Does Low Dose Oral Vitamin K Improve International Normalized Ratio (INR) Stability?

NCT00990158 | Completed Phase 3

• 1 other identifier: NA 6695
• Study Type: interventional
• Target: 235
• Locations: 1 country
• Sites: 4

Brief Summary

Warfarin is highly effective for the prevention of both first and recurrent thrombotic events, however even minor excursions outside the reference INR range of 2.0 to 3.0 are associated with bleeding or thrombotic complications. The importance of maintaining the INR within the desired interval has led to the concept of "time in therapeutic range (TTR)" - the total proportion of time that the INR is between 2.0 and 3.0. The investigators propose a multicentre, double blind, randomized trial which will determine if 0.150 mg of oral vitamin K increases time in the therapeutic range for patients receiving warfarin.

Conditions

Coagulation; Bleeding; Thrombosis

Keywords

Vitamin K1 (phytonadione); Randomized controlled trial; Warfarin; Coagulopathy; Time in therapeutic range; Bleeding; Thrombosis; VKORC1 and CYP2C9 genotypes; Time INR in therapeutic range

Outcome Measures

Primary Outcomes (1)

• When compared with placebo does the addition of 150 micrograms of daily vitamin K to "usual warfarin therapy" improve anticoagulant control as measured by "time in the therapeutic range"?

  7 Months

Secondary Outcomes (1)

• Does low dose Vitamin K (LDVK) increase the frequency of adverse clinical events, including thromboembolism and major and/or all bleeding?

  7 Months

Study Arms (2)

Low dose vitamin K + usual warfarin

ACTIVE COMPARATOR

Low dose oral vitamin K (0.150 mg orally once daily) + warfarin continuation with usual warfarin monitoring

Drug: Phytonadione (Vitamin K1)

Usual warfarin therapy + placebo

PLACEBO COMPARATOR

Patients continue usual warfarin and take one placebo per day

Drug: Placebo

Interventions

Phytonadione (Vitamin K1) DRUG

A daily dose of 150 micrograms of vitamin K medication given orally for a total of 7 months

Low dose vitamin K + usual warfarin

Placebo DRUG

A daily dose of matching placebo medication given orally for a total of 7 months

Usual warfarin therapy + placebo

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Warfarin therapy administered to a target INR of 2.0 to 3.0

You may not qualify if:

• Out of range INR on day of screening - enrolment will only occur if the patient's INR on the day of screening is between 1.8 and 3.4 (inclusive) - if the INR is outside this range the patient will be re-screened when the INR is within this range.
• Recent warfarin initiation - all patients must have received warfarin for a minimum of 3 months
• Planned termination or extended temporary interruption of warfarin within 6 months or anticipated survival of less than 6 months
• Known severe liver disease, known excess alcohol consumption , known malabsorption syndrome or inability to take oral medications
• Use of medications known to interfere with warfarin and whose dose is likely to change over the course of the study (e.g. barbiturates, rifampin etc.)
• Known allergy to vitamin K
• Inability or unwillingness to follow study procedures or provide consent
• Prior participation in this study, or participating in a competing study which may impact INR control

Sponsors & Collaborators

• St. Joseph's Healthcare Hamilton: lead
• McMaster University: collaborator
• University of Western Ontario, Canada: collaborator

Study Sites (4)

Hamilton Health Sciences Centre

Hamilton, Ontario, L8L 2X2, Canada

Location

St. Joseph's Hospital

Hamilton, Ontario, L8N 4A6, Canada

Location

London Health Sciences Centre

London, Ontario, N6A 4G5, Canada

Location

University Health Network, Toronto General Hospital

Toronto, Ontario, M5G 2C4, Canada

Location

Related Publications (38)

• Ansell J, Hirsh J, Hylek E, Jacobson A, Crowther M, Palareti G. Pharmacology and management of the vitamin K antagonists: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest. 2008 Jun;133(6 Suppl):160S-198S. doi: 10.1378/chest.08-0670.

  PMID: 18574265 BACKGROUND

• Oake N, Jennings A, Forster AJ, Fergusson D, Doucette S, van Walraven C. Anticoagulation intensity and outcomes among patients prescribed oral anticoagulant therapy: a systematic review and meta-analysis. CMAJ. 2008 Jul 29;179(3):235-44. doi: 10.1503/cmaj.080171.

  PMID: 18663203 BACKGROUND

• Dentali F, Douketis JD, Lim W, Crowther M. Combined aspirin-oral anticoagulant therapy compared with oral anticoagulant therapy alone among patients at risk for cardiovascular disease: a meta-analysis of randomized trials. Arch Intern Med. 2007 Jan 22;167(2):117-24. doi: 10.1001/archinte.167.2.117.

