Infectious Diseases I
Community-acquired, mild to moderate severity, low risk for treatment failure
Routine culture is not recommended.
ii.
Empiric antibiotic therapy should include agents active against aerobic and facultative enteric
gram-negative bacilli and enteric streptococci. Obligate anaerobic therapy should be initiated
in patients with distal small bowel, appendiceal, or colonic sources. Concerns with emergence
of antibiotic resistance may limit the utility of narrower-spectrum agents (e.g., cefazolin;
cefoxitin). Anti-enterococcal and antipseudomonal therapies are not recommended.
| (a) | Either ceftriaxone or cefotaxime in combination with metronidazole (generally considered |
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first line)
| (b) | Cefuroxime plus metronidazole |
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| (c) | Ertapenem |
| (d) | Moxifloxacin alone; levofloxacin or ciprofloxacin plus metronidazole for patients with |
severe Ξ²-lactam allergies
| (e) | Tigecycline |
|---|---|
| (1) | No longer guideline recommended for empiric use, but can be considered for definitive |
treatment.
| (2) | Pooled results from approval trials across all infections suggests increased mortality |
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in patients treated with tigecycline versus active comparator regimens. The cause of
this increase has not been established.
| (3) | FDA-approved label warns that the increase in all-cause mortality should be |
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considered when selecting among treatment options.
| d. | Community acquired, high risk for treatment failure defined as two or more of the following risk |
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factors: Severe physiologic disturbance (e.g., septic shock); advanced age; immunocompromised
state; diffuse peritonitis; delay in, or high likelihood of failure to achieve primary source control
Routine culture of intra-abdominal fluid is recommended as available.
ii.
Empiric antimicrobial therapy should be broadened to include MDROs, enterococci, and
obligate anaerobes. Agents active against MRSA are not recommended empirically. Although
fluoroquinolones are recommended, emergence of resistant E. coli and P. aeruginosa is a
concern.
| (a) | Broad-spectrum carbapenem (e.g., imipenem, meropenem) |
|---|---|
| (b) | Either cefepime or ceftazidime in combination with metronidazole (may need additional |
anti-enterococcal agent)
| (c) | Either ciprofloxacin or levofloxacin in combination with metronidazole (may need |
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additional anti-enterococcal agent)
| (d) | Piperacillin/tazobactam (or cefepime/ceftazidime) would not be appropriate if an ESBL |
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infection
Health care associated
Routine culture of intra-abdominal fluid is recommended as available.
ii.
Broad-spectrum empiric antimicrobial therapy should include coverage for MDR Gram
negative bacilli (e.g., P. aeruginosa) and obligate anaerobes. Depending on empiric antibiotic
susceptibility rates (i.e., local antibiogram), combination therapy against aerobic gram-
negative bacilli with aminoglycoside, or, if MDROs are prevalent, ceftolozane-tazobactam
and/or polymyxin.
| (a) | Broad-spectrum carbapenem (e.g., imipenem, meropenem with or without anti- |
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enterococcal therapy)
| (b) | Either cefepime or ceftazidime (second line agent) in combination with metronidazole. |
|---|---|
| (c) | Piperacillin/tazobactam |