Nitrofurantoin and lung disease

Nitrofurantoin prophylaxis can, uncommonly, cause interstitial lung disease, acute respiratory distress syndrome (ARDS), alveolar hemorrhage, and bronchiolitis obliterans. 

More commonly, it is associated with an acute syndrome of hypersensitive lung disease that starts less than a month after initiation of therapy, and a more chronic syndrome characterized by alveolitis or fibrosis.