Comparative Effectiveness of Vancomycin Versus Linezolid for the Treatment of Acute Pulmonary Exacerbations of Cystic Fibrosis

Background: Data are limited regarding the preferred antibiotics for treatment of acute pulmonary exacerbations (APEs) of cystic fibrosis (CF), when methicillin-resistant Staphylococcus aureus (MRSA) is suspected. Objective: To compare the rate of return to baseline lung function among individuals with APEs of CF treated with either vancomycin or linezolid. Methods: This retrospective study included individuals hospitalized for APEs of CF from May 1, 2015, to April 30, 2017 who were infected with MRSA and treated with vancomycin or linezolid. The primary outcome was the return to baseline lung function, as measured by forced expiratory volume in 1 s (FEV1). Descriptive and inferential statistics were used. All tests were 2-tailed with α set at 0.05. Results: A total of 122 encounters were included (vancomycin: n = 66; linezolid: n = 66). No difference existed in return to baseline FEV₁ between vancomycin (53 [80.3%]) and linezolid (50 [75.8%]; P = 0.53); nor was there a difference in median percentage change in FEV₁ from admission to follow-up between vancomycin (24.7%) and linezolid (20.7%; P = 0.61). Adverse drug events occurred more frequently in patient encounters treated with vancomycin (10 [15.2%]) compared with linezolid (2 [3%]; P = 0.002). Conclusion and Relevance: Our study observed no difference in the effectiveness of vancomycin compared with linezolid in terms of change in lung function for APEs of CF. The rate of adverse drug events was low. In individuals with CF infected with MRSA who are experiencing an APE, either vancomycin or linezolid appear to be viable treatment options.