Piperacillin Sodium
Piperacillin sodium
Also known as: Pipracil · Pipril · piperacillinum · BL-P 1908 · Cl 867 · CL 227 193 · T 12220 · TA 058
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For bacteremia with or without endocarditis | 30 mg/kg IV q6h for 7-14 days | IV | q6h | 7-14 days | 🌎 NA |
| For respiratory infections | 25-50 mg/kg IV q8h | IV | q8h | — | 🌎 NA |
| For systemic treatment of otitis media or proliferative otitis externa complicated by gram-negative (especially Pseudomonas) bacteria | 20 mg/kg SC three times daily | SC | TID | — | 🌎 NA |
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For bacteremia with or without endocarditis | 30 mg/kg IV q6h for 7-14 days | IV | q6h | 7-14 days | 🌎 NA |
| For respiratory infections | 25-50 mg/kg IV q8h | IV | q8h | — | 🌎 NA |
Birds
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For Bordetella avium infections | 150 mg/kg IM q8-12h | IM | q8-12h | minimum treatment period is two weeks | 🌎 NA |
| For susceptible infections | 100 mg/kg IM two to three times daily | IM | BID-TID | — | 🌎 NA |
| For empirical treatment in Psittacines of gram-negative bacterial infections | 100 mg/kg IM 3-4 times a day if immunocompetent; 4 times a day if immunocompromised | IM | TID-QID | — | 🌎 NA |
Reptiles
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For susceptible infections | 100 mg/kg route not specified q48h | Not specified | q48h | — | 🌎 NA |
| For susceptible infections (Snakes) | 100 mg/kg IM q24h | IM | q24h | — | 🌎 NA |
Horses
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For susceptible infections | 15-50 mg/kg IV or IM q6-12h | IV/IM | q6-12h | — | 🌎 NA |
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Piperacillin is an extended-spectrum acylaminopenicillin antibiotic used primarily for severe or resistant bacterial infections.
- Broad Spectrum: It offers expanded coverage against many aerobic and anaerobic gram-positive and gram-negative bacteria, notably including many strains of Pseudomonas aeruginosa and the family Enterobacteriaceae.
- Clinical Use: While veterinary experience is somewhat limited, it is highly valuable for empiric therapy in critically ill patients pending culture and susceptibility results, or for surgical prophylaxis involving mixed aerobic/anaerobic or gram-negative contamination.
- Beta-Lactamase Susceptibility: Like other aminopenicillins, piperacillin alone is susceptible to destruction by beta-lactamase enzymes. It is frequently combined with a beta-lactamase inhibitor (like tazobactam) to overcome this resistance.
- Administration: It is not absorbed orally and must be administered parenterally (IV, IM, or SC).
Mechanism of action
Piperacillin is a bactericidal time-dependent antibiotic.
- It binds to specific Penicillin-Binding Proteins (PBPs) (especially PBP-3) located inside the bacterial cell wall.
- Binding to PBPs → inhibition of the third and final stage of bacterial cell wall synthesis (cross-linking of peptidoglycan strands).
- This weakens the cell wall → activation of bacterial autolysins → cell lysis and death.
- Note: Its efficacy is highly dependent on the amount of time the drug concentration remains above the Minimum Inhibitory Concentration (MIC) of the target pathogen.
Safety & warnings
Contraindications
- Patients with documented hypersensitivity to beta-lactam antibiotics (penicillins, cephalosporins)
Adverse effects
- Hypersensitivity reactions (allergic reactions)
- Local tissue irritation, pain at IM injection site
- Thrombophlebitis (with IV administration)
- Antibiotic-associated diarrhea (due to alterations in gut flora)
- Coagulation abnormalities (rare, mostly in renal failure)
- Neurotoxicity/seizures (at very high doses or in renal impairment)
- Clostridium difficile superinfections (rare)
Precautions
High Sodium Content: Because of its sodium content (1.85 mEq per gram), high dosages may adversely affect patients with cardiac failure or hypernatremic conditions.
- Renal Impairment: Dosage adjustment may be required in patients with significantly decreased renal function (CrCl <40 mL/min) to prevent neurotoxicity or coagulopathies.
- Laboratory Interference: May cause false-positive urine glucose tests (cupric sulfate method) and false-positive direct Coombs' tests. Can falsely decrease aminoglycoside serum concentrations if samples are stored together prior to analysis.
Drug interactions
Synergistic against certain bacteria in vitro, but penicillins can chemically inactivate aminoglycosides in vivo (especially in renal failure or at massive doses). Do not mix in the same syringe/bag.
Piperacillin may rarely affect platelets; increased monitoring of coagulation parameters is suggested.
Piperacillin may increase methotrexate serum levels.
Reduces renal tubular secretion of piperacillin, maintaining higher systemic levels for longer periods.
Piperacillin may prolong neuromuscular blockade.
Monitoring
- Clinical efficacy (resolution of clinical signs, fever)
- White blood cell count (WBC)
- Renal function (if prolonged use or pre-existing impairment)
- Coagulation parameters (if on concurrent anticoagulants or high doses)
Pharmacokinetics
Half-life
Absorption
Not appreciably absorbed from the gut; must be administered parenterally. IM bioavailability is 86% in mares. Peak levels occur in about 30 minutes after IM administration in humans.
Distribution
Widely distributed into many tissues and fluids (lung, gallbladder, intestinal mucosa, uterus, bile, interstitial fluid). Low protein binding (19% in mares). Volume of distribution is 0.1 L/kg. CSF penetration is poor with normal meninges (6% of serum) but increases with inflamed meninges (30%). Crosses the placenta and enters milk in low concentrations.
Metabolism
Metabolized somewhat in the liver to a desethyl metabolite that has minimal antibacterial activity.
Elimination
Primarily (68%) eliminated unchanged in the urine via active tubular secretion and glomerular filtration; also excreted in the bile.
Overdose
Single overdoses are unlikely to pose much risk.
- Massive Overdoses: May cause vomiting, diarrhea, or neurotoxicity (seizures).
- Chronic High Doses: Dogs receiving up to 800 mg/kg/day of piperacillin/tazobactam for 6 months demonstrated no serious toxic effects. Doses ≥400 mg/kg/day caused transient liver effects (glycogen granules in cytoplasm, increased smooth endoplasmic reticulum) that mostly reversed after one month.
- Treatment: Supportive care. Monitor renal and neurological status.
Available products
Formulations
- Powder for injection (reconstitution)
Human-labeled
- Piperacillin Sodium Injection (powder for reconstitution): 2 gram, 3 gram, & 4 gram (as base) vials
- 40 gram bulk vials
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store powder vials at controlled room temperature (20-25°C). Reconstitute with 5 mL diluent per gram. Once reconstituted, use within 4 hours (do not freeze). Further diluted IV bags (50-150 mL) are stable for 24 hours at room temperature and 1 week if refrigerated. No preservatives are used, so sterility is not assured in stored reconstituted products.
Client information
- Hospital Use: Because this medication must be given by injection (IV, IM, or under the skin) and requires frequent dosing, it is usually administered while your pet is hospitalized.
- Purpose: It is a powerful antibiotic often reserved for severe infections or bacteria that are resistant to more common drugs.
- Side Effects: Generally very safe. Let your veterinarian know if your pet has ever had an allergic reaction to penicillin or cephalosporin antibiotics. Occasionally, it may cause mild stomach upset or diarrhea.
- Pain at Injection Site: If given into the muscle, the injection can be temporarily painful.
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.