Nitrofurantoin related pulmonary disease: a clinical reminder.

A 57-year-old woman presented to the admissions unit with a 2-month history of malaise, chest tightness and non-productive cough. An outpatient chest radiograph arranged by her general practitioner was reported as showing 'changes in keeping with a severe chest infection' and she had been started on oral antibiotics but her clinical condition subsequently deteriorated. On admission she was febrile (39.2°C) and her oxygen saturation was 99% on 60% oxygen via facemask (rapidly desaturating when supplementary oxygen was removed). Auscultation revealed fine mid-late inspiratory crackles over both lung bases. It transpired that 4 months prior to the onset of symptoms she had been started on nitrofurantoin for prophylaxis against urinary tract infections. The nitrofurantoin was stopped and she was started on prednisolone. Her fever and oxygen saturation gradually improved and she was discharged home after 11 days in the hospital. Her improvement was sustained on outpatient review 8 months later.