Gram-negative or anaerobic bacteria
For deep incisional surgical site infection, or surgical site infection with systemic features, if Gram-negative or anaerobic bacteria are suspected (eg the procedure entered the gastrointestinal, respiratory or genital tracts), use:
2+0.2 g formulation
adult, or child 40 kg or more: 2+0.2 g 8-hourly. For dosage adjustment in adults with kidney impairment, see amoxicillin+clavulanate intravenous dosage adjustment
OR
1+0.2 g formulation
adult, or child 40 kg or more: 1+0.2 g 6-hourly. For dosage adjustment in adults with kidney impairment, see amoxicillin+clavulanate intravenous dosage adjustment
child 1 month to younger than 3 months and less than 4 kg: 25+5 mg/kg 12-hourly
child 1 month to younger than 3 months and 4 kg or more: 25+5 mg/kg 8-hourly
child 3 months or older and less than 40 kg: 25+5 mg/kg up to 1+0.2 g 8-hourly.
If Pseudomonas aeruginosa is suspected (eg based on previous culture results or local epidemiology), use:
piperacillin+tazobactam 4+0.5 g (child: 100+12.5 mg/kg up to 4+0.5 g) intravenously, 6-hourly1. For dosage adjustment in adults with kidney impairment, see piperacillin+tazobactam dosage adjustment. See below for switch to oral therapy and duration of therapy. piperacillin + tazobactam piperacillin+tazobactam piperacillin+tazobactam
For patients who report hypersensitivity to a penicillin, seek expert advice.
If the patient is at increased risk of MRSA infection (see Risk factors for infection with methicillin-resistant Staphylococcus aureus) or infection is associated with a prosthetic implant, add vancomycin to the above regimens. Use:
vancomycin intravenously; see Intermittent vancomycin dosing in noncritically ill adults or Intermittent vancomycin dosing for young infants and children for initial dosing. See below for switch to oral therapy and duration of therapy. vancomycin vancomycin vancomycin
Modify therapy based on the results of culture and susceptibility testing. If susceptibility results are not available by 72 hours and empirical intravenous therapy is still required, continue amoxicillin+clavulanate or piperacillin+tazobactam as monotherapy. Switch to oral antibiotic therapy when systemic features have resolved and source control has been achieved—see Empirical therapy for superficial surgical site infection.
The total duration of therapy depends on clinical response.