Acute lung toxicity by nitrofurantoin

Area of Science:

• Pharmacology
• Pulmonology
• Toxicology

Background:

• Nitrofurantoin is a widely prescribed antibiotic for uncomplicated urinary tract infections (UTIs).
• It functions by inhibiting bacterial DNA, RNA, and cell wall synthesis.
• Prophylactic and long-term suppression of UTIs are common uses, effective against Gram-positive organisms.

Observation:

• A case report details an 81-year-old woman experiencing dyspnea and cough three days after starting nitrofurantoin.
• Chest CT revealed bilateral pleural effusion and interstitial lung prominence, indicative of pulmonary fibrosis.
• The Naranjo Adverse Drug Reaction Probability Scale assigned a score of 6, strongly suggesting nitrofurantoin as the cause.

Findings:

• Nitrofurantoin-associated pulmonary injury is a rare but serious adverse effect, occurring in approximately 1% of patients.
• Symptoms can include shortness of breath and dry cough, mimicking interstitial lung disease.
• Discontinuation of nitrofurantoin resulted in marked clinical improvement and resolution of symptoms within 10 days.

Implications:

• This case highlights the potential for nitrofurantoin to induce acute pulmonary toxicity, even with short-term use.
• Clinicians should maintain a high index of suspicion for drug-induced lung disease in patients on nitrofurantoin presenting with respiratory symptoms.
• Early recognition and cessation of nitrofurantoin are crucial for favorable outcomes in managing these pulmonary injuries.