Intravenous fat emulsion in clinical practice: nutrient and antidote.

For more than 50 years intravenous fat emulsions (IVFEs), or intravenous lipid emulsions, have been used for nutritive support for patients who are unable to attain adequate nourishment via the gastrointestinal tract 1, . This made IVFEs an important part of total parenteral nutrition regimens 3, . Although used to meet the caloric requirements, their role is not only to provide fat as physiological nonprotein energy source, but also to prevent or correct essential fatty acids (FAS) deficiency (linoleic acid and linolenic acid) . These acids cannot be synthesized in the body, and they are important to maintain the normal composition of the structural body lipids, as well as in the synthesis of the various important metabolic mediators . IVFEs advantages include limitation of likely side effects of infusing large amounts of glucose. Substituting some glucose calories with lipids reduces undesirable effects of high glucose such as hyperglycemia, excessive CO2 production, and liver FA infiltration. Lipid emulsions provide different tissues with potentially liposoluble vitamins or therapeutic agents as IVFEs were found to be useful as a delivery vehicle for drugs that are poorly soluble in water. Some of these drugs include anesthetics, sedatives, cytotoxic drugs, analgesics, and anti-inflammatory agents. Those products are prepared by dissolving drugs in the vehicle, or by addition of the drug to oil phase prior to the homogenization process for the emulsion. In recent animal studies and human case reports, IVFEs have been proven to be an effective antidote for treating useful toxicity effects from overdose of several lipid-soluble drugs including local anesthetics, calcium channel blockers, beta blockers, tricyclic antidepressants and other psychotropic agents . Composition of IVFEs