Antibiotic Choice in Open Fractures

The most important factor to preventing infection in open fractures is time to antibiotics, less than 1 hour from time of injury is ideal.

Summary Chart:

Injury Type

Penicillin Allergic

Type 1 and 2


Clinda or Vanc 

Type 3

Ancef or Ceftriaxone


Gent or Cipro

Some institutions: Cefepime + Vanc 




Barnyard Type 3 (Feces or Soil Gross Contamination)



Ceftriaxone + Metro

Levo + Metronidazole*


Clinda + Levo


Fresh Water

Fluoroquinolone (Cipro) or 

3rd/4th gen cephalosporin

Levo + Metronidazole*


Clinda + Levo



Ceftazidime or Fluoroquinolone (Cipro)

*Can’t use metronidazole with intoxicated folks

  • Levo 500mg IV q24h

  • Metro 500mg IV q8h

  • Ceftriaxone 2gIV q 24h

  • Vanc 15mg/kg IV q12h

  • Clinda 900mg IV q8h

  • Zosyn 4.5g IV q8h

  • Ancef 2g IV q8 (3g if >120kg)

Gustillo-Anderson Classification for Open Fractures:

  • Type 1: Laceration <1cm in diameter

  • Type 2: Laceration >1cm <10cm without signs of high energy (Extensive soft tissue injury despite intact skin)

  • Type 3: >10cm soft injury (All High Energy open fracture or those with gross contamination regardless of the size of the wound)

    • Type 3 A: Adequate soft tissue for coverage of fracture

    • Type 3 B: Inadequate soft tissue coverage, Flap required

    • Type 3 C: Associated arterial injury requiring repair

  • Open Fractures

    • Always Start with Cefazolin (Ancef)

      • 2-grams IV immediately and then every 8 hours 

      • Infection rate after Ancef prophylaxis is markedly lower than compared with other antibiotics

      • If allergic to Ancef, give Clindamycin or Vancomycin (if high prevalence of MRSA) 

    • Gram-negative coverage for type 3 open fractures

      • Aminoglycosides

        • Once daily dose Gentamicin 5mg/kg/d is preferred to decrease risk of acute kidney injury and ototoxicity

      • Fluoroquinolone if concern for kidney problems

        • Avoid if on warfarin (can decrease warfarin liver metabolism

        • Inhibits endochondral ossification (Don’t use in pediatric open fractures)

        • May inhibit fracture healing in rats (not well defined in adults)

    • Barnyard Type Injuries (Soil or Feces = Clostridium Species)

      • High Dose Penicillins for anaerobic coverage

      • Piperacillin-Tazobactam (Zosyn)

        • Noninferiority to use as monotherapy instead of Ancef and Gentamicin in type 3 open fractures

        • Avoids adverse reactions to aminoglycosides (kidney injury and ototoxicity)

      • Penicillin allergy

  • Author example of other antibiotic options

    • Type 1 and 2

      • Ancef 2g IV immediately then Q8 hours 

      • Penicillin allergic

        • Clindamycin 900mg IV immediately and q8 hours

    • Type 3 injuries

      • Ceftriaxone 2g IV immediately for 1 dose

      • Vancomycin 1g IV immediately and q12 hours

      • Penicillin allergy

        • Aztreonam 2g IV immediately and q8 hours

        • Vancomycin 1g IV immediately and q12 hours

  •  Duration of Therapy

    • Type 1 and 2 open fractures

      • Discontinue antibiotics 24 hours after wound closure in type 1 and type 2 injuries regardless of duration of therapy between presentation and surgery

    • Type 3 open fractures

      • Antibiotics for 72 hours after injury or 24 hours after soft-tissue coverage


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