Cefazolin was used in the treatment of nine patients with acute
enteric fever proven by positive blood cultures. In seven patients the causative organism was Salmonella typhi and in two it was Salmonella paratyphi B. Minimal inhibitory and minimal bactericidal concentrations of
cefazolin against the nine isolates ranged between 1.95 and 3.90 mug/ml.
Cefazolin was administered either intramuscularly or intravenously in a daily dose of 3 to 6 g for 11 to 16 days. The mean peak serum
antibiotic concentration after a 0.5-g
intravenous injection was 64.4 mug/ml, and the mean trough concentration, 3 h later, was 12.7 mug/ml. The highest serum inhibitory dilution at peak level was frequently 1/64, and at trough level it was 1/16 to 1/32. The acute
infection was satisfactorily controlled in all patients.
Phlebitis, complicating intravenous
therapy, in five out of eight patients, was the only side effect observed. Relapse of
typhoid fever, as documented by positive blood culture, occurred in one patient 11 days
after treatment course was completed. More extensive clinical studies are required before drawing any conclusions regarding the efficacy of
cefazolin in acute
enteric fever.