LINEZOLID FOR METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS PNEUMONIA: THE IMPACT OF OBESITY ON CLINICAL OUTCOMES

Objectives: Linezolid is an antibiotic used for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. Previous studies provided conflicting results regarding fixed-dose linezolid for obese patients with MRSA pneumonia. Some reported decreased concentrations in obese patients, while others reported similar concentrations and clinical outcomes. This study compared clinical efficacy and safety outcomes between obese and non-obese patients treated with linezolid for MRSA pneumonia. Methods: This was a retrospective chart review of adults who received at least 3 days of linezolid for MRSA pneumonia from October 1, 2009 to December 31, 2014. Primary outcome was clinical cure rate at 21 days. Secondary outcomes included inpatient mortality, thrombocytopenia, and anemia. Categorical and continuous data were evaluated using the Fisher's exact test and the student's t test, respectively. A p-value < 0.05 was considered statistically significant. Results: Forty-five patients in the non-obese group [body mass index (BMI) < 30 kg/m?], and 25 patients in the obese group [BMI ? 30 kg/m?] were identified. Clinical cure rate was 60% in the non-obese group and 48% in the obese group. Results of the secondary outcomes were reported as follows: anemia (64% in the non- obese group, 31% in the obese group), thrombocytopenia (40% in the non-obese group, 20% in the obese group), and in-hospital mortality (20% in the non-obese group, 15.6 % in the obese group). Conclusions: Similar incidence rates of clinical cure, mortality, thrombocytopenia, and anemia were found between obese and non-obese patients who received standard dose linezolid for MRSA pneumonia.