Consider Nitrofurantoin as a Cause of Lung Injury

Nitrofurantoin-induced diffuse lung toxicity is well documented in the literature but is often misdiagnosed. We describe an 82-year-old female medicated with nitrofurantoin for the previous 2 years who was admitted for dyspnoea, dry cough and fatigue for 4 months. She was febrile and tachypnoeic and she presented with bilateral basal crackles, hypoxaemic respiratory failure and slightly elevated C-reactive protein levels. A chest radiograph showed bilateral air-space consolidation and interstitial infiltrates and the high-resolution computed tomography scan was evocative of a perilobular pattern of organising pneumonia (OP). Due to the clinical-radiological context, she was diagnosed with a presumable nitrofurantoin-induced OP. She was started on prednisolone 60 mg daily with a progressive improvement. It is important that clinicians are aware of the spectrum of side effects associated with nitrofurantoin so as to monitor patients.

Learning points: It is crucial to ensure that a thorough medical history with a systems review and a complete drug history are carried out.Chronic pulmonary toxicity due to nitrofurantoin is rare and it occurs primarily in older women who have been prescribed relatively small doses of nitrofurantoin for UTI prevention.The cessation of nitrofurantoin is the basis of the treatment and may be sufficient for clinical and radiological improvement.