Cefuroxime
Cefuroxime is a semi-synthetic **2nd generation cephalosporin** antibiotic available in both oral (axetil) and parenteral (sodium) formulations. * **Spectrum of Activity**: It offers enhanced activity against certain **gram-negative pathogens** (e.g., *E. coli*, *Klebsiella pneumoniae*, *Salmonella*, *Enterobacter*) compared to 1st generation cephalosporins like cephalexin, while retaining good efficacy against many gram-positive organisms. * **Clinical Utility**: It is particularly useful in small animal medicine when treating infections resistant to 1st generation cephalosporins, when broader gram-negative coverage is needed for **surgical prophylaxis**, or when **high central nervous system (CNS) concentrations** are required (as it can cross inflamed meninges). * **Limitations**: It is not effective against methicillin-resistant *Staphylococcus* (MRSA/MRSP), *Pseudomonas*, *Serratia*, or *Enterococcus*.
Mechanism: Cefuroxime is a **bactericidal** time-dependent antibiotic. It binds to specific **penicillin-binding proteins (PBPs)** located inside the bacterial cell wall โ inhibits the third and final stage of bacterial cell wall synthesis (peptidoglycan cross-linking) โ weakens the cell wall โ leads to **cell lysis and death** due to osmotic pressure. *Clinical Pearl*: Like other beta-lactams, its efficacy depends on the amount of time the drug concentration remains above the Minimum Inhibitory Concentration (MIC) at the site of infection.
Dosing by species
- Soft tissue infections ยท 10 mg/kg PO q12h ยท PO ยท q12h ยท 10 days ยท Extrapolated from human dosages.
- Systemic infections ยท 15 mg/kg IV q8h ยท IV ยท q8h ยท Extrapolated from human dosages.
- Meningitis ยท 30 mg/kg IV q8h ยท IV ยท q8h ยท Extrapolated from human dosages.
- Surgery prophylaxis ยท 20 mg/kg IV 30 minutes prior to surgery and every 2 hours during surgery. ยท IV ยท 30 mins prior and q2h during ยท Perioperative
- Surgical prophylaxis ยท 20 mg/kg ยท IV ยท 30 min prior to surgery and then repeat q1.5-3h during surgery ยท Perioperative ยท Administer slowly over 5 min
- Susceptible infections ยท 10-30 mg/kg ยท IV ยท q8-12h ยท As directed
- Surgical prophylaxis ยท 20 mg/kg ยท IV ยท 30 min prior to surgery and then repeat q1.5-3h during surgery ยท Perioperative ยท Administer slowly over 5 min
- Susceptible infections ยท 10-30 mg/kg ยท IV ยท q8-12h ยท As directed
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Known hypersensitivity to cefuroxime or other cephalosporins
Adverse effects
- Inappetence
- Vomiting
- Diarrhea
- Injection site inflammation (IV use)
- Eosinophilia
- Hypersensitivity reactions (including anaphylaxis)
- Neurologic effects (hearing loss, seizures - rare)
- Pseudomembranous colitis (rare)
- Serious dermatologic reactions (TEN, Stevens-Johnson syndrome - rare)
- Hematologic effects (pancytopenia, thrombocytopenia - rare)
- Interstitial nephritis (rare)
Drug interactions
- Aminoglycosides ยท Potential for increased risk of nephrotoxicity; monitor renal function. However, may have synergistic or additive actions against some gram-negative bacteria (Enterobacteriaceae). ยท minor
- Furosemide ยท Possible increased risk of nephrotoxicity. ยท moderate
- Torsemide ยท Possible increased risk of nephrotoxicity.
- Probenecid ยท Reduced renal excretion of cephalosporins, potentially increasing serum levels.
- Oxytetracycline ยท Bacteriostatic agents may antagonize the bactericidal activity of cefuroxime. ยท moderate
- Erythromycin ยท Bacteriostatic agents may antagonize the bactericidal activity of cefuroxime. ยท moderate
- Amphotericin B ยท Increased risk of nephrotoxicity; monitor renal function. ยท major
Monitoring
- Clinical efficacy (resolution of infection signs)
- Renal function in patients with pre-existing renal insufficiency
- Gastrointestinal tolerance
Overdose
Cefuroxime has a wide margin of safety. Beagles receiving daily dosages up to 1600 mg/kg/day orally tolerated the drug well, with only minor vomiting, slight weight gain suppression, and minor hematologic changes at the highest doses. In humans, massive overdoses have caused **cerebral irritation and seizures**. If severe toxicity occurs, plasma levels can be reduced via hemodialysis or peritoneal dialysis. Treatment is largely supportive.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturerโs current label.