Compared with aspirin , thienopyridines significantly reduced gastrointestinal adverse effects .
However , thienopyridines increased the odds of skin rash and diarrhoea , ticlopidine more than clopidogrel .
Allocation to ticlopidine , but not clopidogrel , significantly increased the odds of neutropenia .
The thienopyridine derivatives are at least as effective as aspirin in preventing serious vascular events in patients at high risk , and possibly somewhat more so .
However , the size of any additional benefit is uncertain and could be negligible .
Clopidogrel has a more favourable adverse effects profile than ticlopidine and so is the thienopyridine of choice .
BACKGROUND Aspirin is the most widely studied and prescribed antiplatelet agent for preventing serious vascular events , reducing the odds of such events among high vascular risk patients by about a quarter .
Thienopyridine derivatives inhibit platelet activation by a different mechanism and so may be more effective .
OBJECTIVES To determine the effectiveness and safety of thienopyridine derivatives ( ticlopidine and clopidogrel ) versus aspirin for preventing serious vascular events ( stroke , myocardial infa rct ion ( MI ) or vascular death ) in patients at high risk , and specifically in patients with a previous TIA or ischaemic stroke .
Effects of Combined Therapy With Clopidogrel and Acetylsalicylic Acid on Platelet Glycoprotein Expression and Aggregation
This study aim ed to compare the effects of clopidogrel , acetylsalicylic acid ( ASA ) , and the combination of both substances on platelet aggregation and expression of platelet membrane glycoproteins in patients with chronic coronary artery disease . We investigated platelet activation by flow cytometry and by platelet aggregation and disaggregation in 60 patients r and omly assigned to 3 treatment groups : ASA , clopidogrel , combination of clopidogrel and ASA , treated for 14 days . Adenosine diphosphate (ADP)–induced expression of P-selectin and of PAC-1 was significantly reduced after 2 wk of clopidogrel but not of ASA treatment . Treatment with clopidogrel reduced the ADP-induced platelet aggregation . The combination of clopidogrel and ASA did not increase the inhibition of platelet activation compared with clopidogrel alone . A significant increase in platelet disaggregation was observed with clopidogrel alone and was more pronounced with the combination of clopidogrel and ASA . ADP-induced platelet degranulation , activation of GPIIb/IIIa receptor , and aggregation in vivo are effectively inhibited by clopidogrel . The significantly increased disaggregation under clopidogrel and ASA suggests that the combined therapy may be superior to the monotherapy in patients with coronary artery disease and a high risk for vascular events
Compared with aspirin , thienopyridines significantly reduced gastrointestinal adverse effects .
However , thienopyridines increased the odds of skin rash and diarrhoea , ticlopidine more than clopidogrel .
Allocation to ticlopidine , but not clopidogrel , significantly increased the odds of neutropenia .
The thienopyridine derivatives are at least as effective as aspirin in preventing serious vascular events in patients at high risk , and possibly somewhat more so .
However , the size of any additional benefit is uncertain and could be negligible .
Clopidogrel has a more favourable adverse effects profile than ticlopidine and so is the thienopyridine of choice .
BACKGROUND Aspirin is the most widely studied and prescribed antiplatelet agent for preventing serious vascular events , reducing the odds of such events among high vascular risk patients by about a quarter .
Thienopyridine derivatives inhibit platelet activation by a different mechanism and so may be more effective .
OBJECTIVES To determine the effectiveness and safety of thienopyridine derivatives ( ticlopidine and clopidogrel ) versus aspirin for preventing serious vascular events ( stroke , myocardial infa rct ion ( MI ) or vascular death ) in patients at high risk , and specifically in patients with a previous TIA or ischaemic stroke .