Pharm 101: Cefuroxime

Class

Second generation cephalosporin
Other second generation cephalosporins: cefotetan, cefoxitin, cefaclor
Second generation cephalosporins are a heterogenous group with individual differences in activity, pharmacokinetics, and toxicity

Pharmacodynamics

• Beta lactam antibiotic
• Inhibits transpeptidation reaction of bacterial cell wall synthesis
• Halts peptidoglycan synthesis, leading to inhibition of bacterial growth, and ultimately cell death (bacteriocidal)
• Beta-lactam antibiotics kill bacterial cells only when they are actively growing and synthesising cell wall

Pharmacokinetics

• Crosses blood-brain barrier
• Renal clearance

Antimicrobial activity of second generation cephalosporins

• Similiar to first generation cephalosporins, with additional expanded gram negative coverage:
  • Klebsiella sp.
  • H influenzae
  • Moraxella catarrhalis
• No activity against enterococci or P aeruginosa
• Cefoxitin and cefotetan have activity against anaerobes (e.g. B fragilis), therefore useful to treat mixed anaerobic infections such as peritonitis, diverticulitis, PID

Adverse effects of cephalosporins

• Allergy:
  • Cross-allergenicity between penicillins and cephalosporins is ~1%
• Toxicity:
  • Thrombophlebitis after IVI
  • Renal toxicity: interstitial nephritis, tubular necrosis (rare)
• Methylthiotetrazole-containing agents (cefotetan, cefoperazone) may cause bleeding disorders and disulfiram-like reactions

Precautions/contraindications

• Penicillin anaphylaxis
• Dose adjustment in renal failure

Further reading

• Buttner R. Pharm 101: Cephazolin. LITFL
• Buttner R. Pharm 101: Ceftriaxone. LITFL
• Buttner R. Pharm 101: Cefepime. LITFL

References

• Katzung BG. Basic and Clinical Pharmacology. 14e. 2018: 802-806, 812