• 1st generation cephalosporin, moderate spectrum antibiotic active against staphylococci, streptococci, and some Gram-positive anaerobes. It has poor activity against Gram-negative bacilli.
  • Interferes with bacterial cell wall synthesis by binding to penicillin-binding proteins, leading to cell lysis and death.
  • Reduces incidence of infection in fractures and surgical procedures.
  • Peak action around 90 minutes. Excreted unchanged in the urine, with 80% excreted in first 24 hours.

Antibiotic prophylaxis for;

  • Open fractures
  • Significant wounds that are grossly contaminated and cannot be cleaned
  • Traumatic pneumothorax that requires pleural decompression by finger thoracostomy
  • History of allergy to cephalosporins or of immediate or severe hypersensitivity to penicillins
  • Isolated open fracture of the distal phalanx
  • Patients with closed fractures that do not meet any other indiciation
 Precautions / Notes
  • Do not delay transport for the administration of antibiotics
  • The safety of cefazolin for use during pregnancy and breastfeeding has not been established (Category B1), the benefit in this scenario outweighs the risk
  • Increased risk of bleeding due to effect on clotting factors, monitor INR in patients on anticoagulants
  • Cefazolin should not be given via the same administration line as any blood products
  • Intramuscular administration (IM) route not to be used
  • Where possible, prophylactic use of antibiotics in surgical procedures should occur prior to the commencement of the procedure if resources allow. 
  • Reconstitute 2g powder vial with 19mL of water for injection in 20mL syringe to make a concentration of 100mg/ml.
 Weight-based Calculations
IV Cefazolin for fractures/prophylaxis
Presentation: /mL
Calculated dose:  in

Extended Care


  • 2 g IV, administered over 3-5 minutes


  • 30 mg/kg IV (maximum of 2 g) administered over 3-5 minutes
  • Reconstitute 1 g vial with 9.5 mL of water for injection to make a concentration of 100 mg/mL; administer at concentration of 100 mg/mL or weaker
 Special Considerations
  • Allergy & anaphylaxis
  • Nausea & vomiting
  • Rash
  • Pain and inflammation at injection site

2g powder for injection

Cephazolin 2g
Current mode:
Extended Care:
Colour assist:


Document Control

Clinical Services

Responsible Manager
Head of Clinical Services


Issue Date

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