Relationships between vancomycin minimum inhibitory concentration, dosing strategies, and outcomes in methicillin-resistant Staphylococcus aureus bacteremia

• Published in: Diagnostic microbiology and infectious disease Vol. 71; no. 4; pp. 408 - 414
• Main Authors: Clemens, Evan C., Chan, Jeannie D., Lynch, John B., Dellit, Timothy H.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.12.2011; Elsevier
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents - administration & dosage; Anti-Bacterial Agents - pharmacokinetics; Anti-Bacterial Agents - pharmacology; antibiotic resistance; Bacteremia; Bacteremia - drug therapy; Bacteremia - microbiology; Bacterial diseases; Bacterial sepsis; Bacteriology; Biological and medical sciences; blood serum; Cohort Studies; confidence interval; Female; Fundamental and applied biological sciences. Psychology; Human bacterial diseases; Humans; Infectious Disease; Infectious diseases; Internal Medicine; Male; Medical sciences; methicillin; Methicillin-resistant Staphylococcus aureus; Methicillin-Resistant Staphylococcus aureus - drug effects; Methicillin-Resistant Staphylococcus aureus - isolation & purification; Microbial Sensitivity Tests; Microbiology; Middle Aged; Minimum inhibitory concentration; Miscellaneous; patients; pharmacokinetics; Retrospective Studies; Staphylococcal Infections - drug therapy; Staphylococcal Infections - microbiology; Staphylococcus aureus; Treatment Outcome; Vancomycin; Vancomycin - administration & dosage; Vancomycin - pharmacokinetics; Vancomycin - pharmacology; Young Adult; Vancomycin; Methicillin-resistant Staphylococcus aureus; Bacteremia; Minimum inhibitory concentration; Prognosis; Peptides; Infection; Antibiotic; Glycopeptide; Polypeptide; Bacteriosis; Bacteria; Micrococcales; Micrococcaceae; Antibacterial agent; Staphylococcus aureus
• ISSN: 0732-8893; 1879-0070; 1879-0070
• DOI: 10.1016/j.diagmicrobio.2011.08.002

Retrospective study aimed to examine outcomes of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia in relationship to vancomycin minimum inhibitory concentration (VAN MIC) and serum trough concentrations among subjects who had ≥1 blood culture positive for MRSA between April 2008 and August 2009. Treatment failure occurred in 7/24 (29%) subjects with VAN MIC = 2 mg/L versus 20/94 (21%) subjects with VAN MIC ≤1.5 mg/L (adjusted OR 1.11, 95% confidence interval [CI] 0.24–5.14). Among subjects who had documented VAN serum trough concentrations, treatment failure occurred in 5/26 (19%) subjects with concentrations <15 mg/L versus 18/68 (27%) subjects with concentrations ≥15 mg/L (adjusted OR 0.91, 95% CI 0.21–3.84). In conclusion, treatment outcomes were similar regardless of VAN MIC, although there was a non–statistically significant trend towards decreased clinical efficacy among patients with VAN MIC = 2 mg/L. Optimization of VAN pharmacokinetic indices did not appear to correlate with clinical responses.