Cefazolin as Effective as Anti-Staphylococcal Penicillin for MSSA Spinal Epidural Abscess

Anesthetist injects anesthetic into a patient’s spine.
Investigators compared cefazolin and anti-staphylococcal penicillin for the treatment of methicillin-susceptible S aureus spinal epidural abscesses.

Investigators found no difference in efficacy between cefazolin and anti-staphylococcal penicillins (ASPs) for the treatment of methicillin-susceptible Staphylococcus aureus (MSSA) spinal epidural abscesses. The results of this retrospective multicenter study were published in Open Forum Infectious Diseases.              

Cefazolin is a common alternative to an ASP when treating MSSA. However, the 2 types of drug had yet to be compared for the treatment of MSSA spinal epidural abscesses. Using electronic health records and clinical microbiology databases, 79 adult patients with spinal epidural abscess secondary to MSSA were identified and included in the analysis.

Cefazolin was administered to 45 of 79 patients, and 34 patients received ASPs. Every patient except for 1 underwent aspiration or debridement, and the median time from diagnosis to aspiration or surgery was 1 day for both treatment groups. All patients were started with antibiotics at treatment initiation. The total duration of inpatient treatment for ASPs was 12.5 days compared with 9 days for cefazolin. The duration of outpatient therapy was 37 days and 38 days, respectively. There was no significant difference in intravenous vs oral antibiotics between groups or in hospital length of stay.

The percentage of patients undergoing treatment with ASP requiring antibiotic extension at 6 weeks because of clinical failure was 82.4%. For cefazolin this was similar at 75.6% (P =.58). By week 12, failure occurred in 44.1% of patients receiving ASP and 33.3% of patients receiving cefazolin (P =.35). In total, 11 (13.9%) patients died. Death related to spinal epidural abscess occurred in 2 patients in each group at week 6, with no further deaths by week 12. No significant differences in mortality were observed based on antibiotic therapy, and 90-day recurrence was reported in 8 patients (10.1%; P =1.00).

Both the retrospective nature of the study and small sample size were limitations. Differences in treatment outcomes using propensity scores were undetectable due to the small number of patients; so, too, were predictors of failure. Furthermore, the small number who did not receive surgical debridement meant that investigators could not comment on optimal therapy duration. There was also a potential confounding bias because more patients in the ASP group than in the cefazolin group were admitted to intensive care at baseline. Finally, a cefazolin inoculum effect was not directly measured in clinical isolates so that no associations between cefazolin failure and an inoculum effect by type A β-lactamases could be evaluated.

The investigators found no differences in efficacy between ASP or cefazolin treatment, suggesting that cefazolin can be an alternative for treating MSSA spinal epidural abscesses. The median duration of treatment in this study was 8 weeks, not the 6 weeks recommended by most experts, as explained by the investigators. They also concluded that further high-quality clinical trials are needed in order to determine the most beneficial form of treatment.


Campioli CC, Go JR, Abu Saleh O, Challener D, Yetmar Z, Osmon DR. Antistaphylococcal penicillin vs cefazolin for the treatment of methicillin-susceptible Staphylococcus aureus spinal epidural abscesses. Open Forum Infect Dis. Published online February 16, 2021. doi:10.1093/ofid/ofab071