What antibiotics are effective against Staphylococcus aureus (Staph aureus) in wound infections?

From the Guidelines

For wounds potentially infected with Staphylococcus aureus, first-line antibiotic treatment typically includes cephalexin (500 mg orally four times daily for 5-10 days), dicloxacillin (500 mg orally four times daily for 5-10 days), or clindamycin (300-450 mg orally three times daily for 5-10 days) for uncomplicated infections. The choice of antibiotic should be guided by the severity of the infection, the presence of comorbidities, and the potential for methicillin-resistant Staphylococcus aureus (MRSA) 1.

Key Considerations

• For suspected MRSA, consider trimethoprim-sulfamethoxazole (1-2 double-strength tablets twice daily for 5-10 days) or doxycycline (100 mg orally twice daily for 5-10 days) 1.
• Wound care is equally important, including cleaning the wound with soap and water, applying topical antibiotic ointment like mupirocin, and covering with a sterile dressing 1.
• For deeper or more severe infections, intravenous antibiotics like vancomycin, linezolid, or daptomycin may be necessary 1.
• Treatment duration should be adjusted based on clinical response, with reassessment after 48-72 hours to ensure improvement 1.

Antibiotic Options

• Cephalexin: 500 mg orally four times daily for 5-10 days
• Dicloxacillin: 500 mg orally four times daily for 5-10 days
• Clindamycin: 300-450 mg orally three times daily for 5-10 days
• Trimethoprim-sulfamethoxazole: 1-2 double-strength tablets twice daily for 5-10 days
• Doxycycline: 100 mg orally twice daily for 5-10 days
• Vancomycin: 15-20 mg/kg/dose IV every 8-12 hours
• Linezolid: 600 mg PO/IV twice daily
• Daptomycin: 4 mg/kg/dose IV once daily

Special Considerations

• Patients with systemic toxicity or rapidly progressive infections may require inpatient management and surgical intervention 1.
• Cultures from abscesses and other purulent SSTIs are recommended in patients treated with antibiotic therapy, patients with severe local infection or signs of systemic illness, patients who have not responded adequately to initial treatment, and if there is concern for a cluster or outbreak 1.

From the FDA Drug Label

Staphylococcus aureus 73/83 (88) 72/84 (86) Methicillin-resistant S aureus 2/3 (67) 0/0 (-) Staphylococcus aureus 49/63 (78) 20/29 (69) Methicillin-resistant S aureus 12/17 (71) 2/3 (67)

Antibiotics that cover Staph aureus for wounds include:

• Linezolid, with cure rates of 88% for Staphylococcus aureus and 71% for Methicillin-resistant S aureus in complicated skin and skin structure infections, and 78% for Staphylococcus aureus and 71% for Methicillin-resistant S aureus in diabetic foot infections 2. Key points:
• Linezolid has been shown to be effective against Staphylococcus aureus and Methicillin-resistant S aureus in various types of infections.
• The cure rates for Linezolid are 88% for Staphylococcus aureus and 71% for Methicillin-resistant S aureus in complicated skin and skin structure infections.
• The cure rates for Linezolid are 78% for Staphylococcus aureus and 71% for Methicillin-resistant S aureus in diabetic foot infections.

From the Research

Antibiotics for Staph Aureus Wound Infections

• The choice of antibiotic for Staphylococcus aureus wound infections depends on the severity of the infection and local susceptibility patterns 3, 4, 5.
• For methicillin-susceptible S. aureus (MSSA) infections, penicillinase-resistant penicillins (flucloxacillin, dicloxacillin) are the antibiotics of choice, while first generation cephalosporins (cefazolin, cephalothin and cephalexin), clindamycin, lincomycin and erythromycin have important therapeutic roles in less serious MSSA infections 3.
• For methicillin-resistant S. aureus (MRSA) infections, vancomycin is reserved for treatment of infections caused by multiresistant MRSA strains and for patients with suspected endocarditis or severe sepsis, while macrolides, clindamycin and cotrimoxazole are options for community-acquired MRSA 3, 4.
• Newer antibiotics such as linezolid and quinupristin/dalfopristin have good antistaphylococcal activity, but are very expensive and should be reserved for patients who fail on or are intolerant of conventional therapy or who have highly resistant strains 3, 6.
• Oral antibiotics such as linezolid, trimethoprim-sulfamethoxazole, doxycycline, and minocycline may be used to treat less severe MRSA skin and soft tissue infections, but their efficacy has not been well studied and more clinical studies are needed 7.

Factors to Consider When Choosing an Antibiotic

• Local susceptibility patterns: The choice of antibiotic should be guided by local susceptibility patterns to ensure effective treatment 3, 4, 5.
• Severity of the infection: The severity of the infection determines the choice of treatment, with more severe infections requiring parenteral antibiotics such as vancomycin 3, 4.
• Potential adverse effects: The potential adverse effects of the antibiotic should be considered, with some antibiotics having a higher risk of adverse effects than others 6, 7.
• Cost: The cost of the antibiotic should also be considered, with some antibiotics being more expensive than others 3, 7.