In vitro activity: Tirofiban (MK-383, Aggrastat) is a nonpeptide derivative of tyrosine that selectively inhibits the GP-IIb/IIIa receptor, with minimal effects on the ɑvβ3 vitronectin receptor. It inhibits platelet aggregation of gel-filtered platelets induced by 10 μM ADP with IC50 of 9 nM, but the IC50 for inhibition of human umbilical vein adhesion to vitronectin, which depends on ɑvβ3 vitronectin receptors, is 62 μmol/L.

Kinase Assay: Tirofiban hydrochloride monohydrate is a potent non-peptide, glycoprotein IIb/IIIa (integrins alphaIIbbetaIII) antagonist IC50 value: Target: integrin IIb/IIIa Tirofiban hydrochloride monohydrate blocks platelet aggregation and thrombus formation. Tirofiban is an antithrombotic used in the treatment of unstable angina. Tirofiban, in a concentration-dependent manner reduced platelet aggregation evoked by ADP (IC50 approximately 70 ng/ml), collagen (IC50 approximately 200 ng/ml), and thrombin (IC50 approximately 5,000 ng/ml).