Cefpodoxime Proxetil
**Cefpodoxime proxetil** is an oral, third-generation cephalosporin antibiotic used primarily in veterinary medicine for the treatment of susceptible bacterial infections, particularly skin infections in dogs. * **Prodrug Formulation**: The esterified "proxetil" component enhances lipid solubility and gastrointestinal absorption. Once absorbed, it is rapidly hydrolyzed in the intestinal wall to the active metabolite, cefpodoxime. * **Spectrum of Activity**: Highly effective against Gram-positive organisms like *Staphylococcus pseudintermedius*, *Staphylococcus aureus*, and *Streptococcus canis*, as well as many Gram-negative Enterobacteriaceae (e.g., *E. coli*, *Proteus mirabilis*, *Pasteurella multocida*, and *Klebsiella*). * **Clinical Pearl**: It is notably ineffective against *Pseudomonas aeruginosa*, *Enterococcus* spp., anaerobes, and methicillin-resistant *Staphylococcus* (MRSA/MRSP). Its once-daily dosing in dogs makes it highly convenient for owners, improving compliance compared to first-generation cephalosporins like cephalexin.
Mechanism: Cefpodoxime is a **bactericidal** antibiotic that disrupts bacterial cell wall synthesis. * It binds to specific **Penicillin-Binding Proteins (PBPs)** located inside the bacterial cell wall. * Inhibition of PBPs → prevents the cross-linking of peptidoglycan chains → weakens the bacterial cell wall. * This structural instability → osmotic pressure changes → **cell lysis** and death. * As a third-generation cephalosporin, it exhibits increased stability against many bacterial **beta-lactamase** enzymes compared to earlier generations.
Dosing by species
- For susceptible skin and soft tissue infections · 5 mg/kg PO q12h or 10 mg/kg PO once daily · PO · q12h or q24h · Extrapolated from human dosage.
- Foals (neonates) with bacterial infections · 10 mg/kg PO q6-12 hours · PO · q6-12h · Additional studies required to confirm clinical efficacy and safety.
- For susceptible skin infections · 5-10 mg/kg PO once daily · PO · q24h · 5-7 days or 2-3 days beyond cessation of clinical signs, up to a maximum of 28 days. Treatment of acute infections should not be continued for more than 3-4 days if no response to therapy is seen. · May be given with or without food.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Hypersensitivity to cefpodoxime or other cephalosporins
Adverse effects
- Inappetence
- Diarrhea
- Vomiting
- Hypersensitivity reactions
- Positive direct Coombs' test
- Blood dyscrasias (rare, following high doses)
Drug interactions
- Aminoglycosides / Nephrotoxic drugs (e.g., amphotericin B) · Potentially additive nephrotoxicity (controversial). In vitro synergy exists, but do not mix together in the same syringe/fluid.
- Antacids · Drugs that increase stomach pH may decrease the absorption of cefpodoxime.
- H-2 Antagonists (ranitidine, famotidine) · Drugs that increase stomach pH may decrease the absorption of cefpodoxime.
- Probenecid · Competitively blocks tubular secretion of cephalosporins, increasing serum levels and half-lives.
- Proton Pump Inhibitors (omeprazole) · Drugs that increase stomach pH may decrease the absorption of cefpodoxime.
Monitoring
- Clinical efficacy (resolution of infection)
- Adverse GI effects
Overdose
Cephalosporin overdoses are unlikely to cause significant problems. The most likely signs of acute toxicity or overdose are gastrointestinal disturbances (vomiting, diarrhea, inappetence). Supportive care should be provided if necessary.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.