  PMID: 17242311 BACKGROUND

• Kaufman DW, Kelly JP, Rosenberg L, Anderson TE, Mitchell AA. Recent patterns of medication use in the ambulatory adult population of the United States: the Slone survey. JAMA. 2002 Jan 16;287(3):337-44. doi: 10.1001/jama.287.3.337.

  PMID: 11790213 BACKGROUND

• Verhovsek M, Motlagh B, Crowther MA, Kennedy C, Dolovich L, Campbell G, Wang L, Papaioannou A. Quality of anticoagulation and use of warfarin-interacting medications in long-term care: a chart review. BMC Geriatr. 2008 Jul 3;8:13. doi: 10.1186/1471-2318-8-13.

  PMID: 18598364 BACKGROUND

• Schmitt L, Speckman J, Ansell J. Quality assessment of anticoagulation dose management: comparative evaluation of measures of time-in-therapeutic range. J Thromb Thrombolysis. 2003 Jun;15(3):213-6. doi: 10.1023/B:THRO.0000011377.78585.63.

  PMID: 14739631 BACKGROUND

• Rosendaal FR, Cannegieter SC, van der Meer FJ, Briet E. A method to determine the optimal intensity of oral anticoagulant therapy. Thromb Haemost. 1993 Mar 1;69(3):236-9.

  PMID: 8470047 BACKGROUND

• Pirmohamed M, James S, Meakin S, Green C, Scott AK, Walley TJ, Farrar K, Park BK, Breckenridge AM. Adverse drug reactions as cause of admission to hospital: prospective analysis of 18 820 patients. BMJ. 2004 Jul 3;329(7456):15-9. doi: 10.1136/bmj.329.7456.15.

  PMID: 15231615 BACKGROUND

• Wysowski DK, Nourjah P, Swartz L. Bleeding complications with warfarin use: a prevalent adverse effect resulting in regulatory action. Arch Intern Med. 2007 Jul 9;167(13):1414-9. doi: 10.1001/archinte.167.13.1414.

  PMID: 17620536 BACKGROUND

• Sconce EA, Avery PJ, Wynne HA, Kamali F. Vitamin K epoxide reductase complex subunit 1 (VKORC1 ) polymorphism influences the anticoagulation response subsequent to vitamin K intake: a pilot study. J Thromb Haemost. 2008 Jul;6(7):1226-8. doi: 10.1111/j.1538-7836.2008.03003.x. Epub 2008 Jul 1. No abstract available.

  PMID: 18466315 BACKGROUND

• Sconce E, Khan T, Mason J, Noble F, Wynne H, Kamali F. Patients with unstable control have a poorer dietary intake of vitamin K compared to patients with stable control of anticoagulation. Thromb Haemost. 2005 May;93(5):872-5. doi: 10.1160/TH04-12-0773.

  PMID: 15886802 BACKGROUND

• Khan T, Wynne H, Wood P, Torrance A, Hankey C, Avery P, Kesteven P, Kamali F. Dietary vitamin K influences intra-individual variability in anticoagulant response to warfarin. Br J Haematol. 2004 Feb;124(3):348-54. doi: 10.1046/j.1365-2141.2003.04787.x.

  PMID: 14717783 BACKGROUND

• Cushman M, Booth SL, Possidente CJ, Davidson KW, Sadowski JA, Bovill EG. The association of vitamin K status with warfarin sensitivity at the onset of treatment. Br J Haematol. 2001 Mar;112(3):572-7. doi: 10.1046/j.1365-2141.2001.02635.x.

  PMID: 11260056 BACKGROUND

• Reese AM, Farnett LE, Lyons RM, Patel B, Morgan L, Bussey HI. Low-dose vitamin K to augment anticoagulation control. Pharmacotherapy. 2005 Dec;25(12):1746-51. doi: 10.1592/phco.2005.25.12.1746.

  PMID: 16305294 BACKGROUND

• Booth SL, Charnley JM, Sadowski JA, Saltzman E, Bovill EG, Cushman M. Dietary vitamin K1 and stability of oral anticoagulation: proposal of a diet with constant vitamin K1 content. Thromb Haemost. 1997 Mar;77(3):504-9.

  PMID: 9066002 BACKGROUND

• Bovill EG, Fung M, Cushman M. Vitamin K and oral anticoagulation: thought for food. Am J Med. 2004 May 15;116(10):711-3. doi: 10.1016/j.amjmed.2004.02.020. No abstract available.

