Duration of antibiotic treatment in surgical infections of the abdomen. Undesired effects of antibiotics and future studies.

Effects of antibiotic administration other than bacterial killing are common and include drug interactions, toxic, and allergic reactions. Effective antibiotics do release endotoxin from enteric bacteria, but the clinical significance of this effect is uncertain, and present knowledge does not support alteration of clinical practice based on this information. The duration of antibiotic administration that is necessary for prophylactic purposes is short, probably 12 hours or less in all cases. The duration of administration that is necessary for treatment of established infections is not known in most cases. It is likely that current clinical practice errs on the side of continuing antibiotics longer than necessary. Prospective studies to find out the necessary duration of antibiotic treatment are needed. The design and interpretation of these studies will be difficult. Studies of a decision rule for stopping antibiotics are probably preferable to studies of arbitrary duration.