Cefepime effectiveness in Gram-negative bloodstream infections

Background: We used a retrospective cohort to evaluate the 28 day all-cause mortality in adult patients with Gram-negative bloodstream infection (BSI) who received cefepime therapy compared with those who received other β-lactam antibiotics with in vitro activity against aerobic Gram-negative bacilli. Methods: We identified 398 adult patients who received β-lactam antibiotic monotherapy during hospitalization at Mayo Clinic hospitals in Rochester, MN, USA, for monomicrobial Gram-negative BSI from 1 January 2001 to 31 October 2006. After adjusting for the propensity to receive cefepime, multivariable Cox proportional hazard regression was used to compare the 28 day mortality in patients who were treated with cefepime with that in those who received other β-lactam antibiotics. Results: The median age of patients with Gram-negative BSI was 65 years (interquartile range 51-77) and 230 (58%) were male. Compared with patients who received other β-lactams, patients treated with cefepime were more likely to have cancer (59% versus 44%, P=0.007) and immunocompromising conditions (55% versus 21%, P<0.001). Patients who received cefepime were less likely to have community-acquired infection acquisition (18% versus 33%, P=0.002) and urinary source of BSI (14% versus 23%, P=0.04) than those treated with other β-lactam antibiotics. After adjusting for the propensity to receive cefepime and other covariates in the multivariable Cox model, cefepime therapy was not associated with an increased 28 day all-cause mortality (hazard ratio 0.99, 95% confidence interval 0.53-1.79, P=0.97). Conclusions: In adult patients with monomicrobial Gram-negative BSI, cefepime therapy was not associated with increased mortality when compared with other β-lactam antibiotics,