Warfarin-5-FU interaction - A consecutive case series

Jill M. Kolesar, Carrie L. Johnson, Betty L. Freeberg, Jordan D. Berlin, Joan H. Schiller

Research output: Contribution to journalArticlepeer-review

58 Scopus citations


Five patients from a single institution received concomitant warfarin and 5-fluorouracil (5-FU) during a 3-year period. The mean weekly warfarin dose before starting chemotherapy was 40.66 mg and during chemotherapy it was 24 mg (p=0.0026). All patients required a warfarin dosage reduction (range 18-74%, mean 44%). Two patients were hospitalized, one with a major retroperitoneal bleed, the other for fresh-frozen plasma administration and observation. Maximum international normalized ratios (INRs) ranged from 3.66- 23.7. This series confirms a common, clinically significant interaction between warfarin and 5-FU. An interaction between capecitabine, the orally available prodrug of 5-FU, and warfarin also has been reported. We recommend weekly monitoring of prothrombin time and INR for all patients receiving concomitant warfarin and 5-FU or capecitabine.

Original languageEnglish
Pages (from-to)1445-1449
Number of pages5
Issue number12
StatePublished - 1999

ASJC Scopus subject areas

  • Pharmacology (medical)


Dive into the research topics of 'Warfarin-5-FU interaction - A consecutive case series'. Together they form a unique fingerprint.

Cite this