What are the contraindications for Nitrofurantoin (antibiotic)?

Nitrofurantoin Contraindications

Nitrofurantoin is contraindicated in patients with creatinine clearance below 30 mL/min due to increased risk of inefficacy and potential for toxicity, particularly peripheral neuropathy. 1, 2, 3

Major Contraindications

• Renal impairment with creatinine clearance <30 mL/min: While historically contraindicated at CrCl <60 mL/min, more recent evidence supports its use down to 30 mL/min 2, 3, 4
• Anuria or oliguria: Inadequate urinary concentrations will be achieved 1
• History of pulmonary reactions to nitrofurantoin: Including pulmonary fibrosis, as recurrence can be severe or fatal 1
• Hepatic disease: Due to risk of hepatotoxicity including hepatitis, cholestatic jaundice, and hepatic necrosis 1
• G6PD deficiency: Can cause hemolytic anemia in affected individuals 1
• Pregnancy at term (38-42 weeks): Risk of hemolytic anemia in the newborn 1
• Infants under 1 month of age: Risk of hemolytic anemia due to immature enzyme systems 1
• Known hypersensitivity to nitrofurantoin or any components of the formulation 1

Neurological Considerations

• Pre-existing peripheral neuropathy: Nitrofurantoin can cause or worsen peripheral neuropathy, which may become severe or irreversible 1
• Conditions that predispose to peripheral neuropathy: Including diabetes mellitus, vitamin B deficiency, electrolyte imbalance, and debilitating diseases 1

Pulmonary Considerations

• Pre-existing pulmonary disease: Particularly chronic conditions, as nitrofurantoin can cause acute and chronic pulmonary reactions 1
• History of pulmonary reactions to nitrofurantoin: Including pneumonitis, which can be severe and potentially fatal 1

Special Populations

• Pediatric patients with suspected or documented urinary tract dilation: Nitrofurantoin is not recommended in infants under 1 month of age 5
• Patients with alkaline urine: Nitrofurantoin is less effective in alkaline environments 2
• Patients with infections due to intrinsically resistant organisms: Including Proteus species, Pseudomonas aeruginosa, and other naturally resistant pathogens 2

Precautions (Not Absolute Contraindications)

• Moderate renal impairment (CrCl 30-60 mL/min): Historically contraindicated, but recent evidence suggests it may be effective in this range, particularly for short-term use in uncomplicated UTIs 2, 3, 6
• Elderly patients: Higher risk of adverse effects, particularly pulmonary and neurological reactions 4
• Patients with anemia, electrolyte imbalances: Increased risk of peripheral neuropathy 1

Clinical Implications

• For patients with CrCl between 30-60 mL/min, nitrofurantoin may still be considered for uncomplicated urinary tract infections when other options are limited 2, 3
• Nitrofurantoin should not be used for pyelonephritis or perinephric abscess, as it does not achieve adequate tissue concentrations 5
• For patients with vancomycin-resistant enterococci causing uncomplicated UTIs, nitrofurantoin 100 mg PO every 6 hours is a recommended treatment option 5

Monitoring Recommendations

• Monitor for signs of pulmonary reactions (cough, chest pain, fever, dyspnea) especially during the first week of therapy 1
• Monitor for peripheral neuropathy (numbness, tingling) particularly in long-term use 1
• Monitor liver function in prolonged therapy 1
• Discontinue immediately if pulmonary, hepatic, or neurological adverse reactions occur 1

Remember that nitrofurantoin is primarily indicated for uncomplicated lower urinary tract infections and should not be used for systemic infections or upper urinary tract infections due to inadequate tissue penetration 5.