title: Influence of the CYP4F2 polymorphism on the risk of hemorrhagic complications in coumarin-treated patients.
abstract: OBJECTIVE
  To evaluate the impact of the CYP4F2 polymorphism on bleeding complications and over-anticoagulation due to coumarin.
  
  
  METHODS
  A comprehensive literature search was performed to look for eligible studies published prior to February 2015 in EMBASE and PubMed. References were strictly identified by inclusion and exclusion criteria, and authors of primary studies were consulted for additional information and data. Revman 5.3 software was used to analyze the impact of the CYP4F2 polymorphism on hemorrhagic complications and over-anticoagulation events (international normalized ratio greater than 4).
  
  
  RESULTS
  Eight studies involving 3,101 samples met the specified inclusion criteria. Compared with wild-type homozygotes (CYP4F2*1*1), carriers of the CYP4F2*3 variant had no significant effects on total bleeding events (odds ratio [OR]: 0.86; 95% confidence interval [CI]: 0.71-1.05; p=0.15), major hemorrhage complications in coumarin users (OR: 0.80; 95% CI: 0.64-1.01; p=0.06). Patients carried CYP4F2*3 also had nonsignificant associations with the risk of over-anticoagulation (relative risk [RR]: 079; 95% CI: 0.59-1.06; p=0.12). We found a lower risk in patients with homozygotes for CYP4F2*3, but there was no statistical significance (RR: 0.66; 95% CI: 0.43-1.01; p=0.05).
  
  
  CONCLUSIONS
  This meta-analysis indicated the impact of the CYP4F2 polymorphism on bleeding complications and over-anticoagulation in coumarin-treated patients failed to reach the level of statistical significance. However, large-scale and well designed studies are necessary to determine conclusively the association between the CYP4F2 polymorphism and hemorrhage risk.
authors.affiliation: Institute of Pharmacy & Pharmacology, University of South China, Hengyang, Hunan, China. E-mail. easypeng@163.com.
authors.forename: Peng
authors.initials: P
authors.lastname: Chen
authors.forename: Ye-Qi
authors.initials: YQ
authors.lastname: Sun
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Yang
authors.forename: Rong
authors.initials: R
authors.lastname: Li
authors.forename: Jie
authors.initials: J
authors.lastname: Pan
authors.forename: Yu-Sheng
authors.initials: YS
authors.lastname: Zhou
mesh_terms: D000925:Anticoagulants / Q000009:adverse effects*; D003374:Coumarins / Q000009:adverse effects*; D000072470:Cytochrome P450 Family 4 / Q000235:genetics*; D006470:Hemorrhage / Q000139:chemically induced* / Q000235:genetics*; D006801:Humans; D019934:International Normalized Ratio; D011110:Polymorphism, Genetic
chemical_list: D000925:Anticoagulants; D003374:Coumarins; C030123:coumarin; D000072470:Cytochrome P450 Family 4; C117480:CYP4F2 protein, human