Intravenous Fat Emulsion
Intravenous Lipid Emulsion
Also known as: Intralipid · Liposyn III · IFE · ILE · Intravenous Lipid Emulsion · Lipid Rescue
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 |
|---|---|---|---|---|---|
| Parenteral Nutrition (PN) | 25-60% of calories administered. Traditionally not recommended at > 2 g/kg/day for TPN therapy. | IV | CRI | As needed | 🌎 NA |
| Rescue agent for fat-soluble drug/toxin intoxication | IFE 20% via a sterile, peripheral IV catheter as a 1.5 mL/kg bolus over 1-3 minutes, then 0.25-0.5 mL/kg/min for 30-60 min. The bolus could be repeated in case of cardiac arrest. If symptomatic after traditional dosing, consider additional doses of 1.5 mL/kg IV over 30 min q4-6h for 24-36 hours until clinical signs resolve, or maintaining a CRI of 0.5 mL/kg/hour until clinical signs resolve. | IV | Bolus followed by CRI | Until clinical signs resolve | 🌎 NA |
- Parenteral Nutrition (PN): Consult a veterinary nutritionist. Keep PPN solutions below 600 mOsm/L.
- Rescue agent for fat-soluble drug/toxin intoxication: Do not exceed 8 mL/kg/day generally, though this has been exceeded in acute toxicosis without ill effect.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Parenteral Nutrition (PN) | 25-60% of calories administered. Traditionally not recommended at > 2 g/kg/day for TPN therapy. | IV | CRI | As needed | 🌎 NA |
| Rescue agent for fat-soluble drug/toxin intoxication | IFE 20% via a sterile, peripheral IV catheter as a 1.5 mL/kg bolus over 1-3 minutes, then 0.25-0.5 mL/kg/min for 30-60 min. The bolus could be repeated in case of cardiac arrest. If symptomatic after traditional dosing, consider additional doses of 1.5 mL/kg IV over 30 min q4-6h for 24-36 hours until clinical signs resolve, or maintaining a CRI of 0.5 mL/kg/hour until clinical signs resolve. | IV | Bolus followed by CRI | Until clinical signs resolve | 🌎 NA |
- Parenteral Nutrition (PN): Consult a veterinary nutritionist.
- Rescue agent for fat-soluble drug/toxin intoxication: Extrapolated from general veterinary/human guidelines.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Intravenous Fat Emulsion (IFE/ILE) is a sterile, non-pyrogenic fat emulsion prepared for intravenous administration.
Historically utilized primarily as a parenteral calorie and essential fatty acid source, it has emerged as a critical rescue antidote in veterinary toxicology. It is highly effective for treating life-threatening toxicities caused by highly lipophilic (fat-soluble) drugs when traditional therapies fail.
Key Clinical Applications:
- Toxicology Rescue: Local anesthetics (bupivacaine, lidocaine), macrocyclic lactones (ivermectin, moxidectin), calcium channel blockers (amlodipine), beta-blockers, and certain antidepressants/antipsychotics.
- Parenteral Nutrition (PN): Provides dense calories (approx. 2 kCal/mL for 20% solutions). Note: Its use in critically ill patients for nutrition is controversial due to potential immunosuppression and infection risks.
Clinical Pearl: Always use the 20% emulsion for toxicology rescue, as the 10% emulsion provides too much fluid volume and the 30% is not formulated for direct IV administration without compounding.
Mechanism of action
Toxicologic Mechanism (Antidote):
- "Lipid Sink" Theory: IFE creates an expanded intravascular lipid phase. Highly lipophilic toxins partition out of target tissues (e.g., myocardium, CNS) and into this "lipid sink" within the plasma, reducing the free (active) drug concentration at receptor sites.
- Metabolic/Cardiac Enhancement: Provides a direct energy substrate (free fatty acids) to the myocardium, overcoming mitochondrial lipid metabolism blockade (e.g., by bupivacaine) and increasing intracellular calcium to improve cardiac contractility.
Nutritional Mechanism:
- Provides a dense source of calories and essential fatty acids (linoleic, linolenic acids) necessary for cellular integrity and metabolism.
