Ertapenem
Ertapenem sodium
Also known as: Invanz · L-749345 · ML-0826 · ZD-4433 · ertapenemum
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 |
|---|---|---|---|---|---|
| Susceptible infections (Investigational) | 15 mg/kg IV or IM every 12 hours (not to exceed a daily dosage of 1 gram) | IV/IM | q12h | — | 🌎 NA |
- Susceptible infections (Investigational): Monitor literature for additional data.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Susceptible infections (Investigational) | 15 mg/kg IV or IM every 12 hours (not to exceed a daily dosage of 1 gram) | IV/IM | q12h | — | 🌎 NA |
- Susceptible infections (Investigational): Monitor literature for additional data.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Ertapenem is a broad-spectrum carbapenem antibiotic structurally similar to imipenem and meropenem, but with a narrower spectrum of activity.
- Key Difference: Unlike other carbapenems, it is not effective against Pseudomonas aeruginosa or Acinetobacter.
- Clinical Utility: It is particularly useful for treating resistant gram-negative bacterial infections, especially when aminoglycosides are contraindicated (e.g., renal failure) or ineffective, and when meropenem is unavailable.
- Veterinary Use: Currently, there is very limited information regarding its use in dogs and cats; it is considered investigational in veterinary medicine.
- Advantage: It has a longer half-life in humans, potentially allowing for once-daily dosing, though twice-daily dosing is currently suggested for small animals.
Mechanism of action
Ertapenem is a beta-lactam antibiotic that exerts its bactericidal effect by inhibiting bacterial cell wall synthesis.
- Mechanism: It binds to penicillin-binding proteins (PBPs) → inhibits peptidoglycan cross-linking → weakens the bacterial cell wall → causes cell lysis and death.
- Enzyme Stability: It is highly resistant to degradation by most beta-lactamases, including penicillinases and cephalosporinases.
- Renal Stability: Unlike imipenem, ertapenem is stable against renal dehydropeptidase I, meaning it does not require co-administration with cilastatin.
Safety & warnings
Contraindications
- Hypersensitivity to ertapenem or other carbapenems
- History of anaphylaxis to any beta-lactam antibiotic
- Hypersensitivity to lidocaine or amide-type local anesthetics (if using 1% lidocaine as an IM diluent)
Adverse effects
- Injection site reactions (most common in humans)
- Gastrointestinal effects (nausea, vomiting, diarrhea)
- Headache
- Tachycardia
- Hypersensitivity reactions (rare)
- CNS effects (hallucinations, agitation, seizures - rare)
Precautions
Investigational Use: Consider its use in dogs and cats as investigational due to limited published data.
- Diluent Warning: Do not use diluents containing dextrose.
- IM Administration: If given IM, it must be diluted with 1% lidocaine HCl (without epinephrine) to minimize pain, and must be used within one hour. Do not give this lidocaine mixture IV.
Drug interactions
Can increase ertapenem AUC by 25% and elimination half-life by about 20%. Not recommended to be used concurrently to extend half-life.
Monitoring
- Clinical efficacy (WBC count, resolution of fever, etc.)
- Adverse effects (GI signs, neurotoxicity, hypersensitivity)
- Hepatic, hematopoietic, and renal function (suggested for periodic assessment during prolonged use)
Pharmacokinetics
Absorption
Not appreciably absorbed after oral administration. Intramuscular bioavailability is about 90% with peak plasma levels occurring in approximately 2.3 hours (in humans).
Distribution
Exhibits concentration-dependent binding to plasma proteins (85% to 95% bound depending on concentration).
Metabolism
Biotransformation is not dependent on hepatic mechanisms; the major inactive metabolite is formed by hydrolysis of the beta-lactam ring.
Elimination
Approximately 80% of an IV dose is excreted in the urine (evenly split between inactive metabolites and unchanged drug). Approximately 10% is excreted in feces.
Overdose
Inadvertent overdoses are unlikely. In humans, a 3-gram IV dose caused an increased incidence of nausea and diarrhea. If overdose occurs and adverse effects are noted, treat supportively.
Available products
Formulations
- Lyophilized powder for injection
Human-labeled
- Ertapenem Sodium Lyophilized Powder for Injection: 1 g (as 1.045 g ertapenem) in single-dose vials; Invanz®
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store unmixed vials at or below 25°C (77°F). Reconstitute with water for injection or 0.9% NaCl, then immediately transfer to a 50 mL bag of 0.9% NaCl. Once diluted in normal saline for IV use, it is stable at room temperature for 6 hours, or refrigerated for 24 hours (use within 4 hours of removal). Do not freeze. If diluted with lidocaine for IM use, use within 1 hour.
Client information
Important Note: This medication is considered investigational in veterinary medicine and is typically reserved for highly resistant infections.
- Administration: This drug must be administered by a veterinary professional via injection.
- Monitoring: Watch your pet closely for any signs of nausea, vomiting, diarrhea, or unusual neurological behavior (like agitation or twitching) and report these to your veterinarian immediately.
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.