Adverse reaction reporting of interaction between warfarin and fluoroquinolones.
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.
Jolson
H M
HM
Center for Drug Evaluation and Research, Food and Drug Administration, Rockville, MD.
Tanner
L A
LA
Green
L
L
Grasela
T H
TH
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*
D002939:Ciprofloxacin; D014859:Warfarin; D009643:Norfloxacin