From the Guidelines
For an 89-year-old female with ESBL-producing E. coli UTI, impaired renal function (GFR 45), one kidney, and concurrent medications, the recommended treatment is oral fosfomycin 3 grams as a single dose or nitrofurantoin 100 mg twice daily for 5-7 days if the organism is susceptible, as suggested by the European Society of Clinical Microbiology and Infectious Diseases guidelines 1. The patient's reduced GFR necessitates dose adjustments for renally cleared antibiotics, and fluoroquinolones like ciprofloxacin should be avoided due to high resistance rates among ESBL producers and risk of adverse effects in elderly patients, as noted in a study on urinary infection management in frail or comorbid older individuals 1. Some key points to consider in the treatment of this patient include:
- The importance of guiding treatment by culture and sensitivity results to ensure the chosen antibiotic is effective against the specific ESBL-producing E. coli strain.
- Close monitoring of renal function is essential during treatment, as is assessment for drug interactions with her current medications, including amlodipine, Ozempic, and metformin.
- Adequate hydration should be encouraged to help prevent further renal impairment and support the urinary system.
- Follow-up urine culture after treatment completion is recommended to confirm resolution of the infection. Given the patient's advanced age and comorbidities, including impaired renal function and diabetes, the choice of antibiotic must balance efficacy against ESBL organisms with considerations for potential adverse effects and drug interactions, emphasizing the need for careful selection and monitoring, as highlighted in the guidelines for the treatment of infections caused by multidrug-resistant Gram-negative bacilli 1.
From the FDA Drug Label
- 4 Complicated Urinary Tract Infections Including Pyelonephritis Ertapenem for Injection is indicated for the treatment of adult patients and pediatric patients (3 months of age and older) with complicated urinary tract infections including pyelonephritis due to Escherichia coli, including cases with concurrent bacteremia, or Klebsiella pneumoniae.
The patient has a complicated urinary tract infection (UTI) caused by an E. coli ESBL producer. Given the patient's impaired renal function (GFR of 45) and one kidney, the dose of ertapenem should be adjusted according to renal function. However, the provided drug label does not explicitly state the dosage adjustment for a patient with a GFR of 45.
- The patient's medications, including amlodipine, Ozempic, and metformin, do not have direct interactions with ertapenem that would affect its dosage.
- Considering the patient's age (89 years) and moderate body aches and fatigue, careful monitoring of the patient's condition is necessary.
- Since the patient has no signs of sepsis, including no fever, no mental status changes, and no flank pain, ertapenem can be considered as a treatment option.
- However, the dosage adjustment for renal impairment is crucial, and the label recommends considering local epidemiology and susceptibility patterns in selecting therapy. Given the information provided and the need for dosage adjustment based on renal function, ertapenem could be considered for the treatment of the UTI, but the dosage must be adjusted according to the patient's renal function. It is essential to consult the complete prescribing information and consider the patient's overall clinical condition when making treatment decisions 2.
From the Research
Treatment Options for E. coli ESBL Producer UTI
The patient in question is an 89-year-old female with a urinary tract infection (UTI) caused by an E. coli Extended-Spectrum Beta-Lactamase (ESBL) producer, impaired renal function (GFR of 45), one kidney, and no signs of sepsis. Considering her age, renal function, and the presence of ESBL-producing E. coli, the treatment options are limited.
- The patient's medications, including amlodipine, Ozempic (semaglutide), and metformin, do not directly interfere with the treatment of UTI caused by ESBL-producing E. coli.
- According to the study 3, treatment options for UTIs due to ESBLs-E. coli include nitrofurantoin, fosfomycin, pivmecillinam, amoxicillin-clavulanate, finafloxacin, and sitafloxacin.
- Another study 4 suggests that cefixime and amoxicillin-clavulanate combination therapy could be an effective oral outpatient treatment option for ESBL-E. coli.
- The study 5 found that fosfomycin and amoxicillin-clavulanate appear to be effective for cystitis caused by susceptible isolates of ESBL-producing E. coli.
- The study 6 recommends ertapenem as a first-line empirical treatment for patients with an upper UTI and fosfomycin and nitrofurantoin for those with a lower UTI when ESBL-producing E. coli is suspected.
Considerations for the Patient's Condition
Given the patient's age, impaired renal function, and the presence of only one kidney, it is essential to choose an antibiotic that is effective against ESBL-producing E. coli and has a favorable safety profile in patients with renal impairment.
- Fosfomycin and nitrofurantoin may be suitable options, considering their effectiveness against ESBL-producing E. coli and relatively favorable safety profiles in patients with renal impairment 3, 5, 6.
- Amoxicillin-clavulanate and cefixime may also be considered, but their effectiveness depends on the susceptibility of the E. coli isolate 4, 5.
- Ertapenem, a carbapenem antibiotic, is effective against ESBL-producing E. coli but may require dose adjustment in patients with renal impairment 6, 7.
Monitoring and Follow-up
It is crucial to monitor the patient's response to treatment, renal function, and potential side effects of the chosen antibiotic. Regular follow-up appointments and urine cultures should be performed to ensure the infection is resolved and to detect any potential relapse or development of resistance.