What antibiotics have Methicillin-resistant Staphylococcus aureus (MRSA) coverage?

From the Guidelines

Antibiotics effective against Methicillin-resistant Staphylococcus aureus (MRSA) include vancomycin, linezolid, daptomycin, ceftaroline, telavancin, dalbavancin, oritavancin, tedizolid, tigecycline, and trimethoprim-sulfamethoxazole. The most recent and highest quality study 1 recommends the following oral antibiotics for the management of MRSA skin and soft-tissue infections (SSTIs): linezolid, trimethoprim-sulfamethoxazole (TMP-SMX), a tetracycline (doxycycline or minocycline), or tedizolid. For intravenous (IV) antibiotic coverage of MRSA in patients with SSTI, the study suggests the following agents: daptomycin, IV linezolid, IV ceftaroline, IV dalbavancin, IV vancomycin, IV tigecycline, or IV tedizolid. Some key points to consider when choosing an antibiotic for MRSA treatment include:

• The severity of the infection and the patient's clinical response
• The potential for resistance, particularly with clindamycin
• The need for coverage against other potential pathogens, such as streptococci
• The advantages and disadvantages of each antibiotic, including their spectrum of activity, tissue penetration, and potential side effects. Seven to 14 days of therapy is recommended but should be individualized on the basis of the patient’s clinical response 1. It's also important to note that vancomycin remains the first-line treatment for serious MRSA infections, with target trough levels of 15-20 μg/mL 1. Linezolid offers excellent tissue penetration and 100% oral bioavailability, making it a useful option for skin and soft tissue infections 1. Daptomycin is particularly useful for bacteremia and endocarditis but should not be used for pneumonia 1. Treatment duration varies by infection type, with 5-14 days for skin infections, 2-6 weeks for bacteremia, and 4-6 weeks for osteomyelitis 1.

From the FDA Drug Label

The linezolid resistance in these organisms was associated with a point mutation in the 23S rRNA (substitution of thymine for guanine at position 2576) of the organism. Linezolid has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections, as described in the INDICATIONS AND USAGE section Aerobic and facultative Gram-positive microorganisms Enterococcus faecium (vancomycin-resistant strains only) Staphylococcus aureus (including methicillin-resistant strains) Streptococcus agalactiae Streptococcus pneumoniae (including multi-drug resistant isolates [MDRSP]1) Streptococcus pyogenes

• Antibiotics with MRSA coverage include:
  • Daptomycin (IV) 2
  • Linezolid (PO) 3
• Key points:
  • Daptomycin has been shown to be effective against MRSA in clinical trials.
  • Linezolid is active against most isolates of MRSA, both in vitro and in clinical infections.
  • Resistance to linezolid has been reported in some cases, but it remains a viable option for treating MRSA infections.

From the Research

Antibiotics with MRSA Coverage

The following antibiotics have been shown to have coverage against Methicillin-resistant Staphylococcus aureus (MRSA):

• Vancomycin: remains an acceptable treatment option for MRSA infections, with a recommendation to maintain trough concentrations of 15-20 mg/L for serious infections 4, 5, 6
• Linezolid: has been shown to be superior to vancomycin in improving clinical and microbiological success in the treatment of MRSA-caused skin and soft tissue infections, and may be a preferred antibiotic for this indication 7, 8
• Daptomycin: is currently the only antibiotic to have shown noninferiority to vancomycin in the treatment of MRSA bacteremia, and may be a potential first-line drug against MRSA bacteremia 4, 8
• Ceftaroline: is a newer anti-MRSA antibiotic that has been approved for the treatment of MRSA infections, and may be used as a first-line option in certain cases 5
• Tedizolid: is a newer antibiotic that has been shown to be effective in the treatment of MRSA infections, and may be a potential alternative to linezolid 7
• Quinupristin/dalfopristin and tigecycline: may be options in patients with no other alternatives, but there are insufficient data to recommend them as first-line treatments for severe MRSA infections 4

Key Considerations

When selecting an antibiotic for the treatment of MRSA infections, the following factors should be considered:

• The severity of the infection and the patient's clinical status
• The presence of any underlying medical conditions or comorbidities
• The potential for resistance to certain antibiotics
• The need for individualized dosing and monitoring of vancomycin trough concentrations
• The potential for adverse effects, such as nephrotoxicity, associated with certain antibiotics 4, 5, 6