Case report: successful lipid resuscitation in multi-drug overdose with predominant tricyclic antidepressant toxidrome

Effect of lipid emulsion on neuropsychiatric drug-induced toxicity: A narrative review

Lipid emulsion has been shown to effectively relieve refractory cardiovascular collapse resulting from toxic levels of nonlocal anesthetics. The goal of this study was to examine the effect of lipid emulsions on neuropsychiatric drug-induced toxicity using relevant case reports of human patients, with a particular focus on the Glasgow Coma Scale (GCS) score and corrected QT interval, to analyze drugs that frequently require lipid emulsion treatment. The following keywords were used to retrieve relevant case reports from PubMed: "antidepressant or antipsychotic drug or amitriptyline or bupropion or citalopram or desipramine or dosulepin or dothiepin or doxepin or escitalopram or fluoxetine or haloperidol or olanzapine or phenothiazine or quetiapine or risperidone or trazodone" and "lipid emulsion or Intralipid." Lipid emulsion treatment reversed the corrected QT interval prolongation and decreases in Glasgow Coma Scale scores caused by toxic doses of neuropsychiatric drugs, especially lipid-soluble drugs such as amitriptyline, trazodone, quetiapine, lamotrigine, and citalopram. The log P (octanol/water partition coefficient) of the group which required more than 3 lipid emulsion treatments was higher than that that of the group which required less than 3 lipid emulsion treatments. The main rationale to administer lipid emulsion as an adjuvant was as follows: hemodynamic depression intractable to supportive treatment (88.3%) > lipophilic drugs (8.3%) > suspected overdose or no spontaneous breathing (1.6%). Adjuvant lipid emulsion treatment contributed to the recovery of 98.30% of patients with neuropsychiatric drug-induced toxicity. However, further analyses using many case reports are needed to clarify the effects of lipid emulsion resuscitation.

Biodetoxification Using Intravenous Lipid Emulsion, a Rescue Therapy in Life-Threatening Quetiapine and Venlafaxine Poisoning: A Case Report

The administration of intravenous lipid emulsion (ILE) is a proven antidote used to reverse local anesthetic-related systemic toxicity. Although the capacity of ILE to generate blood tissue partitioning of lipophilic drugs has been previously demonstrated, a clear recommendation for its use as an antidote for other lipophilic drugs is still under debate. Venlafaxine (an antidepressant acting as a serotonin-norepinephrine reuptake inhibitor (SNRI)) and quetiapine (a second-generation atypical antipsychotic) are widely used in the treatment of psychotic disorders. Both are lipophilic drugs known to induce cardiotoxicity and central nervous depression. We report the case of a 33-year-old man with a medical history of schizoaffective disorder who was admitted to the emergency department (ED) after having been found unconscious due to a voluntary ingestion of 12 g of quetiapine and 4.5 g of venlafaxine. Initial assessment revealed a cardiorespiratory stable patient but unresponsive with a GCS of 4 (M2 E1 V1). In the ED, he was intubated, and gastric lavage was performed. Immediately after the admission to the intensive care unit (ICU), his condition quickly deteriorated, developing cardiovascular collapse refractory to crystalloids and vasopressor infusion. Junctional bradycardia occurred, followed by spontaneous conversion to sinus rhythm. Subsequently, frequent ventricular extrasystoles, as well as patterns of bigeminy, trigeminy, and even episodes of non-sustained ventricular tachycardia, occurred. Additionally, generalized tonic-clonic seizures were observed. Alongside supportive therapy, antiarrhythmic and anticonvulsant therapy, intravenous lipid emulsion bolus, and continuous infusion were administered. His condition progressively improved over the following hours, and 24 h later, he was tapered off the vasopressor. On day 2, the patient repeated the cardiovascular collapse and a second dose of ILE was administered. Over the next few days, the patient's clinical condition improved, and he was successfully weaned off ventilator and vasopressor support. ILE has the potential to become a form of rescue therapy in cases of severe lipophilic drug poisoning and should be considered a viable treatment for severe cardiovascular instability that is refractory to supportive therapy.

