Abstract
Studies of the aggregation of human platelets indicate that compounds GP 44296 and GP 45840 inhibit the secondary phase of ADP-induced aggregation and collagen-induced aggregation; GP 44296 also inhibits the primary phase of ADP-induced aggregation. Our results suggest that these compounds are more active on platelet behavior in vitro than phenylbutazone, oxyphenbutazone, and sulfinpyrazone.