Piperacillin Sodium

Antibiotic Penicillin (Ureidopenicillin)

Dosage & Administration Guidelines

Species Route Dose Frequency Duration & Clinical Notes
Dog IV 20-40 mg/kg q6-8h Duration: Varies with infection; typically 5-7 days
Notes: Administer slowly over 30 minutes. For severe infections, higher doses may be used.
Cat IV 20-40 mg/kg q6-8h Duration: Varies with infection; typically 5-7 days
Notes: Administer slowly over 30 minutes. Monitor renal function.
Horse IV 20-50 mg/kg q6h Duration: Varies with infection; typically 5-7 days
Notes: Administer slowly over 30 minutes. For neonatal septicemia, use higher doses.
Cattle IV 20-40 mg/kg q6-8h Duration: Varies with infection; typically 5-7 days
Notes: Not approved for food animals in many countries; extra-label use requires veterinary oversight and extended withdrawal times.
Small Ruminants (sheep/goats) IV 20-40 mg/kg q6-8h Duration: Varies with infection; typically 5-7 days
Notes: Extra-label use; observe withdrawal times.
Rabbits IV 50-100 mg/kg q6-8h Duration: Varies with infection
Notes: Use with caution; limited data.
Birds/Poultry IM or IV 100 mg/kg q6-8h Duration: Varies with infection
Notes: Extra-label; not approved for food birds.

Clinical Indications & Species Uses

General Indications
  • Treatment of serious infections caused by susceptible Gram-negative bacteria, especially Pseudomonas aeruginosa, in various species
Dog (Canine)
  • Infections caused by susceptible Gram-negative bacteria, including Pseudomonas aeruginosa, Klebsiella spp., and Proteus spp.
  • Septicemia
  • Pneumonia
  • Urinary tract infections
  • Skin and soft tissue infections
  • Intra-abdominal infections
  • Bone and joint infections
Cat (Feline)
  • Infections caused by susceptible Gram-negative bacteria, including Pseudomonas aeruginosa
  • Septicemia
  • Pneumonia
  • Urinary tract infections
  • Skin and soft tissue infections
Horse (Equine)
  • Septicemia in neonates
  • Pneumonia
  • Peritonitis
  • Metritis
  • Wound infections
  • Infections caused by susceptible Gram-negative bacteria
Cattle (Bovine)
  • Septicemia
  • Pneumonia
  • Metritis
  • Mastitis (systemic therapy)
  • Foot infections
  • Infections caused by susceptible Gram-negative bacteria
Small Ruminants (Sheep / Goat)
  • Septicemia
  • Pneumonia
  • Metritis
  • Infections caused by susceptible Gram-negative bacteria

Pharmacology & Mechanism of Action

Drug Class: Antibiotic | Pharmacological Group: Penicillin (Ureidopenicillin)

Mechanism of Action: Piperacillin is a ureidopenicillin that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to disruption of peptidoglycan cross-linking and eventual cell lysis. It has an extended spectrum compared to other penicillins, including activity against Pseudomonas aeruginosa and many Gram-negative bacilli, due to enhanced penetration through the outer membrane of Gram-negative bacteria and higher affinity for PBPs.

Pharmacodynamics: Piperacillin is bactericidal and exhibits time-dependent killing. Its efficacy is optimized when drug concentrations exceed the minimum inhibitory concentration (MIC) for a significant portion of the dosing interval. It is generally more potent than ampicillin against Pseudomonas and Klebsiella, but is susceptible to beta-lactamases, hence often combined with beta-lactamase inhibitors like tazobactam.

⚑ Pharmacokinetics Summary

Absorption: Piperacillin is poorly absorbed orally and is administered parenterally (IV or IM). After IM injection, absorption is rapid but peak concentrations are lower than IV.
Distribution: Piperacillin is widely distributed into tissues and body fluids, including pleural, peritoneal, and synovial fluids. It crosses the blood-brain barrier poorly unless meninges are inflamed. It crosses the placenta and is distributed into milk.
Metabolism: Piperacillin is minimally metabolized in the liver to a minor metabolite (desethyl piperacillin).
Excretion: Piperacillin is primarily excreted unchanged in the urine via glomerular filtration and tubular secretion. Biliary excretion also occurs. In renal impairment, dosage adjustment is necessary.
Half-Life: Dog: 0.5-1 hour; Horse: 0.5-1 hour; Cattle: 0.5-1 hour; Humans: 0.5-1 hour (prolonged in renal failure).
Bioavailability: Oral bioavailability is negligible; therefore, it is administered parenterally.
Protein Binding: Piperacillin is approximately 16-20% protein-bound in plasma.

