Racial background is a determinant factor in the maintenance dosage of Warfarin

Abstract

Warfarin is a drug commonly used in the prevention of thromboembolic events. There have been reports suggesting that racial background may influence warfarin dose requirements. Malaysia is a multiracial country in which there are 3 major races, Malay, Chinese, and Indian.We examined 100 patients from our hospital on stable maintenance doses of warfarin, with international normalized ratio (INR) of 2.0 to 3.5.We found that the mean warfarin dose for Indian patients (n = 19) was 6.9 mg, for Chinese patients (n = 55) was 3.6 mg, and for Malay patients (n = 26) was 3.2 mg.The results showed that the Indian patients required a statistically significantly higher warfarin dose than did patients of the other 2 races (P >.0005). Age was also found to affect the daily warfarin maintenance dose.

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References

  1. 1.

    Yu HM, Chan TYK, Critchley JAJH, Woo KS. Factors determining the maintenance dose of warfarin in Chinese patients.Q J Med. 1996;89:127–135.

    CAS  Google Scholar 

  2. 2.

    Blann A, Hewitt J, Siddiqui F, Bareford D. Racial background is a determinant of average warfarin dose required to maintain INR between 2.0 and 3.0.Br J Haematology. 1999;107:207–209.

    Article  CAS  Google Scholar 

  3. 3.

    James AH, Britt RP, Raskino CL, Thompson SG. Factors affecting the maintenance dose of warfarin.J Clin Path. 1992;45: 704–706.

    Article  CAS  PubMed  Google Scholar 

  4. 4.

    Aithal GP, Day CP, Kersteven PJ, et al. Association of polymorphisms in the cytochrome P450 CYP2C9 with warfarin dose requirement and risk of bleeding complications.Lancet. 1999;353: 717–719.

    Article  CAS  PubMed  Google Scholar 

  5. 5.

    Takayashi H, Hirotoshi E. Pharmacogenetics of warfarin elimination and its clinical implications.Clin Pharmacokinet. 2001;40: 587–603.

    Article  Google Scholar 

  6. 6.

    Goldstein JA. Clinical relevance of genetic polymorphisms in the human CYP2C subfamily.Br J Clin Pharmacol. 2001;52:349–355.

    Article  CAS  PubMed  Google Scholar 

  7. 7.

    Zhou HH, Adedoyin A, Wilkinsons GR. Differences in plasma binding of drugs between Caucasians and Chinese subjects.Clin Pharmacol Ther. 1990;48:10–17.

    CAS  PubMed  Google Scholar 

  8. 8.

    Gladman JRF, Dolan G. Effect of age upon the induction and maintenance of anticoagulation with warfarin.Postgrad Med J. 1995;71:153–155.

    Article  CAS  PubMed  Google Scholar 

Download references

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Correspondence to Gin Gin Gan or Alan Teh or Kim Yen Goh or Heng Thay Chong or Kang Wah Pang.

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Gan, G.G., Teh, A., Goh, K.Y. et al. Racial background is a determinant factor in the maintenance dosage of Warfarin. Int J Hematol 78, 84–86 (2003). https://doi.org/10.1007/BF02983247

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Key words

  • Racial background
  • Warfarin