pharmacokinetics of etoricoxib.