Alternatives for MRSA treatment in patients with Penicillin (PCN) allergy?

From the Guidelines

For patients with MRSA infections and a penicillin (PCN) allergy, alternative antibiotic options include doxycycline (100mg orally twice daily) or clindamycin (600mg orally or intravenously every 8 hours) 1.

Key Considerations

• In severe cases, linezolid (600mg orally or intravenously every 12 hours) or daptomycin (4 mg/kg every 24 h IV) may be considered 1.
• Vancomycin (30 mg/kg/d in 2 divided doses IV) is also an option for penicillin-allergic patients with MRSA infections 1.
• Treatment duration typically ranges from 7-14 days, depending on the severity and site of infection, with close monitoring for clinical response and potential adverse effects.

Additional Options

• Ceftaroline (600 mg bid IV) is a bactericidal option for MRSA infections 1.
• Trimethoprim-sulfamethoxazole (1–2 double-strength tablets bid po) may be considered, although its efficacy is poorly documented 1.
• It is essential to choose antibiotics based on in vitro susceptibility, patient allergies, intolerances, and potential drug interactions or contraindications to a specific antimicrobial 1.

From the FDA Drug Label

Clindamycin is indicated in the treatment of serious infections due to susceptible strains of streptococci, pneumococci, and staphylococci Its use should be reserved for penicillin-allergic patients or other patients for whom, in the judgment of the physician, a penicillin is inappropriate. Skin and skin structure infections caused by Streptococcus pyogenes, Staphylococcus aureus, and anaerobes.

Alternatives for MRSA treatment in patients with Penicillin (PCN) allergy:

• Clindamycin (PO or IV) can be considered for the treatment of serious skin and skin structure infections caused by Staphylococcus aureus, including MRSA, in penicillin-allergic patients 2 3.
• However, bacteriologic studies should be performed to determine the causative organisms and their susceptibility to clindamycin.
• The physician should consider the nature of the infection and the suitability of less toxic alternatives before selecting clindamycin.

From the Research

Alternatives for MRSA Treatment in Patients with Penicillin (PCN) Allergy

• Linezolid is an alternative for the treatment of MRSA infections, particularly in patients with penicillin allergy, as it has shown efficacy in eradicating MRSA in several studies 4, 5, 6.
• Tedizolid is another option for the treatment of MRSA infections, with potential advantages over linezolid including once-daily dosing and increased tolerability 7.
• Quinupristin/dalfopristin is also an approved therapeutic option for vancomycin-resistant Enterococcus faecium, and may be considered as an alternative for MRSA treatment in patients with penicillin allergy 5.
• Dose adjustments of linezolid may be necessary based on renal function in populations with different body weight to ensure efficacy and safety 8.

Efficacy of Alternative Treatments

• Linezolid has been shown to be superior to vancomycin in the eradication of MRSA in surgical site infections, with a statistically significant higher proportion of people in whom MRSA was eradicated in the linezolid group 4.
• Linezolid has also been shown to be as effective as vancomycin for the treatment of MRSA infections, with a higher microbiological eradication rate 6.
• Tedizolid has been evaluated in randomized controlled trials for the treatment of acute bacterial skin and soft tissue infections, and has shown potential advantages over linezolid 7.

Safety Considerations

• Linezolid has been associated with reversible anaemia and thrombocytopenia, particularly in patients with renal impairment 6, 8.
• Tedizolid has been shown to have increased tolerability compared to linezolid, but its cost may limit its adoption for ABSSSIs with MRSA 7.
• Quinupristin/dalfopristin has been associated with myalgia/arthralgia as a treatment-limiting adverse effect 5.