New guide shows how to treat abdominal infections

December 8, 2003

A revised set of guidelines has been released on how to treat intra-abdominal infections


Rx Care

New guide shows how to treat abdominal infections

Antibiotic therapy continues to evolve. Keeping pace, the Infectious Diseases Society of America, the Surgical Infection Society, the American Society for Microbiology, and the Society of Infectious Disease Pharmacists recently released updated Guidelines for the Selection of Anti-infective Agents for Complicated Intra-abdominal Infections.

Changes in the new guidelines are probably not earth-shattering in terms of current practice (see box below). However, "they give pharmacists a lot more tools to work with their medical staffs and formulary committees for bringing drug use into more appropriate range for these patients," commented Joseph DiPiro, Pharm.D., professor of pharmacy, assistant dean and head of the department of clinical and administrative pharmacy, University of Georgia. He was one of the authors of the guidelines.

Douglas Fish, Pharm.D., president of the Society of Infectious Disease Pharmacists, associate professor and vice chair, department of clinical pharmacy, School of Pharmacy, University of Colorado, Denver, finds the new guidelines beneficial. He stated, "I think they provide evidence-based guidance for the practitioner and they discuss a lot of the issues (including cost and toxicities) that many practitioners are dealing with on a daily basis. They're not set up in such a way that they really handcuff a practitioner to just a few regimens."

Neither DiPiro nor Fish expect these guidelines to provoke major changes in existing hospital protocol. Fish stated, "I think for most institutions—certainly in our hospital at the University of Colorado—these guidelines fit in with what we are already doing. They just provide more literature-based evidence."

However, there are likely to be some changes. DiPiro believes some of the biggest protocol shifts will occur in the use of antifungals and coverage of Enterococcus. He told Drug Topics, "There are a lot of practitioners in the past few years who have been very ready to use antifungal drugs. This document hits that head-on and says not to use antifungal therapy unless species are identified." Antifungal agents are unnecessary unless a patient has recently received immunosuppressive therapy for neoplasm, transplantation, or inflammatory disease or has postoperative or recurrent intra-abdominal infection.

He continued, "The other thing is with Enterococcus.... The guidelines come out specifically and state that routine coverage is not necessary. If you use a combination like ciprofloxacin and metronidazole, that doesn't cover Enterococcus. But that's OK."

Fish remarked, "I think the comments about the fluoroquinolones were interesting. I know that one of the things we have been thinking about in our hospital is the use of intravenous moxifloxacin (Avelox, Bayer Corp.) for treatment of these types of complicated, mixed infections. It does have good anaerobic activity along with everything else, but these guidelines are pretty clear; because of the Bacteroides resistance that's being reported for fluoroquinolones, they don't recommend fluoroquinolones as single-agent therapies."

Fish also noted, "They [also] came out and very clearly stated that the agents that are being used to treat the nosocomial or ICU-type infections should not be routinely used to treat community-acquired infections. A lot of hospitals, for the sake of keeping the formulary relatively small and keeping costs down, want to pick one or two agents that are pretty versatile that they can use for all types of infections. But these guidelines really differentiate community-acquired from nosocomial: that the drugs used are completely different and you should try to avoid going back and forth between those two types of infections with the drugs that you are routinely using."

The guidelines have been published in short form: Clinical Infectious Diseases 2003;37:997-1005 and in more detail in Surgical Infections 2002; 3: 161-173;175-233.

Kathy Hitchens, Pharm.D.

The AUTHOR is a medical writer based in Indianapolis.

Revised recommendations at a glance

• There's more emphasis on newer carbapenems (meropenem and ertapenem) and fluoroquinolones (especially combinations like ciprofloxacin with metronidazole).

• There's a decreased emphasis on aminoglycoside combinations due to toxicities, and on older cephalosporins (cefoxitin and cefotetan) because of some resistance problems.

• If aminoglycosides must be used, peak concentrations should be adequate.

• Antifungal agents are unnecessary unless a patient has recently received immunosuppressive therapy for neoplasm, transplantation, or inflammatory disease, or has postoperative or recurrent intra-abdominal infection; no antifungal therapy should be given unless species is identified.

• High-risk patients (with prognostic factors for death) may require expanded spectra regimens.

• Routine Enterococcus coverage is not necessary for community-acquired infections.

• There's a possibility of oral completion therapy for patients on oral diets.

• The duration of therapy is five to seven days for most intra-abdominal infections.


Kathy Hitchens. New guide shows how to treat abdominal infections. Drug Topics Dec. 8, 2003;147:42.