Biochem/physiol Actions

Standard NSAID and cyclooxygenase (COX) inhibitor. Major metabolites are 4´-hydroxydiclofenac and 5´-hydroxydiclofenac. Has been used as substrate selective for CYP2C9.

Diclofenac sodium salt is a nonsteroidal anti-inflammatory drug (NSAID) that acts as a competitive and irreversible inhibitor of prostaglandin synthetase. Its analgesic and anti-inflammatory activities are based on the prevention of the synthesis of arachinodate metabolites via cyclooxygenase inhibition. It is found to hinder the conversion of arachidonic acid to prostaglandins, which mediate inflammatory process. The NSAIDs are found to inhibit both cyclooxygenase enzymes, COX-1 and COX-2, causing undesirable gastrointestinal effect. Diclofenac sodium also functions as a scavenger of free radicals and serves a radioprotective role in restoring supercoiled form of plasmid DNA damaged by radiation back to normal. Diclofenac sodium is oxidized by the donation of electron and transfer of hydrogen atom. It can be a potential radioprotective agent.