title: High-dose clopidogrel loading in percutaneous coronary intervention.
abstract: OBJECTIVE
  To review the use of a 600-mg clopidogrel loading dose in patients undergoing percutaneous coronary intervention (PCI).
  
  
  METHODS
  Human clinical trials and platelet studies available through PubMed (1966-March 2005), bibliographies of pertinent articles, and citations supplied by the drug manufacturer were accessed.
  
  
  RESULTS
  The administration of a 600-mg loading dose of clopidogrel can decrease the time required for maximum platelet inhibition to 2 hours compared with > or =6 hours achieved with 300 mg. This higher loading dose has been investigated in multiple platelet studies and one observational report. Several randomized controlled trials have used a 600-mg loading dose; however, these studies were not designed to evaluate the efficacy and safety of this loading regimen. To date, only one randomized trial has compared the 600-mg loading dose with a 300-mg loading dose.
  
  
  CONCLUSIONS
  When compared with a conventional loading regimen of 300 mg in lower-risk patients, pretreatment with clopidogrel 600 mg was shown to be more effective in reducing periprocedural events and demonstrated similar safety. Studies are needed to clarify the use of a 600-mg loading dose in higher-risk patients, with concomitant glycoprotein IIb/IIIa receptor antagonism, or when administration is delayed until immediately before or after PCI.
authors.affiliation: Department of Pharmaceutical Services, St. Elizabeth Health Center, Youngstown, OH 44501-1790, USA. kristen_longstreth@hmis.org
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Longstreth
authors.forename: James R
authors.initials: JR
authors.lastname: Wertz
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D000077144:Clopidogrel; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use*
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine