Characteristics of Second-Generation Cephalosporins
- Second-generation cephalosporins like cefuroxime have a broader spectrum of activity than first-generation cephalosporins
- They maintain good activity against gram-positive organisms while offering improved coverage against gram-negative bacteria
- Cefuroxime is a semisynthetic cephalosporin derived from the 7-cephalosporanic acid nucleus of cephalosporin C 2
- The molecular formula of cefuroxime is C16H15N4NaO8S 4
Antimicrobial Spectrum
Cefuroxime demonstrates activity against:
Gram-Positive Organisms:
- Methicillin-sensitive Staphylococcus aureus
- Streptococcus pneumoniae (penicillin-susceptible and intermediate strains)
- Streptococcus pyogenes and other streptococci (excluding group D streptococci)
Gram-Negative Organisms:
- Haemophilus influenzae (including β-lactamase producing strains)
- Moraxella catarrhalis
- Many Enterobacteriaceae (Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis)
- Neisseria gonorrhoeae
Limitations:
- Not effective against Pseudomonas aeruginosa
- Limited activity against anaerobes like Bacteroides fragilis
- Not effective against MRSA 2, 3, 5
Clinical Applications
Cefuroxime is used for various infections including:
- Respiratory tract infections (bronchitis, pneumonia)
- Upper respiratory tract infections (otitis media, sinusitis, pharyngitis)
- Urinary tract infections
- Skin and soft tissue infections
- Early Lyme disease
- Gonorrhea 2, 5, 6
Position in Cephalosporin Hierarchy
In terms of activity against common pathogens, cefuroxime ranks in the middle of the cephalosporin spectrum:
- More active than first-generation cephalosporins like cephalexin against gram-negative bacteria
- Less active than third-generation cephalosporins like ceftriaxone against gram-negative organisms
- The rank order of decreasing activity is: cefpodoxime = ceftriaxone > cefprozil = cefuroxime > cephalexin 1
Formulations
Cefuroxime is available in multiple formulations:
- Parenteral form (cefuroxime sodium) for intravenous or intramuscular administration
- Oral form (cefuroxime axetil) as tablets or suspension 4, 2
Important Clinical Considerations
- Cefuroxime can be used as part of sequential IV-to-oral therapy in moderate to severe infections 7, 6
- For moderate to severe infections, cefuroxime is often listed as a potential empiric regimen, particularly for infections involving gram-positive cocci and gram-negative rods 7
- Dosing is typically twice daily for most infections, which offers convenience compared to some other antibiotics 2, 5
Understanding cefuroxime's classification as a second-generation cephalosporin is important for appropriate prescribing decisions, particularly when considering its spectrum of activity against specific pathogens and its role in sequential therapy.