title: Clopidogrel in interventional cardiology: questions answered and questions remaining.
abstract: Clopidogrel is appropriate as a replacement for ticlopidine when used in combination with acetylsalicylic acid in the setting of percutaneous coronary intervention (PCI). Compared with ticlopidine, clopidogrel has comparable efficacy in reducing adverse cardiac events and a lower risk of hematological toxicity; both medications have been associated with rare cases of the very serious syndrome of thrombotic thrombocytopenic purpura. Clopidogrel should preferably be initiated with a loading dose of 300 mg before PCI, because most cases of thrombotic stent occlusion occur shortly after stent implantation, and attainment of target platelet inhibition is delayed for several days if a loading dose is not given. Bypass surgery in patients recently treated with clopidogrel appears to be associated with a significant increase in hemorrhagic complications. Long term therapy with clopidogrel after PCI may decrease late thrombotic stent occlusion and late vascular events; this hypothesis is currently being evaluated in randomized trials. By inhibiting platelet activation, clopidogrel may have a mechanism of benefit that is independent of the potent inhibition of platelet aggregation produced by the glycoprotein IIb/IIIa inhibitors.
authors.affiliation: Schulich Heart Program and Department of Pharmacy, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario.
authors.forename: Janarthan Y
authors.initials: JY
authors.lastname: Nikhil
authors.forename: Sam
authors.initials: S
authors.lastname: Radhakrishnan
authors.forename: Fran L
authors.initials: FL
authors.lastname: Paradiso-Hardy
authors.forename: Eric A
authors.initials: EA
authors.lastname: Cohen
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D001241:Aspirin / Q000627:therapeutic use; D000077144:Clopidogrel; D004359:Drug Therapy, Combination; D006801:Humans; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic; D015607:Stents; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin