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 .
Aspirin and extended-release dipyridamole versus clopidogrel for recurrent stroke.
BACKGROUND Recurrent stroke is a frequent , disabling event after ischemic stroke . This study compared the efficacy and safety of two antiplatelet regimens -- aspirin plus extended-release dipyridamole ( ASA-ERDP ) versus clopidogrel . METHODS In this double-blind , 2-by-2 factorial trial , we r and omly assigned patients to receive 25 mg of aspirin plus 200 mg of extended-release dipyridamole twice daily or to receive 75 mg of clopidogrel daily . The primary outcome was first recurrence of stroke . The secondary outcome was a composite of stroke , myocardial infa rct ion , or death from vascular causes . Sequential statistical testing of noninferiority ( margin of 1.075 ) , followed by superiority testing , was planned . RESULTS A total of 20,332 patients were followed for a mean of 2.5 years .  Recurrent stroke occurred in 916 patients ( 9.0 % ) receiving ASA-ERDP and in 898 patients ( 8.8 % ) receiving clopidogrel ( hazard ratio , 1.01 ; 95 % confidence interval [ CI ] , 0.92 to 1.11 ) . The secondary outcome occurred in 1333 patients ( 13.1 % ) in each group ( hazard ratio for ASA-ERDP , 0.99 ; 95 % CI , 0.92 to 1.07 ) . There were more major hemorrhagic events among ASA-ERDP recipients ( 419 [ 4.1 % ] ) than among clopidogrel recipients ( 365 [ 3.6 % ] ) ( hazard ratio , 1.15 ; 95 % CI , 1.00 to 1.32 ) , including intracranial hemorrhage ( hazard ratio , 1.42 ; 95 % CI , 1.11 to 1.83 ) . The net risk of recurrent stroke or major hemorrhagic event was similar in the two groups ( 1194 ASA-ERDP recipients [ 11.7 % ] , vs. 1156 clopidogrel recipients [ 11.4 % ] ; hazard ratio , 1.03 ; 95 % CI , 0.95 to 1.11 ) . CONCLUSIONS The trial did not meet the predefined criteria for noninferiority but showed similar rates of recurrent stroke with ASA-ERDP and with clopidogrel . There is no evidence that either of the two treatments was superior to the other in the prevention of recurrent stroke . ( Clinical Trials.gov number , NCT00153062 .
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 .