Abstract
OBJECTIVE:
To report a possible interaction between warfarin and ceftaroline, resulting in hemarthrosis, and provide readers with an understanding of mechanisms of interaction between cephalosporins and warfarin.
CASE SUMMARY:
Ceftaroline was prescribed for an 85-year-old female with a therapeutic international normalized ratio (INR) hospitalized for the treatment of cellulitis. She was subsequently readmitted with shoulder pain and a supratherapeutic INR. The patient was diagnosed with hemarthrosis, presumably related to elevated INR. Evaluation using the drug interaction probability scale for warfarin and ceftaroline yielded a score consistent with a possible or probable interaction.
DISCUSSION:
Cephalosporins may interact with warfarin through a variety of mechanisms, including potentiation of hypoprothrombinemia related to certain side chain groups, inhibition of P-glycoprotein, or alteration of gastrointestinal flora. All mechanisms reported in the medical literature as of April 2012 are briefly examined, but the latter is the most reasonable mechanism for a ceftaroline interaction with warfarin.
CONCLUSIONS:
Health care providers should consider closely monitoring patients receiving antibiotics with activity against Enterobacteriaceae and warfarin, even if no direct mechanism of interaction has been reported. Further research regarding a ceftaroline-warfarin interaction is warranted.
Get full access to this article
View all access options for this article.
