title: Clopidogrel versus low-dose aspirin as risk factors for epistaxis.
abstract: OBJECTIVE
  To quantify the relative risk of epistaxis for patients taking low-dose aspirin or clopidogrel compared to patients taking neither drug.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Primary care.
  
  
  METHODS
  10,241 patients from three GP practices in the West Midlands.
  
  
  METHODS
  Epistaxis resulting in presentation to the GP, attendance at Accident & Emergency, or referral to ENT outpatients.
  
  
  RESULTS
  There was a significant difference in the proportion of patients with epistaxis across the three groups (chi(2) = 84.1; 2 degrees of freedom; P < 0.000001). Relative risk of epistaxis was increased in both the aspirin (RR = 9.04; 95% CI = 5.13-15.96) and clopidogrel (RR = 6.40; 95% CI = 2.33-17.56) groups compared to the no drug group. There was no increased risk of epistaxis with aspirin compared to clopidogrel (RR = 1.4; 95% CI = 0.6-3.4).
  
  
  CONCLUSIONS
  There is an increased risk of troublesome epistaxis in patients taking aspirin or clopidogrel. There is no significant difference in risk of epistaxis between the two drug groups.
authors.affiliation: ENT Department, Russells Hall Hospital, Dudley, West Midlands, UK. j_rainsbury@yahoo.co.uk
authors.forename: J W
authors.initials: JW
authors.lastname: Rainsbury
authors.forename: N C
authors.initials: NC
authors.lastname: Molony
mesh_terms: D001241:Aspirin / Q000008:administration & dosage / Q000009:adverse effects*; D000077144:Clopidogrel; D004305:Dose-Response Relationship, Drug; D004844:Epistaxis / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D017202:Myocardial Ischemia / Q000517:prevention & control; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects*; D012307:Risk Factors; D013988:Ticlopidine / Q000009:adverse effects / Q000031:analogs & derivatives*
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin