American College of Medical Toxicology. ACMT Position Statement: Duration of Intravenous Acetylcysteine Therapy Following Acetaminophen Overdose

Comparison of two-bag and three-bag acetylcysteine regimens in the treatment of paracetamol poisoning: a systematic review and meta-analysis

INTRODUCTION

Worldwide, paracetamol poisoning is a common cause of acute liver failure and referral to transplant centers. Acetylcysteine has long been the mainstay of treatment, but recent literature suggests that a simplification of the "three-bag" method may decrease adverse effects. Our primary hypothesis is that a simplified dosing regimen (two-bag regimen) is non-inferior to the three-bag method in preventing liver injury. Our secondary hypothesis is that a simplified regimen will have lower rates of adverse effects.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we searched Medline/PubMed, Google, Google Scholar, Cochrane Library, Embase and Toxnet on May 23, 2022. The Medical Subject Headings terms were NAC, acetaminophen toxicity, acetyl-cysteine, N-acetylcysteine, paracetamol, APAP, 2-bag, and 3-bag. The Embase terms were acetylcysteine, NAC, 2-bag, two bag, 3-bag, three bag, simplified dosing, acetaminophen, Tylenol®, paracetamol, APAP, drug overdose, poisoning, and overdose. Studies included both non-United States Food and Drug Administration-approved and United States Food and Drug Administration-approved acetylcysteine regimens. Case reports, review articles, and animal studies were excluded. Two authors independently reviewed each study using Rayyan QCRI to determine if the studies met search criteria while blinded to the selections of each other. The two authors discussed until reaching a consensus. We used a primary outcome of non-inferiority of hepatotoxicity. We used secondary outcomes of non-allergic anaphylactoid reactions and adverse events. We conducted a fixed-effect meta-analysis using R package meta. To visually summarize the meta-analysis results, we also produced forest plots. We used Cochran's Q test and I2 statistical analysis to assess heterogeneity between the studies.

RESULTS

Our search resulted in 657 total citations, which were reduced to unique citations. Of the 643 studies, 46 met the criteria for full text review, and eight met the study criteria. Of the eight studies investigating a simplified acetylcysteine regimen, four studies utilized some form of a modified two-bag infusion regimen, varying in duration or dosing of infusions, and four studies shared the same "common" two-bag treatment, a regimen that delivers acetylcysteine 200 mg/kg over 4 h, followed by 100 mg/kg acetylcysteine over 16 h. The six studies comparing a two-bag dosing regimen to the three-bag technique were utilized for our random effect model meta-analysis. We found no significant heterogeneity amongst the six studies for either hepatotoxicity (Q(5) = 1.11; P = 0.95; I2 = 0%; 95% CI: 0%-74.6%) or non-allergic anaphylactoid reactions and adverse events (Q(5) = 10.15; P = 0.07; I2 = 50.7%; 95% CI: 0%-80.4%). Compared to the traditional three-bag dosing regimen, the two-bag method did not demonstrate a difference in relative risk for hepatotoxicity (OR: 0.88; 95% CI: 0.72-1.08; P = 0.23) but did demonstrate a significantly decreased likelihood of non-allergic anaphylactoid reactions and other adverse events (OR: 0.24; 95% CI: 0.17-0.35; P <0.0001).

DISCUSSION

The two-bag method is a safe and effective treatment for acute paracetamol poisoning. The two-bag regimen is correlated with a significant reduction in non-allergic anaphylactoid reactions, compared to the three-bag method, and is non-inferior with respect to hepatotoxicity. While we feel this information is practice changing for many, further research in the form of a randomized control trial would be beneficial to compare even more abbreviated methods such as a "single bag method."

CONCLUSION

Two-bag acetylcysteine dosing regimens appear to be non-inferior to the three-bag method with respect to hepatotoxicity, and result in fewer anaphylactoid, cutaneous, and gastrointestinal reactions.

Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement

Importance

The US and Canada currently have no formal published nationwide guidelines for specialists in poison information or emergency departments for the management of acetaminophen poisoning, resulting in significant variability in management.

Objective

To develop consensus guidelines for the management of acetaminophen poisoning in the US and Canada.

Evidence Review

Four clinical toxicology societies (America's Poison Centers, American Academy of Clinical Toxicology, American College of Medical Toxicology, and Canadian Association of Poison Control Centers) selected participants (n = 21). Led by a nonvoting chairperson using a modified Delphi method, the panel created a decision framework and determined the appropriate clinical management of a patient with acetaminophen poisoning. Unique to this effort was the collection of guidelines from most poison centers in addition to systematic collection and review of the medical literature. Comments from review by external organizations were incorporated before the guideline was finalized. The project began in March 2021 and ended in March 2023.

Findings

The search retrieved 84 guidelines and 278 publications. The panel developed guidelines for emergency department management of single or repeated ingestion of acetaminophen. In addition, the panel addressed extended-release formulation, high-risk ingestion, coingestion of anticholinergics or opioids, age younger than 6 years, pregnancy, weight greater than 100 kg, and intravenous acetaminophen use. Differences from current US practice include defining acute ingestion as an ingestion presentation from 4 to 24 hours after overdose was initiated. A revised form of the Rumack-Matthew nomogram was developed. The term massive ingestion was replaced with the term high-risk ingestion and denoted by a specific nomogram line. Other recommendations include specific criteria for emergency department triage, laboratory evaluation and monitoring parameters, defining the role of gastrointestinal decontamination, detailed management of acetylcysteine treatment, associated adverse effects, and stopping criteria for acetylcysteine treatment, as well as criteria for consultation with a clinical toxicologist. Finally, specific treatment considerations, including acetylcysteine dosing, fomepizole administration, and considerations for extracorporeal elimination and transplant evaluation, were addressed.

Conclusions and Relevance

This qualitative study provides a consensus statement on consistent evidence-based recommendations for medical, pharmacy, and nursing education and practice to optimize care of patients with acetaminophen poisoning.

Implementation of a pharmacist toxicology service on treatment of paracetamol (acetaminophen) overdose

INTRODUCTION

Paracetamol is a leading cause of fatality following a toxic ingestion. Individualized treatment is imperative in improving outcomes. Acetylcysteine is the standard of care for paracetamol overdose. Laboratory values and other clinical criteria can be used to guide treatment duration. Our hospital's protocol allows paracetamol overdose to be managed by the emergency department pharmacists. The purpose of this study was to evaluate the effect of a pharmacist toxicology service on the management of paracetamol overdose.

METHODS

This was a single center, retrospective, cohort evaluation. All patients receiving acetylcysteine were divided into pre- and post-implementation groups with data obtained from August 1, 2013 to January 14, 2018 and January 15, 2018 to September 30, 2021, respectively. The primary outcome was the frequency of individualized acetylcysteine therapy.

RESULTS

A total of 238 patients were screened for inclusion in the study with 120 patients included in the final analysis. There were 60 patients included in each cohort. The frequency of individualized acetylcysteine therapy was significantly higher in the post-implementation group versus the pre-implementation group (85% vs. 60% [95% CI 9.1-39.4; P = 0.002]).

CONCLUSIONS

The implementation of a pharmacist toxicology service correlated with increased poison center consultation as well as increased frequency of individualized acetylcysteine therapy and decreased number of missed acetylcysteine doses.

An acute change? Does treatment within a therapeutic community for personality disorders affect local acute service use

Purpose

The intensive 18-month treatment in the personality disorder (PD) therapeutic community (TC) is felt to offer improvement in many aspects of patients’ lives. This study aims to understand if the use of acute services was also affected via a service evaluation project.

