DrugLib.com — Drug Information Portal

Rx drug information, pharmaceutical research, clinical trials, news, and more



Time course of reversal of anticoagulant effect of warfarin by intravenous and subcutaneous phytonadione.

Author(s): Raj G, Kumar R, McKinney WP

Affiliation(s): Section of General Internal Medicine, Dallas Veterans Affairs Medical Center, and Department of Medicine, University of Texas Southwestern Medical Center, 75216, USA. raj.guna@dallas.va.gov

Publication date & source: 1999-12-13, Arch Intern Med., 159(22):2721-4.

Publication type: Clinical Trial; Randomized Controlled Trial

BACKGROUND: Excessive anticoagulation increases the risk of hemorrhagic complications associated with oral anticoagulant therapy. Oral or parenteral phytonadione is used to reverse excessive anticoagulation. Intravenous (IV) phytonadione, while effective, is associated with a small risk of serious anaphylactic reactions. Subcutaneous (SC) administration is safer, but there is little information on its relative efficacy in small doses. METHODS: Twenty-two patients with asymptomatic prolongation of prothrombin time were prospectively randomized and treated with 1 mg of phytonadione IV or 1 mg SC. Prothrombin time was measured at baseline and at 8 and 24 hours after phytonadione administration and expressed as international normalized ratio (INR). RESULTS: Mean INR at baseline was 8.0 and 8.5 in the IV and SC groups, respectively (P = .70). At 8 hours, mean INR was 4.6 in the IV group and 8.0 in the SC group (P = .006), and at 24 hours, mean INR was 3.1 in the IV group and 5.0 in the SC group (P = .009). Mean decrease in INR 8 hours after administration of phytonadione was 3.4 in the IV group and 0.4 in the SC group (P = .02), and mean decrease in INR after 24 hours was 4.9 in the IV group and 3.4 in the SC group (P = .18). CONCLUSIONS: For patients who are excessively anticoagulated with warfarin, small doses of SC phytonadione may not correct the INR as rapidly or as effectively as when administered IV. Higher doses must be considered for more rapid and complete reversal of anticoagulation by the SC route.

Page last updated: 2006-01-31

-- advertisement -- The American Red Cross
 
Home | About Us | Contact Us | Site usage policy | Privacy policy

All Rights reserved - Copyright DrugLib.com, 2006-2014