Daptomycin in endocarditis and bacteraemia: a British perspective.

Assessment of the place of daptomycin in the treatment of endocarditis and bacteraemia requires assimilation of data from one open-label randomized comparative clinical trial sized for equivalence, from registry data and from case reports. Selected relevant animal models and in vitro data are also considered in an effort to produce an integrated assessment of the current place of daptomycin in treatment. The evidence for the use of daptomycin is best in Staphylococcus aureus bacteraemia and endocarditis, but also includes some data on infections due to Enterococcus spp., especially if vancomycin-resistant. The emergence of resistance in a minority of patients on current dose regimens may mean that trials have to be repeated with higher doses, or the drug used in a combined therapy where rifampicin may be the best choice. In general, equivalence to comparator antibiotic regimens and a correlation for in vitro and in vivo findings have been demonstrated, but there are important gaps in the clinical data including a comparative equivalence trial in streptococcal and enterococcal endocarditis. Clinical benefit might be anticipated, but has not been proved, over aminoglycoside-containing regimens, and economic assessments are critical in the decision as to when and how daptomycin is deployed.