Design/methodology/approach

The authors collected data from electronic records on the use of local services in the two years before, during and the two years after treatment in the TC. Specifically, the authors counted inpatient bed days, Emergency department (ED) presentations and days under home treatment team and liaison psychiatry; the authors used ANOVA to analyse the data.

Findings

The study included 25 adult service users, 17 female and 8 male, with an average age of 40. Whilst there were reductions in the use of inpatient beds and ED presentations, on analysis, these were not found statistically significant. The small size of the study is a limitation and may limit the generalisability of the findings. The study concludes there may be reductions in acute psychiatric service use during and after treatment in the TC. The findings were not statistically significant; the authors suggest larger multi-centre studies may be able to demonstrate statistical significance.

Originality/value

PD patients have a relatively high use of acute psychiatric services compared to other patient groups. The authors are not aware of any similar studies in the published literature.

Comparative Analysis of the Antioxidative and Hepatoprotective Activities of Dimethyl Diphenyl Bicarboxylate in Four Animal Models of Hepatic Injury

As a well-known hepatoprotective and antioxidant agent, dimethyl diphenyl bicarboxylate (DDB) has frequently been employed to remedy various liver diseases. However, it is still uncertain whether DDB exerts consistent hepatoprotective and antioxidative activities against varying degrees of hepatic damage. Therefore, DDB (100, 25, 5, or 50 mg/kg depending on the model) was administered to animals in four representative models of liver injury (CCl4 chemical acute model, DMN subchronic model, TAA chronic model, and restraint stress psychological acute model). Horizontal comparative analysis indicated that DDB significantly lowered the excess serum AST and ALT levels in the CCl4 and DMN models but not in the TAA and restraint stress models. In accordance with this result, DDB markedly reduced oxidative stress indices (hepatic MDA and ROS) but restored five main antioxidant components (GSH content, GSH-peroxidase, GSH-reductase, SOD, and catalase activity) in the CCl4 and DMN models. DDB failed to normalize oxidative stressors in the restraint stress-induced injury model and restore these five antioxidant components in the TAA model. Overall, our results produced a comprehensive overview of the effects of DDB on oxidative stressors and the main antioxidative components using four animal models. These findings will provide valuable clues to guide therapeutic clinical applications.

The Crashing Toxicology Patient

This article examines, using an organ-systems based approach, rapid diagnosis, resuscitation, and critical care management of the crashing poisoned patient in the emergency department. The topics discussed in this article include seizures and status epilepticus, respiratory failure, cardiovascular collapse and mechanical circulatory support, antidotes and drug-specific therapies, acute liver failure, and extracorporeal toxin removal.

Extracorporeal Removal of Poisons and Toxins

Extracorporeal therapies have been used to remove toxins from the body for over 50 years and have a greater role than ever before in the treatment of poisonings. Improvements in technology have resulted in increased efficacy of removing drugs and other toxins with hemodialysis, and newer extracorporeal therapy modalities have expanded the role of extracorporeal supportive care of poisoned patients. However, despite these changes, for at least the past three decades the most frequently dialyzed poisons remain salicylates, toxic alcohols, and lithium; in addition, the extracorporeal treatment of choice for therapeutic removal of nearly all poisonings remains intermittent hemodialysis. For the clinician, consideration of extracorporeal therapy in the treatment of a poisoning depends upon the characteristics of toxins amenable to extracorporeal removal (e.g., molecular mass, volume of distribution, protein binding), choice of extracorporeal treatment modality for a given poisoning, and when the benefit of the procedure justifies additive risk. Given the relative rarity of poisonings treated with extracorporeal therapies, the level of evidence for extracorporeal treatment of poisoning is not robust; however, extracorporeal treatment of a number of individual toxins have been systematically reviewed within the current decade by the Extracorporeal Treatment in Poisoning workgroup, which has published treatment recommendations with an improved evidence base. Some of these recommendations are discussed, as well as management of a small number of relevant poisonings where extracorporeal therapy use may be considered.