Intravenous lipid-emulsion therapy in a patient with cardiac arrest after overdose of diphenhydramine

Antidotes in Clinical Toxicology-Critical Review

Poisoning and overdose are very important aspects in medicine and toxicology. Chemical weapons pose a threat to civilians, and emergency medicine principles must be followed when dealing with patients who have been poisoned or overdosed. Antidotes have been used for centuries and modern research has led to the development of new antidotes that can accelerate the elimination of toxins from the body. Although some antidotes have become less relevant due to modern intensive care techniques, they can still save lives or reduce the severity of toxicity. The availability of antidotes is crucial, especially in developing countries where intensive care facilities may be limited. This article aims to provide information on specific antidotes, their recommended uses, and potential risks and new uses. In the case of poisoning, supportive therapies are most often used; however, in many cases, the administration of an appropriate antidote saves the patient's life. In this review, we reviewed the literature on selected antidotes used in the treatment of poisonings. We also characterised the antidotes (bio)chemically. We described the cases in which they are used together with the dosage recommendations. We also analysed the mechanisms of action. In addition, we described alternative methods of using a given substance as a drug, an example of which is N-acetylcysteine, which can be used in the treatment of COVID-19. This article was written as part of the implementation of the project of the Polish Ministry of Education and Science, "Toxicovigilance, poisoning prevention, and first aid in poisoning with xenobiotics of current clinical importance in Poland", grant number SKN/SP/570184/2023.

Efficacy of lipid emulsion therapy in treating cardiotoxicity from diphenhydramine ingestion: a review and analysis of case reports

INTRODUCTION

Lipid emulsion therapy (LET) has been most thoroughly studied to reverse local anesthetic systemic toxicity (LAST). Case reports suggest that LET can successfully rescue cardiovascular collapse from bupropion, amitriptyline, and propranolol. The efficacy of LET against refractory hypotension and dysrhythmias from diphenhydramine, a commonly ingested lipophilic cardiotoxic agent, is less well described.

OBJECTIVE

Summarize the evidence that LET rescues cardiac ion channel blockade (QRS, QTc widening) or hypotension attributable to diphenhydramine overdose.

METHODS

We searched MEDLINE, EMBASE, and Google Scholar for English-language full-length case reports of diphenhydramine (DPH) intoxication in patients 17 years of age or older. We extracted data with a PRISMA-compliant protocol, dividing the case reports into two groups, one that received LET and one that did not. We performed a pooled analysis to compare the change in mean arterial pressure (MAP), QRS duration, and QTc duration between the two groups.

RESULTS

We identified 23 reports (25 patients). Lipid emulsion therapy (LET) was used in 6 cases because the patient suffered from hypotension refractory to traditional resuscitation. Those who received LET and those who did not were comparable in age, gender, amount ingested, and frequency of seizures. The mean arterial pressure (MAP) decreased by 4.5 ± 11.5 mm Hg in those who did not receive LET compared to an increase in MAP 37 ± 17.5 mm Hg in those who did receive LET. The QRS narrowed by 29 ± 33.9 ms (no LET group) vs 68 ± 49.5 ms (LET group) and QTc by 168.5 ± 126.75 ms (no LET group) vs 134 ± 88 ms (LET group). All values are expressed as median ± interquartile range. One out of the 6 patients who received LET died after withdrawal of care. In the group that did not receive LET 4 out of 19 died and 3 had no outcome reported.

DISCUSSION

LET may improve MAP in patients with hypotension refractory to vasopressors due to diphenhydramine toxicity. We found no significant effect of LET on QRS or QTc duration. These results are limited by a small sample size, reporting bias of case reports, incomplete data, and heterogeneity.

CONCLUSION

An analysis of pooled case reports suggests that LET may rescue hypotension when other methods have failed in patients with hypotension attributable to diphenhydramine overdose.

QT interval prolongation and rhabdomyolysis associated with diphenhydramine toxicity: a case report

Diphenhydramine is a widely available, over-the-counter medication used for allergies and as a sleeping aid. When used in prescription doses, it is generally safe.

Overdose of the medication has been associated with dangerous and life-threatening outcomes. Our case describes diphenhydramine toxicity manifesting with two rare but potentially

life-threatening complications, rhabdomyolysis, and QT prolongation. Laboratory testing for diphenhydramine levels are not widely available. We recommend a high degree of suspicion for these complications when evaluating patients with diphenhydramine overdose, to adequately manage and prevent untoward outcomes.

A Bitter Taste in Your Heart

The human genome contains ∼29 bitter taste receptors (T2Rs), which are responsible for detecting thousands of bitter ligands, including toxic and aversive compounds. This sentinel function varies between individuals and is underpinned by naturally occurring T2R polymorphisms, which have also been associated with disease. Recent studies have reported the expression of T2Rs and their downstream signaling components within non-gustatory tissues, including the heart. Though the precise role of T2Rs in the heart remains unclear, evidence points toward a role in cardiac contractility and overall vascular tone. In this review, we summarize the extra-oral expression of T2Rs, focusing on evidence for expression in heart; we speculate on the range of potential ligands that may activate them; we define the possible signaling pathways they activate; and we argue that their discovery in heart predicts an, as yet, unappreciated cardiac physiology.

Endosulfan induced cardiac arrest treated with intravenous lipid emulsion

OBJECTIVE

Endosulfan is an organochlorine pesticide with high lipophilic features that makes it a well-absorbed agent and penetrates easily to the site of action. Endosulfan toxicities may result in disastrous complications and have high rates of mortality. Several case reports and some researchs discuss the evidence supporting intravenous lipid emulsion (ILE) therapy as a rescue therapy in lipophilic agents' toxicity.

CASE REPORT

A 33-years-old healthy woman with  a history of endosulfan ingestion of uncertain quantity in a suicide attempt six hours ago was admitted to our emergency department. Cardiac arrest ensued after one hour of admission. Cardiopulmonary resuscitation was initiated in accordance with advanced cardiac life support (ACLS) algorithm for asystole. During resuscitation, 2 mL/kg bolus of 20% intravenous lipid emulsion (ILE) was administered for three times at five-minute intervals in addition to ACLS guidance. Spontaneous circulation returned after twenty minutes of resuscitation. No additional antidotal or vasopressor therapies were required during the hospital course of the patient. To our knowledge, this is the first reported case with responded use of ILE treatment for endosulfan toxicity.

CONCLUSION

This case report indicates that ILE treatment should be considered for life-threatening endosulfan intoxications.

Cardiac arrest caused by diphenhydramine overdose

Case

A 45‐year‐old man presented to our emergency department with disturbance of consciousness; he had mentioned to his family earlier about a drug overdose. When first responders arrived, he suffered cardiac arrest. Cardiac arrest due to drug overdose was diagnosed.The patient was supported with venoarterial extracorporeal membrane oxygenation. Arterial blood gas showed mixed acidosis, and electrocardiogram showed junctional rhythm and complete right bundle branch block.

Outcome

The patient's blood pressure gradually decreased, and he died on the third day of hospitalization. After death, his serum diphenhydramine concentration at the time of arrival was found to be 18.7 μg/mL.

Conclusion

Although diphenhydramine is regarded as a safe medication, it shows dose‐dependent toxicity. High intake is associated with death; therefore, caution should be exercised in cases of drug overdose. Developing a procedure for rapid measurement in the emergency department should be a priority.