A comparison of the abilities of acetylsalicylic acid, flurbiprofen and indomethacin to inhibit the release reaction and prostaglandin synthesis in human blood platelets.

1 A quantitative comparison has been made of the abilities of acetylsalicylic acid, flurbiprofen and indomethacin to inhibit the adenosine diphosphate (ADP)-induced platelet release reaction and to inhibit the synthesis of prostaglandins from arachidonic acid. 2 Experiments were carried out on human platelets that had been incubated with the agents in vitro and on platelets obtained from volunteers who had ingested standard doses of the drugs. 3 The results obtained for acetylsalicylic acid show that there is a close relation between the release reaction and the synthesis of prostaglandins in platelets. 4 Flurbiprofen and indomethacin appear to inhibit the release reaction rather more effectively than they inhibit the synthesis of prostaglandins. It is possible that these agents inhibit the release reaction by another mechanism.