fat emulsions
Intralipid 10%, Intralipid 20%, Intralipid 30%, Liposyn II 10%, Liposyn II 20%, Liposyn III 10% and 20%

Available forms
Available by prescription only
Injection: 50 ml (10%, 20%), 100 ml (10%, 20%, 30%), 200 ml (10%, 20%), 250 ml (10%, 20%), 500 ml (10%, 20%)

Indications and dosages
 Source of calories adjunctive to TPN. Adults: 1 ml/minute I.V. for 15 to 30 minutes (10% emulsion). Infuse only 500 ml the fiirst day. Or, 0.5 ml/ minute I.V. for 15 to 30 minutes (20% emulsion). Infuse only 250 ml of 20% Liposyn emulsion or 500 ml of 20% Intralipid emulsion the first day. If no adverse reactions occur, increase rate to deliver 500 ml over 4 to 8 hours. Total daily dose shouldn’t exceed 2.5 g/kg (10% emulsion) and 3 g/kg (20% emulsion).
Children: 0.1 ml/minute for 10 to 15 minutes (10% emulsion). Or, 0.05 ml/minute I.V. for 10 to 15 minutes (20% emulsion). If no adverse reactions occur, increase rate to deliver 1 g/kg over 4 hours. Daily dose shouldn’t exceed 4 g/kg, which equals 60% of daily caloric intake. Protein-carbohydrate TPN should supply remaining 40%.
 Fatty acid deficiency. Adults and children: 8% to 10% of total caloric intake I.V.

Pharmacodynamics
Metabolic action: I.V. fat emulsions are prepared from soybean or safflower oil and provide a mixture of neutral triglycerides, predominantly fatty acids. Besides fatty acids (linoleic, oleic, palmitic, stearic, and linolenic), these preparations also contain 1.2% egg yolk phospholipids (an emulsifier) and glycerol (to adjust tonicity). I.V. fat emulsions are isotonic and may be given centrally or peripherally.
 Linoleic, linolenic, and arachidonic acids are essential in humans. Signs of essential fatty acid deficiency (EFAD) include scaly dermatitis, alopecia, growth retardation, poor wound healing, thrombocytopenia, and fatty liver. I.V. fat emulsions prevent or reverse the biochemical and clinical signs of EFAD and provide 1.1 kcal/ml (10%) or 2 kcal/ml (20%).

Pharmacokinetics
Absorption: Administered I.V.
Distribution: Distributed through plasma compartment.
Metabolism: Metabolized and used as energy source, causing increased heat production, decreased respiratory quotient, and increased oxygen consumption.
Excretion: Infused fat particles cleared from bloodstream in manner similar to chylomicrons.

Contraindications and precautions
Contraindicated in patients with hyperlipidemia, lipid nephrosis, acute pancreatitis accompanied by hyperlipidemia, or severe egg allergies. Use cautiously in patients with severe hepatic disease, pulmonary disease, anemia, or blood coagulation disorders (especially thrombocytopenia) and in those at risk for fat embolism.

Interactions
None reported.

Adverse reactions
Early reactions to fat overload
CNS: headache, sleepiness, dizziness, fever.
CV: flushing.
EENT: pressure over eyes.
GI: nausea, vomiting.
Hematologic: hypercoagulability.
Metabolic: hyperlipidemia.
Musculoskeletal: chest and back pain.
Respiratory: dyspnea, cyanosis.
Skin: diaphoresis, irritation (at infusion site).
Other: hypersensitivity reactions.
Delayed reactions to fat overload
CNS: focal seizures.
Hematologic: thrombocytopenia, leukopenia, leukocytosis.
Hepatic: hepatomegaly.
Other: splenomegaly.

Effects on lab test results
• May increase lipid, bilirubin, and liver enzyme levels.
• May decrease platelet count. May increase or decrease WBC count.

Overdose and treatment
Signs and symptoms of overdose or "overloading syndrome" include focal seizures, splenomegaly, leukocytosis, fever, and shock.
 Discontinue infusion until visual inspection of plasma, determination of triglyceride levels, or nephelometric measurement of plasma light-scattering activity confirms lipid clearance. Reevaluate patient and institute appropriate corrective measures.

Special considerations
• Some brands of fat emulsion can be mixed with amino acid solution and dextrose in the same I.V. container. The order of mixing is important; see package insert for further information.
• Don’t use a 0.22-micron filter when administering drug; fat particles (0.5 micron) are larger than 0.22-micron cellulose filter.
• Fat emulsions may extract small amounts of plasticizers from I.V. administration sets made of polyvinyl chloride. Nonphthalate administration sets are available; however, phthalate extraction can be minimized from regular I.V. tubing by not storing primed administration sets.
• Discard fat emulsion if it separates or becomes oily.
• Change all I.V. tubing at each infusion because lipids support bacterial growth.
• Avoid rapid infusion by using infusion pump to regulate rate.
• Abnormally high mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration values may be found in blood samples drawn during or shortly after fat emulsion infusion.
• Monitor lipid levels before and during treatment.
• Monitor hepatic function with long-term use.
• Check injection site daily for signs of inflammation or infection.
• Watch closely for adverse effects, especially during the first half hour of infusion.
• Monitor patient for allergic reactions.
• In neonates, monitor platelet count frequently; these patients tend to develop thrombocytopenia.
• In jaundiced infants, monitor bilirubin levels.
• In premature infants, monitor bilirubin level and triglyceride or serum free fatty acid levels daily; free fatty acids displace bilirubin bound to albumin.
Pediatric patients
• Because premature and small-for-gestational-age infants have poor clearance of I.V. fat emulsions, lower doses are needed to reduce likelihood of fat overload.
• Cautiously administer fat emulsions to jaundiced or premature infants. Deaths in preterm infants have been reported from intravascular fat accumulation in lungs.

Patient education
• Explain the need for fat emulsion therapy and answer questions.
• Tell patient to report adverse reactions promptly.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use