{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,29]],"date-time":"2026-05-29T18:27:08Z","timestamp":1780079228405,"version":"3.54.0"},"reference-count":11,"publisher":"SAGE Publications","issue":"4","license":[{"start":{"date-parts":[[1994,4,1]],"date-time":"1994-04-01T00:00:00Z","timestamp":765158400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Ann Pharmacother"],"published-print":{"date-parts":[[1994,4]]},"abstract":"<jats:sec>\n                    <jats:title>OBJECTIVE:<\/jats:title>\n                    <jats:p>To report a possible drug interaction between the combination of fluorouracil (5-FU), levamisole, and warfarin.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>CASE SUMMARY:<\/jats:title>\n                    <jats:p>An elderly patient with chronic atrial fibrillation and prosthetic valve replacements had been taking warfarin 22.5 mg\/wk. Following the diagnosis of colon cancer (Duke's classification D), a chemotherapy regimen of 5-FU and levamisole was started. Within four weeks after initiation of chemotherapy, the International Normalization Ratio (INR) increased from 3.04 to 39.56. Warfarin was discontinued and restarted at 7.5 mg\/wk. Discontinuation of levamisole and 5-FU for a five-week period resulted in the INR falling to a subtherapeutic level. Reinstitution of the chemotherapeutic regimen once again led to an increase in INR.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>DISCUSSION:<\/jats:title>\n                    <jats:p>A literature search showed no reports of an interaction between warfarin and levamisole. However, prolongation of 5-FU half-life and an increase in INR have been reported with the concurrent use of 5-FU and warfarin. Inhibition of the hepatic metabolism of warfarin by 5-FU and levamisole is the postulated mechanism of this drug interaction.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>CONCLUSIONS:<\/jats:title>\n                    <jats:p>This case describes the clinically significant increase of INR in an elderly patient after adding a chemotherapy regimen of levamisole and 5-FU to a previous regimen of warfarin alone. The increasing incidence of both atrial fibrillation and colon cancer with age could potentially require the concomitant use of 5-FU, levamisole, and warfarin. Because of the potential severity of this interaction, close monitoring of INR and warfarin dosage adjustment is recommended in patients receiving warfarin along with levamisole and 5-FU.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/106002809402800408","type":"journal-article","created":{"date-parts":[[2017,1,12]],"date-time":"2017-01-12T20:47:44Z","timestamp":1484254064000},"page":"464-467","source":"Crossref","is-referenced-by-count":28,"title":["Possible Drug Interaction between Warfarin and Combination of Levamisole and Fluorouracil"],"prefix":"10.1177","volume":"28","author":[{"given":"Mary A.","family":"Scarfe","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marc K.","family":"Israel","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[1994,4,1]]},"reference":[{"key":"bibr-bibr1-106002809402800408","doi-asserted-by":"publisher","DOI":"10.1378\/chest.101.4.1095"},{"key":"bibr-bibr2-106002809402800408","doi-asserted-by":"publisher","DOI":"10.1200\/JCO.1989.7.10.1447"},{"key":"bibr-bibr3-106002809402800408","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199002083220602"},{"key":"bibr-bibr4-106002809402800408","doi-asserted-by":"publisher","DOI":"10.1016\/0165-6147(92)90107-H"},{"key":"bibr-bibr5-106002809402800408","first-page":"95","volume":"10","author":"Mutch RS","year":"1991","journal-title":"Clin Pharm"},{"key":"bibr-bibr6-106002809402800408","volume-title":"Package insert. Fluorouracil (Efudex)","year":"1990"},{"key":"bibr-bibr7-106002809402800408","first-page":"4827","volume":"42","author":"Chlebowski RT","year":"1982","journal-title":"Cancer Res"},{"key":"bibr-bibr8-106002809402800408","first-page":"100","volume":"19","author":"Chan K","year":"1978","journal-title":"Clin Res"},{"key":"bibr-bibr9-106002809402800408","doi-asserted-by":"publisher","DOI":"10.1002\/ajh.2830400317"},{"key":"bibr-bibr10-106002809402800408","volume-title":"Package insert. Levamisole (Ergamisol).","year":"1992"},{"key":"bibr-bibr11-106002809402800408","unstructured":"McEvoy GK, ed. AHFS drug information 1993. Bethesda, MD: American Society of Hospital Pharmacists, 1993: 827."}],"container-title":["Annals of Pharmacotherapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/106002809402800408","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/106002809402800408","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T11:05:59Z","timestamp":1777374359000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/106002809402800408"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1994,4]]},"references-count":11,"journal-issue":{"issue":"4","published-print":{"date-parts":[[1994,4]]}},"alternative-id":["10.1177\/106002809402800408"],"URL":"https:\/\/doi.org\/10.1177\/106002809402800408","relation":{},"ISSN":["1060-0280","1542-6270"],"issn-type":[{"value":"1060-0280","type":"print"},{"value":"1542-6270","type":"electronic"}],"subject":[],"published":{"date-parts":[[1994,4]]}}}