Choice of Antibiotics for Necrotising Fasciitis

Emperical Therapy

• Empiric antibiotics should be started immediately. Initial antimicrobial therapy should be broad-based, to cover aerobic gram-positive and gram-negative organisms and anaerobes. 
• A foul smell in the lesion strongly suggests the presence of anaerobic organisms. 
• The maximum doses of the antibiotics should be used, with consideration of the patient's weight and liver and renal status
• Clindamycin is often added due to  for its antitoxin effects against toxin-elaborating strains of streptococci and staphylococci

Duration

• no specific duration based on clinical trials
• based on available recommendations, to use based on clinical response, no requirement for surgical debridements and fever free for at least 48-72 hours.

Acceptable regimens include administration of:

• A carbapenem or beta-lactam-beta-lactamase inhibitor, plus
• Clindamycin (dosed at 600 to 900 mg intravenously every eight hours in adults or 40 mg/kg per day divided every eight hours in neonates and children) for its antitoxin effects against toxin-elaborating strains of streptococci and staphylococci), plus
• An agent with activity against methicillin-resistant S. aureus (MRSA; such as vancomycin, daptomycin, or linezolid) (table 3). In neonates and children, vancomycin (15 mg/kg/dose every six to eight hours) is the usual empiric antibiotic for MRSA; the six-hour dosing interval is employed for sicker children

Organism Specific Treatment

Management of Skin and Soft Tissue Infections: 2014 Update IDSA

NAG 2014

Malaysian ICU Antibiotic Guideline 2012

references:
1. www.uptodate.com
2. http://emedicine.medscape.com/article/2012058-overview
3. Practice Guidelines on the Management of Soft Tissue and Skin Infection 2014 (IDSA)