Safety & warnings
Contraindications
- Severe egg yolk allergies
- Abnormal fat metabolism
- Premature and low-birth weight infants (human black box warning)
- Blood coagulation disorders
- Pulmonary disease
- Renal impairment
- Severe liver damage
- Patients at high risk for fat emboli
Adverse effects
- Sepsis or thrombophlebitis (secondary to IV catheterization)
- Fat overload syndrome (hyperlipidemia, hepatomegaly, icterus, splenomegaly, fat embolism, thrombocytopenia, hemolysis, prolonged clotting times)
- Pulmonary toxicity (temporary)
- GI effects
- Somnolence
- Headache
- Flushing
- Pancreatitis
- Hypercoagulability
- Hypersensitivity
Precautions
Strict aseptic technique and excellent IV catheter care are imperative to prevent sepsis. When used alone, IFE may be given via a peripheral line; when combined with amino acids/dextrose as Total Parenteral Nutrition (TPN), a dedicated central line is required due to hypertonicity. Use with caution in critically ill animals due to potential immunosuppression, exacerbation of pulmonary pathology, and increased infection rates. Blood samples for diagnostics should be drawn prior to administration to avoid severe lipemia artifacts (falsely high hemoglobin, MCH, MCHC, and altered bilirubin).
Drug interactions
IFE may act as a 'lipid sink', reducing the free circulating levels and clinical efficacy of concurrently administered lipophilic medications.
Monitoring
- Serum/plasma drug levels (for toxicology tracking)
- Blood glucose
- Serum triglycerides and gross lipemia
- PCV and Total Protein
- IV catheter site status (phlebitis/sepsis)
- Hydration status and vital signs (temp, HR, RR)
- Serum electrolytes (including phosphorus)
- Renal and liver function tests
- CBC
- Coagulation times (if using heparin)
Pharmacokinetics
Absorption
Administered intravenously; 100% bioavailable.
Distribution
Removed from the blood stream about as rapidly as chylomicrons.
Metabolism
Requires prior lipolysis of IFE into free fatty acids. Clearance seems to be increased with heparin-activated lipoprotein lipase.
Elimination
Elimination half-life in humans is about 30 minutes.
Overdose
In the event of inadvertent overdose or severe fat overload, stop the infusion until the lipid has cleared from the plasma. Clearance can be evaluated visually (inspecting hematocrit tubes for lipemia) or via laboratory methods (triglyceride concentrations, nephelometry).
If severe hyperlipidemia occurs during toxicity treatment, heparin therapy (75-250 Units/kg SQ q6h) may be considered to increase lipid clearance via lipoprotein lipase activation. However, weigh risks carefully, as heparin may alter the antidote mechanism. Monitor PTT; if PTT exceeds 2-2.5X normal, lower heparin dose (75 Units/kg SQ q6-8h) or discontinue.
Available products
Formulations
- Intravenous injection (10%, 20%, 30% emulsions)
Human-labeled
- Fat Emulsion, Intravenous 10%, 20%, 30% in 50 mL, 100 mL, 200 mL, 250 mL, & 500 mL bottles or bags (Intralipid, Liposyn II, Liposyn III)
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store unopened products at room temperature (not above 25°C / 77°F). Do not freeze; discard if accidentally frozen. Once opened, store the remaining product in the refrigerator (2-8°C) and discard after 24 hours. A new bag/vial must be used every 24 hours. Admixtures must be used promptly or stored under refrigeration for 24 hours or less.
Client information
Intravenous Fat Emulsion (IFE) is a specialized hospital-only treatment.
- For Poisonings: It acts as a "sponge" in the bloodstream to soak up certain severe, life-threatening toxins (like heart medications, local anesthetics, or certain parasiticides). It can be a life-saving rescue therapy when standard treatments fail.
- For Nutrition: It provides essential calories and fats for pets that cannot eat and require intravenous feeding.
- Because it is given directly into the vein, your pet will require hospitalization, an IV catheter, and close monitoring by the veterinary team to watch for signs of infection or fat overload in the blood.
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.