Adult
Cefazolin associated coagulation disorders
Warning
- Cefazolin injection in rare cases may be associated with an increase in INR/PT and APTT.
- Those at risk include patients with:
- Longer than 2 days of cefazolin treatment
- Renal or hepatic impairment
- Poor nutritional state
- Receiving TPN
- Concurrent anticoagulant therapy
- Concurrent rifampicin
- Any other disorders that are associated with bleeding (eg. thrombocytopenia, haemophilia, gastric and duodenal ulcers)
- Check a coagulation screen (INR/PT and APTT) ideally at baseline and at 72 hours after initiating cefazolin, and then twice weekly whilst treatment continues. If the INR is prolonged then discuss with haematology and administer vitamin K as appropriate.
- For patients on concurrent oral anticoagulants, (e.g. warfarin) and cefazolin, prothrombin time (INR) should be monitored more frequently (minimum twice a week) and warfarin dose adjusted accordingly.
References
- Guo, J. et al. (2025) A real-world pharmacovigilance study of FDA adverse event reporting system events for cefazolin, Medicine. Wolters Kluwer Health. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC12708135/pdf/medi-104-e46293.pdf (Accessed: 10 February 2026).
- Noridem Enterprises Ltd. Cefazolin 2g Powder for solution for injection/infusion summary of product characteristics. Electronic Medicines Compendium. Last revision of the text 11/9/2024. Available at MHRA Products | Product results Accessed: 13/2/26.