Etoricoxib is a highly selective, second-generation cyclooxygenase-2 (COX-2) inhibitor, classified as a nonsteroidal anti-inflammatory drug (NSAID). It is prescribed for its potent analgesic, anti-inflammatory, and antipyretic properties. The 120mg strength is primarily indicated for acute gouty arthritis and chronic conditions like osteoarthritis and rheumatoid arthritis requiring higher anti-inflammatory effect. It offers the advantage of once-daily dosing due to its long half-life and is associated with a lower risk of gastrointestinal (GI) adverse events compared to non-selective NSAIDs, though it carries a class-related increased risk of cardiovascular (CV) thrombotic events.
Adult: Osteoarthritis: 60 mg once daily. Rheumatoid Arthritis: 90 mg once daily. Ankylosing Spondylitis: 90 mg once daily. Acute Gouty Arthritis: 120 mg once daily for a maximum of 8 days. Acute Pain/Primary Dysmenorrhea: 120 mg once daily for a maximum of 3 days.
Note: Can be taken with or without food. Food may delay absorption but does not significantly affect overall bioavailability. Swallow the tablet whole with a glass of water. Do not crush or chew. For acute gout, the 120mg dose should be used only for the acute flare duration (max 8 days), then the dose should be reduced or discontinued.
Etoricoxib selectively inhibits the enzyme cyclooxygenase-2 (COX-2), which is induced during inflammation and is responsible for the synthesis of prostanoids (prostaglandins, prostacyclin, thromboxane). By inhibiting COX-2, it reduces the production of prostaglandin E2 (PGE2) at the site of inflammation, thereby exerting anti-inflammatory, analgesic, and antipyretic effects. Its high selectivity (COX-2:COX-1 ratio >106) results in minimal inhibition of constitutively expressed COX-1 in the gastrointestinal tract and platelets, leading to a better GI safety profile and no effect on platelet aggregation.
Pregnancy: Category C (US FDA). Avoid use in first and second trimesters unless potential benefit justifies potential risk. Contraindicated in the third trimester (risk of premature closure of ductus arteriosus, oligohydramnios, inhibition of labor, increased risk of maternal and neonatal bleeding).
Driving: May cause dizziness, vertigo, somnolence, or visual disturbances in some patients. Patients should be cautioned about operating machinery or driving if they experience these effects.
| Warfarin/Acenocoumarol | Increased risk of bleeding due to potential pharmacodynamic interaction (no PK effect on INR, but anti-inflammatory effect may mask signs of bleeding). | Major |
| Aspirin (low-dose cardioprotective) | Concomitant use increases risk of GI ulceration and bleeding without added therapeutic benefit. Etoricoxib does not inhibit platelet aggregation. | Major |
| Lithium | Etoricoxib may decrease renal lithium clearance, leading to increased lithium plasma levels and risk of toxicity. | Major |
| Methotrexate | NSAIDs may reduce renal excretion of methotrexate, increasing its blood levels and risk of hematologic and GI toxicity, especially with high-dose methotrexate. | Major |
| Diuretics (Furosemide, Thiazides) | Reduced diuretic and antihypertensive efficacy. Increased risk of renal impairment due to decreased prostaglandin-mediated renal blood flow. | Moderate |
| ACE Inhibitors (Ramipril, Enalapril) / ARBs (Losartan) | Reduced antihypertensive efficacy. Increased risk of renal impairment, especially in volume-depleted patients. | Moderate |
| Ciclosporin, Tacrolimus | Increased risk of nephrotoxicity. | Moderate |
| SSRIs/SNRIs (Fluoxetine, Venlafaxine) | Increased risk of upper GI bleeding. | Moderate |
| Corticosteroids (Prednisolone) | Increased risk of GI ulceration and bleeding. | Moderate |
| Rifampicin | Strong CYP3A4 inducer; may decrease etoricoxib plasma levels, reducing efficacy. | Moderate |
| Ketoconazole, Itraconazole | Strong CYP3A4 inhibitors; may increase etoricoxib plasma levels. Clinical significance unclear but monitor for adverse effects. | Minor |