  PMID: 15121498 BACKGROUND

• Sconce E, Avery P, Wynne H, Kamali F. Vitamin K supplementation can improve stability of anticoagulation for patients with unexplained variability in response to warfarin. Blood. 2007 Mar 15;109(6):2419-23. doi: 10.1182/blood-2006-09-049262. Epub 2006 Nov 16.

  PMID: 17110451 BACKGROUND

• Rombouts EK, Rosendaal FR, Van Der Meer FJ. Daily vitamin K supplementation improves anticoagulant stability. J Thromb Haemost. 2007 Oct;5(10):2043-8. doi: 10.1111/j.1538-7836.2007.02715.x. Epub 2007 Jul 31.

  PMID: 17666020 BACKGROUND

• de Assis MC, Rabelo ER, Avila CW, Polanczyk CA, Rohde LE. Improved oral anticoagulation after a dietary vitamin k-guided strategy: a randomized controlled trial. Circulation. 2009 Sep 22;120(12):1115-22, 3 p following 1122. doi: 10.1161/CIRCULATIONAHA.109.849208. Epub 2009 Sep 8.

  PMID: 19738137 BACKGROUND

• Schurgers LJ, Shearer MJ, Hamulyak K, Stocklin E, Vermeer C. Effect of vitamin K intake on the stability of oral anticoagulant treatment: dose-response relationships in healthy subjects. Blood. 2004 Nov 1;104(9):2682-9. doi: 10.1182/blood-2004-04-1525. Epub 2004 Jul 1.

  PMID: 15231565 BACKGROUND

• Ford SK, Misita CP, Shilliday BB, Malone RM, Moore CG, Moll S. Prospective study of supplemental vitamin K therapy in patients on oral anticoagulants with unstable international normalized ratios. J Thromb Thrombolysis. 2007 Aug;24(1):23-7. doi: 10.1007/s11239-007-0014-z. Epub 2007 Feb 24.

  PMID: 17323135 BACKGROUND

• Crowther MA, Ageno W, Garcia D, Wang L, Witt DM, Clark NP, et al. Effectiveness of low dose oral vitamin K for patients with elevated INR values: results of a randomized trial examining clinical outcomes. Journal of Thrombosis & Haemostasis 5[S2], PS 219. 2008.

  BACKGROUND

• Woods K, Douketis JD, Kathirgamanathan K, Yi Q, Crowther MA. Low-dose oral vitamin K to normalize the international normalized ratio prior to surgery in patients who require temporary interruption of warfarin. J Thromb Thrombolysis. 2007 Oct;24(2):93-7. doi: 10.1007/s11239-007-0022-z. Epub 2007 Mar 23.

  PMID: 17380255 BACKGROUND

• Whitlock RP, Crowther MA, Warkentin TE, Blackall MH, Farrokhyar F, Teoh KH. Warfarin cessation before cardiopulmonary bypass: lessons learned from a randomized controlled trial of oral vitamin K. Ann Thorac Surg. 2007 Jul;84(1):103-8. doi: 10.1016/j.athoracsur.2007.03.014.

  PMID: 17588394 BACKGROUND

• Crowther MA, Ageno W, Schnurr T, Manfredi E, Kinnon K, Garcia D, Douketis JD. Oral vitamin K produces a normal INR within 24 hours of its administration in most patients discontinuing warfarin. Haematologica. 2005 Jan;90(1):137-9.

  PMID: 15642685 BACKGROUND

• Ageno W, Garcia D, Silingardi M, Galli M, Crowther M. A randomized trial comparing 1 mg of oral vitamin K with no treatment in the management of warfarin-associated coagulopathy in patients with mechanical heart valves. J Am Coll Cardiol. 2005 Aug 16;46(4):732-3. doi: 10.1016/j.jacc.2005.05.022. No abstract available.

  PMID: 16098445 BACKGROUND

• Wilson SE, Watson HG, Crowther MA. Low-dose oral vitamin K therapy for the management of asymptomatic patients with elevated international normalized ratios: a brief review. CMAJ. 2004 Mar 2;170(5):821-4. doi: 10.1503/cmaj.1030478.

  PMID: 14993179 BACKGROUND

• Gunther KE, Conway G, Leibach L, Crowther MA. Low-dose oral vitamin K is safe and effective for outpatient management of patients with an INR>10. Thromb Res. 2004;113(3-4):205-9. doi: 10.1016/j.thromres.2004.03.004.

