Nitrofurantoin is an antibacterial agent frequently used in the management of urinary tract infections (UTIs). This antimicrobial drug is generally used in the following clinical settings:
- The short-term prophylaxis of infections acquired by invasive urologic diagnostic procedures and operations
- The long-term prevention of recurrent UTIs
- The treatment of acute or recurrent cystitis
The most common adverse reactions to nitrofurantoin (apart from turning the urine color a harmless brown) are nausea (8 percent), headache (6 percent), and flatulence (1.5 percent). Among the rare adverse reactions (<1 percent), pulmonary injury is the most severe .
Pulmonary toxicity due to nitrofurantoin has two main presentations: an acute onset approximately nine days after a short course of therapy and a chronic onset developing after several months or years of nitrofurantoin therapy. The clinical manifestations, diagnosis, and treatment of nitrofurantoin toxicity will be reviewed here. Pulmonary reactions due to other drugs are discussed separately. (See appropriate topic reviews).
The vast majority of patients (85 to 95 percent) who present with pulmonary reactions to nitrofurantoin are women . This is related to the greater susceptibility of women to recurrent urinary tract infections, so that women are more often exposed to long-term nitrofurantoin than are men. The median age among those presenting with the acute or chronic forms of the illness is approximately 60 and 70 years, respectively [3,4].