From the Guidelines
For a urinary tract infection (UTI) caused by E. coli that is resistant to ciprofloxacin and levofloxacin but not ESBL-producing, I recommend nitrofurantoin (Macrobid) 100 mg twice daily for 5-7 days as first-line oral therapy. Alternatively, trimethoprim-sulfamethoxazole (Bactrim DS) 160/800 mg twice daily for 3-5 days can be used if susceptibility is confirmed 1. For patients who cannot take either of these medications, oral fosfomycin (Monurol) 3 grams as a single dose is another effective option 1. When selecting treatment, consider the patient's renal function, as nitrofurantoin should be avoided if creatinine clearance is below 30 ml/min. Fluoroquinolone resistance in E. coli is increasingly common, occurring in up to 30% of isolates in some regions, which is why these alternative agents are important. If symptoms are severe or there are concerns about complicated infection (fever, flank pain, or systemic symptoms), consider obtaining urine culture and sensitivity testing before starting treatment to ensure appropriate antibiotic selection. Ensure adequate hydration during treatment and advise the patient to complete the full course of antibiotics even if symptoms resolve quickly.
Some key points to consider when treating UTIs include:
- The choice of antibiotic should be based on local resistance patterns and the patient's specific needs 1
- Nitrofurantoin and trimethoprim-sulfamethoxazole are effective options for uncomplicated UTIs, but their use should be guided by susceptibility testing 1
- Fosfomycin is a single-dose option that can be used for uncomplicated UTIs, but its use should be reserved for cases where other options are not suitable 1
- Patient education on adequate hydration and completion of the full course of antibiotics is crucial for effective treatment and prevention of recurrence.
It's worth noting that the most recent and highest quality study 1 provides guidance on the treatment of UTIs, and its recommendations should be prioritized when making treatment decisions.
From the Research
Oral Treatment Options for UTI Caused by E. coli
The oral treatment for a urinary tract infection (UTI) caused by Escherichia coli (E. coli) that is not extended-spectrum beta-lactamase (ESBL) producing but is resistant to ciprofloxacin (Cipro) and levofloxacin (Levaquin) can be considered based on the following options:
- Nitrofurantoin: This is a recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 2.
- Fosfomycin: This is also a recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 2.
- Pivmecillinam: This is another recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 2.
- Amoxicillin-clavulanate: This can be considered as a second-line option for the treatment of UTI caused by E. coli 2.
Resistance Patterns of E. coli
The resistance patterns of E. coli to various antibiotics are as follows:
- High rates of resistance to trimethoprim-sulfamethoxazole and ciprofloxacin have been reported 2, 3, 4, 5.
- Nitrofurantoin and fosfomycin have been shown to be effective against E. coli, with low resistance rates 3, 6, 5.
- Amoxicillin-clavulanate has been reported to have a higher resistance rate compared to nitrofurantoin and fosfomycin 3.
Considerations for Treatment
When considering treatment options for UTI caused by E. coli, it is essential to take into account the local susceptibility patterns and the patient's medical history 2, 4, 5.
- The use of fluoroquinolones, such as ciprofloxacin and levofloxacin, may not be suitable due to high resistance rates 2, 3, 4, 5.
- Nitrofurantoin, fosfomycin, and pivmecillinam may be considered as alternative treatment options due to their effectiveness against E. coli and low resistance rates 2, 3, 6, 5.