Oral Beta-Lactam Step-Down Therapy for Uncomplicated Bacteremia

Pharmacokinetic/Pharmacodynamic Considerations

For optimal efficacy, beta-lactam antibiotics should maintain free plasma concentrations between four and eight times the MIC of the causative bacteria for 100% of the dosing interval (fT ≥ 4–8 × MIC = 100%) 1
When selecting oral beta-lactam therapy, consideration should be given to the susceptibility of the organism (lower MICs are more favorable for oral therapy) 1
The bioavailability of the specific beta-lactam being used should also be considered 2

Immunocompromised patients should not be given oral beta-lactams without careful consideration, according to the Infectious Diseases Society of America 3

Critical Care, 2019

American Journal of Respiratory and Critical Care Medicine, 2005

Clinical Infectious Diseases, 2014