Daptomycin-induced Pneumonitis in a Patient with Chronic Obstructive Pulmonary Disease (COPD)

An 82-year-old Japanese man with severe chronic obstructive pulmonary disease (COPD) presented with lumbago and a consequent fever. He was subsequently diagnosed with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia (minimum inhibitory concentration (MIC) of vancomycin: 2 g/mL) complicated with a psoas abscess, facet joint and septic arthritis. Following the start of vancomycin treatment, the bacteremia persisted for eight days, despite an adequate trough level and source control. Therefore, we changed the medication to daptomycin (10 mg/kg/day) according to the appropriate guidelines (1), and the patient's blood culture became negative. After 16 days of treatment with daptomycin, he developed a low-grade fever and hypoxia. Because chest CT (Picture B) showed ground glass opacity in the bilateral lungs, which had not been present before 27 days (Picture A), we suspected daptomycin-induced pneumonitis (2) and changed the daptomycin to teicoplanin. Although sputum cytology was negative for eosinophils, the patient's symptoms and CT findings improved following the discontinuation of daptomycin (Picture C). In addition, the psoas abscess improved six weeks after the initiation of antibiotic therapy. These data demonstrate that it is important to provide a careful evaluation in Japanese patients receiving high doses of daptomycin.