We performed laboratory and clinical studies of Cefazolin, lately developed in Japan, and obtaine following results :
1) The sensitivities tests of Cefazolin and Cephaloridine were measured by using 53 strains of Staph. aureus, isolated from the osteomyelitis patients and cultured by the plate dilution method. It was found that the MIC values of Cefazolin were 0. 20 to 3. 13 mcg/ml, and peak was 0. 78 mcg/ml, which was half of all values. The antimicrobial activity of Cefazolin revealed less potent than that of Cephaloridine, but there were no strains having high resistance to Cefazolin.
2) Five hundreds mg of intramuscular injections dose revealed a peak of serum level at 1 hr. (18. 3 mcg/ml) and a peak of synovial fluid level at 2 hrs. (10. 3 mcg/ml) after injections. A thousand mg of intramuscular injections dose also revealed one and half times higher than that of 500 mg, especially the synovial fluid level of 500 mg of intramuscular injections dose showed considerably low value after 6 hrs. compared with that of 1, 000 mg of intramuscular dose.Therefore, it might be considered that 1, 000 mg of intramuscular dose giving twice daily is the reasonable way to administrate for the bone and joint infections in adults.
3) Thirteen cases of osteomyelitis and 4 cases of pyogenic arthritis and 5 cases of subcutaneous infection were treated with Cefazolin. The results for above infectious disease were excellent in 6 cases, good in 10 cases, fair 3 cases, and no effectiveness in 3 cases of Gram negative infections.
4) No side reaction was found in all cases.
