IN-VIVO THERAPEUTIC EFFICACY OF CEFDINIR (FK482), A NEW ORAL CEPHALOSPORIN, AGAINST STAPHYLOCOCCUS-AUREUS AND HAEMOPHILUS-INFLUENZAE IN MOUSE INFECTION MODELS

Cefdinir (FK482), a new oral cephalosporin, displayed patent oral acti vity versus induced infections in mice. In studies using beta-lactamas e-nonproducing (beta LAC-) and -producing (beta LAC+) Staphylococcus a ureus strains, respective PD(50)s (in mg/kg) were 11 and 24 for preven ting subcutaneous abscess and 2.7 and 2.3 for preventing lethal system ic infection. In studies using beta LAC- and beta LAC+ Haemophilus inf luenzae, respective PD(50)s were 5.8 and 3.1 for preventing lethal sys temic infection. Time-kill studies versus H. influenzae showed that 6- to 12-mg/kg dosing was effective in reducing viable counts of these s trains in blood by greater than or equal to 100-foId by 24 h after cha llenge. This in vivo performance was comparable to or exceeded values generated by cefaclor, cefpodoxime proxetil, and ampicillin.