Combined use of topical and systemic antibiotics

An animal wound model was used to compare the effectiveness of topical and systemic antibiotics and to examine the validity of using a combined regimen of both routes of antibiotic delivery. Gross infection rates and wound bacterial concentrations were determined after contamination with Staphylococcus aureus or Escherichia coli. Both moderate (10(8) colony-forming units [CFU]) and heavy (10(12) CFU) contamination were studied for each organism. Following moderate contamination, topical and systemic antibiotics were equally effective in reducing both wound bacterial content and infection rate, but there was no benefit from the combined use of both modes of antibiotic delivery. An additive effect of the combined regimen was noted only when the level of wound contamination was heavy.