Ceftazidime as single-agent therapy for gram-negative aerobic bacillary osteomyelitis

Systemic antibiotic therapy for chronic osteomyelitis in adults

The standard recommendation for treating chronic osteomyelitis is 6 weeks of parenteral antibiotic therapy. However, oral antibiotics are available that achieve adequate levels in bone, and there are now more published studies of oral than parenteral antibiotic therapy for patients with chronic osteomyelitis. Oral and parenteral therapies achieve similar cure rates; however, oral therapy avoids risks associated with intravenous catheters and is generally less expensive, making it a reasonable choice for osteomyelitis caused by susceptible organisms. Addition of adjunctive rifampin to other antibiotics may improve cure rates. The optimal duration of therapy for chronic osteomyelitis remains uncertain. There is no evidence that antibiotic therapy for >4-6 weeks improves outcomes compared with shorter regimens. In view of concerns about encouraging antibiotic resistance to unnecessarily prolonged treatment, defining the optimal route and duration of antibiotic therapy and the role of surgical debridement in treating chronic osteomyelitis are important, unmet needs.

Treatment recommendations and strategies for the management of bone and joint infections

Bone and joint infections are a cause of rising concern, mainly owing to the increasing number of traumatic accidents, the appearance of new groups of patients at risk, the widespread use of prosthetic devices and the emergence of new patterns of antimicrobial resistance. Treatment guidelines and particular strategies for the management of such infections are reviewed. Decisions regarding the best therapeutic modality can be challenging and take into account the factors involved in infection staging, along with a better knowledge of the bacterial biofilm status. Surgery and antibiotic therapy are the keystones of the management, but overall the timing and length of treatment and follow-up should be posed to obtain the best quality of life for the patient. These infections are characteristically intriguing and sometimes need multiple surgical interventions and several courses of therapy. A multi-disciplinary approach is worthwhile in each institution. The collaboration of a specialized team composed by surgeons, pathologists, microbiologists and clinicians will permit diagnostic and therapeutic protocol-guided decisions.

Treatment of bone and joint infections caused by Gram-negative bacilli with a cefepime-fluoroquinolone combination

A 3-year retrospective study evaluated the effectiveness and safety of cefepime plus a fluoroquinolone for treating bone and joint infections caused by Gram-negative bacilli (GNB) in 28 patients. Intra-operative cultures yielded primarily Pseudomonas spp. and Enterobacter cloacae. Full recovery (cure) was observed in 79% of patients. There were no serious adverse effects and no resistant organisms were isolated. The results of the study confirmed the safety and effectiveness of cefepime combined with a fluoroquinolone for the treatment of bone and joint infections caused by Gram-negative bacilli.

Antibiotic treatment of osteomyelitis: what have we learned from 30 years of clinical trials?

OBJECTIVES AND DESIGN

To determine the most appropriate approach to antibiotic therapy for osteomyelitis, the medical literature for articles published from 1968 to 2000 was reviewed.

RESULTS

Ninety-three clinical trials in children and adults were identified using almost every antibiotic class. Most studies were non-comparative and the comparative trials involved relatively few patients. Publications generally did not provide clinically important information regarding infection staging or classification, surgical treatment provided, or the presence of orthopedic hardware. The median duration of follow-up after treatment was only 12 months. The clinical outcome was better for acute than chronic osteomyelitis in eight of the 12 studies allowing comparison. In the comparative trials, few statistically significant differences were observed between the tested treatments. In one small trial, the combination of nafcillin plus rifampin was more effective than nafcillin alone. In pediatric osteomyelitis, oral therapy with cloxacillin was more effective than tetracycline in one study, and oral clindamycin was as effective as parenteral anti-staphylococcal penicillins in another. In several investigations oral fluoroquinolones were as effective as standard parenteral treatments.

CONCLUSIONS

Although the optimal duration of antibiotic therapy remains undefined, most investigators treated patients for about six weeks. Despite three decades of research, the available literature on the treatment of osteomyelitis is inadequate to determine the best agent(s), route, or duration of antibiotic therapy.

Prolonged treatment of chronic Pseudomonas aeruginosa osteomyelitis with a combination of two effective antibiotics

Emergence of Pseudomonas aeruginosa resistant to antibiotic monotherapy is one of the causes of therapeutic failure in chronic P. aeruginosa osteomyelitis. We report 15 cases of chronic (> 3 months of evolution) biopsy culture proven P. aeruginosa osteomyelitis included in an open prospective study evaluating the efficacy of prolonged treatment (> 4 months) with two effective antibiotics in combination. Mean post-treatment follow-up was 38 months. A regimen of cefsulodin in combination with oral ofloxacin was used for six patients, cefsulodin-pefloxacin for three patients, cefsulodin-ciprofloxacin for one patient, piperacillin-pefloxacin for one patient, cefsulodin-fosfomycin for one patient, imipenem-ciprofloxacin for two patients and amoxicillin-ciprofloxacin-fosfomycin for one patient as home therapy. The clinical cure rate of 73% and bacteriological cure rate of 93% are far superior to those previously described in the literature. We did not observe adverse drug reactions. We think that a prolonged use of two effective antibiotics in combination is a safe and improved therapeutic schedule for chronic P. aeruginosa osteomyelitis.

Serious Infections Caused by Pseudomonas Aeruginosa

Over the last 3 decades, Pseudomonas aeruginosa has become a leading cause of infectious morbidity and mortality in certain predisposed patient populations. It primarily affects those with impaired host defenses, and its prevalence in the hospital environment makes it an important nosocomial pathogen. Infection with this organism may result in a broad spectrum of clinical manifestations, many of which may be seen in the intensive care setting. This review focuses on epidemiology, clinical presentations, nad treatment of serious Pseudomonas infections.

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.

Oral ciprofloxacin treatment of Pseudomonas aeruginosa osteomyelitis

Twenty-two adult patients with osteomyelitis due to Pseudomonas aeruginosa were enrolled in an open, prospective cooperative study to determine the efficacy of oral ciprofloxacin therapy in a dosage of 750 mg twice a day. Twenty patients received a complete course of treatment and could be assessed for efficacy. There were 12 men and 8 women, with a mean age of 55 years. Six patients had undergone previous, unsuccessful attempts at therapy. Eight patients had clinically important underlying conditions. The most common sites of infection were the sternum (six patients), hip (four patients), vertebrae (four patients), and tibia (two patients). Initial surgical debridement was performed in 18 of the 20 assessable patients. The mean duration of treatment was 2.85 months (range, 1 to 4 months), and that of the follow-up was 27 months (range, 6 to 52 months). Cure was achieved in 19 of the 20 (95%) patients. The only significant adverse effect (which prompted discontinuation of therapy) was severe nausea in one case. Oral ciprofloxacin coupled with adequate debridement is an effective, convenient, and safe therapy in patients with acute and subacute P. aeruginosa osteomyelitis.