Pharmacology: Pharmacodynamics: MEXIB is a nonsteroidal anti-inflammatory drug (NSAID) with a potent highly selective cyclooxygenase-2 (COX-2) inhibitor activity. The drug exhibits anti-inflammatory, analgesic and antipyretic activities in animal models. Since COX-2 has been shown to be primarily responsible for the synthesis of prostanoid mediators of pain, inflammation and fever, selective inhibition of COX-2 by etoricoxib decreases these clinical signs and symptoms with decreased GI toxicity and without effects on platelet function.
Pharmacokinetics: Orally administered etoricoxib is well absorbed. The mean oral bioavailability is approximately 100%. The pharmacokinetics of etoricoxib is linear across the clinical dose range. In some studies, the onset of action of etoricoxib is reported to have occurred as early as 24 minutes after dosing.
Etoricoxib is approximately 92% bound to human plasma protein.
Etoricoxib is extensively metabolized with <1% of a dose recovered in urine as the parent drug. The major route of metabolism to form the 6'-hydroxymethyl derivative is catalyzed by cytochrome P450 (CYP) enzymes.
Elimination of etoricoxib occurs almost exclusively through metabolism followed by renal excretion.
Hepatic insufficiency: Patients with mild/moderate hepatic insufficiency are reported to have similar mean AUC compared to the healthy subjects. There are no clinical or pharmacokinetic data in patients with severe hepatic insufficiency (Child-Pugh score >9).
Renal insufficiency: The pharmacokinetics of etoricoxib in patients with moderate to severe renal insufficiency and patients with end-stage renal disease on Hemodialysis were not reported to be significantly different from those in healthy subjects.
Pediatric Patients: Safety and effectiveness of etoricoxib in paediatric patients (<12 years) have not been established.
Toxicology: Carcinogenicity, mutagenicity and impairment of fertility: This drug was neither found to be carcinogenic nor mutagenic. It is also not reported to impair fertility.