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 .
Gastroduodenal tolerance of 75 mg clopidogrel versus 325 mg aspirin in healthy volunteers. A gastroscopic study.
BACKGROUND Clopidogrel is a new antiplatelet agent that offers increased protection over aspirin in preventing vascular ischaemic events in patients with symptomatic atherosclerosis . In a large , r and omized , international study of clopidogrel and aspirin ( n = 19,185 patients )  clopidogrel was associated with a lower incidence of gastrointestinal adverse events , including gastrointestinal haemorrhage and hospitalizations because of gastrointestinal haemorrhage . The aim of the study was to determine whether macroscopic differences in the gastric mucosa between  aspirin- and clopidogrel-treated subjects could be detected by gastroscopy after short-term treatment . METHODS Thirty-six healthy volunteers were r and omized in a double-blind , double-dummy , parallel design , to 75 mg/day of clopidogrel or 325 mg/day of aspirin for 8 days . Gastroscopy was performed at base line before administration of study drug and directly after treatment completion . Gastroduodenal effects were measured in accordance with a modified Lanza scale . RESULTS At base line no difference between the groups was detected ( median Lanza score , 0.0 in both groups ) . At the end of treatment the aspirin group showed a median score of 7.5 , and the clopidogrel group showed an unchanged median score of 0.0 ( P < 0.001 ) . In the aspirin group 13 individuals reported 19 adverse events versus 8 individuals and 13 adverse events for clopidogrel , with approximately half of the adverse events being gastrointestinal in each group . No serious adverse events were reported . CONCLUSION In contrast to aspirin , short-term treatment with clopidogrel does not induce macroscopic changes in the gastroduodenal mucosa . The study results show that in patients without gastroduodenal disease  clopidogrel , but not aspirin , does not induce any gastroscopically evident erosions during short-term treatment
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 .