Managing acute acetaminophen poisoning with oral versus intravenous N-acetylcysteine: a provider-perspective cost analysis

Fomepizole should be used more liberally in paracetamol overdose

Growing clinical and basic science data support the use of fomepizole as an adjunct to N-acetylcysteine in paracetamol poisoning. This safe antidote may be helpful in severely poisoned patients.

Expert consensus for a national essential antidote list: E-Delphi method

Antidote stocking represents a major challenge to hospitals all over the world, including Kuwait. In order to assist hospitals to reduce costs and improve patient care, an essential antidote list can be used as an initial foundation for securing sufficient antidote availability at healthcare institutions. The aim of our study is to generate a nationally relevant essential antidote list for emergency care hospitals in Kuwait using the e-Delphi method by establishing consensus through a multidisciplinary expert group of healthcare providers. An electronic survey with 47 essential antidotes was developed. The e-Delphi method was used, with three rounds of voting, to determine expert consensus on an essential antidote list for hospitals in Kuwait. A purposive sample of healthcare professionals from governmental and private hospitals were selected for this study (n = 30). Consensus was gained if ≥75% of the expert panel agreed on the inclusion of the antidote, without any strong disagreements. Round 1 of the e-Delphi resulted in 41 antidotes reaching consensus and seven new antidotes suggested by the expert panel. Round 2 had two antidotes (out of seven newly suggested ones) reaching consensus. Round 3 was a confirmatory round, where the expert group agreed on their previous rounds’ opinions. This resulted in the development of an essential antidote list with 43 antidotes. The optimal approach for ensuring adequate availability of antidotes is continuous monitoring of local poisoning incidence and antidote requirements through collaborations between academic researchers and emergency care clinicians. The development of an essential antidote list, with expert consensus, is one of the initial steps in securing a foundation for appropriate provision of antidotes at all healthcare institutions. This is the first study that the authors are aware of that demonstrates that the e-Delphi technique can consolidate recommendations of experts in emergency medicine to provide a list of essential antidotes.

Fomepizole as an adjunctive therapy for acetaminophen poisoning: cases reported to the toxicology investigators consortium (ToxIC) database 2015-2020

INTRODUCTION

Fomepizole inhibits formation of toxic acetaminophen (APAP) metabolites and may prevent or reverse mitochondrial toxicity. Given these mechanisms, it may be beneficial in patients with severe APAP toxicity. Current patterns of use for this indication are not well-studied.

METHODS

This is a secondary analysis of patients enrolled in the Toxicology Investigators Consortium (ToxIC) database from January 2015 to July 2020. We queried cases in which APAP was listed as an ingested agent and fomepizole was also administered. We excluded cases in which APAP was not the primary agent, N-acetylcysteine (NAC) was not administered, or fomepizole was explicitly administered for another indication. Additionally, we sent a survey to each ToxIC site that administered fomepizole for APAP toxicity to better understand when, why, and how they were using it for this indication.

RESULTS

Twenty-five cases of fomepizole administration following an APAP ingestion met our inclusion criteria. There were one to four cases per year between 2015 and 2019 and eight cases in 2020. Seventeen of 25 (68%) cases were for a known acute ingestion. Eighteen of 25 (72%) patients developed hepatotoxicity (AST or ALT > 1000 IU/L) and 10 of 25 (40%) developed coagulopathy (PT > 15s). This was an ill patient population, with 18 of 25 (72%) developing metabolic acidosis (pH <7.20), 12 of 25 (48%) were intubated, 9 of 25 (36%) receiving vasopressors, and 6 of 25 (24%) receiving continuous renal replacement therapy. Overall, mortality was 24%.

CONCLUSION

The use of fomepizole is increasing in frequency in a small subset of critically ill and acutely APAP-poisoned patients.

Oral and Intravenous Acetylcysteine for Treatment of Acetaminophen Toxicity: A Systematic Review and Meta-analysis

INTRODUCTION

There are few reports summarizing the effectiveness of oral and intravenous (IV) acetylcysteine. We determined the proportion of acetaminophen poisoned patients who develop hepatotoxicity (serum transaminase > 1000 IU/L) when treated with oral and IV acetylcysteine.

METHODS

Studies were double abstracted by trained researchers. We determined the proportions of patients who developed hepatotoxicity for each route using a random effects model. Studies were further stratified by early and late treatment.

RESULTS

We screened 4,416 abstracts; 16 articles, including 5,164 patients, were included in the meta-analysis. The overall rate of hepatotoxicity for the oral and IV routes were 12.6% and 13.2%, respectively. Treatment delays are associated with a higher rate of hepatotoxicity.

CONCLUSION

Studies report similar rates of hepatotoxicity for oral and IV acetylcysteine, but direct comparisons are lacking. While it is difficult to disentangle the effects of dose and duration from route, our findings suggest that the rates of hepatotoxicity are similar for oral and IV administration.

Undifferentiated Altered Mental Status: A Late Presentation of Toxic Acetaminophen Ingestion

Altered mental status is a common undifferentiated presentation in the emergency department. We describe a case of acetaminophen-induced acute liver failure that was diagnosed and treated prior to obtaining definitive historical or laboratory information about the etiology. The physical exam finding of scleral icterus in this case was a key element to rapid identification and treatment of this life-threatening condition. A discussion of appropriate N-acetylcysteine treatment for acute liver failure and acetaminophen intoxication is included.

The clinical management of acetaminophen poisoning in a community hospital system: factors associated with hospital length of stay

Acetaminophen (APAP) overdose is the most common pharmaceutical poisoning. The objective of this study was to examine the management of patients admitted for treatment of APAP overdose. Factors impacting hospital length of stay (LOS) were of particular interest. This was a retrospective cohort study of patients admitted to Kaiser Permanente Northern California hospitals for APAP overdose from July 2003 through December 2007. Medical records were abstracted for patient demographic data, key factors of overdose, California Poison Control System (CPCS) contact, data regarding hospital course, transfer for liver transplantation, and death. Four hundred thirty-five patients were included. The mean hospital LOS was 66.5 h (95% CI 62.1, 71.0). Four patients (0.9%) died. Eight patients (1.8%) were transferred for liver transplantation, but all of these patients later recovered without transplant. Of 289 cases eligible for placement on the Rumack-Matthew nomogram (acute ingestion with known time of ingestion <24 h and normal liver enzymes), 161 (55.7%) had APAP levels above the "200" line and 77 (26.6%) fell below the "150" line. CPCS was contacted in 295 cases (67.8%). Mean LOS in cases with CPCS consultation was 61.9 h (95% CI 57.2, 66.5 h) versus 76.3 h (95% CI 66.6, 86.0 h) in those without. LOS in cases treated with IV NAC was 67.1 h (95% CI 57.7, 76.5 h) versus 66.4 h (95% CI 61.2, 71.5 h) in cases treated with oral NAC. Many patients admitted for APAP overdose had serum APAP levels below the minimum toxicity level. Use of IV NAC did not impact hospital LOS. CPCS consultation appeared to decrease mean hospital LOS.