Evaluation of Response to High-Dose Intravenous Vitamin K Administration

• Published in: The Annals of pharmacotherapy p. 10600280231154246
• Main Authors: Chapman, April R, Yerke, Jason R, Lumpkin, Mollie, Rudoni, Michael A, Militello, Michael, Wang, Lu, Bass, Stephanie N
• Format: Journal Article
• Language: English
• Published: United States 01.10.2023
• Subjects: phytonadione; liver failure; coagulopathy; vitamin K; cirrhosis
• ISSN: 1542-6270
• DOI: 10.1177/10600280231154246

Essential to the coagulation pathway, vitamin K (phytonadione) is used to correct clotting factor deficiencies and for reversal of warfarin-induced bleeding. In practice, high-dose intravenous (IV) vitamin K is often used, despite limited evidence supporting repeated dosing. This study sought to characterize differences in responders and nonresponders to high-dose vitamin K to guide dosing strategies. This was a case-control study of hospitalized adults who received vitamin K 10 mg IV daily for 3 days. Cases were represented by patients who responded to the first dose of IV vitamin K and controls were nonresponders. The primary outcome was change in international normalized ratio (INR) over time with subsequent vitamin K doses. Secondary outcomes included factors associated with response to vitamin K and incidence of safety events. The Cleveland Clinic Institutional Review Board approved this study. There were 497 patients included, and 182 were responders. Most patients had underlying cirrhosis (91.5%). In responders, the INR decreased from 1.89 at baseline (95% CI = [1.74-2.04]) to 1.40 on day 3 (95% CI = [1.30-1.50]). In nonresponders, the INR decreased from 1.97 (95% CI = [1.83-2.13]) to 1.85 ([1.72-1.99]). Factors associated with response included lower body weight, absence of cirrhosis, and lower bilirubin. There was a low incidence of safety events observed. In this study of mainly patients with cirrhosis, the overall adjusted decrease in INR over 3 days was 0.3, which may have minimal clinical impact. Additional studies are needed to identify populations who may benefit from repeated daily doses of high-dose IV vitamin K.