From the Guidelines
Vancomycin is the primary recommended antibiotic for surgical prophylaxis against Methicillin-resistant Staphylococcus aureus (MRSA). For surgical prophylaxis against MRSA, the recommended antibiotic regimen is based on the most recent and highest quality evidence available.
- The dosage of vancomycin is typically administered at a dose of 15-20 mg/kg (actual body weight) intravenously within 120 minutes before surgical incision, as supported by 1.
- A single dose of vancomycin administered immediately before surgery is sufficient unless the procedure lasts greater than 6 hours, in which case the dose should be repeated, as stated in 1.
- Prophylaxis should be discontinued after a maximum of two doses, according to 1.
- It is essential to note that vancomycin is specifically chosen because it maintains activity against MRSA, which is resistant to traditional beta-lactam antibiotics.
- In patients with documented vancomycin allergy, alternative options such as daptomycin or linezolid may be considered.
- For patients known to be colonized with MRSA or in facilities with high MRSA prevalence, adding MRSA coverage to standard surgical prophylaxis is particularly important to reduce the risk of surgical site infections. Key considerations for surgical prophylaxis against MRSA include:
- Limiting prophylaxis to a single preoperative dose unless the procedure lasts longer than two half-lives of the antibiotic or there is excessive blood loss.
- Choosing antibiotics that maintain activity against MRSA, such as vancomycin.
- Discontinuing prophylaxis after a maximum of two doses to minimize the risk of antibiotic resistance.
From the FDA Drug Label
The cure rates by pathogen for microbiologically evaluable patients are presented in Table 18. Table 18 Cure Rates at the Test-of-Cure Visit for Microbiologically Evaluable Adult Patients with Complicated Skin and Skin Structure Infections Pathogen Cured ZYVOX n/N (%) Oxacillin/Dicloxacillin n/N (%) Methicillin-resistant S aureus 2/3 (67) 0/0 (-)
The cure rates in microbiologically evaluable patients with MRSA skin and skin structure infection were 26/33 (79%) for linezolid-treated patients and 24/33 (73%) for vancomycin-treated patients
Table 16: Clinical Success Rates by Infecting Pathogen in the cSSSI Trials in Adult Patients (Population: Microbiologically Evaluable) Pathogen Success Rate n/N (%) Daptomycin for Injection Comparator* Methicillin-resistant Staphylococcus aureus (MRSA) 21/28 (75%) 25/36 (69%)
- Surgical prophylaxis against MRSA:
- Linezolid and vancomycin have been shown to be effective against MRSA in the treatment of complicated skin and skin structure infections.
- Daptomycin has also been shown to be effective against MRSA in the treatment of complicated skin and skin structure infections.
- The choice of antibiotic for surgical prophylaxis against MRSA should be based on the specific clinical scenario and local antimicrobial resistance patterns.
- It is essential to note that the FDA drug label does not directly address the use of these antibiotics for surgical prophylaxis against MRSA, but rather for the treatment of complicated skin and skin structure infections. 2 3
From the Research
Surgical Prophylaxis for MRSA
The recommended antibiotics for surgical prophylaxis against Methicillin-resistant Staphylococcus aureus (MRSA) include:
- Vancomycin: The traditional dose of 1 gram intravenous is no longer considered adequate, and weight-based dosing of 15 mg/kg is recommended 4, 5.
- Daptomycin: Has been shown to have a broader effective dose range than vancomycin as prophylaxis against MRSA surgical implant infections in mice 6.
- Tigecycline: Also has a broader effective dose range than vancomycin as prophylaxis against MRSA surgical implant infections in mice 6.
Key Considerations
- Timing of vancomycin prophylaxis: Administration between 16 and 60 minutes before the first surgical incision is associated with the lowest incidence of surgical site infections (SSI) 7.
- Weight-based dosing: Is crucial to ensure adequate vancomycin levels, as a fixed 1-g dose may result in underdosing or overdosing 4, 5.
- Alternative antibiotics: Such as daptomycin and tigecycline, may be effective as prophylactic agents against MRSA infections, but further studies are needed to confirm their efficacy in humans 6, 8.
Important Findings
- Vancomycin prophylaxis has been associated with a higher rate of periprosthetic joint infection (PJI) compared to cefazolin prophylaxis 5.
- The majority of patients given vancomycin prophylaxis are underdosed according to weight-based dosage recommendations 5.
- MRSA did not occur in patients who were adequately dosed with vancomycin 5.