Available Formulations & Strengths

Injectable Solution (powder for reconstitution) 2 g, 3 g, 4 g, 40 g vials (IV or IM)

Contraindications & Clinical Warnings

Contraindications:
  • Known hypersensitivity to penicillins, cephalosporins, or other beta-lactam antibiotics
  • Severe renal impairment without dose adjustment
  • Concurrent use with methotrexate (increased risk of methotrexate toxicity)
Warnings & Clinical Precautions:
  • Use with caution in animals with a history of allergic reactions to beta-lactams.
  • In renal impairment, adjust dose or extend dosing interval.
  • Prolonged use may result in superinfection with resistant organisms.
  • In horses, monitor for diarrhea and Clostridioides difficile-associated colitis.
  • In food animals, observe withdrawal times; extra-label use requires veterinary oversight.
  • Administer IV slowly to avoid adverse reactions.
  • Use with caution in neonates and geriatric animals.

Adverse Effects & Reactions

Common:

  • Injection site pain or phlebitis
  • Gastrointestinal disturbances (nausea, diarrhea)
  • Allergic reactions (urticaria, rash)

Serious / Severe:

  • Anaphylaxis
  • Acute interstitial nephritis
  • Clostridioides difficile-associated diarrhea
  • Bleeding disorders (thrombocytopenia, platelet dysfunction)
  • Neurotoxicity (seizures) at high doses or in renal failure

Rare:

  • Hepatotoxicity
  • Eosinophilia
  • Leukopenia
  • Hypokalemia

Key Drug Interactions

Interacting Drug / Class Clinical Effect & Mechanism Severity
Aminoglycosides (e.g., gentamicin, amikacin) Synergistic antibacterial effect; may be used in combination, but do not mix in same IV line due to inactivation. Moderate
Probenecid Decreases renal tubular secretion of piperacillin, increasing its plasma concentration and duration. Moderate
Methotrexate Piperacillin may reduce renal clearance of methotrexate, increasing risk of toxicity. High
Vecuronium and other neuromuscular blockers Piperacillin may enhance neuromuscular blockade. Moderate
Oral contraceptives (in humans) May reduce efficacy of oral contraceptives; not relevant in animals. Mild

Overdose & Toxicity Management

Signs of Toxicity:

  • Neurological signs including seizures
  • Gastrointestinal upset
  • Electrolyte imbalances (hypernatremia due to sodium content)
  • Bleeding tendencies

Emergency Treatment Protocol: Discontinue drug, provide supportive care, monitor renal function and electrolytes. In severe cases, hemodialysis may be considered. There is no specific antidote.

Food Animal Withdrawal Times

πŸ₯© Meat: 14 daysπŸ₯› Milk: 3 days

Withdrawal times are not established for piperacillin in food animals in many countries; extra-label use requires extended withdrawal periods. Consult regulatory guidelines. For cattle, a meat withdrawal of at least 14 days and milk withdrawal of at least 3 days is often recommended, but verify with local regulations.

Storage, Handling & Regulatory Information

Storage Temperature: Store powder at controlled room temperature (20-25Β°C). Reconstituted solution is stable for 24 hours at room temperature and 48 hours under refrigeration (2-8Β°C).

Handling & Special Conditions: Protect from freezing. Discard unused portions after the stability period.

Dispensing Status: Prescription Required (Rx Only)

Approval Status: Not FDA-approved for veterinary use; approved for human use. Veterinary use is extra-label.

Extra-Label (Off-Label) Use: Piperacillin is not approved for veterinary use in many countries; extra-label use is permitted under AMDUCA in the US for non-food animals and with veterinary oversight for food animals, with extended withdrawal times.

Clinical Pearls & Practice Notes

πŸ’‘ Clinical Insights: Piperacillin is a broad-spectrum ureidopenicillin with enhanced activity against Pseudomonas aeruginosa and other Gram-negative bacteria. It is often used in combination with beta-lactamase inhibitors (e.g., tazobactam) to overcome resistance. In veterinary medicine, it is reserved for serious infections where other antibiotics are ineffective or contraindicated. Due to its short half-life, frequent dosing is required. It is administered parenterally, and IV administration is preferred for severe infections. Monitor renal function and adjust dosing in renal impairment. In food animals, extra-label use requires careful consideration of withdrawal times. Always culture and susceptibility testing to guide therapy.

References & Literature

  • πŸ“š Plumb's Veterinary Drug Handbook
  • πŸ“š Papich Veterinary Pharmacology and Therapeutics
  • πŸ“š Compendium of Veterinary Products (CVP)