Cefotetan

The Infectious Diseases Society of America, the Surgical Infection Society, the American Society for Microbiology, and the Society of Infectious Disease Pharmacists have released guidelines for the selection of antimicrobial therapy for adults with complicated intra-abdominal infections. The recommendations were published in the Oct. 15, 2003, issue of Clinical Infectious Diseases and are available online at: http://www. journals.uchicago.edu/CID/journal/ issues/v37n8/31800/31800.html.

The likely infectious agent(s), and therefore the drugs used to treat the infection, are determined by whether the infection is community acquired or health care associated. Health care-associated intra-abdominal infections are acquired most commonly as complications of previous elective or emergent intra-abdominal operations and are caused by nosocomial isolates particular to the site of the operation and the specific hospital and unit. For community-acquired infections, the location of the gastrointestinal perforation defines the infecting flora. Established infection beyond the proximal small bowel is caused by facultative and aerobic gram-negative organisms; infections beyond the proximal ileum also can be caused by a variety of anaerobic microorganisms.

Given the activity of common regimens against the anaerobic organisms identified in community-acquired infections, microbiologic work-up for specimens from such infections should be limited to identification and susceptibility testing of facultative and gram-negative bacilli. Susceptibility profiles for Bacteroides fragilis group isolates show substantial resistance to clindamycin, cefotetan, and quinolones, and these agents should not be used alone empirically in contexts in which B. fragilis is likely to be encountered.

Infections may be managed with a variety of single- and multiple-agent regimens (see accompanying table). No regimen has been shown consistently to be superior. Although many regimens have been studied in prospective trials, many of the studies have had serious methodologic flaws. Therefore, recommendations are based on in vitro activities.

For patients with community-acquired infections of mild to moderate severity, agents that have a narrower spectrum of activity and that are not commonly used for nosocomial infections are preferable to agents with broader coverage against gram-negative organisms or a greater risk of toxicity. Patients with more severe infections or those thought to be immunosuppressed may benefit from regimens with a broader spectrum of activity against facultative and aerobic gram-negative organisms.

Postoperative infections are likely to be caused by more resistant flora, such as Pseudomonas aeruginosa, Enterobacter species, Proteus species, methicillin-resistant Staphylococcus aureus, enterococci, and Candida species. For these infections, complex, multidrug regimens are recommended because adequate empiric therapy appears to decrease mortality. Local nosocomial resistance patterns should dictate treatment, and treatment should be altered on the basis of results of a thorough microbiologic work-up of infected fluid.

COPYRIGHT 2004 American Academy of Family Physicians
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