What is the best course of treatment for a recurring bilateral hand MRSA infection?

From the Guidelines

I recommend prescribing linezolid 600 mg twice daily for 10 days for this 48-year-old male patient with recurrent bilateral hand MRSA infection that has not fully resolved despite previous treatment with Bactrim, Keflex, and Clindamycin. The patient should return for follow-up in 14 days to assess treatment response. Linezolid is an appropriate choice for this case as it has excellent activity against MRSA and achieves good tissue penetration in skin and soft tissue infections, as supported by the 2018 WSES/SIS-E consensus conference recommendations 1. It works by inhibiting bacterial protein synthesis through a different mechanism than previous antibiotics used, which may help overcome resistance.

The patient should be advised to complete the full 10-day course even if symptoms improve earlier to prevent recurrence. Common side effects include diarrhea, nausea, and headache. If the patient is taking serotonergic medications, they should be monitored for serotonin syndrome. Blood counts should be monitored if treatment extends beyond 14 days due to potential bone marrow suppression with prolonged use, as noted in the practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America 1. The patient should avoid tyramine-rich foods during treatment.

Key considerations for this patient's treatment include:

• The use of linezolid as an oral antibiotic option for empirical coverage of CA-MRSA in outpatients with SSTI, as recommended by the clinical practice guidelines by the Infectious Diseases Society of America for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children 1.
• The importance of individualizing the duration of therapy based on the patient's clinical response, with a recommended 7-14 days of therapy for complicated SSTI, as suggested by the 2018 WSES/SIS-E consensus conference recommendations 1.
• The need for careful monitoring of potential side effects and interactions, particularly when using linezolid in combination with other medications, as noted in the practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America 1.

From the FDA Drug Label

Complicated Skin and Skin Structure Infections Adult patients with clinically documented complicated skin and skin structure infections were enrolled in a randomized, multi-center, double-blind, double-dummy trial comparing study medications administered IV followed by medications given orally for a total of 10 to 21 days of treatment. The cure rates in clinically evaluable patients were 90% in linezolid-treated patients and 85% in oxacillin-treated patients A separate study provided additional experience with the use of ZYVOX in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. 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

The patient has a bilateral hand MRSA infection. The cure rate for MRSA skin and skin structure infection with linezolid is 79%. The recommended treatment duration for linezolid is 10 to 21 days. You are planning to prescribe linezolid for 10 days, which is within the recommended treatment duration.

• Key points:
  • Linezolid is effective against MRSA infections
  • The cure rate for MRSA skin and skin structure infection with linezolid is 79%
  • The recommended treatment duration for linezolid is 10 to 21 days
  • You are planning to prescribe linezolid for 10 days, which is within the recommended treatment duration 2

From the Research

Treatment of MRSA Infections

• The patient has a bilateral hand MRSA infection that has shown some improvement with Bactrim, Keflex, and Clindamycin, but is recurring 3.
• Linezolid (600 mg BID) for 10 days has been prescribed, with a follow-up in 14 days.
• According to a 2018 study, linezolid alone or in combination with a carbapenem is a possible treatment option for persistent MRSA bacteraemia 3.
• A 2016 study suggests that linezolid can be used as an empirical therapy for MRSA infections, particularly for moderate skin and soft tissue infections 4.
• Another study from 2015 discusses the use of combination antibiotic treatment for serious MRSA infections, including the combination of linezolid with other agents, but notes that there is limited evidence to support this approach 5.

Efficacy of Linezolid

• A 2012 review of linezolid for the treatment of MRSA infections found that it is an effective option for various types of infections, including pneumonia, skin and soft tissue infections, and osteomyelitis 6.
• A 2014 review of treatments for resistant Staphylococcus aureus infections notes that linezolid is probably the drug of choice for complicated MRSA skin and soft tissue infections, but its use in pneumonia is debatable 7.
• The same review also mentions that linezolid is one of several effective drugs for treating MRSA infections, along with vancomycin, quinupristin-dalfopristin, tigecycline, telavancin, ceftaroline, and daptomycin 7.

Considerations for Treatment

• When treating MRSA infections, it is essential to consider the site and severity of the infection, as well as the patient's recent exposure and source control 3, 4.
• The choice of antibiotic therapy should be based on the specific characteristics of the infection and the patient's individual needs 3, 4.
• Further research is needed to establish a preferred regimen for treating MRSA infections and to develop a universal treatment algorithm 3.