From the Guidelines
For urinary tract infections caused by E. coli, the recommended first-line antibiotic treatments are nitrofurantoin for 5 days, trimethoprim-sulfamethoxazole for 3 days, or fosfomycin as a single dose, as these options are effective and have a lower propensity for resistance and collateral damage 1.
Key Considerations
- The choice of antibiotic should be guided by local resistance patterns and patient factors, including pregnancy status, kidney function, and medication allergies.
- E. coli is the most common cause of UTIs, accounting for more than 75% of all bacterial cystitis, and empirical antibiotics should target this organism.
- The treatment duration for uncomplicated UTIs is typically 3-5 days, while complicated UTIs or pyelonephritis may require longer treatment durations of 7-14 days.
Antibiotic Options
- Nitrofurantoin: 100 mg twice daily for 5 days
- Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 3 days
- Fosfomycin: single 3-gram dose
- Fluoroquinolones: reserved for more complicated infections due to resistance concerns
Patient Advice
- Complete the full course of antibiotics even if symptoms improve
- Drink plenty of water to help flush out the infection
- Seek medical attention if symptoms worsen or don't improve within 48 hours The most recent and highest quality study 1 supports the use of these first-line antibiotic treatments, and they are effective in achieving high concentrations in urine and targeting the bacterial cell wall or protein synthesis mechanisms.
From the FDA Drug Label
Fosfomycin tromethamine granules for oral solution is indicated only for the treatment of uncomplicated urinary tract infections (acute cystitis) in women due to susceptible strains of Escherichia coli and Enterococcus faecalis. Amoxicillin and clavulanate potassium tablets USP is a combination penicillin-class antibacterial and beta-lactamase inhibitor indicated in the treatment of infections due to susceptible isolates of the designated bacteria in the conditions listed below*: 1.5 Urinary Tract Infections – caused by beta-lactamase–producing isolates of E. coli, Klebsiella species, and Enterobacter species. Ciprofloxacin is indicated for the treatment of complicated urinary tract infections and pyelonephritis due to Escherichia coli
The recommended antibiotics for a urinary tract infection (UTI) caused by Escherichia coli (E. coli) are:
- Fosfomycin for uncomplicated urinary tract infections (acute cystitis) in women
- Amoxicillin-clavulanate for urinary tract infections caused by beta-lactamase–producing isolates of E. coli
- Ciprofloxacin for complicated urinary tract infections and pyelonephritis due to E. coli 2, 3, 4
From the Research
Recommended Antibiotics for UTI caused by E. coli
The recommended antibiotics for a urinary tract infection (UTI) caused by Escherichia coli (E. coli) include:
- Nitrofurantoin: a 5-day course is recommended for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 5, 6, 7, 8
- Fosfomycin tromethamine: a 3-g single dose is recommended for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 5, 6, 8
- Pivmecillinam: a 5-day course is recommended for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 5
Second-line Options
Second-line options for UTI caused by E. coli include:
- Oral cephalosporins such as cephalexin or cefixime 5
- Fluoroquinolones 5, 6, 7
- β-lactams such as amoxicillin-clavulanate 5, 6, 7
Treatment Options for ESBL-producing E. coli
Treatment options for UTI caused by ESBL-producing E. coli include:
- Nitrofurantoin 5, 9, 8
- Fosfomycin 5, 9, 8
- Pivmecillinam 5
- Amoxicillin-clavulanate 5
- Finafloxacin 5
- Sitafloxacin 5
- Ertapenem administered intravenously or subcutaneously 9
Resistance and Treatment Considerations
High rates of resistance to trimethoprim-sulfamethoxazole and ciprofloxacin preclude their use as empiric treatment of UTIs in several communities, particularly if patients who were recently exposed to them or in patients who are at risk of infections with extended-spectrum β-lactamases (ESBLs)-producing Enterobacteriales 5, 7, 8. The choice of agent for treating uncomplicated UTIs should be based on the pharmacokinetic characteristics of the molecule so that clinical benefit is optimized and the risk of antibacterial resistance is minimized 6.