Can I Get a Side of Fat with that Overdose?

​An 88-year-old woman with a history of dementia presented with dizziness. Her daughter reported that she may have taken at least 12 tablets of diltiazem, which she mistook for her other medications. She is alert and oriented with normal vital signs. Her heart rate is 40 beats per minute and blood pressure is 70/45 mm Hg. Boluses of calcium gluconate and high-dose insulin therapy are initiated. The patient remains hypotensive at 80/40 mm Hg. Toxicology is consulted about intravenous lipid emulsion therapy.How does lipid emulsion therapy work?Two main theories describe the mechanism of action of intravenous lipid emulsion therapy (ILE): the metabolic theory and the lipid sink theory. The metabolic theory proposed that lipids increase the fatty acid uptake of the mitochondria in the cardiac myocytes and therefore acted as an energy substrate. This theory fails, however, to answer why ILE appears to have neuroprotective effects in some drug overdoses.The lipid sink theory is generally more accepted and has been validated by several animal and in vitro studies. The infused intravascular lipids pull the offending agent from the target tissues into the intravascular space, lessening their organ toxicity. This theory is supported by the fact that all drug overdoses responding to this antidote are found to have an n-octanol:water partition coefficient, a measure of a drug's lipophilicity, greater than 2.What drug overdoses benefit from ILE therapy?ILE has been proven to be ...
Source: The Tox Cave - Category: Emergency Medicine Tags: Blog Posts Source Type: blogs