Clopidogrel is indicated in-

• Unstable angina
• Stroke
• Non ST-elevation Myocardial infarction
• Patients with ST-elevation myocardial infarction (STEMI) when managed with either primary or delayed PCI

Angina

Myocardial Infarction

Stroke

• Recent MI, Recent Stroke, or Established Peripheral Arterial Disease: The recommended daily dose of Clopidogrel is 75 mg once daily. 
• Acute Coronary Syndrome: For patients with non-ST-segment elevation acute coronary syndrome (unstable angina/non-Q wave MI), Clopidogrel should be initiated with a single 300-mg loading dose and then continued at 75 mg once daily. Aspirin (75 mg-325 mg once daily) should be initiated and continued in combination with Clopidogrel. 

Side effects of clopidogrel include-

• Bleeding, including life-threatening and fatal bleeding
• Thrombotic thrombocytopenic purpura

Bleeding

Purpura

• Clopidogrel can cause significant, sometimes fatal, bleeding.
• Do not use Clopidogrel in patients with active pathological bleeding or a history of transient ischemic attack or stroke.
• In patients ≥ 75 years of age, Clopidogrel is generally not recommended, because of the increased risk of fatal and intracranial bleeding and uncertain benefit, except in high-risk situations (patients with diabetes or a history of prior MI) where its effect appears to be greater and its use may be considered.
• Do not start Clopidogrel in patients likely to undergo urgent coronary artery bypass graft surgery (CABG).  When possible, discontinue Clopidogrel at least 7 days prior to any surgery. Additional risk factors for bleeding include:
  • body weight < 60 kg
  • propensity to bleed
  • concomitant use of medications that increase the risk of bleeding (e.g., warfarin, heparin, fibrinolytic therapy, chronic use of non-steroidal anti-inflammatory drugs [NSAIDS])
• Suspect bleeding in any patient who is hypotensive and has recently undergone coronary angiography, percutaneous coronary intervention (PCI), CABG, or other surgical procedures in the setting of Clopidogrel. If possible, manage bleeding without discontinuing Clopidogrel.  Discontinuing Clopidogrel, particularly in the first few weeks after acute coronary syndrome, increases the risk of subsequent cardiovascular events.
• Discontinuation of Clopidogrel: Premature discontinuation increases risk of stent thrombosis, MI, and death.
• Thrombotic thrombocytopenic purpura (TTP): TTP has been reported with Clopidogrel.