In Vitro Activity of Doripenem

Doripenem is a carbapenem antibiotic that covers a wide range of gram-positive and gram-negative pathogens. In vitro studies have provided insight into certain features of doripenem's activity profile that may have particular relevance in the clinical setting. For instance, in vitro data indicate that doripenem combines the intrinsic activity of meropenem against gram-negative pathogens with the intrinsic activity of imipenem against gram-positive pathogens. Also notable is the fact that the in vitro activity of doripenem against problematic gram-negative pathogens, in particular Pseudomonas aeruginosa, is potent-recent data show that the minimum concentration necessary for inhibition of 90% of all isolates (MIC(90)) of doripenem with respect to P. aeruginosa (4 microg/mL) is 2-4 times lower than the corresponding MIC(90) values of meropenem and imipenem. Furthermore, doripenem shows a limited ability to select for carbapenem-resistant mutants in vitro. Such experimental findings suggest that doripenem may represent a valuable option when carbapenem therapy is warranted for the treatment of serious infection.