What are the recommendations for intravenous (IV) antibiotics for severe cellulitis?

Intravenous Antibiotic Recommendations for Severe Cellulitis

For hospitalized patients with severe cellulitis, intravenous vancomycin is the first-line recommended therapy with the strongest evidence (A-I), with alternatives including linezolid, daptomycin, telavancin, and clindamycin. 1

First-Line IV Options for Severe Cellulitis

• Vancomycin IV (15-20 mg/kg/dose every 8-12 hours) - Strongest recommendation (A-I) 1
• Linezolid 600 mg IV twice daily - Strong evidence (A-I) 1
• Daptomycin 4 mg/kg/dose IV once daily - Strong evidence (A-I) 1
• Telavancin 10 mg/kg/dose IV once daily - Strong evidence (A-I) 1
• Clindamycin 600 mg IV three times daily - Moderate evidence (A-III) 1

Treatment Duration and Transition to Oral Therapy

• 7-14 days of therapy is recommended for complicated skin and soft tissue infections 1
• Treatment duration should be guided by clinical response rather than a fixed duration 1
• Transition to oral therapy is appropriate when clinical improvement occurs 2
• Recent evidence suggests that shorter courses (5 days) may be as effective as longer courses if clinical improvement is observed 2

Special Considerations

MRSA Coverage

• For hospitalized patients with complicated skin and soft tissue infections (cSSTI), empirical therapy for MRSA should be considered pending culture data 1
• Vancomycin is the preferred agent for MRSA coverage in severe infections 1

Pediatric Dosing

• For hospitalized children with cSSTI:
  • Vancomycin is recommended (A-II) 1
  • Clindamycin 10-13 mg/kg/dose IV every 6-8 hours (to administer 40 mg/kg/day) is an option if clindamycin resistance rate is low (<10%) 1
  • Linezolid 600 mg IV twice daily for children >12 years and 10 mg/kg/dose IV every 8 hours for children <12 years 1

Factors Affecting Treatment Duration

Several factors may influence the duration of IV antibiotic therapy:

• Patient age (older patients may require longer treatment) 3
• Elevated C-reactive protein levels before treatment 3
• Presence of diabetes mellitus 3
• Presence of bloodstream infection 3

When to Consider Alternative Antibiotics

• If beta-lactam therapy fails to produce improvement 4
• In patients with systemic toxicity 4
• In areas with high prevalence of community-associated MRSA 5
• In patients with purulent drainage (suggesting MRSA involvement) 1

Monitoring and Follow-up

• Regular assessment of clinical response is essential
• Monitor for adverse effects, particularly with vancomycin (nephrotoxicity)
• Consider transitioning to oral therapy once clinical improvement is observed 2

Common Pitfalls to Avoid

• Failing to obtain cultures from purulent drainage before starting antibiotics 1
• Inadequate dosing of vancomycin (target trough levels of 15-20 μg/mL for serious infections)
• Prolonged IV therapy when oral therapy would be sufficient 2
• Failure to consider host factors (diabetes, immunosuppression) that may affect response 3

The evidence strongly supports the use of IV vancomycin as first-line therapy for severe cellulitis requiring hospitalization, with several effective alternatives available based on patient factors and local resistance patterns.