Did you know 20% Liposyn® can be used
as an adjunct treatment of certain poisonings including
ivermectin? The mechanism is suspected to be related
to the lipophilic nature of the toxic drug.
There are three theories of how intravenous fat emulsions
may help:
• They create a pharmacological sink for fat soluble
drugs. By creating a serum lipid partition, the effective
concentration of the fat soluble drug to the tissues
is decreased.
• They augment cardiac energy supplies. Fatty
acids are the primary substrate for myocardial ATP production.
Supplementation improves performance in the ischemic,
hypo dynamic heart.
• They may restore myocyte function by increasing
intracellular calcium
Human physicians started using Liposyn® to treat
the cardiac toxicity associated with the accidental
overdose of local anesthetics. Assorted other toxins
treated with Liposyn® that have been reported in
human and lab animal literature include: bupivacaine,
buproprion, Lamictal, chlorpromazine, propranalol, thiopental,
verapamil, and clomipramine.
The ASPCA Poison Control is now recommending lipid
infusion for the treatment of toxicity associated
with ivermectin, moxidectin, and calcium channel blockers.
Theoretically Liposyn® could be beneficial for
treating other common lipophilic toxins affecting
small animals such as baclophen, pyrethroids, and
marijuana. So far the results of its use with different
lipohpilic drugs are mixed. An additional use of Liposyn®
for milbemycin toxicity will be reported in a paper
pending publication. At this time we are still extrapolating
the best dosage and administration from limited anticdotal
results and from human and lab animal literature.
Liposyn® is relatively inexpensive, stored at
room temperature, and has a two year shelf life. It
is safe to use. Negative side effects from the hyperlipidemia
may be of some concern. It was suggested by the ASPCA
Poison Control Center to check the plasma before repeating
the dose of lipids. If the plasma is still lipemic
it is advised not to repeat administration until the
plasma clears.
Current recommended dosing of Liposyn® (using
a 20% solution) to treat a toxicity by Dr Wismer at
the ASPCA Animal Poison Control Center are as follows:
give an initial bolus of 1.5 ml/kg followed by a CRI
of 0.25 ml/kg/min for 30 – 60 minutes. This
can be repeated in 6-8 hours if the serum is not lipemic
and if the patient is still symptomatic.
Treatment with Liposyn® does not replace the
other basic treatment of certain toxicities including
the standard decontamination procedures of emesis
or lavage, a cathartic or enema, and activated charcoal
when indicated. Liposyn® infusion has been successfully
used at SOVSC for several cases of Ivermectin toxicity
as an adjunct treatment and has shortened the hospital
stay with positive outcomes.
References:
• Picard J, Meek T. A response to “lipid
emulsion to treat bupivacaine toxicity.” Anesthesia
60:1158, 2005
• Weinberg, G Lipid rescue resuscitation from
local anesthetic cardiac toxicity. Toxicol Rev. 25:139-45,
2006
• Di Gregorio et al. Lipid emulsion is superior
to vasopressin in rodent model of resuscitation from
toxin-induced cardiac arrest. Crit Care Med. March
2009:373):993-9
• Animal Poison Control Center, An Allied Agency
of the University of Illinois
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