Comparative evaluation of cefazolin and clindamycin in the treatment of experimental Staphylococcus aureus osteomyelitis in rabbits.

A rabbit model for Staphylococcus aureus osteomyelitis was used to compare treatment with clindamycin and cefazolin. Cefazolin (5 mg/kg), cefazolin (15 mg/kg), and clindamycin (70 mg/kg) were injected subcutaneously every 6 h for 28 days. After treatment, S. aureus was found in bone cultures from 22 of 23 control rabbits, 12 of 22 rabbits treated with cefazolin (5 mg/kg), 12 of 23 rabbits treated with cefazolin (15 mg/kg), and 2 of 20 rabbits treated with clindamycin. Drug concentrations in serum, uninfected bone, and infected bone were measured 30 min after cefazolin or clindamycin was injected into a group of rabbits which had been infected for 3 to 4 weeks. Clindamycin gave the highest concentration in infected and uninfected bone. The results of the study showed that clindamycin was superior to cefazolin in the eradication of S. aureus from infected bone in an experimental model.