Piperacillin
Piperacillin is an antipseudomonal ureidopenicillin used for selected serious susceptible bacterial infections. It is commonly supplied with tazobactam, a beta-lactamase inhibitor that broadens activity against some enzyme-producing organisms. Veterinary applications mainly involve hospitalized patients needing parenteral treatment for invasive gram-negative, mixed or other susceptible infections.
Group
Ureidopenicillin antibacterial
Mechanism of Action
Piperacillin binds bacterial penicillin-binding proteins and inhibits peptidoglycan cross-linking. Loss of cell-wall integrity causes bactericidal activity during bacterial growth. Tazobactam inhibits selected beta-lactamases, protecting piperacillin from enzymatic degradation and extending its useful spectrum. The combination retains time-dependent antibacterial activity, with clinical effect determined by susceptibility and exposure at the infection site.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Bacterial infection | Reference only | IV | Piperacillin-tazobactam guidance gives 50 mg/kg every 6 hours IV or IM, but does not specify combined-total versus piperacillin-component basis. Do not apply as a single-agent or component calculator dose. | |
| Bacterial infection | Reference only | IM | Same combination regimen: 50 mg/kg every 6 hours IM; component dose basis is unspecified. | |
| Antibacterial infusion | Reference only | IV | Combination protocol: 4 mg/kg IV loading followed by 3.2 mg/kg/hour. Dose basis and relation to the intermittent regimen require clarification. | |
| Bacteremia or endocarditis | 30 mg/kg | IV | Every 6 h | Up to 14 days; Single-agent piperacillin regimen, reported 7-14 days. |
| Respiratory bacterial infection | 25–50 mg/kg | IV | Every 8 h | |
| Gram-negative otitis systemic treatment | 20 mg/kg | SC | Every 8 h |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Bacterial infection | Reference only | IV | Piperacillin-tazobactam guidance gives 50 mg/kg every 6 hours IV or IM, but does not specify combined-total versus piperacillin-component basis. Do not apply as a single-agent or component calculator dose. | |
| Bacterial infection | Reference only | IM | Same combination regimen: 50 mg/kg every 6 hours IM; component dose basis is unspecified. | |
| Antibacterial infusion | Reference only | IV | Combination protocol: 4 mg/kg IV loading followed by 3.2 mg/kg/hour. Dose basis and relation to the intermittent regimen require clarification. | |
| Bacteremia or endocarditis | 30 mg/kg | IV | Every 6 h | Up to 14 days; Single-agent piperacillin regimen, reported 7-14 days. |
| Respiratory bacterial infection | 25–50 mg/kg | IV | Every 8 h |
Birds
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Bordetella avium infection | 150 mg/kg | IM | Every 8–12 h | At least 14 days. |
| Susceptible infection | 100 mg/kg | IM | Every 8–12 h | |
| Psittacine empirical gram-negative treatment | 100 mg/kg | IM | Every 6–8 h | Every 6 hours if immunocompromised. |
Horses
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Susceptible infection | 15–50 mg/kg | IV, IM | Every 6–12 h |
Snakes
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Susceptible infection | 100 mg/kg | IM | Every 24 h |
Indications
- Parenteral treatment of selected serious susceptible bacterial infections in veterinary patients, including sepsis and invasive respiratory or soft-tissue infection.
- Treatment of selected susceptible Pseudomonas aeruginosa infections.
- Treatment of selected susceptible intra-abdominal or mixed aerobic–anaerobic infections, particularly with the piperacillin–tazobactam combination.
- Treatment of selected susceptible complicated urinary infections or endocarditis within a specialist antimicrobial plan.
Contraindications
- Penicillin hypersensitivity
- High doses add sodium.
Interactions
- Do not mix indiscriminately with other medicines in a syringe or vial.
- Aminoglycosides should be administered separately because in-syringe inactivation can occur; renal function and sodium load affect systemic therapy.
Adverse effects
- Allergy and impaired platelet function at high doses.
Toxicity
Very large beta-lactam exposure can produce GI or neurologic effects; treatment is supportive and renal function may alter risk.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Piperacillin/tazobactam 2000/250 mg vial Amounts expressed as labeled active components; no final mL concentration inferred. | Injection | piperacillin 2000 mg / vial + tazobactam 250 mg / vial | IV |
| Piperacillin/tazobactam 3000/375 mg vial Amounts expressed as labeled active components; no final mL concentration inferred. | Injection | piperacillin 3000 mg / vial + tazobactam 375 mg / vial | IV |
| Piperacillin/tazobactam 4000/500 mg vial Amounts expressed as labeled active components; no final mL concentration inferred. | Injection | piperacillin 4000 mg / vial + tazobactam 500 mg / vial | IV |
| Piperacillin sodium vial 2000 mg piperacillin base Strength explicitly expressed as piperacillin base; no final mL volume inferred. | Injection | 2000 mg / vial | IV, IM |
| Piperacillin sodium vial 3000 mg piperacillin base Strength explicitly expressed as piperacillin base; no final mL volume inferred. | Injection | 3000 mg / vial | IV, IM |
| Piperacillin sodium vial 4000 mg piperacillin base Strength explicitly expressed as piperacillin base; no final mL volume inferred. | Injection | 4000 mg / vial | IV, IM |
Monitoring and Administration
Use susceptibility and clinical response to guide treatment. Earlier guidance concerns the piperacillin-tazobactam combination, usually in an 8:1 ratio.
Reconstituted combination solutions are described as stable for 24 hours, or 7 days refrigerated; exact compatibility depends on formulation.
Single-agent piperacillin vials: reconstitution guidance uses 5 mL diluent per gram, then 50-150 mL further dilution for infusion. Use reconstituted vial within 4 hours of puncture; further-diluted IV bags have reported stability of 24 hours ambient or 7 days refrigerated, but sterility is not assured by chemical stability. With lactated Ringer fluid, the cited in-use period is 2 hours. Do not freeze reconstituted vials.