From the Guidelines
For a woman with a UTI caused by E. coli resistant to trimethoprim-sulfamethoxazole, I recommend nitrofurantoin (Macrobid) 100 mg twice daily for 5 days as first-line treatment. This recommendation is based on the most recent and highest quality study available, which suggests that nitrofurantoin is an effective treatment for uncomplicated cystitis, with a clinical cure rate of 88-93% and a bacterial cure rate of 81-92% 1. Alternative options include fosfomycin (Monurol) 3 grams as a single dose, or ciprofloxacin 250 mg twice daily for 3 days.
Treatment Options
- Nitrofurantoin (Macrobid) 100 mg twice daily for 5 days
- Fosfomycin (Monurol) 3 grams as a single dose
- Ciprofloxacin 250 mg twice daily for 3 days
Rationale
The European Association of Urology guidelines on urological infections suggest that nitrofurantoin is a first-line treatment for uncomplicated cystitis in women, with a recommended dose of 100 mg twice daily for 5 days 1. The guidelines also recommend fosfomycin as a first-line treatment, with a dose of 3 grams as a single dose. Ciprofloxacin is recommended as an alternative treatment, with a dose of 250 mg twice daily for 3 days.
Important Considerations
- Patients should increase fluid intake to help flush out the bacteria
- Phenazopyridine (Pyridium) 200 mg three times daily for 2 days can be taken to relieve urinary pain and burning
- It is essential to complete the full course of antibiotics, even if symptoms improve quickly
- E. coli resistance to trimethoprim-sulfamethoxazole is increasingly common, occurring in 15-30% of isolates in many regions, and develops through bacterial acquisition of genes that encode for altered dihydrofolate reductase enzymes 1
From the FDA Drug Label
Levofloxacin tablets are indicated for the treatment of uncomplicated urinary tract infections (mild to moderate) due to Escherichia coli, Klebsiella pneumoniae, or Staphylococcus saprophyticus. Levofloxacin tablets are indicated for the treatment of complicated urinary tract infections due to Escherichia coli, Klebsiella pneumoniae, or Proteus mirabilis Levofloxacin tablets are indicated for the treatment of acute pyelonephritis caused by Escherichia coli, including cases with concurrent bacteremia
The treatment of UTI for a woman with the presence of E coli resistant to trimethoprim sulfamethoxazole can be done with levofloxacin (PO), as it is indicated for the treatment of uncomplicated urinary tract infections and complicated urinary tract infections due to Escherichia coli 2.
From the Research
Treatment Options for UTI
- For a woman with a UTI caused by E. coli resistant to trimethoprim-sulfamethoxazole, several treatment options are available 3, 4, 5, 6.
- The recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females is a 5-day course of nitrofurantoin, a 3-g single dose of fosfomycin tromethamine, or a 5-day course of pivmecillinam 3.
- Second-line options include oral cephalosporins such as cephalexin or cefixime, fluoroquinolones, and β-lactams, such as amoxicillin-clavulanate 3.
- For UTIs due to ESBL-E. coli, treatment oral options include nitrofurantoin, fosfomycin, pivmecillinam, amoxicillin-clavulanate, finafloxacin, and sitafloxacin 3, 5.
- Fosfomycin, pivmecillinam, and nitrofurantoin have been shown to be effective against ESBL-producing Enterobacteriaceae, with high sensitivity rates 5, 6.
Antibiotic Resistance
- High rates of resistance to trimethoprim-sulfamethoxazole and ciprofloxacin have been reported, making them less effective as empiric treatment options for UTIs 3, 4, 7.
- The emergence of multidrug-resistant ESBL-producing Enterobacteriaceae restricts therapeutic options, highlighting the need for alternative treatment options 5.
- Fosfomycin, nitrofurantoin, and pivmecillinam have been identified as potential alternatives for the treatment of UTIs caused by multidrug-resistant organisms 3, 5, 6.
Specific Antibiotic Susceptibility
- Fosfomycin has been shown to be highly effective against E. coli, with a susceptibility rate of 100% in one study 6.
- Nitrofurantoin has also been shown to be effective against E. coli, with a susceptibility rate of 99.4% in one study 6.
- Pivmecillinam has been shown to be effective against E. coli and Klebsiella species, with susceptibility rates of 96% and 83%, respectively 5.