From the Guidelines
Ancef (cefazolin) does not effectively cover MRSA (Methicillin-resistant Staphylococcus aureus). Ancef is a first-generation cephalosporin antibiotic that works well against many bacteria, including methicillin-sensitive Staphylococcus aureus (MSSA), but it is not effective against MRSA. This is because MRSA has developed resistance to beta-lactam antibiotics, including cephalosporins like Ancef, through the production of altered penicillin-binding proteins (specifically PBP2a) that have low affinity for these antibiotics.
Key Points to Consider
- For MRSA infections, alternative antibiotics such as vancomycin, linezolid, daptomycin, or trimethoprim-sulfamethoxazole are typically used, depending on the site and severity of infection 1.
- If MRSA is suspected or confirmed, it's essential to switch to one of these MRSA-active agents rather than continuing with Ancef, as treatment failure could occur and potentially lead to worsening infection.
- The most recent guidelines suggest using linezolid, trimethoprim-sulfamethoxazole, a tetracycline (doxycycline or minocycline), or tedizolid for oral antibiotic coverage of MRSA in patients with skin and soft-tissue infections (SSTIs) 1.
- For intravenous antibiotic coverage of MRSA in patients with SSTIs, suggested agents include daptomycin, IV linezolid, IV ceftaroline, IV dalbavancin, IV vancomycin, IV tigecycline, or IV tedizolid 1.
Treatment Recommendations
- Seven to 14 days of therapy is recommended but should be individualized on the basis of the patient’s clinical response 1.
- IV to oral switch should occur when criteria of clinical stability have been reached 1.
From the FDA Drug Label
Methicillin-resistant staphylococci are uniformly resistant to cefazolin, and many strains of enterococci are resistant The FDA drug label does not answer the question about MRSA coverage by the name "ancef", but it does state that Methicillin-resistant staphylococci are uniformly resistant to cefaolin.
- MRSA is a type of methicillin-resistant staphylococcus.
- Ancef is another name for Cefazolin. Therefore, based on the information provided, Ancef (Cefazolin) does not cover MRSA. 2
From the Research
Antibiotic Coverage for MRSA
- Ancef (cefazolin) is a cephalosporin antibiotic that is effective against methicillin-susceptible Staphylococcus aureus (MSSA) but not against methicillin-resistant Staphylococcus aureus (MRSA) 3.
- Vancomycin is a glycopeptide antibiotic that is effective against MRSA and is often used as a first-line treatment for MRSA infections 4, 5, 6, 7.
- Linezolid is an oxazolidinone antibiotic that is effective against MRSA and has been shown to be superior to vancomycin in some studies 4, 5, 6.
- Ceftaroline is a cephalosporin antibiotic that is effective against MRSA and has been shown to be non-inferior to daptomycin in the treatment of MRSA bacteremia 7.
- Daptomycin is a cyclic lipopeptide antibiotic that is effective against MRSA and is often used as a first-line treatment for MRSA bacteremia 5, 6, 7.
Treatment Recommendations for MRSA
- The choice of antibiotic for the treatment of MRSA infections depends on the severity of the infection, the site of infection, and the patient's underlying medical conditions 7.
- Vancomycin, linezolid, and daptomycin are all effective treatments for MRSA infections, but the choice of antibiotic should be based on the patient's specific needs and the local epidemiology of MRSA 4, 5, 6.
- Cefazolin and other beta-lactam antibiotics are not effective against MRSA and should not be used as monotherapy for the treatment of MRSA infections 3.
- Source control, such as removal of infected intravascular devices or drainage of abscesses, is a critical component of the treatment of MRSA bacteremia 7.