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 .
A randomized trial comparing ticlopidine hydrochloride with indobufen for the prevention of stroke in high-risk patients (TISS Study). Ticlopidine Indobufen Stroke Study.
Two treatments , based on either ticlopidine or indobufen at their optimal individual daily dose ( median dose : 250 and 200 mg/day , respectively ) , were compared in an open r and omized multicenter trial in patients at risk of cerebral ischemia ( men and women , aged 39 to 80 years , who had experienced in the month before entry into the study transient ischemic attack or amaurosis fugax or minor stroke ) . The total number of patients screened was 4033 ; 1632 were enrolled , 821 r and omized to ticlopidine , 811 to indobufen .  The overall frequency of the composite primary end-point ( stroke , myocardial infa rct ion , and death from any cause ) was 4.4 % . The ticlopidine-based regimen proved significantly better than the indobufen one in preventing the composite of fatal and non fatal events ( 49.6 % relative risk reduction ) , or death alone ( 54.4 % relative risk reduction ) . The two groups had similar percentages of adverse events ( 5.5 % and 6.4 % for ticlopidine and indobufen group , respectively ) with withdrawals because of adverse events in 3.4 % and 2.5 % ; gastrointestinal disorders and bleeding were more frequent in the indobufen group , whereas rash and abnormal liver function were more frequent in the ticlopidine one
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 .