Indications

Clopidogrel is licensed to be used in patients with the following atherosclerotic complications:

• coronary artery disease
• cerebrovascular disease
• peripheral vascular disease

The CAPRIE study shows a small but significant reduction in risk of atherosclerotic events in patients taking clopidogrel vs. aspirin.

In practise many clinicians will prescribe clopidogrel rather than aspirin in the following circumstances:

• when events occur while the patient is taking aspirin
• in patients with multiple atherosclerotic risk factors
• in patients with atherosclerotic complications in multiple vascular territories

Clopidogrel has been granted a licence extension (in the UK) and can now be prescribed (in combination with aspirin) for patients suffering from acute coronary syndrome (i.e. non-Q-wave myocardial infarction or unstable angina). This licence extension was based on the results of the CURE study. The optimum duration of treatment has not been established - however clinical trial data support use for up to 12 months, and maximum benefit was seen at 3 months (1).

There is evidence concerning the effectiveness of use of clopidogrel in ST-elevation myocardial infarction:

• clopidogrel is also indicated in patients < 75 years of age with ST-elevation myocardial infarction based on the CLARITY-TMI study (2):
  • the CLARITY-TMI 28 study revealed that, in patients with an ST-elevation myocardial infarction and who were receiving aspirin and standard fibrinolytic therapy, the addition of clopidogrel lowered the composite rate of an occluded infarct related artery, recurrent MI and all cause mortality
  • there was not any associated clinically relevant excess bleeding associated with use of clopidogrel. However this trial excluded patients >= 75 years of age and thus the population most at risk and vulnerable to haemorrhage was not studied
  • clopidogrel treatment was continued up to and including the day of coronary angiography, or, if the patients were not having angiography, then for either 8 days or until hospital discharge

Reference:

1. MeReC Extra (November 2002), 7.
2. Sabatine MS et al. Addition of clopidogrel to aspirin and fibrinolytic therapy for myocardial infarction with ST-segment elevation. N Eng J Med 2005; 352:1179-89