Organizing pneumonia and pulmonary eosinophilic infiltration associated with daptomycin

To report a case of organizing pneumonia with pulmonary eosinophilic infiltrates in a patient receiving daptomycin.

An 84-year-old man developed bilateral, irregularly shaped nodules and infiltrates in the mid and peripheral lung and multiple mediastinal lymph nodes following treatment with intravenous daptomycin for infection of his left knee prosthesis. His other symptoms included decreased appetite, weight loss (6.8 kg over 4-6 wk), malaise, and generalized weakness after 4 weeks of daptomycin therapy. Transthoracic needle biopsy revealed organizing pneumonia with scattered eosinophils. His symptoms and results of computed tomography (CT) scan improved in the month following discontinuation of daptomycin. The Naranjo probability scale indicated a probable reaction to daptomycin.

Pulmonary reactions have been reported with numerous drugs and have a wide range of clinical and radiographic presentations. Clinical trials have shown that daptomycin is well tolerated and has an adverse effect profile similar to that of vancomycin and the semisynthetic penicillins. This case report suggests that chronic use of daptomycin caused organizing pneumonia with eosinophilic infiltrates in a patient treated for an infected knee prosthesis. A definite mechanism for this reaction is not known. We speculate that the chronic administration of daptomycin allowed drug accumulation in surfactant in the alveolar spaces. This may result in higher concentrations of drug near the alveolar epithelial surface, which could injure the epithelium, resulting in organizing pneumonia.

Development of new pulmonary infiltrates in patients treated with chronic daptomycin therapy should alert healthcare workers to this potential association.