2023 American Heart Association Focused Update on the Management of Patients With Cardiac Arrest or Life-Threatening Toxicity Due to Poisoning: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

In this focused update, the American Heart Association provides updated guidance for resuscitation of patients with cardiac arrest, respiratory arrest, and refractory shock due to poisoning. Based on structured evidence reviews, guidelines are provided for the treatment of critical poisoning from benzodiazepines, β-adrenergic receptor antagonists (also known as β-blockers), L-type calcium channel antagonists (commonly called calcium channel blockers), cocaine, cyanide, digoxin and related cardiac glycosides, local anesthetics, methemoglobinemia, opioids, organophosphates and carbamates, sodium channel antagonists (also called sodium channel blockers), and sympathomimetics. Recommendations are also provided for the use of venoarterial extracorporeal membrane oxygenation. These guidelines discuss the role of atropine, benzodiazepines, calcium, digoxin-specific immune antibody fragments, electrical pacing, flumazenil, glucagon, hemodialysis, hydroxocobalamin, hyperbaric oxygen, insulin, intravenous lipid emulsion, lidocaine, methylene blue, naloxone, pralidoxime, sodium bicarbonate, sodium nitrite, sodium thiosulfate, vasodilators, and vasopressors for the management of specific critical poisonings.

Lipid Emulsion to Treat Acute Poisonings: Mechanisms of Action, Indications, and Controversies

Biodetoxification using intravenous lipid emulsion (ILE) in acute poisoning is of growing interest. As well as for local anesthetics, ILE is currently used to reverse toxicity caused by a broad-spectrum of lipophilic drugs. Both pharmacokinetic and pharmacodynamic mechanisms have been postulated to explain its possible benefits, mainly combining a scavenging effect called "lipid sink" and cardiotonic activity. Additional mechanisms based on ILE-attributed vasoactive and cytoprotective properties are still under investigation. Here, we present a narrative review on lipid resuscitation, focusing on the recent literature with advances in understanding ILE-attributed mechanisms of action and evaluating the evidence supporting ILE administration that enabled the international recommendations. Many practical aspects are still controversial, including the optimal dose, the optimal administration timing, and the optimal duration of infusion for clinical efficacy, as well as the threshold dose for adverse effects. Present evidence supports the use of ILE as first-line therapy to reverse local anesthetic-related systemic toxicity and as adjunct therapy in lipophilic non-local anesthetic drug overdoses refractory to well-established antidotes and supportive care. However, the level of evidence is low to very low, as for most other commonly used antidotes. Our review presents the internationally accepted recommendations according to the clinical poisoning scenario and provides the precautions of use to optimize the expected efficacy of ILE and limit the inconveniences of its futile administration. Based on their absorptive properties, the next generation of scavenging agents is additionally presented. Although emerging research shows great potential, several challenges need to be overcome before parenteral detoxifying agents could be considered as an established treatment for severe poisonings.

Successful Treatment of Amoxapine-Induced Intractable Seizures With Intravenous Lipid Emulsion

BACKGROUND

Amoxapine is a second-generation tricyclic antidepressant with a greater seizure risk than other antidepressants. If administered in large amounts, amoxapine can cause severe toxicity and death. Therefore, it is necessary to terminate seizures immediately if amoxapine toxicity occurs. However, intractable seizures often occur in these patients. We describe a case of intractable seizures caused by amoxapine poisoning, in which intravenous lipid emulsion (ILE) was used successfully.

CASE REPORT

A 44-year-old woman with a history of depression ingested 3.0 g of amoxapine during a suicide attempt. Although she was initially treated with intravenous diazepam, her seizures persisted. Levetiracetam and phenobarbital were then administered, but seizures persisted. Hence, ILE was injected for over 1 min. At 2 min after ILE administration, the patient's status seizures ceased. Recurrence of seizures was observed 30 min after ILE, and the seizures disappeared after re-administration of ILE. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: ILE may be effective in amoxapine intoxication. Emergency physicians may consider ILE as an adjunctive therapy for amoxapine poisoning with a high mortality rate. ILE should be implemented carefully with monitoring of total dosage and adverse events.

