New antiplatelet agents.
Aspirin is an established therapy for the management of acute myocardial infarction (AMI) and unstable angina. Secondary prevention with chronic aspirin therapy is also indicated for patients with stable angina. Aspirin inhibits cyclo-oxygenase-I, a key enzyme in the biosynthetic pathway leading to the production of thromboxane A2. It therefore inhibits only one of the many activation pathways leading to platelet aggregation. Other antiplatelet agents that have also been evaluated in clinical trials include ticlopidine and clopidogrel, which inhibit adenosine diphosphate-mediated platelet aggregation, but these agents are known to be effective against only one of the 90 known agonists that stimulate platelet aggregation. The final common pathway for platelet aggregation involves the glycoprotein IIb/IIIa receptor combining with fibrinogen. Several inhibitors of the glycoprotein IIb/IIIa receptor have been developed and have an important role as adjunctive therapy in angioplasty. Recent trials have been performed in patients with unstable angina, and trials of adjunctive therapy are currently underway in patients receiving thrombolysis for AMI, and for secondary prevention. These drugs have various different features, including specificity for blockade of the glycoprotein IIb/IIIa receptor, half life, duration of the haemostatic effect and potential for antigenicity. Recently concluded and ongoing trials of both intravenous and oral agents are expected to provide further support for the introduction of these agents into clinical management of patients with acute coronary syndromes.
Green Lane Hospital, Auckland, New Zealand.
H D
HD
White
J K
JK
French
C J
CJ
Ellis
D000077284:Abciximab; D000789:Angina, Unstable / Q000188:drug therapy* / Q000628:therapy; D015906:Angioplasty, Balloon, Coronary; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D001241:Aspirin / Q000494:pharmacology / Q000627:therapeutic use; D000077144:Clopidogrel; D005260:Female; D005343:Fibrinolytic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000627:therapeutic use; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000628:therapy; D010974:Platelet Aggregation / Q000502:physiology; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000187:drug effects*; D016032:Randomized Controlled Trials as Topic; D015912:Thrombolytic Therapy; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use*
D000911:Antibodies, Monoclonal; D005343:Fibrinolytic Agents; D007140:Immunoglobulin Fab Fragments; D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin; D000077284:Abciximab