| Adults | Children |
| Options for empiric gram-negative and anaerobic coverage include: | |
| Monotherapy with a beta-lactam/beta-lactamase inhibitor, such as one of the following: | |
| Ampicillin-sulbactam 3 g IV every six hours | 50 mg/kg per dose (based on ampicillin component) every six hours* |
| Piperacillin-tazobactam 3.375 g IV every six hours | 100 mg/kg per dose (based on piperacillin component) every eight hours* |
| A third-generation cephalosporin such as ceftriaxone 1 to 2 g IV every 24 hours PLUS Metronidazole 500 mg IV every eight hours | A third-generation cephalosporin such as ceftriaxone 100 mg/kg IV daily, given in one to two divided doses* PLUS Metronidazole 10 mg/kg IV per dose every eight hours* |
| Alternative empiric regimens include: | |
| A fluoroquinolone (eg, ciprofloxacin 400 mg IV every 12 hours, levofloxacin 500 mg IV daily, or moxifloxacin 400 mg IV daily) PLUS Metronidazole 500 mg IV every eight hours | Use fluoroquinolones with caution in children <18 years of age; if unable to tolerate other choices: A fluoroquinolone (ciprofloxacin 20 mg/kg IV per dose twice daily or levofloxacin 10 mg/kg IV per dose twice daily if <5 years old or once daily if ≥5 years) PLUS Metronidazole 10 mg/kg IV per dose every eight hours |
| Monotherapy with a carbapenem¶, such as one of the following: | |
| Imipenem-cilastatin 500 mg every six hours | 25 mg/kg per dose every six hours (maximum 500 mg per dose) |
| Meropenem 1 g every eight hours | 20 mg/kg per dose every eight hours (maximum 1 g per dose) |
| Ertapenem 1 g daily | Children ≤12 years old: 15 mg/kg per dose every 12 hours (maximum 500 mg per dose) Children >12 years old: Refer to adult dosing |