What antibiotics are used to treat open fractures?

From the Guidelines

Antibiotics for open fractures should be administered as soon as possible, ideally within 1 hour of injury, with cefazolin or clindamycin as the first-line regimen, and additional gram-negative coverage for Type III open fractures. The recommended regimen is based on the most recent and highest quality study, which suggests that antibiotic prophylaxis with systemic cefazolin or clindamycin be administered, except for Type III (and possibly Type II) open fractures, for which additional gram-negative coverage is preferred 1.

Key Considerations

• The choice of antibiotic should be based on the type of open fracture and the likely contaminants, with cefazolin or clindamycin as the first-line option for most cases 1.
• For Type III open fractures or farm/heavily contaminated wounds, additional gram-negative coverage is recommended, which can be achieved with the use of gentamicin or other broad-spectrum antibiotics 1.
• The duration of antibiotic therapy should be 24-72 hours after definitive wound closure, with 24 hours sufficient for type I/II fractures and up to 72 hours for type III fractures 1.
• Local antibiotic prophylactic strategies, such as vancomycin powder or tobramycin-impregnated beads, may also be beneficial in reducing the risk of surgical site infection 1.

Special Considerations

• For patients with penicillin allergy, clindamycin 600-900mg IV every 8 hours can be used as an alternative to cefazolin 1.
• In cases where there is concern for anaerobic contamination, such as soil or fecal matter, the addition of penicillin G or metronidazole may be necessary 1.
• Tetanus prophylaxis should also be administered according to the patient's immunization status, as tetanus is a potential complication of open fractures.

Summary of Recommendations

• Administer antibiotics as soon as possible, ideally within 1 hour of injury.
• Use cefazolin or clindamycin as the first-line regimen.
• Add gram-negative coverage for Type III open fractures.
• Continue antibiotics for 24-72 hours after definitive wound closure.
• Consider local antibiotic prophylactic strategies.
• Administer tetanus prophylaxis according to the patient's immunization status.

From the Research

Antibiotic Selection for Open Fractures

• For Grade I and II open fractures, a first-generation cephalosporin (e.g., cefazolin) is recommended 2
• For Grade III open fractures, coverage with an aminoglycoside in addition to a first-generation cephalosporin is recommended 2
• If a fracture is at risk of contamination with clostridium species, such as a farm-related injury, penicillin should be added to the antibiotic regimen 2

Optimal Timing and Duration of Administration

• Antibiotics should be administered within 3 hours of initial injury 2
• For Grade I and II open fractures, antibiotics should be continued for 24 hours after initial injury 2
• For Grade III open fractures, antibiotics should be continued for 48-72 hours after initial injury, but no more than 24 hours after wound closure 2

Alternative Antibiotic Options

• Ceftriaxone is a safe and effective alternative for open fracture management, offering the advantage of 24-hour dosing and single antibiotic coverage for Grade 3 open fractures 3
• Ceftriaxone plus vancomycin may be considered as an alternative to cefazolin plus gentamicin for Grade 3 open fractures, with a trend towards lower treatment failure rates 4

Important Considerations

• Antibiotic prophylaxis should be given as soon as possible to all patients with open fractures 5
• The expected microbial spectrum should be covered, and antibiotics should be selected based on patient-specific factors and hospital protocols 6
• Pitfalls to avoid include utilizing cultures immediately post-injury to direct choice of agent for antimicrobial prophylaxis, failure to consider patients' medication allergy history, and failure to obtain a thorough history to determine injury exposure 2