Sunprox Mechanism of Action

Pharmacology: Naproxen sodium is a non-steroidal anti-inflammatory drug with analgesic and antipyretic activity. The exact mechanisms of action have not been clearly established, but many of the actions appear to be associated principally with the inhibition of prostaglandin synthesis. Naproxen inhibits the synthesis of prostaglandins in body tissues by inhibiting cyclooxygenase, an enzyme that catalyzes the formation of prostaglandin precursors (endoperoxides) from arachidonic acid. Prostaglandins appear to sensitize pain receptors to mechanical stimulation and to other chemical mediators (e.g. bradykinin, histamine).
Naproxen sodium is rapidly and completely absorbed from the gastrointestinal tract. After administration of naproxen sodium, peak plasma levels of naproxen anion are attained in 1 to 2 hours, with steady state conditions normally achieved after 4 - 5 doses. The mean biological half-life of the anion in humans is approximately 13 hours and at the therapeutic levels it is greater than 99% albumin bound. Approximately 95% of the dose is excreted in the urine, primarily as naproxen, 6-0-desmethylnaproxen or their conjugates. The rate of excretion has been found to coincide closely with the rate of drug disappearance from the plasma.