Successful Outcome Following Intravenous Lipid Emulsion Rescue Therapy in a Patient with Cardiac Arrest Due to Amitriptyline Overdose

BACKGROUND The management of patients with tricyclic antidepressant drug overdose can be a challenge for the emergency department physician. Tricyclic antidepressants block alpha-adrenergic receptors and the anticholinergic effects may lead to cardiotoxicity, resulting in arrhythmias and hypotension that can lead to patient mortality. This report is of a case of a 28-year-old woman who presented with cardiac arrest due to amitriptyline overdose and who responded to intravenous lipid emulsion (ILE) therapy. CASE REPORT A 28-year-old woman was admitted to the emergency department with amitriptyline overdose. She suffered a cardiac arrest followed by cardiovascular and neurological complications. Hypotension and lack of a pulse did not respond to treatment with high-dose sodium, but she stabilized following treatment with ILE. The prompt response from the emergency team guaranteed rapid intervention that may have influenced the successful results. CONCLUSIONS Despite the frequency and severity of poisoning with tricyclic antidepressants, there is little consensus among physicians regarding patient management. This case showed the successful use of ILE as rescue therapy in a patient in cardiac arrest following amitriptyline overdose. However, the successful outcome obtained in this case is not a recommendation for the use of ILE as a first-line treatment for the management of patients with tricyclic antidepressant drug overdose. Controlled clinical studies are required to evaluate the safety and efficacy of ILE in the management of tricyclic antidepressant drug overdose.

Superior Efficacy of Lipid Emulsion Infusion Over Serum Alkalinization in Reversing Amitriptyline-Induced Cardiotoxicity in Guinea Pig

BACKGROUND

Tricyclic antidepressants (TCAs) are a major cause of fatal drug poisoning due to their cardiotoxicity. Alkalinization by sodium bicarbonate (NaHCO3) administration, the first-line therapy for TCA-induced cardiotoxicity, can occasionally yield insufficient efficacy in severe cases. Because most TCAs are highly lipophilic, lipid emulsion may be more effective than alkalinization. However, it remains to be determined whether lipid emulsion is more beneficial than alkalinization in reversing amitriptyline-induced cardiotoxicity.

METHODS

Hemodynamic variables were recorded from in vivo guinea pig models and Langendorff-perfused hearts. Whole-cell patch-clamp experiments were conducted on enzymatically isolated ventricular cardiomyocytes to record fast sodium currents (INa). Lipid solutions were prepared using 20% Intralipid. The pH of the alkaline solution was set at 7.55. We assessed the effect of lipid emulsion on reversing amitriptyline-induced cardiotoxicity, in vivo and in vitro, compared to alkalinization. The data were evaluated by Student t test, 1-way repeated-measures analysis of variance, or analysis of covariance (covariate = amitriptyline concentration); we considered data statistically significant when P < .05.

RESULTS

In the in vivo model, intervention with lipids significantly reversed the amitriptyline-induced depression of mean arterial pressure and prolongation of QRS duration on electrocardiogram more than alkalinization (mean arterial pressure, mean difference [95% confidence interval]: 19.0 mm Hg [8.5-29.4]; QRS duration, mean difference [95% confidence interval] -12.0 milliseconds [-16.1 to -7.8]). In the Langendorff experiments, perfusion with 1% and 2% lipid solutions demonstrated significant recovery in left ventricular developed pressure (LVdevP), maximum change rate of increase of LVdevP (dP/dtmax) and rate-pressure product compared with alkaline solution (LVdevP [mm Hg], alkaline 57 ± 35, 1% lipid 94 ± 12, 2% lipid 110 ± 14; dP/dtmax [mm Hg/s], alkaline 748 ± 441, 1% lipid 1502 ± 334, 2% lipid 1753 ± 389; rate-pressure product [mm Hg·beats·minute], alkaline 11,214 ± 8272, 1% lipid 19,025 ± 8427, 2% lipid 25,261 ± 4803 with analysis of covariance). Furthermore, lipid solutions (0.5%-4%) resulted in greater recovery of hemodynamic parameters at 3 μM amitriptyline. Amitriptyline inhibited INa in a dose-dependent manner: the half-maximal inhibitory concentration (IC50) was 0.39 μM. The IC50 increased to 0.75 μM in the alkaline solution, 3.2 μM in 1% lipid solution, and 6.1 μM in 2% lipid solution. Furthermore, the lipid solution attenuated the use-dependent block of sodium channels by amitriptyline more than alkaline solution. On 30 consecutive pulses at 1 Hz, the current decreased to 50.1 ± 2.1, 60.3 ± 1.9, and 90.4% ± 1.8% in standard, alkaline, and 1% lipid solution, respectively. Even 0.5% lipid solution showed greater effects than the alkaline solution in all experiments.

