Impact of pre-treatment INR level on the effect of intravenous low dose vitamin K in patients with excessive anticoagulation

 

 Buy Article Permissions and Reprints

Summary

Administration of vitamin K is the common mode of treatment in excessively anticoagulated patients. However, patient’s response to vitamin K varies, depending on the vitamin K dose and the route of administration. Another potential source of variation is the pre-treatment INR which has not been accounted for in most previous studies. In the present study the effect of baseline INR on the response to a single dose of intravenous vitamin K (0.5 mg) was studied in 95 episodes of excessively anticoagulated patients (n = 76).

In 67 episodes of moderately excessive baseline INR (6-10) mean INR declined from 8.0 ± 1.2 to 2.6 ± 0.9 at 24 hours, 59/67 (88%) responding within the first 12 hours and not requiring a second dose. In contrast, in 28 episodes with highly excessive baseline INR (> 10) response was slower; mean INR declining from 13.6 ± 2.7 to 4.0 ± 2.1 at 24 hours. In 14/28 of these episodes, patients failed to respond to vitamin K in the first 12 hours and required a second vitamin K dose.

We conclude that INR at presentation affects the response to vitamin K and that this INR value should be considered in determining appropriate vitamin K doses.

• References

• 1 Penning-van Beest FJ, van Meegen E, Rosendaal FR. et al. Characteristics of anticoagulant therapy and co morbidity related to over anticoagulation. Thromb Haemost 2001; 86: 569-74.
  Article in Thieme ConnectPubMedGoogle Scholar
• 2 Van der Meer FJM, Rosendaal FR, Vandenbroucke JP. et al. Assessment of a bleeding risk index in two cohorts of patients treated with oral anticoagulants. Thromb Haemost 1996; 76: 12-6.
  PubMedGoogle Scholar
• 3 Palareti G, Leali N, Coccheri S. et al. Bleeding complications of oral anticoagulant treatment: an inception-cohort, prospective collaborative study (ISCOAT). Italian Study on Complications of Oral Anticoagulant Therapy. Lancet 1996; 348: 423-8.
  CrossrefPubMedGoogle Scholar
• 4 White RH, McKittrick T, Hutchinson R. et al. Temporary discontinuation of warfarin therapy: changes in the international normalized ratio. Ann Intern Med 1995; 122: 40-2.
  CrossrefPubMedGoogle Scholar
• 5 Hylek EM, Chang YC, Skates SJ. et al. Prospective study of the outcomes of ambulatory patients with excessive warfarin anticoagulation. Arch Intern Med 2000; 160: 1612-7.
  CrossrefPubMedGoogle Scholar
• 6 Andersen P, Godal HC. Predictable reduction in anticoagulant activity of warfarin by small amounts of vitamin K. Acta Med Scand 1975; 198: 269-70.
  PubMedGoogle Scholar
• 7 Rich EC, Drage CW. Severe complications of intravenous phytonadione therapy. Two cases, with one fatality. Postgrad Med 1982; 72: 303-6.
  CrossrefPubMedGoogle Scholar
• 8 De la Rubia J, Grau E, Montserrat I. et al. Anaphylactic shock and vitamin K1. Ann Intern Med 1989; 110: 943
  PubMedGoogle Scholar
• 9 Shetty HG, Backhouse G, Bentley DP. et al. Effective reversal of warfarin-induced excessive anticoagulation with low dose vitamin K1. Thromb Haemost 1992; 67: 13-5.
  Article in Thieme ConnectPubMedGoogle Scholar
• 10 Hung A, Singh S, Tait RC. A prospective ran-domized study to determine the optimal dose of intravenous vitamin K in reversal of over-warfarinization. Br J Haematol 2000; 109: 537-9.
  CrossrefPubMedGoogle Scholar
• 11 Whitling AM, Bussey HI, Lyons RM. Comparing different routes and doses of phytonadione for reversing excessive anticoagulation. Arch Intern Med 1998; 158: 2136-40.
  CrossrefPubMedGoogle Scholar
• 12 Brophy MT, Fiore LD, Deykin D. Low-dose vitamin K therapy in excessively anticoagulated patients: a dose-finding study. J Thromb Thrombolysis 1997; 4: 289-92.
  CrossrefPubMedGoogle Scholar
• 13 Weibert RT, Le DT, Kayser SR, Rapaport SI. Correction of excessive anticoagulation with low dose oral vitamin K1. Ann Int Med 1997; 126: 959-62.
  CrossrefPubMedGoogle Scholar
• 14 Crowther MA, Donovan D, Harrison L. et al. Low dose oral vitamin K reliably reverses over anticoagulation due to warfarin. Thromb Haemost 1998; 79: 1116-8.
  Article in Thieme ConnectPubMedGoogle Scholar
• 15 Ageno W, Crowther M, Steidl L. et al. Low dose oral vitamin K to reverse acenocoumarol induced coagulopathy: a randomized controlled trial. Thromb Haemost 2002; 88: 48-51.
  Article in Thieme ConnectPubMedGoogle Scholar