Indomethacin, salicylates and prostaglandin binding

Aspirin, salicylic acid and indomethacin reversibly inhibit prostaglandin binding to human serum proteins. This effect was demonstrated in the sera of normal subjects and of rheumatoid arthritis patients treated with aspirin as well as by addition of these drugs to serum in vitro. The displacement of serum prostaglandins by salicylate is likely to affect the kinetics of prostaglandin transport and may facilitate the delivery of prostaglandins from serum to tissue receptors.