Lipid Emulsion for Overdoses: Updating Lipid Sink

In emergency medicine pharmacy circles, there is growing awareness of intravenous (IV) lipid emulsion as a potential overdose antidote.

Certain patients who have ingested or been exposed to medications without a specific antidote, such as antipsychotics, calcium channel blockers, or local anesthetics, may be considered to receive “lipid sink” therapy.

Before pulling the trigger on this treatment, however, there are specific concerns that pharmacists should be aware of, which include:

1. It Has Different Dosing Schemes

IV lipid emulsion therapy originated from anesthesia literature that described its successful use in iatrogenic local anesthetic overdoses. Since then, the drug’s use has expanded to include many other lipophilic xenobiotics that have no antidote, such as calcium channel blockers and antipsychotics.

With these new uses, 2 different dosing regimens have arisen: one for local anesthetic systemic toxicity (LAST), and the other for everything else (non-LAST).

These regimens are as follows:

LAST 20% lipid emulsion¹:

1.5 mL/kg as an initial bolus followed by

0.25 mL/kg/min for 30-60 min

Non-LAST 20% lipid emulsion²:

1.5 mL/kg bolus followed by

0.25 mL/kg/min for 3 min

Maintenance infusion of 0.025 mL/kg/min for up to 6.5 hours

2. It Needs Its Own IV Line

While conclusive evidence is lacking, available research suggests that lipid emulsion is not compatible with many of the medications administered during resuscitation efforts.³

To minimize the risk of disrupting the emulsion and potentially causing lipid emboli, it’s advised to use a dedicated IV line.

3. It May Cause Lab Abnormalities^1,2,4

Coined by emergency medicine pharmacy specialist Kyle DeWitt, PharmD, BCPS, an easy acronym to help you remember which abnormalities can occur is BLEACH (Blood gas, Liver transaminases, Electrolytes, Analgesics (acetaminophen, salicylates), Coagulation, H&H, platelets)

To account for these abnormalities, lab tests should be drawn prior to administration of the lipid emulsion, if possible.

References

• Weinberg G. Recommendations for LipidRescue resuscitation. http://lipidrescue.squarespace.com/if-you-are-resuscitating-a-pat. Published February 11, 2010. Accessed January 4, 2016.
• Fettiplace MR, Akpa BS, Rubinstein I, et al. Confusion about infusion: rational volume limits for intravenous lipid emulsion during treatment of oral overdoses. Ann Emerg Med. 2015 Aug;66(2):185-188.
• Cocchio C, et al. Physiochemical stability of intravenous fat emulsion in combination with medications used for resuscitation. SOJ Pharm PharmSci 2014;1(1):3.
• Grunbaum AM, et al. Review of the effect of intravenous lipid emulsion on laboratory analyses. Clin Toxicol. 2015 Dec 1:1-11.