From the Guidelines
For a dirty laceration with a history of MRSA, linezolid is the recommended antibiotic, as suggested by the most recent and highest quality study 1. The typical adult dosage is 600 mg twice daily for 7-14 days. Alternative options include trimethoprim-sulfamethoxazole (TMP-SMX) (one double-strength tablet, 160 mg TMP/800 mg SMX, twice daily), doxycycline (100 mg twice daily), or tedizolid if linezolid cannot be used due to allergies or other contraindications. The wound should also be thoroughly cleaned and debrided to remove foreign material and devitalized tissue. These antibiotics are effective against MRSA because they target different bacterial mechanisms than beta-lactam antibiotics (like methicillin) to which MRSA is resistant. MRSA has developed resistance to beta-lactam antibiotics through the acquisition of the mecA gene, which produces an altered penicillin-binding protein that prevents these antibiotics from disrupting cell wall synthesis. The recommended antibiotics work through different mechanisms, such as inhibiting bacterial folate synthesis (TMP-SMX) or protein synthesis (doxycycline, linezolid, tedizolid), allowing them to remain effective against MRSA strains. Key considerations in choosing an antibiotic include the severity of the infection, the presence of any underlying medical conditions, and the potential for antibiotic resistance 1. It is essential to note that the management of MRSA skin and soft-tissue infections may require individualized treatment based on the patient's clinical response and the results of culture and susceptibility testing 1.
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 (%) Staphylococcus aureus 73/83 (88) 72/84 (86) Methicillin-resistant S aureus 2/3 (67) 0/0 (-)
Recommended Antibiotic:
- Linezolid (ZYVOX) is effective against Methicillin-resistant Staphylococcus aureus (MRSA) with a cure rate of 67% in microbiologically evaluable patients with complicated skin and skin structure infections.
- Another study provided additional experience with the use of ZYVOX in the treatment of MRSA infections, with cure rates of 79% in microbiologically evaluable patients with MRSA skin and skin structure infection.
From the Research
Recommended Antibiotics for Dirty Laceration with MRSA History
- Vancomycin remains a first-line treatment drug for MRSA infections, including dirty lacerations 3, 4, 5.
- Daptomycin is an effective alternative to vancomycin, especially in cases of severe MRSA infections or when vancomycin is not effective 4, 5.
- Linezolid is another option for treating MRSA infections, including complicated skin and soft-tissue infections, and has been shown to be effective in some studies 6, 7.
- Quinolones, such as ciprofloxacin, may be used to treat MRSA infections, but their use is limited due to the risk of resistance emergence, and they are often used in combination with other agents, such as rifampin 3.
- Other antibiotics, such as teicoplanin, pristinamycin, and fusidic acid, may also be effective against MRSA, but their use is less common and may depend on specific circumstances 3, 6.
Considerations for Antibiotic Selection
- The choice of antibiotic should be based on the severity of the infection, the patient's medical history, and the susceptibility of the MRSA isolate to different antibiotics 4, 7.
- Individualized dosing and pharmacokinetic/pharmacodynamic (PK/PD) targets may be necessary to ensure effective treatment with vancomycin 4.
- Combination therapy with multiple antibiotics may be necessary in some cases, especially in severe or complicated infections 3, 5.