CONCLUSIONS

Lipid emulsion significantly suppressed amitriptyline-induced INa, inhibition, which was likely related to the marked improvement in hemodynamic status observed in vivo and in isolated perfused hearts. These results suggest the superiority of lipid emulsion as the first-line therapy for TCA-induced cardiotoxicity compared to alkalinization therapy.

The Effects of Lipid Emulsion, Magnesium Sulphate and Metoprolol in Amitriptyline-Induced Cardiovascular Toxicity in Rats

The aim of this study was to evaluate the effects of metoprolol, lipid emulsion and MgSO₄ which can be recommended for prevention of long QT that is one of the lethal consequences of amitriptyline intoxication. Thirty Sprague-Dawley male rats were included. Five groups respectively received the following: saline intraperitoneally (i.p.); amitriptyline (AMT) 100 mg/kg per os (p.o.) and saline i.p.; AMT 100 mg/kg p.o. and 5 mg/kg metoprolol i.p.; AMT 100 mg/kg p.o. and 20 ml/kg lipid emulsion i.p.; AMT 100 mg/kg p.o. and 75 mg/kg MgSO₄ i.p. After 1 h, all groups were analysed by ECG recordings in DII lead; their blood was taken for biochemical examination and euthanasia was performed. For histological examination, cardiac tissues were removed and sections were prepared. QTc was significantly reduced in treatment groups compared to the AMT+saline group. When compared with the AMT+saline, lipid emulsion did not affect pro-BNP and troponin levels in biochemical analysis, but it significantly reduced Caspase 3 expression in histological examination. In the group treated with AMT and metoprolol, there was no significant effect on Caspase 3 expression. In MgSO₄-treated group, there was a significant decrease in troponin, pro-BNP and urea levels biochemically and significant decrease in Caspase 3 expression histologically when compared with the control group. With further studies including clinical studies, MgSO₄, lipid emulsion or metoprolol may be used to improve AMT-induced cardiotoxicity. They can possibly become alternative approaches in the future for suicidal or accidental intoxication of tricyclic antidepressant in emergency departments.

Intravenous Lipid Emulsion as Antidote: Experience in Hong Kong

Objective

Intravenous lipid emulsion (ILE) is an emerging therapy in the field of toxicology. The purpose of this study was to report the accumulated local experience on using ILE in the management of patients suffering from poisoning by pharmaceutical agents other than local anaesthetics.

Design

Case series.

Setting

Local poison information centre.

Methods

Ten patients were identified from the database of Hong Kong Poison Information Centre. The patients were managed in 6 Hong Kong public hospitals during a 4-year study period (July 2008-June 2012).

Results

Nine of them presented with drug-induced cardiotoxicity, defined as either cardiac arrest (n=3) or hypotension refractory to other treatments (n=6). The overall survival rate is 30%. Possible adverse events from ILE included mild derangement of liver function, elevated amylase and hyperlipidaemia were observed.

Conclusions

About 30% of severe poison-induced cardiotoxicity treated with ILE can survive with no major adverse effects. The use of ILE remains to be a treatment option for lipid-soluble drug induced severe toxicity not responsive to standard resuscitation measures. (Hong Kong j. emerg.med. 2015;22:100-107)

Squarticles as the nanoantidotes to sequester the overdosed antidepressant for detoxification

