title: Adverse reaction reporting of interaction between warfarin and fluoroquinolones.
abstract: Reports to the Food and Drug Administration's Adverse Drug Reaction Reporting System of prolonged prothrombin time due to a suspected interaction between warfarin sodium and a fluoroquinolone were reviewed. Five reports of patients who experienced this adverse reaction 2 to 16 days after the addition of a fluoroquinolone to their treatment regimen are described. Possible mechanisms of action that are discussed include inhibition of warfarin metabolism by the anti-infective agent and displacement of warfarin's binding to protein. Physicians need to be aware of this interaction and closely monitor prothrombin time in patients concurrently receiving warfarin and a fluoroquinolone.
authors.affiliation: Center for Drug Evaluation and Research, Food and Drug Administration, Rockville, MD.
authors.forename: H M
authors.initials: HM
authors.lastname: Jolson
authors.forename: L A
authors.initials: LA
authors.lastname: Tanner
authors.forename: L
authors.initials: L
authors.lastname: Green
authors.forename: T H
authors.initials: TH
authors.lastname: Grasela
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002939:Ciprofloxacin / Q000009:adverse effects*; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009643:Norfloxacin / Q000009:adverse effects*; D011358:Product Surveillance, Postmarketing; D014481:United States; D014486:United States Food and Drug Administration; D014859:Warfarin / Q000009:adverse effects*
chemical_list: D002939:Ciprofloxacin; D014859:Warfarin; D009643:Norfloxacin