Lipid Emulsion Therapy in Lipophilic Drug Toxicity
Article Outline
To the Editor:
We wish to congratulate Sirianni et al on their case publication “Use of Lipid Emulsion in the Resuscitation of a Patient With Prolonged Cardiovascular Collapse After Overdose of Bupropion and Lamotrigine.”1 This represents a major step in the evolution of lipid emulsion as antidotal therapy in lipid-soluble drug cardiotoxicity, and is the first to demonstrate effect in an enteric overdose of lipid soluble drug.
Application of lipid infusion in local anesthetic-induced cardiotoxicity follows pioneering work by Weinberg and others demonstrating efficacy in animal models,2 and subsequently successful case publications.3 Re-establishment of new plasma equibrilium favoring sequestration of lipophilic drugs into a newly created intravascular compartment is the currently proposed mechanism of action. We have additionally demonstrated efficacy for lipid infusion in animal models of clomipramine4 and verapamil5 toxicity, suggesting potential benefit in deliberate overdose from these lipid soluble agents.
Guidelines advocating lipid emulsion as therapy for local anesthetic cardiotoxocity have recently been published by The Association of Anaesthetists of Great Britain and Ireland.6 We would endeavor to contribute to the “bringing over” of lipid therapy for lipophilic drug toxidromes from the anesthetic domain to the general toxicologic domain wherein we believe the greatest benefit is likely to be manifest.
The use of lipid emulsion as antidote should, however, progress with some caution. Enthusiasm and imprudence are common bedfellows in the commendation and application of novel medical therapies. The special setting encountered by Sirianni et al, that of refractory arrest despite all conventional therapy, is one where use of lipid emulsion is rational. The only potential alteration to outcome is benefit. Indiscriminate application of this therapy at the expense of validated antidotal therapies is unwarranted at this point. We would echo the call of the anesthetic literature for the use of lipid emulsion in the setting of lipophilic drug cardiotoxicity where death is adjudged inevitable despite all available alternative therapies.
Finally, as the nature and presentation of life-threatening lipophilic drug intoxication renders systemic human study impractical, animal modelling and case publication are likely to represent the avenues by which lipid therapy may advance. It is therefore the responsibility of individual clinicians to disseminate their experience with lipid therapy, both successes and otherwise. Moreover we would implore editors to publish such case reports both positive and negative. In time a major new therapy may be available to severely intoxicated patients.
References
- Use of lipid emulsion in the resuscitation of a patient with prolonged cardiovascular collapse after overdose of bupropion and lamotrigine. Ann Emerg Med. 2008;51:412–415
- Lipid emulsion infusion rescues dogs from bupivacaine induced cardiac toxicity. Reg Anesth Pain Med. 2003;28:198–202
- Successful use of a 20% lipid emulsion to resuscitate a patient after presumed bupivacaine related cardiac arrest. Anaesthesia. 2006;105:217–218
- . Intralipid outperfroms sodium bicarbonate in a rabbit model of clomipramine toxicity. Ann Emerg Med. 2007;49:178–185
- Intralipid prolongs survival in a rat model of verapamil toxicity. Acad Emerg Med. 2006;13:134–139
- . Guidelines for the management of severe local anaesthetic toxicity. The Association of Anaesthetists of Great Britain and Ireland Website http://www.aagbi.org/publications/guidelines/docs/latoxicity07.pdfAccessed October 2, 2007
Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article, that might create any potential conflict of interest. The authors have stated that no such relationships exist. See the Manuscript Submission Agreement in this issue for examples of specific conflicts covered by this statement.
PII: S0196-0644(07)01673-3
doi:10.1016/j.annemergmed.2007.10.014
© 2008 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.
