A response to ‘The thienopyridine derivatives (platelet adenosine diphosphate receptor antagonists), pharmacology and clinical developments’, Kam PCA, Nethery CM, Anaesthesia 2003; 58: 28-35.

The thienopyridine derivatives (platelet adenosine diphosphate receptor antagonists), pharmacology and clinical developments.

The thienopyridines, ticlopidine and clopidogrel, are antiplatelet drugs. They are prodrugs and are metabolised in the liver to active metabolites that are non-competitive antagonists of the platelet adenosine diphosphate receptor, P2Y12. Inhibition of platelet aggregation by these drugs is delayed until 24-48 h after administration, with maximal inhibition achieved after 3-5 days. Recovery of ...

Platelet glycoprotein IIb/IIIa antagonists: pharmacology and clinical developments.

PLATELETS are critical for normal hemostasis and thrombus formation. Thrombus formation initiated by platelets plays a central role in the pathogenesis of acute coronary syndromes (unstable angina and myocardial infarction). Platelets are involved in events causing angioplasty failure and stent thrombosis and may also play an important role in restenosis through the release of potent prothrombo...

ATP derivatives are antagonists of the P2Y1 receptor: similarities to the platelet ADP receptor.

Pharmacological properties of the human P2Y1 receptor transfected in Jurkat cells and of the endogenous receptor in rat brain capillary endothelial cells were analyzed under conditions in which the purity of adenine triphosphate nucleotides was controlled by creatine phosphate/creatine phosphokinase (CP/CPK). ATP, a partial agonist of the receptor, was inactive in the presence of CP/CPK. Result...

Adenosine Receptor Antagonists(1)

Adenosine diphosphate and the measurement of platelet adhesiveness.

Platelet adhesiveness to glass beads was measured in citrated blood at intervals up to two hours after the addition of adenosine diphosphate (A.D.P.). Adhesiveness increased for 15 minutes, fell towards the original level, and then steadily increased. The initial changes were associated with the formation and subsequent dispersal of platelet clumps. The sequence of events resembled the reported...