  PMID: 15140584 BACKGROUND

• Crowther MA, Wilson S. Vitamin K for the treatment of asymptomatic coagulopathy associated with oral anticoagulant therapy. J Thromb Thrombolysis. 2003 Aug-Oct;16(1-2):69-72. doi: 10.1023/B:THRO.0000014597.87575.e9.

  PMID: 14760216 BACKGROUND

• Ageno W, Crowther M, Steidl L, Ultori C, Mera V, Dentali F, Squizzato A, Marchesi C, Venco A. Low dose oral vitamin K to reverse acenocoumarol-induced coagulopathy: a randomized controlled trial. Thromb Haemost. 2002 Jul;88(1):48-51.

  PMID: 12152676 BACKGROUND

• Crowther MA, McDonald E, Johnston M, Cook D. Vitamin K deficiency and D-dimer levels in the intensive care unit: a prospective cohort study. Blood Coagul Fibrinolysis. 2002 Jan;13(1):49-52. doi: 10.1097/00001721-200201000-00007.

  PMID: 11994567 BACKGROUND

• Crowther MA, Julian J, McCarty D, Douketis J, Kovacs M, Biagoni L, Schnurr T, McGinnis J, Gent M, Hirsh J, Ginsberg J. Treatment of warfarin-associated coagulopathy with oral vitamin K: a randomised controlled trial. Lancet. 2000 Nov 4;356(9241):1551-3. doi: 10.1016/S0140-6736(00)03125-1.

  PMID: 11075768 BACKGROUND

• Crowther MA, Donovan D, Harrison L, McGinnis J, Ginsberg J. Low-dose oral vitamin K reliably reverses over-anticoagulation due to warfarin. Thromb Haemost. 1998 Jun;79(6):1116-8.

  PMID: 9657434 BACKGROUND

• Clark NP, Witt DM, Delate T, Trapp M, Garcia D, Ageno W, Hylek EM, Crowther MA; Warfarin-Associated Research Projects and Other Endeavors Consortium. Thromboembolic consequences of subtherapeutic anticoagulation in patients stabilized on warfarin therapy: the low INR study. Pharmacotherapy. 2008 Aug;28(8):960-7. doi: 10.1592/phco.28.8.960.

  PMID: 18657012 BACKGROUND

• Carlquist JF, Horne BD, Muhlestein JB, Lappe DL, Whiting BM, Kolek MJ, Clarke JL, James BC, Anderson JL. Genotypes of the cytochrome p450 isoform, CYP2C9, and the vitamin K epoxide reductase complex subunit 1 conjointly determine stable warfarin dose: a prospective study. J Thromb Thrombolysis. 2006 Dec;22(3):191-7. doi: 10.1007/s11239-006-9030-7.

  PMID: 17111199 BACKGROUND

• Schulman S, Beyth RJ, Kearon C, Levine MN. Hemorrhagic complications of anticoagulant and thrombolytic treatment: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest. 2008 Jun;133(6 Suppl):257S-298S. doi: 10.1378/chest.08-0674.

  PMID: 18574268 BACKGROUND

• Proportion Difference Power / Sample Size Calculation. 8-7-2008.

  BACKGROUND

• Boonyawat K, Wang L, Lazo-Langner A, Kovacs MJ, Yeo E, Schnurr T, Schulman S, Crowther MA. The effect of low-dose oral vitamin K supplementation on INR stability in patients receiving warfarin. A randomised trial. Thromb Haemost. 2016 Aug 30;116(3):480-5. doi: 10.1160/TH16-04-0320. Epub 2016 Jun 23.

  PMID: 27346552 DERIVED

Related Links

• A webinar describing results of our prior study may be found at this website

MeSH Terms

Conditions

Thrombosis; Hemorrhage; Hemostatic Disorders; Vitamin K-Dependent Clotting Factors, Combined Deficiency Of, Type 2

Interventions

Vitamin K 2

Condition Hierarchy (Ancestors)

Embolism and Thrombosis; Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Hemorrhagic Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases

Intervention Hierarchy (Ancestors)

Vitamin K; Naphthoquinones; Naphthalenes; Polycyclic Aromatic Hydrocarbons; Hydrocarbons, Aromatic; Hydrocarbons, Cyclic; Hydrocarbons; Organic Chemicals; Phytol; Diterpenes; Terpenes; Quinones; Polycyclic Compounds

Study Officials

• Mark A Crowther, MD

  McMaster University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Vice President, Research

Study Record Dates

• First Submitted: October 5, 2009
• First Posted: October 6, 2009
• Study Start: July 1, 2010
• Primary Completion: April 1, 2014
• Study Completion: April 1, 2014
• Last Updated: May 21, 2015

Record last verified: 2013-12

Locations

CA (4)