- Nitrofurantoin is a nitrofuran antibiotic with a molecular formula of C8H6N4O5 and a molecular mass of 238.16 g/mol. Its structure features a nitro group attached to a furan ring, which is critical for its antibacterial activity. This unique structure classifies it as a member of the nitrofuran family and distinguishes it from other classes of antibiotics.
- The antibiotic exerts its bactericidal action through a complex mechanism involving the reduction of its nitro group by bacterial enzymes, leading to the formation of reactive intermediates. These intermediates damage bacterial DNA, ribosomal proteins, and other cellular components, ultimately inhibiting bacterial growth and causing cell death. Nitrofurantoin is particularly effective in the acidic environment of the urinary tract, where its activity is enhanced.
- Nitrofurantoin demonstrates activity primarily against gram-negative and gram-positive bacteria commonly associated with urinary tract infections (UTIs), including Escherichia coli, Enterobacter species, Klebsiella species, and Staphylococcus saprophyticus. It is also effective against some strains of Enterococcus faecalis. However, its spectrum of activity is limited to the urinary tract, as it achieves minimal systemic concentrations.
- The pharmacokinetic profile of nitrofurantoin includes moderate oral bioavailability, rapid absorption, and extensive metabolism in tissues and body fluids. It achieves high concentrations in the urine, making it particularly effective for treating uncomplicated lower urinary tract infections. Nitrofurantoin undergoes rapid enzymatic degradation in the body, with excretion occurring primarily through the kidneys. Its half-life is approximately 20 minutes to 1 hour, necessitating frequent dosing (typically every 6 to 8 hours).
- Despite its efficacy, nitrofurantoin is associated with potential adverse effects, including gastrointestinal disturbances (e.g., nausea, vomiting), pulmonary reactions (e.g., acute or chronic interstitial pneumonitis), and, rarely, hepatotoxicity or peripheral neuropathy. Its use is contraindicated in patients with severe renal impairment (creatinine clearance < 60 mL/min) due to reduced urinary excretion and increased risk of systemic toxicity.
