Pharmacokinetic/Pharmacodynamic Index Linked to Efficacy of the Ampicillin-Ceftriaxone Combination against Enterococcus faecalis.

Combination therapy with ampicillin plus ceftriaxone (AMP+CRO) is the first-line therapy for treating severe infections due to Enterococcus faecalis. However, the pharmacokinetic/pharmacodynamic (PK/PD) index linked to the efficacy of the combination is not yet defined, hindering dose optimization in the clinic. Because classical PK/PD indices are not directly applicable to antimicrobial combinations, two novel indices were tested in the optimized murine model of infection by E.

A new pharmacodynamic approach to study antibiotic combinations against enterococci in vivo: Application to ampicillin plus ceftriaxone.

The combination of ampicillin (AMP) and ceftriaxone (CRO) is considered synergistic against Enterococcus faecalis based on in vitro tests and the rabbit endocarditis model, however, in vitro assays are limited by the use of fixed antibiotic concentrations and the rabbit model by poor bacterial growth, high variability, and the use of point dose-effect estimations, that may lead to inaccurate assessment of antibiotic combinations and hinder optimal translation. Here, we tested AMP+CRO against two strains of E. faecalis and one of E.

[Effectiveness of the antibiotic combinations for enterococcal infections treatment: a critical review].

During the last decades, enterococci have emerged as important etiological agents in bacteremia, osteomyelitis, endocarditis and soft tissue infections. Antimicrobial combinations have been the most used therapeutic strategies for these infections, aiming for a bactericidal synergistic effect. However, besides in vitro and in vivo models, the clinical usefulness of such combinations is controversial, especially in non-endocardic systemic infections.