Efficacy of amoxycillin/clavulanic acid in experimental Staphylococcus aureusendocarditis in the rat

Abstract

The efficacy of amoxycillin/clavulanic acid was compared with that of flucloxacillin, vancomycin and amoxycillin in an experimental model of Staphylococcus aureus endocarditis. Doses of the antibiotics were selected to produce peak concentrations in rat serum similar to those achievable in man after administration of parenteral therapeutic doses. Amoxycillin clavulanic acid was more effective than amoxycillin alone against endocarditis caused by beta-lactamase producing strains of Staph. aureus, illustrating the beta-lactamase inhibitory activity of clavulanic acid in vivo. Amoxycillin/clavulanic acid was as effective as flucloxacillin in these infections whereas vancomycin was generally less active. These results illustrate the clinical potential of amoxycillin/clavulanic acid in the prophylaxis, or in the therapy of severe staphylococcal infections.

Efficacy of ticarcillin-clavulanic acid for treatment of experimental Staphylococcus aureus endocarditis in rats

“…This relatively poor activity of vancomycin has been demonstrated in other S. aureus endocarditis studies, both in rats (3)(4)(5) and in rabbits (6,8). It has also been reported that in vitro vancomycin may kill S.…”

“…The combination of clavulanic acid with amoxicillin has been shown to be effective in rats against early endocarditis in which the vegetations contained approximately 6 to 8 log1o CFU of S. aureus per g (3,5) and against late S. aureus endocarditis in which bacterial counts were 9 to 10 log1o CFU/g (5). The activity of a combination of clavulanic acid with ticarcillin against S. aureus endocarditis in rabbits has been reported elsewhere (7,24).…”

In vitro susceptibility ofStaphylococcus aureustowards amoxycillin‐clavulanic acid, penicillin‐clavulanic acid, dicloxacillin and cefuroxime

“…Only a few clinical and in vitro studies have, however, tried to assess the potential of amoxycillin clavulanic acid in severe staphylococcal infections as compared to other antistaphylococcal drugs. In experimental animal models, amoxycillin-clavulanic acid has been found just as effective as cloxacillinlflucloxacillin for staphylococcal endocarditis (13,14) and at least as effective in osteomyelitis (1 5). Moreillon has in a clinical study of patients with endocarditis found evidence that amoxycillin-clavulanic acid is effective in such infections (16).…”