From the Guidelines
Augmentin (amoxicillin-clavulanate) should not be used as the first-line treatment for E. coli urinary tract infections (UTIs) due to high resistance rates, as reported in the 2020 Global Antimicrobial Resistance Surveillance System (GLASS) report, which found a median of 75% resistance to amoxicillin among E. coli urinary isolates 1.
Treatment Recommendations
Instead, the following antibiotics are recommended for the treatment of E. coli UTIs:
- Nitrofurantoin
- Sulfamethoxazole-trimethoprim
- Fosfomycin
Rationale
The resistance patterns of E. coli strains causing UTIs vary considerably between regions and countries, and local antimicrobial susceptibility patterns should be considered in empirical antimicrobial selection 1. The use of individual-level predictors of resistance, such as recent travel or previous antibiotic use, can also be helpful in informing empirical antimicrobial choice 1.
Dosage and Administration
The typical adult dose of nitrofurantoin is 100 mg taken twice daily for 5-7 days for uncomplicated UTIs, while sulfamethoxazole-trimethoprim is typically dosed at 160/800 mg taken twice daily for 3-5 days. Fosfomycin is usually given as a single dose of 3 grams.
Important Considerations
It is essential to complete the full course of antibiotics even if symptoms improve, and to drink plenty of water to help flush the infection from the urinary tract. If symptoms do not improve within 2-3 days or worsen, medical attention should be sought as antibiotic resistance may be present, requiring a different treatment approach. Common side effects of these antibiotics include diarrhea, nausea, and rash.
Recent Guidelines
The most recent guidelines from the World Health Organization and other reputable sources recommend against the use of amoxicillin-clavulanate as a first-line treatment for E. coli UTIs due to high resistance rates 1.
From the FDA Drug Label
1.5 Urinary Tract Infections – caused by beta-lactamase–producing isolates of E. coli, Klebsiella species, and Enterobacter species. Amoxicillin-clavulanate (Augmentin) is indicated for the treatment of Urinary Tract Infections caused by beta-lactamase–producing isolates of E. coli 2.
- Key points:
- The drug is effective against E. coli that produce beta-lactamase.
- The treatment should be guided by culture and susceptibility information when available.
- In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.
From the Research
Treatment Options for E. coli UTI
- Augmentin (amoxicillin-clavulanate) is listed as a second-line option for treating UTIs due to AmpC- β-lactamase-producing Enterobacteriales and ESBLs-E coli 3
- The sensitivity rate of amoxicillin-clavulanate against E. coli was found to be high in some studies, with 79.6% of all-pathogen susceptibilities and 96.7% of non-ESBL E. coli susceptibilities 4
- However, resistance patterns may differ depending on the geographic area and institution, emphasizing the need for local antibiograms to guide empiric antibiotic prescribing 5, 6
Resistance Patterns and Local Antibiograms
- The prevalence of multidrug-resistant (MDR) E. coli has increased over the years, with a significant increase in resistance to trimethoprim-sulfamethoxazole and ciprofloxacin 7, 6
- Local antibiograms are essential in determining the most effective empiric antibiotic therapy, as resistance rates can vary significantly between institutions and geographic areas 3, 6, 4
- The use of an ED-specific antibiogram or a residential empiric treatment algorithm can help guide antibiotic prescribing and reduce the risk of resistance development 6, 4
Empiric Treatment Algorithms
- Amoxicillin-clavulanate and nitrofurantoin are recommended as first-line options for empiric treatment of symptomatic cystitis in some long-term care facilities, with sulfamethoxazole/trimethoprim as an alternative 4
- The choice of empiric antibiotic therapy should be based on local resistance patterns, patient-specific risk factors, and the severity of the infection 3, 6, 4