Table 1.

Site-Specific Empiric Antibiotic Guideline Recommendations^a

Site of Infection	Initial Empiric Therapy	Other Considerations
Pulmonary  CAP [19]  HAP/VAP [20]	Multidrug therapy with a beta-lactam (ampicillin + sulbactam, ceftriaxone, or ceftaroline) and a macrolide (azithromycin clarithromycin) Monotherapy with a respiratory fluoroquinolone (levofloxacin or moxifloxacin) Multidrug therapy with vancomycin or linezolid and piperacillin-tazobactam, cefepime, ceftazidime, imipenem, meropenem, or aztreonam	Risk factors for MRSA and/or Pseudomonas aeruginosa: add vancomycin or linezolid for MRSA coverage; replace standard CAP therapy with pseudomonal coverage such as piperacillin-tazobactam, cefepime, meropenem, or imipenem Recommendation based on “local validation” of risk factors for community onset MRSA or P aeruginosa or prior isolation of these organisms in the previous year, particularly from respiratory specimens Two antipseudomonal antibiotics from different classes (addition of fluoroquinolones, aminoglycosides, or polymyxins) if prior intravenous antibiotic use within 90 days for HAP/VAP and septic shock at time of VAP, ARDS preceding VAP, 5 or more days of hospitalization before VAP, or acute renal replacement therapy before VAP If prior colonization with carbapenem-resistant Enterobacteriales or KPC-producing organism ceftazidime-avibactam and meropenem-vaborbactam should be considered but further efficacy data is needed Empiric regimens should be informed by local distribution of pathogens and their antimicrobial susceptibilities
Central nervous system healthcare-associated ventriculitis and meningitis [21] Meningitis [22]	Vancomycin and cefepime, ceftazidime or meropenem Vancomycin and ceftriaxone	Beta-lactam choice based on local in vitro susceptibility patterns. If carbapenem-resistant Acinetobacter is suspected addition of meropenem and colistin or polymyxin B Age >50, alcohol abuse or immunocompromised: add ampicillin Penetrating head trauma, CSF shunt or postneurosurgery vancomycin and cefepime, ceftazidime or meropenem Clinical presentation suggestive of Rickettsial or Ehrlichial disease add doxycycline
Skin and soft tissue necrotizing fasciitis including Fournier gangrene [23]Nonpurulent cellulitis/erysipelas (severe) [23] Purulent furuncle/ carbuncle/abscess (severe) [23]	Multidrug therapy with vancomycin or linezolid and piperacillin-tazobactam, a carbapenem, or ceftriaxone and metronidazole Vancomycin and piperacillin-tazobactam Vancomycin, daptomycin, linezolid, telavancin, or ceftaroline	Prompt surgical consultation is recommended for patient with aggressive infections associated with signs of systemic toxicity or suspicion of necrotizing fasciitis or gas gangrene Emergent surgical inspection to rule out necrotizing process Incision and drainage as indicated
Intra-abdominal Community onset extrabiliary (mild) [24] Community onset extrabiliary (severe) [24] Community onset biliary (mild to moderate) [24] Community onset biliary severe or cholangitis [24]	Cefoxitin, ertapenem, moxifloxacin, or tigecycline Imipenem-cilastatin, meropenem, doripenem or piperacillin-tazobactam Cefazolin, cefuroxime, or ceftriaxone Imipenem-cilastatin, meropenem, or piperacillin-tazobactam, Levofloxacin or cefepime each in combination with metronidazole	Healthcare setting with high prevalence of ESBL-producing Enterobacteriales or >20% of Pseudomonas resistant to ceftazidime consider carbapenem or piperacillin-tazobactam Healthcare associated: imipenem-cilastatin, meropenem, or piperacillin-tazobactam, levofloxacin or cefepime each along with metronidazole, vancomycin added to each regimen Empiric therapy should be driven by local microbiological data and source control performed as indicated
Genitourinary Acute pyelonephritis (IDSA archived) [25]	Ceftriaxone, trimethoprim-sulfamethoxazole, or ciprofloxacin	Requiring hospitalization: intravenous fluoroquinolone, aminoglycoside, extended-spectrum cephalosporin, extended-spectrum penicillin, or carbapenem with choice of agents based on local resistance data Do not use fluoroquinolone if >10% resistance prevalence or trimethoprim-sulfamethoxazole in areas of high resistance

Abbreviations: ARDS, acute respiratory distress syndrome; CAP, community acquired pneumonia; CSF, cerebrospinal fluid; ESBL, extended-spectrum beta-lactamase; HAP, hospital-acquired pneumonia; IDSA, Infectious Disease Society of America; KPC, Klebsiella pneumoniae carbapenemase; MRSA, methicillin-resistant Staphylococcus aureus; VAP, ventilator-associated pneumonia.

^aPlease see individual guidelines for further details.