title: The safety of clopidogrel.
abstract: BACKGROUND
  Clopidogrel is an antiplatelet prodrug widely used in acute coronary syndromes and after intravascular stent placement. Acute or chronic use can cause bleeding, a major adverse effect, which can lead to drug discontinuation or noncompliance with therapy.
  
  
  METHODS
  The mechanism of action of clopidogrel, safety of different loading doses of clopidogrel, its use as a solitary antiplatelet agent and concomitant use with other antiplatelet agents such as aspirin and warfarin are discussed. Thrombotic thrombocytopenic purpura, a rare but important adverse event, has also been reviewed. Literature searches including randomized controlled trials were conducted in Medline.
  
  
  RESULTS
  Clinicians will be able to understand the safety profile of using different doses of clopidogrel and the incidence of bleeding when used alone or in combination with other antiplatelet agents.
  
  
  CONCLUSIONS
  Compared to aspirin, clopidogrel when taken alone causes less severe bleeding and less intracranial hemorrhage. Higher loading dose of clopidogrel is associated with increased bleeding. When combined with other antiplatelet agents, risk of bleeding increases, but like any other drug, the risks have to be weighed against potential benefits.
authors.affiliation: Sparrow Hospital, Michigan State University, Lansing, USA.
authors.forename: Kiran Kumar R
authors.initials: KK
authors.lastname: Mangalpally
authors.forename: Neal S
authors.initials: NS
authors.lastname: Kleiman
mesh_terms: D054058:Acute Coronary Syndrome / Q000188:drug therapy; D000077144:Clopidogrel; D064420:Drug-Related Side Effects and Adverse Reactions; D006470:Hemorrhage / Q000139:chemically induced*; D006801:Humans; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects*; D011697:Purpura, Thrombotic Thrombocytopenic / Q000139:chemically induced; D013988:Ticlopidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine