Ertapenem for treatment of osteomyelitis: a case series

BACKGROUND: Ertapenem is a once-daily broad spectrum carbapenem that is increasingly used to treat polymicrobial osteomyelitis due to diabetic foot and traumatic wound infections. However, limited data exists on ertapenem use for osteomyelitis. This study aimed to characterize outcomes and adverse effects with empiric use of ertapenem for osteomyelitis. FINDINGS: A total of 112 patients presenting to Duke, Durham Regional or Durham VA Medical Centers with a suspected diagnosis of osteomyelitis and ertapenem use from 11/2001 to 8/2009 were screened, and 12 subjects met inclusion criteria for the study. Mean age was 60 ± 16 years, 68% were female, 75% were Caucasian, and the most common comorbidities included diabetes (58%), peripheral vascular disease (42%), and history of tobacco use (75%). Over half of the patients presented to a primary care clinic or emergency room greater than six months after the onset of clinical symptoms. Bone culture was obtained for diagnostic guidance in only two cases; and surgical intervention was pursued in three cases. Patients received a mean duration of 34.6 ± 7.8 days of therapy, and in three cases, subsequent suppressive oral antibiotics were given. Six (50%) patients met criteria for clinical success, defined as resolution of clinical signs and symptoms of infection such that discontinuation of antibiotics was deemed appropriate at end of ertapenem therapy, without recurrence at one year follow-up. No adverse drug effects were noted. CONCLUSIONS: In this case series of mostly community-acquired, lower extremity osteomyelitis, bone biopsy was infrequent, and an average six-week course of empiric ertapenem was well-tolerated with curative rates of 50% at one year.