Several substances have been found to inhibit some actions of prostaglandins. Three principal types have shown characteristics of specific, competitive prostaglandin antagonism. These are dibenzoxazepine derivatives (especially SC-19220), 7-oxa-prostaglandin analogs (especially 7-oxa-13-prostynoic acid), and phosphorylated polymers of phloretin (especially polyphloretin phosphate).
As more is learned about prostaglandins, more evidence is accumulating that they may be involved in certain pathological conditions. This has led to suggestions that prostaglandin antagonists may be useful therapeutic agents for treating conditions such as habitual abortion, premature labor, diarrhea, cerebral vasospasm, fever, bone resorption, sickle cell anemia, obstructive lung diseases, inflammation, uveitis, and glaucoma. No proved therapeutic utility has been established for prostaglandin antagonists, but research in animals has indicated that some of the suggested uses may be practical.
John H. Sanner. Substances That Inhibit the Actions of Prostaglandins. Arch Intern Med. 1974;133(1):133–146. doi:10.1001/archinte.1974.00320130135011