Long-Term Linezolid in Cystic Fibrosis Patients Chronically Colonized with Staphylococcus Aureus (Sa)

Treatment of chronic colonization with methicillin-resistant Staphylococcus aureus (MRSA) and non-MR in cystic fibrosis (CF) patients shows a wide variability among CF units. While some caregivers prescribe continuous treatment with inhaled/ oral antibiotics, others only treat infectious exacerbations. Methods: 52 CF patients were included. Mean age was 25, 1 years. All patients were chronically colonized by SA (5% MR) and showed a poor clinical progress and respiratory function after receiving several conventional antibiotic cycles to treat infectious exacerbation. Every patient was prescribed continuous treatment with oral Linezolid: 600mg/12h for 15-21 days every 45 days, for a minimum of 1 year. Serial spirometry, sputum analysis and blood analysis were determined to rule out toxicity derived from a chronic treatment with Linezolid. Health related quality of life was measured every three months with the Cystic Fibrosis Questionnaire-Revised (CFQ-R) to detect any change. Results: An inflection in the pulmonary function drop in FEV1 and FVC was observed, with a recovery and slowing down of this drop after treatment. After a treatment period of at least one-year, no resistances against Linezolid nor serious adverse events were observed. Patient reported outcomes showed improvement in functionality and in clinical symptoms, with a significant decrease of cough and expectoration during the treatment. Conclusion: Treatment with Linezolid cycles is effective and safe in those patients colonized by SA who present both a clinical and functional torpid progress with conventional treatments. Linezolid allows the stabilization of the symptoms and lung function.