Ofloxacin versus parenteral therapy for chronic osteomyelitis.

We conducted a randomized comparison of oral ofloxacin (400 mg twice a day) and parenteral agents (cefazolin, 1.0 g intravenously every 8 h, or ceftazidime, 2.0 g intravenously every 12 h) in biopsy-confirmed, nonprosthesis osteomyelitis. A total of 19 subjects received ofloxacin for an average of 8 weeks, and 14 received parenteral antibiotics for an average of 4 weeks; both therapies were well tolerated. Infections were due to Staphylococcus aureus (40%), Enterococcus spp. (3%), Pseudomonas aeruginosa (15%), and other gram-negative organisms (42%). At the completion of therapy, one P. aeruginosa infection in the ofloxacin group persisted and the organism acquired resistance, accompanied by a resistant Acinetobacter superinfection. In the parenteral group, one S. aureus infection persisted, and there was a resolved superinfection due to S. aureus as well. Eighteen-month follow-up data have been obtained. Among those treated with ofloxacin, four subjects whose initial response to therapy was successful suffered relapses of infection, three due to S. aureus and one due to P. aeruginosa, while in the parenteral group, one subject with a P. aeruginosa infection relapsed. Long-term response to therapy was successful for 14 of 19 (74%) subjects who received ofloxacin and 12 of 14 (86%) who received parenteral antibiotics; the difference was not significant. Oral ofloxacin appears comparable to parenteral antibiotics in chronic osteomyelitis due to susceptible organisms, and oral ofloxacin offers advantages in economics and convenience.