The increasing death rate caused by drug overdose points to an urgent demand for the development of novel detoxification therapy. In an attempt to detoxify tricyclic antidepressant overdose, we prepared a lipid nanoemulsion, called squarticles, as the nanoantidote. Squalene was the major lipid matrix of the squarticles. Here, we present the animal study to investigate both the pharmacokinetic and pharmacodynamic effects of squarticles on amitriptyline intoxication. The anionic and cationic squarticles had average diameters of 97 and 122 nm, respectively. Through the entrapment study, squarticles could intercept 40%–50% of the amitriptyline during 2 h with low leakage after loading into the nanoparticles. The results of isothermal titration calorimetry demonstrated greater interaction of amitriptyline with the surface of anionic squarticles (K_a =28,700) than with cationic ones (K_a =5,010). Real-time imaging showed that intravenous administration of anionic squarticles resulted in a prolonged retention in the circulation. In a rat model of amitriptyline poisoning, anionic squarticles increased the plasma drug concentration by 2.5-fold. The drug uptake in the highly perfused organs was diminished after squarticle infusion, indicating the lipid sink effect of bringing the entrapped overdosed drug in the tissues back into circulation. In addition, the anionic nanosystems restored the mean arterial pressure to near normal after amitriptyline injection. The survival rate of overdosed amitriptyline increased from 25% to 75% by treatment with squarticles. Our results show that the adverse effects of amitriptyline intoxication could be mitigated by administering anionic squarticles. This lipid nanoemulsion is a potent antidote to extract amitriptyline and eliminate it.

Amitriptyline-induced ventricular tachycardia: a case report

Background

In Bangladesh, each emergency physician faces amitriptyline overdose nearly a day. An acute cardiovascular complication, one of the worst complications is mainly responsible for the mortality in tricyclic overdose. Recently, we managed ventricular tachycardia in a young female presented with an impaired consciousness 10 h after intentionally ingesting 2500 mg amitriptyline. Here, we report it, discuss how the electrocardiography is vital to acknowledge and predict it and its’ complications and also the recent update of the management of it.

Case presentation

A young married Bangladeshi-Bengali girl, 25-year-old, having a history of disharmony with her husband, came with an impaired consciousness after intentionally ingesting 2500 mg amitriptyline about 10 h before arrival. There was blood pressure 140/80 mmHg, heart rate 140 beats-per-min, temperature 103 °F, Glasgow coma scale 10/15, wide complex tachycardia with QRS duration of 178 ms in electrocardiography, blood pH 7.36. Initially, treated with 100 ml 8.4% sodium bicarbonate. After that, QRS duration came to 100 ms in electrocardiography within 10 min of infusion. To maintain the pH 7.50–7.55 over the next 24 h, the infusion of 8.4% sodium bicarbonate consisting of 125 ml dissolved in 375 ml normal saline was started and titrated according to the arterial blood gas analysis. Hence, a total dose of 600 mmol sodium bicarbonate was given over next 24 h. In addition to this, gave a 500 ml intravenous lipid emulsion over 2 h after 24 h of admission as she did not regain her consciousness completely. Afterward, she became conscious, though, in electrocardiography, ST/T wave abnormality persisted. So that, we tapered sodium bicarbonate infusion slowly and stopped it later. At the time of discharge, she was by heart rate 124/min, QRS duration 90 ms in electrocardiogram along with other normal vital signs.

Conclusion

Diagnosis of amitriptyline-induced ventricular tachycardia is difficult when there is no history of an overdose obtained. Nevertheless, it should be performed in the clinical background and classic electrocardiographic changes and wise utilization of sodium bicarbonate, intravenous lipid emulsion, and anti-arrhythmic drugs may save a life.

Tricyclic antidepressant overdose treated with adjunctive lipid rescue and plasmapheresis

Tricyclic antidepressant poisoning remains a major cause of morbidity and mortality, particularly in the setting of suicidal attempts. The current standard of care for treatment is the administration of sodium bicarbonate infusion. Adjunctive lipid emulsion therapy and plasmapheresis have received attention recently. We report an 18-year-old patient who was successfully managed with lipid emulsion and plasmapheresis as adjuncts to sodium bicarbonate treatment and review some of the recent literature.

Successful management of aluminium phosphide poisoning using intravenous lipid emulsion: Report of two cases

Aluminum phosphide (ALP) is a cheap, easily available agricultural pesticide which causes lethal poisoning by liberation of phosphine and inhibition of cytochrome c oxidase thereby leading to cellular hypoxia. Although there is no known specific antidote, clinical trials are still going on. We present here two cases of ALP poisoning who were successfully managed by treatment with lipid emulsion and intravenous magnesium sulfate.

