title: Risk of intracranial injury after minor head trauma in patients with pre-injury use of clopidogrel.
abstract: BACKGROUND
  Clopidogrel is an adenosine diphosphate receptor antagonist. The risk of intracranial hemorrhage following minor head trauma in patients with pre-injury use of clopidogrel has not been fully determined.
  
  
  METHODS
  This case-controlled study examined the effects of pre-injury use of clopidogrel in adult (age 14 years and older) patients with minor head trauma.
  
  
  RESULTS
  During the study period, 1660 patients head computed tomography scans were performed in the emergency department, of which 658 met inclusion criteria. Intracranial hemorrhage was noted in 30% of patients on clopidogrel, compared with 2.2% of those patients without pre-injury use of clopidogrel. After performing a logistic regression analysis for confounders, the pre-injury use of clopidogrel was significantly associated with intracranial hemorrhage in this study population (OR 16.7; 95% CI 1.71-162.7).
  
  
  CONCLUSIONS
  The use of clopidogrel is associated with a significantly increased risk of developing intracranial hemorrhage following minor trauma.
authors.affiliation: Department of Emergency Medicine, Section of Medical Toxicology, University of Southern California, Los Angeles, CA, USA. Electronic address: mdlevine@usc.edu.
authors.forename: Michael
authors.initials: M
authors.lastname: Levine
authors.affiliation: Department of Emergency Medicine, University of Southern California, Los Angeles, CA, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Wyler
authors.affiliation: Department of Emergency Medicine, Maricopa Medical Center, Phoenix, AZ, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: Lovecchio
authors.affiliation: Department of Emergency Medicine, Maricopa Medical Center, Phoenix, AZ, USA.
authors.forename: Pedro
authors.initials: P
authors.lastname: Roque
authors.affiliation: Department of Emergency Medicine, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Ali S
authors.initials: AS
authors.lastname: Raja
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D000077144:Clopidogrel; D006259:Craniocerebral Trauma / Q000150:complications* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D020198:Intracranial Hemorrhage, Traumatic / Q000139:chemically induced* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects*; D012307:Risk Factors; D013988:Ticlopidine / Q000009:adverse effects / Q000031:analogs & derivatives*; D014057:Tomography, X-Ray Computed
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine