RiteMED Naproxen Sodium Mechanism of Action

Non-Steroidal Anti-Inflammatory Drug.
Pharmacology: Pharmacokinetics: Naproxen and naproxen sodium are readily absorbed from the gastrointestinal tract. Peak plasma concentrations are attained about 1 to 2 hours after ingestion of naproxen sodium and in about 2 to 4 hours after ingestion of naproxen. Food reduces the rate but not the extent of absorption. Naproxen and naproxen sodium are also well absorbed rectally. At therapeutic concentrations naproxen is more than 99% bound to plasma proteins. Plasma concentrations of naproxen increase proportionally with dose up to about 500 mg daily; at higher doses there is an increase in clearance caused by saturation of plasma proteins. Naproxen diffuses into synovial fluid; it crosses the placenta and is distributed into breast milk in small amounts. Naproxen has a plasma elimination half-life of about 12 to 17 hours. About 95% of a dose is excreted in urine as naproxen and 6-O-desmethylnaproxen and their conjugates. Less than 5% of a dose appears in the feces.