From the FDA Drug Label
1.7 Complicated and Recurrent Urinary Tract Infections Tobramycin for Injection is indicated for the treatment of complicated urinary tract infections caused by susceptible isolates of P. aeruginosa, Proteus spp., (indole-positive and indole-negative), E. coli, Klebsiella spp., Enterobacter spp., Serratia spp., S. aureus, Providencia spp., and Citrobacter spp. in adult and pediatric patients
The antibiotic Tobramycin is indicated for the treatment of complicated urinary tract infections caused by E. coli and S. aureus 1.
- Key points:
- Tobramycin is effective against E. coli and S. aureus in complicated urinary tract infections.
- It is essential to consider local epidemiology and susceptibility patterns when selecting empiric therapy.
- The dosage of Tobramycin should be adjusted based on the patient's renal function and the severity of the infection.
From the Research
For a complicated urinary tract infection with both Staphylococcus aureus and E. coli, a fluoroquinolone such as ciprofloxacin (500mg twice daily for 7-14 days) or levofloxacin (750mg once daily for 5-7 days) would be a good initial choice, as these antibiotics provide broad-spectrum coverage effective against both organisms, according to the most recent evidence 2. When considering the treatment of complicated urinary tract infections (UTIs) involving both Staphylococcus aureus and E. coli, it's crucial to select an antibiotic that is effective against both pathogens. The choice of antibiotic should be guided by culture and sensitivity testing, as resistance patterns can vary geographically.
- Key considerations in managing complicated UTIs include:
- Ruling out underlying abnormalities such as kidney stones, anatomical issues, or systemic infection.
- Ensuring the patient completes the full course of antibiotics, even if symptoms improve quickly.
- Advising the patient to drink plenty of fluids and seek medical attention if symptoms worsen or do not improve within 48-72 hours of starting treatment. Given the potential for Staphylococcus aureus to be associated with more severe infections, such as bacteremia or endocarditis, especially in cases without typical risk factors for urinary tract colonization 3, careful evaluation and management are necessary.
- The most recent and highest quality study 2 suggests that combination therapy, particularly with vancomycin and a beta-lactam, may be effective in preventing the emergence of vancomycin-intermediate Staphylococcus aureus (VISA), highlighting the importance of considering combination therapy in certain cases. However, for the initial treatment of a complicated UTI with both Staphylococcus aureus and E. coli, fluoroquinolones remain a reasonable choice, given their broad-spectrum activity and the importance of promptly initiating effective therapy to reduce morbidity and mortality.