Use of Oral Vitamin K1 by Patients Taking Warfarin Sodium: Experience in an Ambulatory Care Clinic
Bibliographic record
Abstract
ABSTRACT Background and Objective: Warfarin sodium dosing is adjusted according to the patient’s international normalized ratio (INR). On occasion, the INR may be greater than 5.0, and during this time patients experience increased risk of bleeding. The use of oral vitamin K1 has been recommended in this situation, but the tablet formulation of vitamin K1 is not marketed in Canada. This report describes the use of vitamin K1 (in tablet form) to reduce high INR values in patients receiving warfarin sodium. Methods: Patients of a Canadian ambulatory care clinic were given 5-mg tablets of vitamin K1 (phylloquinone; Mephyton, Merck Frosst Canada, Kirkland, Quebec) through special arrangement with Health Canada’s Health Protection Branch. They were instructed to take the vitamin K1, according to an agreed dose schedule, if an INR test result above 5.0 was reported. In such instances, the INR test was repeated the following day. Results: A total of 47 INR test results above 5.0 were reported in 39 patients over a 21-month period. None of the patients reported bruising or bleeding. On 31 of these occasions, 2.5 mg of vitamin K1 was taken, and the mean INR fell from 6.8 (range 5.1 to 8.6) to 2.9 (range 1.4 to 5.9) within 24 h. On 6 occasions, 5.0 mg of vitamin K1 was taken, because the INR value was greater than 9.0; in these cases the mean INR fell from 11.3 (range 9.5 to 13.8) to 2.5 (range 1.8 to 3.9). Data for the remaining 10 INR results were not evaluable. Conclusions: For ambulatory patients taking warfarin sodium, oral vitamin K1 can be used to reduce a high INR value without the need for a clinic visit. RESUME Contexte et objectif : La posologie de la warfarine sodique est ajustee en tenant compte du rapport international normalise (INR). Or, il arrive que la valeur de l’INR soit superieure a 5,0 ce qui, dans ces cas, augmente le risque d’hemorragie chez les patients. On a donc recommande d’administrer de la vitamine K1 orale dans ces cas, mais cette vitamine n’est malheureusement pas commercialisee au Canada sous forme de comprimes. Le present rapport decrit comment les comprimes de vitamine K1 ont ete utilises pour abaisser les valeurs elevees de l’INR chez les patients qui recoivent de la warfarine sodique. Methodes : Les patients d’une clinique canadienne de soins ambulatoires ont recu des comprimes de 5 mg de vitamine K1 (phylloquinone ; Mephyton, Merck Frosst Canada, Kirkland (Quebec)), par suite d’une entente extraordinaire avec la Direction generale de la protection de la sante de Sante Canada. On leur a explique qu’ils devaient prendre les comprimes de vitamine K1 selon un schema posologique determine, seulement lorsque la valeur de l’INR etait superieure a 5,0, auquel cas, on determinait a nouveau la valeur de l’INR le lendemain. Resultats : Sur une periode de 21 mois, on a observe chez 39 patients un INR superieur a 5,0 dans 47 cas. Aucun des patients n’a signale d’ecchymoses ou de saignements. La vitamine K1 a ete administree a raison de 2,5 mg dans 31 cas ; la valeur moyenne de l’INR est passee de 6,8 (fourchette de 5,1 a 8,6) a 2,9 (fourchette de 1,4 a 5,9) 24 heures apres l’administration. La vitamine K1 a ete administree a raison de 5,0 mg dans 6 cas ou la valeur de l’INR etait superieure a 9,0 ; la valeur moyenne de l’INR est passee de 11,3 (fourchette de 9,5 a 13,8) a 2,5 (fourchette de 1,8 a 3,9). Les donnees pour les 10 autres cas n’etaient pas evaluables. Conclusions : On peut administrer de la vitamine K1 orale pour abaisser les valeurs elevees de l’INR chez les patients traites a la warfarine sodique, sans qu’ils n’aient besoin d’etre suivis en clinique.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".