Selexa-400 Mechanism of Action

Pharmacology: Pharmacodynamics: Celecoxib is a nonsteroidal anti-inflammatory drug (NSAID) that is a selective inhibitor of cyclooxygenase-2 (COX-2). Celecoxib inhibits prostaglandin synthesis by decreasing the activity of the enzyme, COX-2, which results in decreased formation of prostaglandin precursors; has antipyretic, analgesic, and anti-inflammatory properties. Celecoxib does not inhibit cyclooxygenase-1 (COX-1) at therapeutic concentrations.
Pharmacokinetics: Absorption: Celecoxib is well absorbed from gastrointestinal tract, peak plasma concentrations of the drug generally are attained within 3 hours after dosing in fasting individuals.
Distribution: The apparent volume of distribution of celecoxib at steady state is about 400 L (7.14 L/kg). At therapeutic plasma concentrations, celecoxib is about 97% bound to plasma protein.
Elimination: The plasma elimination half-life of celecoxib following oral administration of a single 200 mg dose under fasting conditions is about 11 hours, and the apparent clearance of the drug is about 500 mL/minute. Celecoxib is metabolized in liver to inactive metabolites principally by the cytochrome P-450 (CYP) isoenzyme 2C9. Celecoxib is excreted in urine (27%) and feces (57%); less than 3% of dose is excreted unchanged.