From the Guidelines
The total antibiotic course for Gram-negative rod bacteremia is typically 4 to 6 weeks, as indicated in the treatment guidelines for infective endocarditis 1.
Key Considerations
- The specific duration of antibiotic therapy may vary depending on the source of infection, the patient's clinical response, and the specific organism identified.
- For Gram-negative enteric bacilli, the recommended antibiotic regimen includes ceftazidime, cefepime, cefotaxime, or ceftriaxone plus gentamicin (or tobramycin or amikacin, depending on susceptibility) 1.
- The doses for these antibiotics are as follows:
- Ceftazidime: 100–150 mg·kg−1·d−1 IV divided every 8 h up to 2–4 g daily
- Cefotaxime: 200 mg·kg−1·d−1 IV divided every 6 h up to 12 g daily
- Ceftriaxone: 100 mg·kg−1·d−1 IV divided every 12 h or 80 mg·kg−1·d−1 IV every 24 h up to 4 g daily
- Alternative therapy may include a broad-spectrum penicillin plus gentamicin (or tobramycin or amikacin), such as piperacillin/tazobactam 240 mg·kg−1·d−1 divided every 8 h up to 18 g daily 1.
Clinical Context
- The treatment guidelines are based on a consensus of experts and not experimental comparative studies (Class IIa; Level of Evidence C) 1.
- Source control is essential for successful treatment, which may include removing infected catheters or draining abscesses.
- Patients with septic shock may require combination therapy initially, often adding an aminoglycoside like gentamicin or fluoroquinolone such as ciprofloxacin.
- The shorter course is preferred when possible to minimize antibiotic resistance, Clostridioides difficile infections, and other adverse effects, while ensuring complete eradication of the infection.
From the Research
Total ABX Course for Gram-Negative Rod Bacteremia
- The optimal duration of antibiotic treatment for gram-negative rod bacteremia is not clearly established 2.
- Studies have compared short-course (7-10 days) and long-course (>10 days) antibiotic treatments for uncomplicated gram-negative bacteremia 2, 3.
- A systematic review and meta-analysis found no significant difference in 30-day mortality, 30-day recurrent bacteremia, 90-day mortality, and 90-day recurrent bacteremia between short-course and long-course antibiotic treatments 3.
- Short-course therapy may be as safe and effective as longer courses for patients with uncomplicated gram-negative bacteremia 2, 3.
- The choice of antibiotic therapy should take into account local epidemiology and the presence of resistant strains 4.
- Cefepime and ceftazidime have been shown to be efficacious and well-tolerated in the treatment of hospitalized patients with documented gram-negative bacteremia 5.
Duration of Antibiotic Treatment
- Short-course antibiotic treatment (7-10 days) may be sufficient for uncomplicated gram-negative bacteremia 2, 3.
- Long-course antibiotic treatment (>10 days) may not provide additional benefits in terms of mortality or recurrent bacteremia 2, 3.
- The duration of antibiotic treatment should be individualized based on the patient's clinical response and the presence of any complications 3.
Choice of Antibiotic Therapy
- The choice of antibiotic therapy should be guided by local epidemiology and the presence of resistant strains 4.
- Third-generation cephalosporins (e.g., cefotaxime, ceftriaxone) may not be recommended as empirical antibiotic therapy for community-acquired gram-negative bacteremia due to the increasing frequency of cefotaxime-resistant strains 4.
- Cefepime and ceftazidime have been shown to be efficacious and well-tolerated in the treatment of hospitalized patients with documented gram-negative bacteremia 5.