Combination therapy with an aminoglycoside for Staphylococcus aureus endocarditis and/or persistent bacteremia is associated with a decreased rate of recurrent bacteremia: a cohort study

• Published in: Infection 2011-12, Vol.39 (6), p.549-554
• Main Authors: Lemonovich, T. L., Haynes, K., Lautenbach, E., Amorosa, V. K.
• Format: Article
• Language: English
• Subjects: Aged; Aminoglycosides - administration & dosage; Anti-Bacterial Agents - administration & dosage; Bacteremia; Bacteremia - complications; Bacteremia - drug therapy; Bacteremia - microbiology; Bacteremia - mortality; Biological and medical sciences; Brief Report; Cohort Studies; Data processing; Drug Therapy, Combination - methods; Endocarditis; Endocarditis, Bacterial - complications; Endocarditis, Bacterial - drug therapy; Endocarditis, Bacterial - microbiology; Endocarditis, Bacterial - mortality; Family Medicine; Female; General Practice; Humans; Infectious Diseases; Internal Medicine; Length of Stay; Male; Medical sciences; Medicine; Medicine & Public Health; Middle Aged; Miscellaneous; Mortality; Population studies; Public health. Hygiene; Public health. Hygiene-occupational medicine; Renal failure; Retrospective Studies; Risk assessment; Secondary Prevention; Staphylococcal Infections - drug therapy; Staphylococcal Infections - microbiology; Staphylococcal Infections - mortality; Staphylococcus aureus; Survival Analysis; Treatment Outcome
• ISSN: 0300-8126; 1439-0973
• DOI: 10.1007/s15010-011-0189-2

Purpose Although limited data exist on the efficacy and potential risk of synergistic aminoglycoside therapy for persistent Staphylococcus aureus bacteremia and endocarditis, aminoglycosides are frequently used in clinical practice. Methods As our study population, we included subjects fulfilling the modified Duke criteria for S. aureus endocarditis and/or having greater than 72 h of S. aureus bacteremia. Among these subjects, we compared patients who did and did not receive aminoglycoside therapy for their S. aureus bloodstream infection. These groups were compared for the primary outcome of recurrent bacteremia, as well as for the duration of bacteremia, mortality, complication rate, and incident renal failure. Results Eighty-seven subjects fulfilled the inclusion criteria. Of these, 49 received aminoglycoside therapy, whereas 38 did not. There were no significant differences in the baseline characteristics when comparing groups who did or did not receive aminoglycoside therapy. Four (8.2%) subjects treated with aminoglycoside therapy experienced recurrent bacteremia versus nine (23.7%) who did not receive aminoglycoside therapy [relative risk and 95% confidence interval [RR (95%CI)] = 0.51 (0.22−1.17), p  = 0.04]. In multivariable analyses, aminoglycoside use remained significantly associated with a decrease in recurrent bacteremia [adjusted odds ratio (OR) (95%CI) = 0.26 (0.07−0.98), p  = 0.046]. No significant differences were seen between groups treated with and without an aminoglycoside in terms of the 6-month all-cause mortality (51.0 vs. 42.1%, p  = 0.41), complication rate (71.4 vs. 73.7%, p  = 0.82), or incident renal failure (54.5 vs. 46.9%, p  = 0.54). Conclusions The use of combination therapy with an aminoglycoside in persistent S. aureus bacteremia and/or endocarditis may be associated with a lower rate of recurrent bacteremia without significant differences in the incident renal failure.