What is the appropriate management for an 8-year-old male (YOM) with ongoing urinary symptoms, urine culture positive for Escherichia coli (E. coli), who has been treated with cefixime (Cefixime) and is now on amoxicillin-clavulanate (Amox-Clav)?

From the Guidelines

For an 8-year-old male with persistent urinary symptoms and E. coli infection who has already been treated with cefixime and amoxicillin-clavulanate, I recommend switching to a third-line antibiotic such as trimethoprim-sulfamethoxazole (TMP-SMX) at 6-12 mg/kg per day of the trimethoprim component divided twice daily for 7-14 days, as suggested by the guidelines 1. The current treatment with amoxicillin-clavulanate should be reassessed, considering the patient's ongoing symptoms, and the dosage should be verified to be within the recommended range of 20–40 mg/kg per day in 3 doses, as per the guidelines 1. Key considerations in managing this patient include:

• Obtaining a urine culture with susceptibility testing to guide further antibiotic therapy
• Evaluating the child for anatomical abnormalities with renal ultrasound and possibly voiding cystourethrogram (VCUG), especially given the recurrent nature of the infection
• Encouraging increased fluid intake, regular and complete bladder emptying, and proper perineal hygiene
• Monitoring for treatment failure, which may indicate bacterial resistance, an underlying anatomical issue, or incomplete treatment courses, and considering hospitalization for IV antibiotics if symptoms are severe or the child appears toxic
• Ensuring follow-up urine culture after completing antibiotics to confirm resolution of infection, as the total course of therapy should be 7 to 14 days, according to the guidelines 1.

From the FDA Drug Label

Patients should be counseled that antibacterial drugs, including amoxicillin and clavulanate potassium tablets, should only be used to treat bacterial infections. When amoxicillin and clavulanate potassium tablets are prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed Skipping doses or not completing the full course of therapy may: (1) decrease the effectiveness of the immediate treatment, and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by amoxicillin and clavulanate potassium tablets or other antibacterial drugs in the future

The patient has been switched from cefixime to amoxicillin-clavulanate for an E. coli urinary infection.

• The FDA drug label for amoxicillin-clavulanate does not provide information on the specific treatment of E. coli urinary infections or the duration of treatment.
• The label advises patients to take the medication exactly as directed and to complete the full course of therapy to decrease the effectiveness of the immediate treatment and increase the likelihood that bacteria will develop resistance 2.
• However, it does not provide guidance on what to do if symptoms persist after switching antibiotics.
• Given the lack of specific information, it is unclear whether the current treatment is appropriate or if further changes are needed.

From the Research

Patient Profile

• 8 years old
• Ongoing urinary symptoms
• Urine positive for E. coli
• Initially treated with cefixime, now on amoxicillin-clavulanate (amox-clav)

Treatment Considerations

• The patient's E. coli infection is being treated with amox-clav, which is a suitable option according to a study published in 2024 3
• Another study from 2024 found that amox-clav may be a useful alternative therapy for treating ceftriaxone non-susceptible Enterobacterales UTIs 4
• A 2015 study suggested that amox-clav can be effective in treating UTIs caused by ESBL-producing organisms, but resistance may develop during therapy, especially in strains with high minimum inhibitory concentrations (MICs) 5

Antibiotic Resistance Patterns

• A 2013 study found that E. coli susceptibility to ampicillin, amoxicillin-clavulanate, ciprofloxacin, and nitrofurantoin differed significantly between males and females, but the magnitude of the differences was less than 10% for all strata except amoxicillin-clavulanate susceptibility in E. coli isolated from males age 18-64 compared to females of the same age 6
• The same study suggested that male sex alone should not be used as an indication for empiric use of second-line broad-spectrum antibiotic agents for the treatment of UTIs 6

Diagnostic and Management Approaches

• A 2018 study emphasized the importance of proper diagnosis and management of UTIs, including the use of urinalysis and urine cultures, and the consideration of potential pitfalls in interpretation 7
• The study also noted that imaging is often not required, and most patients with simple cystitis and pyelonephritis can be treated as outpatients 7