Ampicillin/Sulbactam Compared with Cefazolin or Cefoxitin for the Treatment of Skin and Skin Structure Infections

Abstract

The increasing prevalence of β-lactamase production by pathogens associated with cellulitis and soft-tissue infections have made the efficacy of standard treatment regimens suspect and demonstrate the need for a reappraisal of optimal medical management for these infections. In an open randomised, prospective study, the efficacy and toxicity of intravenous ampicillin/sulbactam was compared with cefazolin for the treatment of cellulitis and with cefoxitin for the treatment of soft-tissue infections. Ampicillin/sulbactam was given to 24 patients, cefoxitin to 16 and cefazolin to 12 patients. Analysis of clinical and bacteriological responses showed no significant differences between groups despite the fact that by in vitro testing 82 (98%) of isolates from soft-tissue infections were susceptible to ampicillin/sulbactam but only 68 (81%) were susceptible to cefoxitin (p < 0.001). The addition of sulbactam to ampicillin significantly enhanced its in vitro activity against β-lactamase-producing Staphylococcus aureus and anaerobic bacteria. All adverse reactions were subclinical, demonstrable only by mild laboratory abnormalities. Overall, ampicillin/sulbactam appears to be of comparable clinical efficacy in the treatment of polymicrobial soft-tissue infections with cefoxitin, or in the treatment of cellulitis with cefazolin. Additionally, when Enterococcus faecalis and S. aureus are recovered from a single culture, ampicillin/sulbactam, as opposed to cefoxitin monotherapy, would remain effective. Therefore, ampicillin/sulbactam will often be a less expensive therapeutic alternative.