Involvement of Opioid Receptors in the Lipid Rescue of Bupivacaine-Induced Cardiotoxicity

BACKGROUND

Lipid emulsion (LE) has been successfully used for resuscitation of local anesthetic cardiotoxicity caused by bupivacaine overdose. Opioid receptors have been shown to play a key role in cardio protection. We explored whether this rescue action of LE is mediated through opioid receptors.

METHODS

Asystole was induced by bupivacaine (10 mg/kg over 20 seconds, IV) in young male Sprague-Dawley rats, and resuscitation with LE (intralipid 20%; 5 mL/kg bolus and 0.5 mL/kg/min maintenance) was started immediately. The rats were pretreated 2 minutes before inducing asystole with nonselective opioid receptor antagonists such as naloxone and naloxone methiodide, as well as highly selective opioid receptor antagonists for subtype κ, δ, and µ or phosphate buffer solution as a control. Heart rates and ejection fractions were measured using echocardiography.

RESULTS

LE rescue of bupivacaine cardiotoxicity was prevented by high-dose (1 mg/kg) naloxone but not by lower doses of naloxone (1, 5, and 10 µg/kg), by naloxone methiodide (which does not cross the blood-brain barrier), and by a selective δ- and κ-opioid receptor antagonists at a higher (10 mg/kg) dose. Successful LE rescue was not affected by highly selective µ-opioid receptor antagonists. δ-Opioid receptor antagonist (10 mg/kg) pretreatment also resulted in reduced phosphorylation level of cardiac glycogen synthase kinase-3β in rats that were not resuscitated by LE compared with control.

CONCLUSIONS

Our data highlight the involvement of peripheral δ- and κ-opioid receptors in the rescue action of LE.

[The determination of amitriptyline and its metabolite, nortriptyline, in the biological objects of the corpse by the high-performance liquid chromatography technique]

Tricyclic antidepressants are among the preparations that most frequently cause intoxication in adults and children; moreover, poisoning with these substances not infrequently has a fatal outcome. Medications belonging to this group, such as amitriptyline, are extensively used to manage manifestations of depression, anxiety, migraine, neuropathic pain, and hyperactivity syndrome. Amitriptyline overdosage causes non-specific symptoms of intoxication, and its clinical picture does not allow to identify the nature of a psychotropic xenobiotic. Of primary importance in connection with this is to establish the cause of intoxication or death by the clinical toxicological and forensic medical methods based on the results of the fast identification and quantitation of amitriptyline in biological materials including blood, urine, hepatic tissues, etc. The authors describe the method for the determination of amitriptyline and its principal physiological metabolite nortriptyline in biological objects with the help of high performance liquid chromatography (HPLC).

LIPAEMIC report: results of clinical use of intravenous lipid emulsion in drug toxicity reported to an online lipid registry

The use of intravenous lipid emulsion (ILE) as an antidote has prompted significant academic and clinical interest. Between August 2009 and August 2012, data from cases of ILE use in intoxicated patients in different hospitals on different continents were voluntarily entered into a registry based on the world wide web (www.lipidregistry.org). Here, we report data from this project. Participating centers were given access to the registry following institutional subscription. Specifically sought were details of the individual patients' presenting condition, indications for ILE use, ILE administration regimen, potential complications, and of clinical outcome. Forty-eight uses of ILE were reported from 61 participating centers. Ten cases of local anesthetic systemic toxicity were reported; all (10/10) survived. Thirty-eight cases of intoxication by other agents were reported [30 decreased conscious state, 8 cardiovascular collapse (3 deaths)]. There was an elevation in GCS (p < 0.0001) and increased systolic blood pressure (p = 0.012) from immediately prior to ILE administration to 30 min after use. One serious and two minor adverse effects of ILE use were recorded in 48 reported cases (one case of bronchospastic reaction, one case of hyperamylasemia and one case of interference with laboratory testing). In this series of cases reported to the registry, improvements were seen for GCS in patients with central nervous system toxicity and in systolic blood pressure in shocked patients over a short time frame after the injection of ILE. Few adverse effects were recorded. Clinical trials and the reporting of drug concentrations after ILE use are necessary to further elucidate the role of ILE in clinical toxicology.

