title: Impact of pre-treatment INR level on the effect of intravenous low dose vitamin K in patients with excessive anticoagulation.
abstract: 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.
authors.affiliation: Department of Medicine Anticoagulation Clinic, Tel-Hashomer, Israel. aharon.lubetsky@sheba.health.gov.il
authors.forename: Aharon
authors.initials: A
authors.lastname: Lubetsky
authors.forename: Yigal
authors.initials: Y
authors.lastname: Shasha
authors.forename: David
authors.initials: D
authors.lastname: Olchovsky
authors.forename: Ronen
authors.initials: R
authors.lastname: Loebstein
authors.forename: Hillel
authors.initials: H
authors.lastname: Halkin
authors.forename: David
authors.initials: D
authors.lastname: Ezra
mesh_terms: D000074:Acenocoumarol / Q000008:administration & dosage / Q000009:adverse effects / Q000037:antagonists & inhibitors; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects / Q000037:antagonists & inhibitors*; D062787:Drug Overdose / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006470:Hemorrhage / Q000139:chemically induced / Q000517:prevention & control; D006801:Humans; D007262:Infusions, Intravenous; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D012449:Safety; D016896:Treatment Outcome; D014812:Vitamin K / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D014859:Warfarin / Q000008:administration & dosage / Q000009:adverse effects / Q000037:antagonists & inhibitors
chemical_list: D000925:Anticoagulants; D014812:Vitamin K; D014859:Warfarin; D000074:Acenocoumarol