Intravenous lipid emulsion as antidote: How should we chew the fat in 2011?*:

Comparison of intravenous lipid emulsion, bicarbonate, and tailored liposomes in rabbit clomipramine toxicity

OBJECTIVES

Liposome (LIP)-like lipid dispersions have emerged as useful detoxification vehicles in vitro. The authors compare resuscitation with tailored LIPs, 20% intravenous lipid emulsion (ILE), and sodium bicarbonate (BIC), in a rabbit model of clomipramine toxicity.

METHODS

Sedated, instrumented New Zealand white rabbits underwent clomipramine infusion at 3.2 mg/kg/min to 50% baseline mean arterial pressure (MAP) and then at 1.6 mg/kg/min for 30 minutes. BIC (3 mL/kg 8.4%), ILE (3 mL/kg 20%), or LIP (24 mg/kg) were infused as rescue treatments at toxicity and were repeated at 10 minutes (n = 5 in each group).

RESULTS

Thirty-minute MAP was greatest in ILE-treated animals: 61 mm Hg ILE (interquartile range [IQR] = 49 to 64 mm Hg), 43 mm Hg LIP (IQR = 36.5 to 49 mm Hg), and 10 mm Hg BIC (IQR = 10 to 44 mm Hg; all p = 0.02). Two of the five BIC-treated animals survived to 30 minutes, compared with all five of the ILE-treated animals and all five of the LIP-treated animals (p = 0.044).

CONCLUSIONS

Both ILE and LIPs improved hemodynamic recovery compared with bicarbonate in clomipramine-induced cardiotoxicity in rabbits. Greater 30-minute MAP was observed in the ILE group.

Utility of the electrocardiogram in drug overdose and poisoning: theoretical considerations and clinical implications

The ECG is a rapidly available clinical tool that can help clinicians manage poisoned patients. Specific myocardial effects of cardiotoxic drugs have well-described electrocardiographic manifestations. In the practice of clinical toxicology, classic ECG changes may hint at blockade of ion channels, alterations of adrenergic tone, or dysfunctional metabolic activity of the myocardium. This review will offer a structured approach to ECG interpretation in poisoned patients with a focus on clinical implications and ECG-based management recommendations in the initial evaluation of patients with acute cardiotoxicity.

Intravenous lipid emulsion to reverse acute drug toxicity in pediatric patients

OBJECTIVE

To identify and summarize published cases in which intravenous lipid emulsion was used to treat pediatric patients with acute drug toxicities.

DATA SOURCES

PubMed, SCOPUS, and EMBASE were searched up to December 2012 for relevant publications using the terms fat emulsion, lipid emulsion, Intralipid, Liposyn, Medialipide, Medialipid, lipid rescue, ILE, IVLE, IFE, IVFE, or lipid and intoxication, overdose, poisoning, toxicity, resuscitation, antidote, and rescue that were limited to reports in humans aged 18 years or younger.

STUDY SELECTION AND DATA EXTRACTION

A publication was included if an intravenous lipid emulsion was used to treat acute-onset drug toxicity as reported in prospective or retrospective observational studies, case reports, and abstracts for patients aged 18 years or younger.

DATA SYNTHESIS

Fourteen case reports were identified in which intravenous lipid emulsion was used to treat toxicities due to local anesthetics and other medications (amitriptyline, diltiazem, bupropion, dosulepin, lamotrigine, quetiapine, and verapamil). Thirteen cases demonstrated a beneficial response in reversing systemic toxicity; 1 of these patients developed hypertriglyceridemia and pancreatitis. The dosage regimens used in this series were dissimilar.

CONCLUSIONS

There is an increasing interest in use of intravenous lipid emulsions to treat life-threatening toxicity from several lipophilic drugs in adults and children. Although most of the literature describes adult cases, intravenous lipid emulsion has been used in neonates and adolescents, with generally positive outcomes. Given the life-threatening, sometimes near-death situations in which an intravenous lipid emulsion is typically used after conventional resuscitation is unsuccessful and the dramatic positive response to this therapy in most published cases, its use likely will continue. Continued reporting of pediatric cases will guide the optimal use and safety profile of intravenous lipid emulsion for the emergent reversal of drug toxicity.

Intravenous Lipid Emulsion for the Treatment of Drug Toxicity

Intravenous lipid emulsion (ILE) has emerged as a powerful antidote for the treatment of drug toxicity in the past decade. Initial efficacy of ILE was shown in the setting of local anesthetic systemic toxicity (LAST), but recent case reports suggest its consideration in a variety of other drug toxicities. In this review, we will summarize the experimental evidence as well as the clinical experience in using ILE as an antidote. Specifically, we will look at the evidence for using ILE in LAST as well as toxicity due to beta-blockers, calcium-channel blockers, and tricyclic antidepressants. We will also review the current dosing recommendations as well as potential side effects of ILE as an antidote.