Organized antibiotic research since the discovery of penicillin and streptomycin has produced signicant advances along 3 lines. In the first place, the physician now has a choice of about 28 antibiotics and more than 400 preparations of them that are available in the United States for human and/or veterinary use, with more on the way.1 Second, older, widely used drugs among these have been undergoing changes in formulations, thereby improving absorption, reducing side-effects, or both. Third, well-controlled and carefully documented studies have yielded more precise information on how antibiotics may be best used and where their use is best avoided. These advances notwithstanding, the list of bacterial surgical infections treatable with antibiotics has remained unchanged in the past 10 years. The newer antibiotics, of course, provide effective weapons against infections due to bacteria resistant to the older drugs.
The aims of antibiotic therapy in surgical patients can be simply