What is the effectiveness of Ceftriaxone (a third-generation cephalosporin antibiotic) in treating Escherichia coli (E. coli) urinary tract infections (UTIs)?

From the Guidelines

Ceftriaxone is an effective treatment option for E. coli urinary tract infections (UTIs), particularly for complicated or severe cases, and should be administered at a dosage of 1-2 grams intravenously or intramuscularly once daily for 7-14 days, depending on infection severity, as recommended by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases 1. For uncomplicated UTIs, oral antibiotics like trimethoprim-sulfamethoxazole, nitrofurantoin, or fluoroquinolones are usually preferred first-line treatments, with ceftriaxone reserved for more serious infections, hospitalized patients, or cases with antibiotic resistance. When using ceftriaxone, it's essential to obtain a urine culture before starting treatment to confirm the causative organism and its susceptibility, as local resistance patterns can vary significantly 1. Ceftriaxone works by inhibiting bacterial cell wall synthesis, effectively killing the E. coli bacteria, and has excellent penetration into the urinary tract, maintaining therapeutic concentrations in urine for 24 hours, allowing for once-daily dosing 1. However, antibiotic stewardship is crucial as inappropriate use can contribute to resistance development, and patients should complete the full prescribed course even if symptoms improve before finishing treatment, and stay well-hydrated during therapy to help flush bacteria from the urinary tract 1. Some key points to consider when treating UTIs include:

• Local resistance patterns should guide empirical antibiotic selection
• Ceftriaxone is a suitable option for complicated or severe UTIs
• Oral antibiotics are preferred for uncomplicated UTIs
• Urine culture and susceptibility testing are essential for guiding treatment
• Antibiotic stewardship is critical to prevent resistance development.

From the FDA Drug Label

URINARY TRACT INFECTIONS (complicated and uncomplicated) Caused by Escherichia coli, Proteus mirabilis, Proteus vulgaris, Morganella morganii or Klebsiella pneumoniae Ceftriaxone is indicated for the treatment of urinary tract infections caused by Escherichia coli.

• The drug label explicitly states that ceftriaxone is effective against E. coli in urinary tract infections.
• Therefore, ceftriaxone can be used to treat E. coli UTI 2.

From the Research

E. coli UTI and Ceftriaxone

• E. coli is a common cause of urinary tract infections (UTIs), and the choice of antibiotic therapy is crucial in treating these infections effectively 3, 4.
• Ceftriaxone is a third-generation cephalosporin that is sometimes used to treat UTIs, including those caused by E. coli 4, 5.
• However, the use of ceftriaxone may be limited by the increasing resistance of E. coli to this antibiotic, with studies showing high levels of resistance in some regions 6.
• A study comparing ceftriaxone and levofloxacin for the treatment of E. coli UTIs found that ceftriaxone was an effective empiric therapy for most patients, but the choice of antibiotic should be based on local antibiogram data 4.
• Another study found that cefazolin, a first-generation cephalosporin, exhibited high susceptibility for uropathogens commonly implicated in cases of uncomplicated UTI, and may be a suitable alternative to ceftriaxone in some cases 5.
• The increasing resistance of E. coli to fluoroquinolones, such as ciprofloxacin, is also a concern, with studies showing high levels of resistance in some regions 7.
• The treatment of UTIs caused by E. coli should be guided by local susceptibility patterns and antibiogram data, and alternative antibiotics such as nitrofurantoin, fosfomycin, and pivmecillinam may be effective in some cases 3.

Treatment Options

• First-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females includes 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.
• Parenteral treatment options for UTIs due to ESBLs-producing Enterobacteriales include piperacillin-tazobactam, carbapenems, ceftazidime-avibactam, and aminoglycosides including plazomicin 3.

Resistance Patterns

• E. coli isolates from urine samples of inpatients have shown high levels of resistance to ampicillin, amoxicillin-clavulanic acid, norfloxacin, cefuroxime, ceftriaxone, and co-trimoxazole 6.
• The isolates were sensitive to amikacin, piperacillin-tazobactum, nitrofurantoin, and imipenem 6.
• The high rate of resistance may be due to the increased usage of cephalosporins for empirical therapy in some hospitals 6.