Bactericidal effects of amoxycillin/clavulanic acid and ticarcillin/clavulanic acid in in-vitro kinetic models.

The bactericidal effects of amoxycillin and ticarcillin in the presence of clavulanic acid against beta-lactamase-producing bacteria were investigated in in-vitro kinetic models. Amoxycillin/clavulanic acid was rapidly bactericidal as a simulated intravenous 1.2 g bolus dose, against a strain of Klebsiella pneumoniae highly resistant to amoxycillin. Similarly, ticarcillin/clavulanic acid at concentrations similar to those achieved with a 30 min iv infusion of ticarcillin/clavulanic acid (5.0 g/200 mg) produced bactericidal effects against a ticarcillin-resistant strain of Pseudomonas aeruginosa. Addition of gentamicin to the system resulted in a further enhancement of activity.