Which Vitamin K Dosage Form is Preferred in LTC?
Vitamin K in Long-Term Care
Background A skilled-stay rehab patient on Coumadin recently had a supratherapeutic INR of 5.2. The patient had no evidence of abnormal bleeding. The provider was called and the patient was ordered 5 mg vitamin K (also called phytonadione), intramuscularly.
Discussion There is a lot of misunderstanding about the use of vitamin K to reverse the effects of warfarin. Two issues stand out in the case above: First, the use of vitamin K was not needed in this instance because the patient had no evidence of bleeding and the INR was only slightly higher than 5. Holding warfarin with simple daily INR monitoring may suffice in this case. Second, the IM route of administration is not recommended.
Vitamin K dosage form comparison
Intramuscular (IM) – NOT RECOMMENDED. Avoid intramuscular vitamin K due to the risk of hematoma.
Subcutaneous (SC, SQ) – NOT RECOMMENDED. Avoid subcutaneous vitamin K due to unpredictability and delayed efficacy.
Oral (PO) – RECOMMENDED. Oral vitamin K is the safest route of administration and is therefore the recommended route of administration when vitamin K use is indicated.
..A note about intravenous (IV) vitamin K: IV vitamin K is indicated for emergency situations and should be diluted in 50 mL of compatible solution and administered over at least 20 minutes. Because of the risk of anaphylactic reactions, IV vitamin K is typically not administered in a LTC living center situation.
References: 1. Guyatt GH, Akl EA, Crowther M, et al, “Executive Summary: Antithrombotic Therapy and Prevention of Thrombosis”, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines, “Chest 2012, 141(2 suppl); 7-47. 2. Patriquin C, Crowther M. “Treatment of warfarin-associated coagulopathy with vitamin K” Expert Rev Hematol. 2011 Dec;4(6):657-65. 3. Lexi-Comp® version 2.1.0, Lexi-Comp, Inc., 2014.
This article was originally published in our monthly issue of From the Front Lines – a monthly publication that shares best practices and medication-related challenges faced by “front line” staff in long-term care and post-acute (LTCPAC) facilities.