Clinical Experiences with Cefazolin and Other Cephalosporins in Bacterial Endocarditis

Abstract

Eleven patients with bacterial endocarditis were treated with cefazolin, a new cephalosporin antibiotic. The antibiotic was well tolerated, and high levels in blood were achieved without accumulation of the drug or toxicity. Nine of the patients with endocarditis due to Staphylococcus aureus and one with endocarditis due to Bacillus species were cured. One patient with staphylococcal endocarditis failed to respond to cefazolin. Although the organism isolated from this patient was sensitive to cefazolin when a small inoculum was used, tests of susceptibility with a large inoculum showed resistance to cefazolin. The results with cefazolin in the present study and the recorded experience with cephalothin, cephaloridine, and cephalexin indicate that these agents may be used as effective substitutes for penicillin and penicillin derivatives in the treatment of staphylococcal and streptococcal (not enterococcal) endocarditis when penicillin is contraindicated.