From the Guidelines
The next best step for this 48-year-old male with persistent MRSA infection of the bilateral hands is to initiate intravenous vancomycin therapy. The recommended dosing is 15-20 mg/kg every 8-12 hours, with therapeutic drug monitoring to maintain trough levels between 15-20 μg/mL for serious infections, as suggested by the Infectious Diseases Society of America guidelines 1. This treatment should be continued for at least 7-14 days, depending on clinical response. Prior to starting vancomycin, blood cultures, wound cultures with susceptibility testing, and possibly imaging studies should be obtained to assess the extent of infection. The patient should also receive surgical consultation for possible debridement if there are abscesses or necrotic tissue present. Vancomycin is recommended because the patient has failed multiple oral antibiotics including Bactrim, Keflex, and Clindamycin, suggesting a resistant or deep-seated infection requiring more potent therapy. MRSA is inherently resistant to beta-lactam antibiotics, and the failure of multiple alternative agents indicates the need for this glycopeptide antibiotic which disrupts bacterial cell wall synthesis by binding to D-alanyl-D-alanine residues. Close monitoring for nephrotoxicity and other adverse effects is essential during treatment, with regular assessment of renal function and vancomycin levels.
Some key points to consider in the management of this patient include:
- The importance of obtaining cultures and susceptibility testing to guide antibiotic therapy 1
- The need for surgical consultation for possible debridement if there are abscesses or necrotic tissue present 1
- The potential for vancomycin to cause nephrotoxicity and other adverse effects, and the need for close monitoring during treatment 1
- The consideration of alternative antibiotics, such as linezolid or daptomycin, if vancomycin is not tolerated or is ineffective 1
It's worth noting that the most recent guidelines from the Infectious Diseases Society of America, published in 2014, recommend vancomycin as the first-line treatment for MRSA infections, including those of the skin and soft tissues 1. Therefore, initiating intravenous vancomycin therapy is the most appropriate next step in the management of this patient.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Treatment of Persistent MRSA Infection
The patient has a persistent Methicillin-resistant Staphylococcus aureus (MRSA) infection of the bilateral hands, despite initial treatment with Trimethoprim/Sulfamethoxazole (Bactrim), Cephalexin (Keflex), and Clindamycin. The next best step is to prescribe Linezolid 600 mg BID for 10 days and follow-up in 14 days.
Rationale for Linezolid Treatment
- Linezolid has been shown to be effective in treating MRSA infections, including complicated skin and soft-tissue infections (cSSTI) 2, 3, 4, 5.
- A study published in 2009 found that linezolid-based salvage therapy was effective in eradicating S. aureus from the blood in patients with persistent MRSA bacteremia 6.
- Another study published in 2010 found that linezolid was more likely to achieve microbiologic eradication in MRSA evaluable patients compared to vancomycin 4.
- Linezolid has been shown to be well-tolerated, with common adverse events including gastrointestinal tract-related symptoms, such as nausea, vomiting, and diarrhea 3, 4, 5.
Key Considerations
- The patient's infection has persisted despite initial treatment with other antibiotics, making linezolid a suitable alternative 6, 2, 3, 4, 5.
- The patient should be monitored for adverse events, such as gastrointestinal symptoms, and for signs of clinical improvement or worsening of the infection.
- Follow-up in 14 days is necessary to assess the patient's response to linezolid treatment and to determine if further treatment is needed.