Ceftiofur HCl
Ceftiofur HCl is a **veterinary-only, third-generation cephalosporin** antibiotic. It is primarily utilized in large animal medicine (particularly swine and cattle) for the treatment of bacterial respiratory diseases, foot rot, acute metritis, and mastitis. Key characteristics include: * **Broad-Spectrum Activity:** Effective against a wide variety of Gram-positive and Gram-negative pathogens, including *Pasteurella*, *Streptococcus*, *Staphylococcus*, *Salmonella*, and *E. coli*. * **Active Metabolite:** Rapidly converts to desfuroylceftiofur, which is equally potent to the parent drug. * **Clinical Pearl:** Certain formulations of ceftiofur (like Excenel RTU) offer a zero-day milk discard time in lactating dairy cattle, making it highly advantageous for dairy operations, though strict slaughter withdrawal times still apply.
Mechanism: Ceftiofur is a **time-dependent, bactericidal** antibiotic. * **Mechanism:** It binds to **penicillin-binding proteins (PBPs)** located inside the bacterial cell wall โ inhibits the third and final stage of bacterial cell wall synthesis โ leads to weakened cell walls, cell lysis, and bacterial death. * **Metabolism Pathway:** Parent ceftiofur is rapidly cleaved into furoic acid and **desfuroylceftiofur** (the primary active metabolite). * **Reservoir Effect:** The active metabolite is highly protein-bound, which creates a 'reservoir effect' that maintains active, therapeutic drug concentrations at the site of infection for extended periods.
Dosing by species
- Susceptible urinary tract infections ยท 2.2 mg/kg ยท SC ยท q24h ยท Not specified ยท Authorized for use in dogs in other countries where the main indication is UTI treatment.
- Sepsis/bacteraemia ยท 4.4 mg/kg ยท SC ยท q24h ยท Not specified ยท Higher (double) dose indicated to treat sepsis/bacteraemia.
- Bovine respiratory disease and acute bovine interdigital necrobacillosis ยท 1.1 to 2.2 mg/kg ยท IM/SC ยท q24h ยท 3 days (up to 5 days if needed) ยท Do not inject more than 15 mL per injection site.
- Bovine respiratory disease (BRD) only ยท 2.2 mg/kg ยท IM/SC ยท q48h ยท Days 1 and 3 ยท Do not inject more than 15 mL per injection site.
- Acute post-partum metritis ยท 2.2 mg/kg ยท IM/SC ยท q24h ยท 5 consecutive days ยท Do not inject more than 15 mL per injection site.
- Neonatal salmonellosis ยท 5 mg/kg ยท IM ยท q24h ยท 5 days
- Subclinical mastitis at time of dry off ยท Infuse one syringe (500 mg) ยท Intramammary ยท Once ยท At dry off ยท Infuse into each affected quarter.
- Clinical mastitis in lactating dairy cattle ยท Infuse one syringe (125 mg) ยท Intramammary ยท q24h ยท 2 days (up to 8 consecutive days for extended therapy) ยท Infuse into each affected quarter.
- Bacterial respiratory disease ยท 3 to 5 mg/kg ยท IM ยท q24h ยท 3 consecutive days ยท 1 mL of sterile suspension per 22 to 37 lb body weight.
Routes of administration
Contraindications
- Patients with a documented history of hypersensitivity to cephalosporins
- Use with caution in patients hypersensitive to other beta-lactam antibiotics (e.g., penicillins, carbapenems) due to potential cross-reactivity
Adverse effects
- Pain on IM injection (especially in small animals)
- Hypersensitivity reactions (rashes, fever, eosinophilia, lymphadenopathy, anaphylaxis)
- Gastrointestinal distress / diarrhea
- Granulocytopenia (rare)
- Thrombocytopenia (rare)
- Injection site discoloration
Drug interactions
- Aminoglycosides / Nephrotoxic Drugs (e.g., amphotericin B) ยท Potential for additive nephrotoxicity. In vitro studies show synergistic antibacterial activity, but they must NOT be mixed together in the same syringe or fluid line.
- Probenecid ยท Competitively blocks the tubular secretion of most cephalosporins, thereby increasing serum levels and prolonging serum half-lives.
- Aminoglycosides ยท Synergistic antibacterial effect, but should not be mixed in the same syringe due to chemical incompatibility. ยท moderate
- Amphotericin B ยท Increased risk of nephrotoxicity. ยท major
- Loop diuretics (e.g., furosemide) ยท Increased risk of nephrotoxicity. ยท major
Monitoring
- Clinical efficacy and resolution of infection
- Weekly CBC monitoring (if used off-label in small animals)
- Renal function parameters in patients with pre-existing renal impairment
- Injection site reactions
Overdose
Cephalosporin overdoses are generally well-tolerated and unlikely to cause significant problems other than gastrointestinal distress. However, extreme overdoses could theoretically induce hypersensitivity or hematologic abnormalities. > **Important:** Use of dosages in excess of those labeled or via unapproved routes may cause violative tissue or milk residues. Contact FARAD for assistance in determining appropriate withdrawal times if an overdose occurs in food-producing animals.
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.