Ciprofloxacin-warfarin coagulopathy: A case series

Ciprofloxacin, when given to patients previously anticoagulated with warfar in, can occasionally cause an exaggerated hypoprothombinemic response and b leeding diatheses, Two such cases encountered at our institution are presen ted and data is combined with 64 cases reported to the Food and Drug Admini stration's (FDA) Spontaneous Reporting System (SRS) database, which include d all cases reported from 1987 through 1997. Of 66 total cases the median a ge was 72 (range 36-94). The mean time to detection of the coagulopathy fol lowing the ciprofloxacin challenge was 5.5 days (n = 50). Hospitalization w as reported in 15 cases, bleeding in 25 cases, and death in one case. The m edian prothrombin time (PT) and International Normalized Ratio (INR) was 38 .0 (n = 13) and 10.0 (n = 23), respectively. The mean number of medications taken was 6.5 (n = 45). The mean time to correction was significantly shor ter between the treated (2.5 days) and the untreated (4.0 days) groups (P < 0.008). The ciprofloxacin-warfarin coagulopathy occurred most commonly in patients in their seventh decade and in those who require polypharmacy, Act ive treatment of the coagulopathy results in more rapid resolution than obs ervation alone. Clinicians should be aware of the potential bleeding compli cations that can occur with the ciprofloxacin-warfarin drug-drug interactio n. (C) 2000 Wiley-Liss, Inc.