Does Nitrofurantoin cover Pseudomonas aeruginosa?

From the Guidelines

No, nitrofurantoin does not cover Pseudomonas aeruginosa. Nitrofurantoin is an oral antibiotic primarily used for uncomplicated urinary tract infections, but it has significant gaps in its coverage, with Pseudomonas being one of the most notable resistant organisms. The medication works by damaging bacterial DNA and inhibiting protein synthesis, but Pseudomonas has intrinsic resistance mechanisms including efflux pumps and low permeability of its outer membrane that render nitrofurantoin ineffective against it.

Key Points to Consider

• When treating infections where Pseudomonas is suspected or confirmed, alternative antibiotics should be used, such as fluoroquinolones (ciprofloxacin), certain cephalosporins (ceftazidime, cefepime), carbapenems (meropenem), or piperacillin-tazobactam, as recommended by guidelines such as those endorsed by the Italian Society of Infection and Tropical Diseases 1.
• Nitrofurantoin remains effective against many common urinary pathogens including E. coli, Enterococcus, Staphylococcus saprophyticus, and some Klebsiella species, but should not be relied upon for Pseudomonas coverage.
• The choice of antibiotic should be guided by local resistance patterns and the specific clinical scenario, with consideration of the most recent and highest quality evidence available, such as the guidelines from the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases 1.

Clinical Implications

• Clinicians should be aware of the limitations of nitrofurantoin in treating Pseudomonas infections and choose alternative antibiotics when Pseudomonas is suspected or confirmed.
• The use of nitrofurantoin should be reserved for infections where it is known to be effective, and its use should be guided by susceptibility testing and local resistance patterns.

From the Research

Nitrofurantoin Coverage for Pseudomonas

• Nitrofurantoin is not typically considered effective against Pseudomonas aeruginosa, a common cause of urinary tract infections (UTIs) 2, 3.
• The study 2 lists treatment options for UTIs caused by multidrug-resistant (MDR)-Pseudomonas spp., which include fluoroquinolones, ceftazidime, cefepime, piperacillin-tazobactam, carbapenems, and fosfomycin, but does not mention nitrofurantoin as a treatment option.
• Another study 3 discusses the management of P. aeruginosa infections and highlights novel antibiotics that show promise, but does not include nitrofurantoin as a treatment option.
• Nitrofurantoin is effective against other common uropathogens, such as Escherichia coli, Staphylococcus saprophyticus, and Enterococcus species 4, 5.
• The study 4 suggests that nitrofurantoin may be the best choice for treating uncomplicated lower urinary tract infections (UTIs) due to its low frequency of use and high susceptibility against common UTI pathogens.
• However, none of the studies provide evidence that nitrofurantoin is effective against Pseudomonas aeruginosa, and it is not recommended as a treatment option for MDR-Pseudomonas spp. infections 2, 3.