Clopidogrel is an
ADP receptor antagonist that is indicated for the reduction of atherosclerotic events including
myocardial infarction,
ischaemic stroke and vascular death in patients with
atherosclerosis manifested by recent
stroke,
myocardial infarction or established
peripheral vascular disease. In the 19 185 patients enrolled in the multicentre, randomised double-blind CAPRIE study, the annual risk of the combined end-point of
ischaemic stroke,
myocardial infarction and death from
vascular disease (vascular death) was significantly lower during treatment with
clopidogrel 75 mg/day than
aspirin 325 mg/day [5.3 vs 5.8%/year, respectively; relative risk reduction (RRR) 8.7%, p = 0.043] after a mean follow-up of 1.9 years.
Clopidogrel provided even greater reductions in the risk of recurrent ischaemic events than
aspirin in patients with a history of
coronary artery bypass surgery,
diabetes mellitus and in those receiving concomitant
lipid-lowering
therapy. Moreover there was a significant reduction in the incidence of hospitalisation in patients treated with
clopidogrel. In a patient population (Saskatchewan, Canada) with a greater risk of ischaemic events than the CAPRIE study population, the number of patients needed to be treated with
clopidogrel to prevent 1 ischaemic event was estimated to be 70 (vs 200 in the CAPRIE study). In randomised trials and registry surveys,
clopidogrel 75 mg/day plus
aspirin had similar efficacy (as measured by adverse cardiac outcomes) to
ticlopidine 250mg twice daily plus
aspirin during the 30 days after placement of intracoronary
stents. Tolerability of
clopidogrel was significantly better than
ticlopidine in the randomised, double-blind CLASSICS study. Among patients treated with
clopidogrel or
aspirin in the CAPRIE study, the overall gastrointestinal tolerability of
clopidogrel was generally better than that of
aspirin; the frequency of gastrointestinal haemorrhage was significantly lower among patients treated with
clopidogrel than
aspirin. Diarrhoea,
rash and
pruritus were significantly more common with
clopidogrel than
aspirin.
CONCLUSION: