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Howard-Thompson A, Luckey A, George C, et al. Graves' disease and treatment effects on warfarin anticoagulation. Case Rep Med. 2014;2014:292468doi: 10.1155/2014/292468.
Howard-Thompson, A., Luckey, A., George, C., Choby, B. A., & Self, T. H. (2014). Graves' disease and treatment effects on warfarin anticoagulation. Case reports in medicine, 2014292468. https://doi.org/10.1155/2014/292468
Howard-Thompson, Amanda, et al. "Graves' disease and treatment effects on warfarin anticoagulation." Case reports in medicine vol. 2014 (2014): 292468. doi: https://doi.org/10.1155/2014/292468
Howard-Thompson A, Luckey A, George C, Choby BA, Self TH. Graves' disease and treatment effects on warfarin anticoagulation. Case Rep Med. 2014;2014:292468. doi: 10.1155/2014/292468. Epub 2014 Jun 04. PMID: 24991217; PMCID: PMC4065757.
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Case Rep Med. 2014;2014:292468. doi: 10.1155/2014/292468. Epub 2014 Jun 04.

Graves' disease and treatment effects on warfarin anticoagulation.

Case reports in medicine

Amanda Howard-Thompson, Alexis Luckey, Christa George, Beth A Choby, Timothy H Self

Affiliations

  1. Department of Clinical Pharmacy and Family Medicine, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN 38163, USA.
  2. Jackson-Madison County General Hospital, 620 Skyline Drive, Jackson, TN 38301, USA.
  3. Department of Medical Education, University of Tennessee Health Science Center, Room 1002, 910 Madison Avenue, Memphis, TN 38163, USA.
  4. Department of Clinical Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, TN 38163, USA.

PMID: 24991217 PMCID: PMC4065757 DOI: 10.1155/2014/292468

Abstract

Background. Hyperthyroidism causes an increased hypoprothrombinemic response to warfarin anticoagulation. Previous studies have demonstrated that patients with hyperthyroidism require lower dosages of warfarin to achieve a therapeutic effect. As hyperthyroidism is treated and euthyroidism is approached, patients may require increasing warfarin dosages to maintain appropriate anticoagulation. We describe a patient's varying response to warfarin during treatment of Graves' disease. Case Presentation. A 48-year-old African American female presented to the emergency room with tachycardia, new onset bilateral lower extremity edema, gradual weight loss, palpable goiter, and generalized sweating over the prior 4 months. She was admitted with Graves' disease and new onset atrial fibrillation. Primary stroke prophylaxis was started using warfarin; the patient developed a markedly supratherapeutic INR likely due to hyperthyroidism. After starting methimazole, her free thyroxine approached euthyroid levels and the INR became subtherapeutic. She remained subtherapeutic over several months despite steadily increasing dosages of warfarin. Immediately following thyroid radioablation and discontinuation of methimazole, the patient's warfarin dose and INR stabilized. Conclusion. Clinicians should expect an increased response to warfarin in patients with hyperthyroidism and close monitoring of the INR is imperative to prevent adverse effects. As patients approach euthyroidism, insufficient anticoagulation is likely without vigilant follow-up, INR monitoring, and increasing warfarin dosages.

References

  1. Pharmacol Rev. 1970 Mar;22(1):35-96 - PubMed
  2. Johns Hopkins Med J. 1972 Jul;131(1):69-73 - PubMed
  3. Chest. 2012 Feb;141(2 Suppl):e44S-e88S - PubMed
  4. Q J Med. 1986 Jan;58(225):43-51 - PubMed
  5. Blood Coagul Fibrinolysis. 2008 Jan;19(1):89-91 - PubMed
  6. Thromb Diath Haemorrh. 1964 Jan 1;10:267-77 - PubMed
  7. JAMA. 1975 Mar 17;231(11):1165-6 - PubMed
  8. Am J Hosp Pharm. 1976 Apr;33(4):387-9 - PubMed
  9. Am J Cardiol. 1963 Jan;11:112-4 - PubMed
  10. N Engl J Med. 1962 Jan 11;266:76-9 - PubMed
  11. Ann Pharmacother. 2006 Jun;40(6):1200-3 - PubMed
  12. Experientia. 1957 Jun 15;13(6):253-4 - PubMed
  13. JAMA. 1960 Jul 2;173:1014-5 - PubMed
  14. South Med J. 1989 Dec;82(12):1585-6 - PubMed

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