{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T23:27:10Z","timestamp":1777418830142,"version":"3.51.4"},"reference-count":0,"publisher":"SAGE Publications","issue":"1","license":[{"start":{"date-parts":[[2011,1,1]],"date-time":"2011-01-01T00:00:00Z","timestamp":1293840000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Ann Pharmacother"],"published-print":{"date-parts":[[2011,1]]},"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To report a case of a critically elevated international normalized ratio (INR) following discontinuation of a vitamin K supplement in a patient receiving warfarin.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Case Summary:<\/jats:title>\n                    <jats:p>A 64-year-old man with atrial fibrillation received warfarin for primary stroke prevention. He was initialed on tow-dose vitamin K supplementation therapy secondary to a high level of INR variability. The patient was stabilized on this therapy for approximately 9 months with a mean INR of 2.02 and a warfarin dose ranging from 6.5 to 7.5 mg\/week. At a visit with his primary care physician, the patient's INR was subtherapeutic at 1.5. He had not been taking his vitamin K supplement for nearly a week, but had not missed any doses of warfarin. The vitamin K supplement was discontinued and his warfarin dose was increased by 14.3%. Nearly 2 weeks later the patient presented with a critically elevated INR of 8.5, but no acute bleeding. No other factors affecting the INR could be determined. After a dose of 2.5 mg of vitamin K was administered and warfarin was withheld for 2 days, the patient's INR returned to 2.9. Low-dose vitamin K supplementation and warfarin at a lower dose of 7 mg\/week were restarted. His INR remained relatively stable, with no ensuing critical INR changes or other sequelae.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion:<\/jats:title>\n                    <jats:p>Vitamin K supplement removal was believed to be a major contributor to the critically elevated INR. White the warfarin dose had been increased according to the clinic protocol (14.3% for an INR of 1.5), the timing of the INR elevation following supplement removal follows pharmacodynamic expectations of clotting factor synthesis. This case is labeled a category D error.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions:<\/jats:title>\n                    <jats:p>Discontinuation of vitamin K supplementation therapy might result in elevation of INR.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1345\/aph.1p461","type":"journal-article","created":{"date-parts":[[2011,1,4]],"date-time":"2011-01-04T20:54:42Z","timestamp":1294174482000},"page":"124-124","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":3,"title":["Elevated International Normalized Ratio from Vitamin K Supplement Discontinuation"],"prefix":"10.1177","volume":"45","author":[{"given":"Andrew R","family":"Miesner","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Timothy S","family":"Sullivan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[2011,1,4]]},"container-title":["Annals of Pharmacotherapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1345\/aph.1P461","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1345\/aph.1P461","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T11:07:59Z","timestamp":1777374479000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1345\/aph.1P461"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2011,1]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2011,1]]}},"alternative-id":["10.1345\/aph.1P461"],"URL":"https:\/\/doi.org\/10.1345\/aph.1p461","relation":{},"ISSN":["1060-0280","1542-6270"],"issn-type":[{"value":"1060-0280","type":"print"},{"value":"1542-6270","type":"electronic"}],"subject":[],"published":{"date-parts":[[2011,1]]}}}