From the FDA Drug Label
Adult Patients: Urinary Tract Infections caused by Escherichia coli (including cases with secondary bacteremia), Klebsiella pneumoniae subspecies pneumoniae, Enterobacter cloacae, Serratia marcescens, Proteus mirabilis, Providencia rettgeri, Morganella morganii, Citrobacter diversus, Citrobacter freundii, Pseudomonas aeruginosa, methicillin-susceptible Staphylococcus epidermidis, Staphylococcus saprophyticus, or Enterococcus faecalis.
Skin and Skin Structure Infections caused by beta-lactamase producing strains of Staphylococcus aureus, Escherichia coli,* Klebsiella spp. * (including K. pneumoniae*), Proteus mirabilis,* Bacteroides fragilis,* Enterobacter spp.,* and Acinetobacter calcoaceticus.
The patient has a Urinary Tract Infection (UTI) with Enterobacter aerogenes.
- Ampicillin-sulbactam is indicated for skin and skin structure infections caused by Enterobacter spp., but it is not explicitly indicated for UTIs caused by Enterobacter aerogenes.
- Ciprofloxacin is indicated for UTIs caused by Enterobacter cloacae, but it is not explicitly indicated for UTIs caused by Enterobacter aerogenes. Given the information available, neither ampicillin-sulbactam nor ciprofloxacin can be recommended with certainty for the treatment of this patient's UTI caused by Enterobacter aerogenes 1 2.
From the Research
For a 96-year-old female with a urinary tract infection (UTI) caused by Enterobacter aerogenes with a colony count exceeding 100,000, I recommend treatment with ciprofloxacin 500 mg orally twice daily for 7 days, as supported by the most recent study 3 which highlights the importance of appropriate antibiotic selection in the context of increasing resistance. Given the patient's advanced age, it's crucial to monitor renal function and adjust dosing accordingly, as noted in the study 4 which emphasizes the need for careful consideration of treatment in older adults. Ensure adequate hydration during treatment and consider a follow-up urine culture after completion of antibiotics to confirm resolution, especially important in this elderly patient, as suggested by the study 5 which discusses the importance of effective treatment and follow-up in UTIs. Enterobacter aerogenes is a gram-negative bacterium that commonly develops resistance to many antibiotics, including cephalosporins, through production of AmpC beta-lactamases, making fluoroquinolones or TMP-SMX often more effective choices, as discussed in the study 3. In this elderly patient, watch closely for adverse effects including confusion, dizziness, or gastrointestinal disturbances, and adjust treatment if necessary, as cautioned by the study 6 which highlights the importance of considering the potential risks and benefits of different treatment options. Some key points to consider in the treatment of this patient include:
- The importance of selecting an appropriate antibiotic based on susceptibility results, as emphasized by the study 7 which compares the effectiveness of different antibiotics in treating UTIs.
- The need for careful monitoring of renal function and adjustment of dosing as necessary, as noted in the study 4.
- The importance of ensuring adequate hydration and considering follow-up urine culture to confirm resolution, as suggested by the study 5.
- The potential for adverse effects and the need for close monitoring, as cautioned by the study 6.