From the Guidelines
Cephalexin is a suitable option for treating E. coli urinary tract infections (UTIs) in an 18-month-old female, with a recommended dosage of 50–100 mg/kg per day in 4 doses, as outlined in the clinical practice guideline for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months 1.
Key Considerations
- The dosage of cephalexin for children is crucial, and according to the guideline, it should be 50–100 mg/kg per day in 4 doses 1.
- It is essential to know local patterns of susceptibility of coliforms to antimicrobial agents, particularly cephalexin, because there is substantial geographic variability that needs to be taken into account during selection of an antimicrobial agent before sensitivity results are available 1.
- The total course of therapy should be 7 to 14 days, with evidence suggesting that shorter courses are inferior 1.
Treatment and Monitoring
- Cephalexin comes as a suspension, which is appropriate for young children, making it a practical choice for treatment 1.
- Parents should ensure adequate hydration for the child and watch for signs of worsening infection, such as persistent fever, vomiting, or increased irritability.
- Follow-up with the pediatrician is recommended to ensure resolution of the infection and to consider further evaluation if this is a recurrent UTI, as anatomical abnormalities may need to be ruled out.
Antibiotic Resistance and Culture
- Local resistance patterns can vary, so urine culture and sensitivity testing should be performed to confirm the appropriate antibiotic 1.
- E. coli is the most common cause of UTIs in children, and cephalexin, a first-generation cephalosporin, typically has good coverage against this organism, but resistance should always be considered 1.
From the Research
E. coli UTI Treatment Options
- The provided studies do not directly address the use of cephalexin for E. coli UTI in an 18-month-old female.
- However, studies 2, 3, and 4 discuss alternative antibiotic treatments for UTIs caused by resistant E. coli strains.
- Amoxicillin-clavulanate is suggested as a potential treatment option for UTIs caused by ESBL-producing E. coli 3, 4.
- The effectiveness of amoxicillin-clavulanate depends on the susceptibility of the E. coli strain to this antibiotic 4, 5.
- Study 6 presents a case report of an 18-month-old female with a severe vulvar infection, but it is not directly related to E. coli UTI treatment.
Antibiotic Susceptibility and Resistance
- The susceptibility of E. coli to amoxicillin-clavulanic acid can vary depending on the testing methodology used 5.
- EUCAST and CLSI guidelines may yield different results for amoxicillin-clavulanic acid susceptibility testing 5.
- The development of resistance to amoxicillin-clavulanic acid is a concern, particularly in strains with high MIC values 4.
Treatment Considerations
- When treating UTIs caused by resistant E. coli strains, it is essential to consider the susceptibility of the strain to the chosen antibiotic 3, 4.
- Alternative treatment options, such as amoxicillin-clavulanate, may be effective in some cases 3, 4.
- Close monitoring and meticulous wound care may be necessary in certain cases, such as ecthyma gangrenosum 6.