Ceftazidime

Ceftazidime is an injectable third-generation cephalosporin with particular activity against susceptible gram-negative bacteria, including Pseudomonas aeruginosa. It is used for serious gram-negative infections in companion animals and has an established role in reptile medicine. Its clinical spectrum differs from cephalosporins selected primarily for staphylococcal skin disease.

Group

Third-generation antipseudomonal cephalosporin

Mechanism of Action

Ceftazidime binds bacterial penicillin-binding proteins and blocks the transpeptidation reactions required for peptidoglycan cross-linking. This weakens the cell wall of growing bacteria and produces bactericidal activity. Its structure supports activity against susceptible Pseudomonas and other gram-negative bacilli. Efficacy is time dependent and depends on maintaining adequate unbound concentrations at the infection site.

Dose Rates

Dogs

Use / stage	Dose	Route	Schedule	Instructions
Bacterial infections	25 mg/kg	IV, SC, IM	Every 8 h	Subcutaneous and intramuscular injections may sting.
Antibacterial infusion — Loading	2 mg/kg	IV	Once
Antibacterial infusion — Maintenance	2 mg/kg/hour	IV	Continuous
Gram-negative infection	25 mg/kg	IM, SC	Every 8–12 h
Orthopedic infection	25 mg/kg	IV, IM	Every 8–12 h
Soft-tissue infection	30–50 mg/kg	IV, IM	Every 8–12 h
Sepsis or bacteremia	15–30 mg/kg	IV, IM	Every 6–8 h

Cats

Use / stage	Dose	Route	Schedule	Instructions
Bacterial infections	25 mg/kg	IV, SC, IM	Every 8 h	Subcutaneous and intramuscular injections may sting.
Antibacterial infusion — Loading	2 mg/kg	IV	Once
Antibacterial infusion — Maintenance	2 mg/kg/hour	IV	Continuous
Systemic infection	25–30 mg/kg	IV, IM, IO	Every 8–12 h

Horses

Use / stage	Dose	Route	Schedule	Instructions
Bacterial infections	20 mg/kg	IV, IM	Every 8 h

Reptiles

Use / stage	Dose	Route	Schedule	Instructions
Bacterial infections	20 mg/kg	IM, SC	Every 72 h

Snakes

Use / stage	Dose	Route	Schedule	Instructions
Bacterial infections	20 mg/kg	IM	Every 72 h	Regimen studied around 30°C; maintain an appropriate species-specific thermal environment.

Chelonians

Use / stage	Dose	Route	Schedule	Instructions
Bacterial infections	50 mg/kg	IM	Every 24 h

Indications

Treatment of serious susceptible gram-negative infections in dogs and cats, including Pseudomonas aeruginosa infections of the urinary, respiratory or other tissues.
Treatment of susceptible systemic, respiratory and soft-tissue bacterial infections in reptiles.
Treatment of selected susceptible gram-negative infections in birds and other exotic veterinary patients.

Contraindications

Cephalosporin hypersensitivity; assess prior severe beta-lactam allergy.

Interactions

Avoid mixing with other drugs in the same vial or syringe unless compatibility is established.
Aminoglycosides can inactivate the drug in mixtures; vancomycin can precipitate.

Adverse effects

Hypersensitivity
Gastrointestinal upset
Injection-site reactions with parenteral products

Preparations

Preparation	Form	Strength	Route
Ceftazidime 500 mg vial Strength is per vial; no final mL concentration is implied.	Injection	500 mg / vial	IV, SC, IM
Ceftazidime 1000 mg vial Strength is per vial; no final mL concentration is implied.	Injection	1000 mg / vial	IV, SC, IM
Ceftazidime 2000 mg vial Strength is per vial; no final mL concentration is implied.	Injection	2000 mg / vial	IV, SC, IM
Ceftazidime 6000 mg vial Strength is per vial; no final mL concentration is implied.	Injection	6000 mg / vial	IV, SC, IM

Monitoring and Administration

Choose treatment using organism identity, infection site and susceptibility testing. Reassess clinical response and renal function where impaired clearance may increase exposure.

Food-animal authorization and withdrawal periods depend on the exact formulation, species, regimen and jurisdiction; do not transfer foreign approvals or residue intervals to another product.

Some sodium-carbonate vials release carbon dioxide during reconstitution and require venting. Lidocaine reconstitution is for IM delivery only. In sterile water the described stability is 12 hours at room temperature or 3 days refrigerated; other testing reports 5 refrigerated days. Original-container frozen solution at −20°C is described for 3 months; do not refreeze.

Stability differs between sodium-carbonate and arginine preparations. A separate product description supports 24 hours at room temperature (18 hours for an arginine formulation) and seven days refrigerated; these must not replace a shorter period on the actual preparation.

Avoid sodium bicarbonate as diluent. Never use lidocaine-containing reconstitution fluid for IV delivery.