Can Escherichia coli (E. coli) bacteremia be treated with oral antibiotics?

From the Guidelines

Bacteremia caused by E. coli typically requires initial intravenous antibiotic therapy, not oral treatment. For most patients with E. coli bacteremia, treatment begins with IV antibiotics such as ceftriaxone, piperacillin-tazobactam, or a carbapenem for 3-7 days, depending on the severity and source of infection 1. After clinical improvement (typically resolution of fever, normalization of vital signs, and improving inflammatory markers), some patients may be switched to oral antibiotics to complete a total 7-14 day course.

Key Considerations

• Common oral step-down options include fluoroquinolones (ciprofloxacin 500mg twice daily or levofloxacin 750mg daily), trimethoprim-sulfamethoxazole (1-2 DS tablets twice daily), or amoxicillin-clavulanate (875mg/125mg twice daily), based on susceptibility testing 1.
• This sequential IV-to-oral approach is only appropriate for patients who are clinically stable, can tolerate oral medications, have a susceptible E. coli strain, and have good source control of any underlying infection.
• Purely oral treatment from the start is generally not recommended for bacteremia due to the serious nature of bloodstream infections and the need for reliable drug delivery and high blood levels that IV antibiotics provide.

Rationale

• The choice of empiric antibiotic regimens in patients with intra-abdominal infections, including those with bacteremia, should be based on the clinical condition of the patients, the individual risk for infection by resistant pathogens, and the local resistance epidemiology 1.
• In patients with complicated intra-abdominal infections, including those with bacteremia, a short course of antibiotic therapy (3-5 days) after adequate source control is a reasonable option, but the total duration of treatment may need to be extended based on the patient's response and the presence of any complications 1.

From the FDA Drug Label

CLINICAL STUDIES Complicated Urinary Tract Infection and Pyelonephritis – Efficacy in Pediatric Patients: Bacteriologic Eradication of the Baseline Pathogen at 5 to 9 Days Post-Treatment Escherichia coli 156/178 (88%) 161/179 (90%)

The FDA drug label does not answer the question about treating bacteremia E. coli orally. The provided text discusses the treatment of complicated urinary tract infections and pyelonephritis, but it does not address bacteremia specifically. Therefore, no conclusion can be drawn about the oral treatment of bacteremia E. coli based on this information 2.

From the Research

Treatment for Bacteremia E. coli

• Bacteremia E. coli can be treated with various antibiotics, including ciprofloxacin, carbapenems, and cephalosporins 3, 4, 5, 6, 7
• The choice of antibiotic depends on the severity of the infection, the patient's underlying health conditions, and the susceptibility of the E. coli strain to different antibiotics 4, 5, 6

Oral Treatment Options

• Oral antibiotics, such as ciprofloxacin, can be effective in treating bacteremia E. coli, especially in patients with a urinary source of infection 3, 6, 7
• A study found that oral transition therapy did not increase the risk of treatment failure within 60 days and shortened the length of hospital stay compared to intravenous therapy 7
• However, the use of oral antibiotics should be guided by antimicrobial susceptibility testing to ensure that the chosen antibiotic is effective against the E. coli strain 4, 6

Specific Antibiotics

• Ciprofloxacin has been shown to be effective in treating bacteremia E. coli, with an overall clinical efficacy of 94% in one study 3
• Carbapenems, such as meropenem and imipenem, are considered the drugs of choice for treating serious infections caused by extended-spectrum beta-lactamase (ESBL)-producing E. coli 5, 6
• Cefmetazole may be a treatment option for patients with ESBL-producing E. coli bacteremia, with a success rate of 87.5% in one study 5