Combination Antimicrobial Treatment Versus Monotherapy: The Contribution of Meta-analyses

Interactions between antibiotic combinations predicted by in vitro studies are not consistently reflected in clinical trials. Beta-lactam–aminoglycoside combinations, synergistic in vitro, do not confer improved survival or cure and do not prevent breakthrough infections. These conclusions are derived from recent systematic reviews and meta-analyses of randomized, controlled trials. Often, pertinent clinical outcomes could not be assessed meaningfully in individual randomized trials, but their compilation leads to strong conclusions relating to outcomes that affect the individual patient. Systematic reviews have made possible the evidence-based use of antibiotic combinations.