Oral ciprofloxacin therapy for chronic contiguous osteomyelitis caused by aerobic gram-negative bacilli.

Twenty adult patients with chronic contiguous osteomyelitis caused by aerobic gram-negative bacilli were enrolled in an open, prospective cooperative study to determine the effect of oral ciprofloxacin therapy in a dosage of 750 mg every 12 hours. There were 14 men and six women, with a mean age of 55 years. Fifteen of the 20 patients had undergone previous unsuccessful attempts at therapy; seven of the 20 patients had clinically important underlying diseases. Osteomyelitis involved the sternum in three patients and the bones of the lower extremity in 17 patients. Initial surgical debridement was performed in 15 of 20 patients. The predominant organism isolated was Pseudomonas aeruginosa, which was found as a single pathogen in 13 patients and as part of a polymicrobic flora in three patients. Based on posttreatment follow-up of seven to 21 months, clinical cure was achieved in 13 of 20 (65 percent) patients and bacteriologic cure was achieved in 14 of 20 (70 percent) patients. Minimal inhibitory concentrations of ciprofloxacin against P. aeruginosa increased during therapy in four of 16 (25 percent) patients. Minor gastrointestinal side effects occurred in five patients. Oral ciprofloxacin was an effective and safe therapy in patients with chronic contiguous osteomyelitis due to aerobic gram-negative bacilli.