The Safety Profile of Sustained Release Paracetamol During Therapeutic Use and Following Overdose

Paracetamol (acetaminophen) overdose and hepatotoxicity: mechanism, treatment, prevention measures, and estimates of burden of disease

INTRODUCTION

Paracetamol is one of the most used medicines worldwide and is the most common important poisoning in high-income countries. In overdose, paracetamol causes dose-dependent hepatotoxicity. Acetylcysteine is an effective antidote, however despite its use hepatotoxicity and many deaths still occur.

AREAS COVERED

This review summarizes paracetamol overdose and toxicity (including mechanisms, risk factors, risk assessment, and treatment). In addition, we summarize the epidemiology of paracetamol overdose worldwide. A literature search on PubMed for poisoning epidemiology and mortality from 1 January 2017 to 26 October 2022 was performed to estimate rates of paracetamol overdose, liver injury, and deaths worldwide.

EXPERT OPINION

Paracetamol is widely available and yet is substantially more toxic than other analgesics available without prescription. Where data were available, we estimate that paracetamol is involved in 6% of poisonings, 56% of severe acute liver injury and acute liver failure, and 7% of drug-induced liver injury. These estimates are limited by lack of available data from many countries, particularly in Asia, South America, and Africa. Harm reduction from paracetamol is possible through better identification of high-risk overdoses, and better treatment regimens. Large overdoses and those involving modified-release paracetamol are high-risk and can be targeted through legislative change.

Patient safety in ambulance services: a scoping review

Background

The role of ambulance services has changed dramatically over the last few decades with the introduction of paramedics able to provide life-saving interventions, thanks to sophisticated equipment and treatments available. The number of 999 calls continues to increase, with adverse events theoretically possible with each one. Most patient safety research is based on hospital data, but little is known concerning patient safety when using ambulance services, when things can be very different. There is an urgent need to characterise the evidence base for patient safety in NHS ambulance services.

Objective

To identify and map available evidence relating to patient safety when using ambulance services.

Design

Mixed-methods design including systematic review and review of ambulance service documentation, with areas for future research prioritised using a Delphi process.

Setting and participants

Ambulance services, their staff and service users in UK.

Data sources

A wide range of data sources were explored. Multiple databases, reference lists from key papers and citations, Google and the NHS Confederation website were searched, and experts contacted to ensure that new data were included in the review. The databases MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, Science Direct, Emerald, Education Resources Information Center (ERIC), Applied Social Sciences Index and Abstracts, Social Services Abstracts, Sociological Abstracts, International Bibliography of the Social Sciences (IBSS), PsycINFO, PsycARTICLES, Health Management Information Consortium (HMIC), NHS Evidence, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), NHS Economic Evaluation Database (NHS EED),Health Technology Assessment, the FADE library, Current Awareness Service for Health (CASH), OpenDOAR (Directory of Open Access Repositories) and Open System for Information on Grey Literature in Europe (OpenSIGLE) and Zetoc (The British Library's Electronic Table of Contents) were searched from 1 January 1980 to 12 October 2011. Publicly available documents and issues identified by National Patient Safety Agency (NPSA), NHS Litigation Authority (NHSLA) and coroners’ reports were considered. Opinions and perceptions of senior managers, ambulance staff and service users were solicited.

Review methods

Data were extracted from annual reports using two-stage thematic analysis, data from quality accounts were collated with safety priorities tabulated and considered using thematic analysis, NPSA incident report data were collated and displayed comparatively using descriptive statistics, claims reported to NHSLA were analysed to identify number and cost of claims from mistakes and/or poor service, and summaries of coroners’ reports were assessed using thematic analysis to identify underlying safety issues. The depth of analysis is limited by the remit of a scoping exercise and availability of data.

Results

We identified studies exploring different aspects of safety, which were of variable quality and with little evidence to support activities currently undertaken by ambulance services. Adequately powered studies are required to address issues of patient safety in this service, and it appeared that national priorities were what determined safety activities, rather than patient need. There was inconsistency of information on attitudes and approaches to patient safety, exacerbated by a lack of common terminology.

Conclusion

Patient safety needs to become a more prominent consideration for ambulance services, rather than operational pressures, including targets and driving the service. Development of new models of working must include adequate training and monitoring of clinical risks. Providers and commissioners need a full understanding of the safety implications of introducing new models of care, particularly to a mobile workforce often isolated from colleagues, which requires a body of supportive evidence and an inherent critical evaluation culture. It is difficult to extrapolate findings of clinical studies undertaken in secondary care to ambulance service practice and current national guidelines often rely on consensus opinion regarding applicability to the pre-hospital environment. Areas requiring further work include the safety surrounding discharging patients, patient accidents, equipment and treatment, delays in transfer/admission to hospital, and treatment and diagnosis, with a clear need for increased reliability and training for improving handover to hospital.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

A review of acetaminophen poisoning

Acetaminophen poisoning remains one of the more common drugs taken in overdose with potentially fatal consequences. Early recognition and prompt treatment with N-acetylcysteine can prevent hepatic injury. With acute overdose, the Rumack-Matthew nomogram is a useful tool to assess risk and guide management. Equally common to acute overdose is the repeated use of excessive amounts of acetaminophen. Simultaneous ingestion of several different acetaminophen-containing products may result in excessive dosage. These patients also benefit from N-acetylcysteine. Standard courses of N-acetylcysteine may need to be extended in patients with persistently elevated plasma concentrations of acetaminophen or with signs of hepatic injury.