Nitrofurantoin Drug Classification
Nitrofurantoin is a synthetic nitrofuran antibiotic with broad-spectrum bactericidal activity against both Gram-positive and Gram-negative uropathogens. 1, 2
Pharmacological Class
- Nitrofurantoin belongs to the nitrofuran class of antimicrobials, a unique category of synthetic antibiotics that have been in clinical use since 1953 1, 2
- It is classified as a broad-spectrum bactericidal antibiotic with activity specifically concentrated in urinary tract tissues 2, 3
Mechanism of Action
- Nitrofurantoin interferes with multiple bacterial targets through a complex mechanism that is not completely understood 2
- It affects bacterial cell wall synthesis, protein synthesis, and DNA replication in both Gram-positive and Gram-negative organisms 3
- This multi-target mechanism contributes to its low propensity for resistance development 1, 2
Antimicrobial Spectrum
- Active against common uropathogens including E. coli, Klebsiella species, Enterobacter species, Enterococcus species (including VRE), and Staphylococcus aureus 3, 4
- Maintains activity against multidrug-resistant organisms, making it valuable in the current era of antimicrobial resistance 2, 3
- Not effective against Pseudomonas species or for systemic infections due to poor tissue penetration outside the urinary tract 5
Regulatory Classification
- WHO AWaRe Classification: Access Group antibiotic for uncomplicated urinary tract infections 4
- FDA-approved since the 1950s specifically for treatment of lower urinary tract infections 4
- Categorized as a first-line agent for uncomplicated cystitis in multiple international guidelines 4
Clinical Positioning
- Recommended as first-choice therapy for uncomplicated lower UTIs by IDSA/ESMID guidelines alongside trimethoprim-sulfamethoxazole and fosfomycin 4
- Preferred over fluoroquinolones for empiric treatment to preserve broader-spectrum agents and minimize resistance 4
- Should only be used for lower urinary tract infections, not for pyelonephritis or systemic infections due to inadequate tissue concentrations 5, 4