From the FDA Drug Label
Thirty-three percent to 67% of a ceftriaxone dose was excreted in the urine as unchanged drug and the remainder was secreted in the bile and ultimately found in the feces as microbiologically inactive compounds
- Ceftriaxone is converted to microbiologically inactive compounds, which are then excreted in the feces. 1
From the Research
Ceftriaxone is metabolized to inactive metabolites, with the majority being excreted unchanged in the bile and urine, and does not convert to any other active antibiotic 2.
Mechanism of Action and Metabolism
Ceftriaxone, a third-generation cephalosporin antibiotic, works by inhibiting cell wall synthesis in bacteria, ultimately leading to cell lysis and death. It is administered intravenously or intramuscularly and has a broad spectrum of activity against Gram-positive and Gram-negative aerobic, and some anaerobic, bacteria. The drug's pharmacokinetics allow for once-daily dosing due to its long half-life, which is approximately 5.8-8.7 hours in healthy volunteers 2.
Clinical Use and Efficacy
Ceftriaxone is effective against a wide range of bacterial infections, including those caused by Streptococcus pneumoniae, Neisseria meningitidis, and many Enterobacteriaceae. It is also used to treat serious infections such as meningitis, septicemia, and pneumonia. However, its effectiveness against methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus species, or Pseudomonas aeruginosa is limited 3, 4.
Resistance and Sensitivity
The sensitivity of ceftriaxone against different clinical isolates has been evaluated in various studies, with results showing a high sensitivity against Escherichia coli and a lower sensitivity against Klebsiella pneumoniae 5. Continuous surveillance is necessary to determine the current resistance status of clinical pathogens and to guide effective antimicrobial therapy.
Key Points
- Ceftriaxone does not convert to any other active antibiotic.
- It is effective against a broad spectrum of bacterial infections.
- Its use should be guided by sensitivity patterns and used judiciously to prevent the development of antibiotic resistance.
- Ceftriaxone is commonly used for treating serious infections such as meningitis, septicemia, and pneumonia.
- Its effectiveness against anaerobic bacteria is limited.