Prolonged use of intravenous lipid emulsion in a severe tricyclic antidepressant overdose

INTRODUCTION

Intravenous lipid emulsion (ILE) resuscitation is now frequently being used for severe overdoses due to lipophilic drugs. However, the optimal dose, duration, and safety are still unclear.

CASE REPORT

A patient with refractory cardiovascular collapse following an amitriptyline overdose was treated with ILE with initial improvement. Instability recurred after ILE discontinuation and lipid therapy was restarted, but high-dose treatment was complicated by severe lipemia. A low-dose infusion was instead used, and the patient did not experience further toxicity despite amitriptyline levels in the toxic range for 21 days. He survived to discharge without long-term sequelae.

DISCUSSION

A low-dose infusion of ILE was well tolerated and may have successfully prevented recurrent toxicity in a case of severe tricyclic antidepressant overdose.

Two lessons from the empiric management of a combined overdose of liraglutide and amitriptyline

We report the case of a 52-year-old man with a combined liraglutide and amitriptyline overdose who presented with a seizure and then pulseless electrical activity cardiac arrest. This is the largest reported overdose of liraglutide (36 mg), a novel glucagon-like peptide-1 analog recommended for certain patients with type 2 diabetes mellitus. The subsequent biochemical effects included severe electrolyte disturbances associated with polyuria. Regarding the amitriptyline, treatment with lipid emulsion correlated with resolution of electrocardiographic changes and successful resuscitation. The treatment of amitriptyline overdose with lipid emulsion is briefly discussed.

[Acute poisoning in adults]

Acute poisoning is one of the more frequent presentations in acute and emergency medicine. Poisoning with pharmaceuticals is predominantly observed in adults. A detailed medical history and an accurate clinical examination establish the basis for the diagnostics. Typical poisoning syndromes can be classified based on the clinical presentation. Drug screening in urine and examination of blood alcohol levels are useful additional tools because of the rapid and widespread availability. Securing vital organ functions is the mainstay of treatment and early contact with a poisons centre is useful for the assessment of the hazard and the further procedures. Primary and secondary poison elimination methods should be carefully considered because of insufficient evidence. Specific antidotes are only available for a few poisoning cases.

Should we consider the infusion of lipid emulsion in the resuscitation of poisoned patients?

The use of intravenous lipid emulsions (ILEs) as antidote in local anaesthetic systemic toxicity has gained widespread support following convincing data from animal models, and successful case reports in humans. Proposed beneficial mechanisms of action for ILEs include intravascular sequestration of intoxicant and subsequent enhanced redistribution to biologically inert tissues, augmentation of fatty acid utilisation for ATP synthesis in the context of metabolic poisoning, and direct cardiotonic and ion channel effects. The evidence base for use of ILEs in acute drug intoxication is evolving. The present evidence supports use of ILEs only in local anaesthetic systemic toxicity and in lipophilic cardiotoxin intoxication when there is an immediate threat to life, and other therapies have proven ineffective.

Toxicologic emergencies in the intensive care unit: management using reversal agents and antidotes

PURPOSE

To review the most common drugs implicated in overdoses admitted to the intensive care unit focusing on antidotes and reversal agents used in their management.

SUMMARY

Poisonings and overdoses due to pharmaceutical agents result in more than 100 000 critical care unit admissions each year. Ingestion of toxic alcohols, calcium channel blockers, beta-adrenergic antagonists, benzodiazepines, opioids, acetaminophen, tricyclic antidepressants, and salicylates are associated with a high rate of morbidity and mortality. Reviewing the mechanism of toxicity due to specific agents along with the mechanism of action, dosing, and adverse effects of appropriate antidotes is important for the successful management of these patients within the critical care unit.

CONCLUSION

Understanding the most prevalent overdoses and their management using reversal agents and antidotes is essential to the overall treatment of these critically ill patients.

Review of the use of lipid emulsion in nonlocal anesthetic poisoning

Intravenous lipid emulsion (ILE) has been used widely for the treatment of poisoning due to local anesthetic agent and is increasingly reported as a therapy for other forms of poisoning. This article will review the proposed mechanisms of action for ILE in poisoning and the evidence from animal studies and human experience supporting the use of ILE for poisoning due to nonlocal anesthetic agents.