From the Guidelines
Yes, nitrofurantoin can cause immune-mediated pneumonitis.
Evidence Summary
- According to a recent position paper from the Fleischner Society 1, antibiotics such as nitrofurantoin are a known cause of drug-related pneumonitis (DRP), which can manifest as a variety of clinical syndromes of lung injury.
- The incidence of DRP varies widely, but it is estimated to account for 2.5% to 5% of prevalent cases of interstitial lung disease (ILD) 1.
- A guideline on recurrent uncomplicated urinary tract infections in women notes that nitrofurantoin has potentially serious risks of pulmonary toxicity, although the rates of possible serious pulmonary adverse events are extremely low, reported to be 0.001% 1.
- The clinical features of DRP can range from mild to life-threatening, and the severity of symptoms can be graded using the Common Terminology Criteria for Adverse Events 1.
- Laboratory tests and pulmonary function testing may not be useful in specifically diagnosing DRP, but can help establish other etiologies for pulmonary infiltrates and assess the degree of pulmonary impairment 1.
- Key points to consider when prescribing nitrofurantoin include discussing potential risks with patients and monitoring for signs of pulmonary toxicity.
From the FDA Drug Label
ADVERSE REACTIONS: Respiratory: CHRONIC, SUBACUTE, OR ACUTE PULMONARY HYPERSENSITIVITY REACTIONS MAY OCCUR. A lupus-like syndrome associated with pulmonary reactions to nitrofurantoin has been reported
Yes, nitrofurantoin can cause immune-mediated pneumonitis, as evidenced by reports of pulmonary hypersensitivity reactions, including chronic, subacute, or acute reactions, and a lupus-like syndrome associated with pulmonary reactions 2.
From the Research
Nitrofurantoin-Induced Immune-Mediated Pneumonitis
- Nitrofurantoin has been associated with pulmonary toxicity, including immune-mediated pneumonitis, as reported in several studies 3, 4, 5, 6, 7.
- The exact mechanism of nitrofurantoin-induced pneumonitis is not fully understood, but it is believed to be an immune-mediated reaction, with some studies suggesting an Arthus-type immune complex-mediated reaction 4.
- Clinical manifestations of nitrofurantoin-induced pneumonitis can vary, but common symptoms include dyspnea, cough, and fever, with imaging abnormalities and pathologic findings consistent with interstitial inflammation and fibrosis 3, 4, 6.
- The majority of patients who develop nitrofurantoin-induced pneumonitis are women, with a mean age of 40-59 years, and most cases occur after long-term treatment with the medication 4.
- Withdrawal of nitrofurantoin is essential for management, and prompt recognition of the condition can prevent irreversible fibrosis and improve patient outcomes 5, 6, 7.