Reduction in incidence of severe paracetamol poisoning

A novel electronic tongue using electropolymerized molecularly imprinted polymers for the simultaneous determination of active pharmaceutical ingredients

The combination of chemometrics and electrochemical sensors modified with molecularly imprinted polymers (MIPs) towards the development of MIP-based electronic tongues (ETs) was explored herein. To demonstrate the potential of such an approach, the simultaneous determination of paracetamol, ascorbic acid and uric acid mixtures in pharmaceutical samples was evaluated. To this aim, MIP-based sensors for the different compounds were prepared by in situ electropolymerization of pyrrole in the presence of p-toluenesulfonate anion (pTS^-), which acted as functional doping ion of the polypyrrole (PPy) MIP backbone. Morphological characterization of the MIPs was done by scanning electron microscopy (SEM), while functionalization of the electrodes was monitored electrochemically. Under the optimized measuring conditions, the developed sensors showed a good performance, with good linearity at the μM level (R² > 0.992, limits of detection between 1 and 24 μM) as well as good repeatability (intra- and inter-day RSD values between 3 and 6% over 30 consecutive measurements). Finally, the quantification of the individual substances in different pharmaceutical samples was achieved by an artificial neural networks (ANNs) model, showing satisfactory agreement between expected and obtained values (R² > 0.987).

Restriction of non-opioid analgesics sold over-the-counter in Denmark: A national study of impact on poisonings

OBJECTIVE

Self-poisoning with non-opioid analgesics presents a growing challenge to health care providers. We aimed to assess the impact of an 18-year age restriction of OTC sales and a pack size restriction of non-opioid analgesics sold OTC in pharmacies on hospital-treated poisonings and poisoning severity measured using biomarkers.

METHODS

We applied a before and after design using interrupted time series analysis. Data on all poisonings recorded as hospital admissions were obtained during 2002-2015 and biochemical parameters from laboratory databases during 2011-2015, both covering the entire Danish population.

RESULTS

The age restriction was followed by a 17% level reduction in admissions for non-opioid analgesic poisoning among young people age 10-17 years (RR 0.830; 95% CI 0.697-0.988; p < 0.036). After the pack size restriction, an instant level reduction of 18.5% (RR 0.815; 95% CI 0.729-0.912; p < 0.001) was observed for the entire population. A 27% decrease in the number of poisonings with alanine transaminase levels (ALT) ≥ 210 U/L was observed (RR 0.734; 95% CI 0.579-0.931; p = 0.011) followed by 40% decrease in biomarkers indicative of liver failure (RR 0.597; 95% CI 0.421-0.847; p = 0.004). We also observed similar reductions for other poisonings such as psychotropics.

LIMITATIONS

Although declines in poisonings were observed after implementation of means restrictive measures, a causal link cannot be inferred.

CONCLUSION

Age and pack size restriction were assiociated with a reduction in the numbers of poisonings. This was also observed for pharmaceutical poisonings in general, which might suggest a non-specific or spill-over effect.

Availability of drug at convenient stores is not associated with an increased incidence of their poisoning

PURPOSE

In late 2012, South Korea revised the Pharmaceutical Affairs Act to make selected medications including acetaminophen, ibuprofen, and cold medications available in nonpharmacy outlets, including the 24-hour convenient stores (CVS). The objective of this study was to identify whether the characteristics and trend of self-poisonings associated with these medications were altered after the legislative change.

METHODS

A retrospective study was performed using national data from the Emergency Department (ED)-based Injury In-depth Surveillance database. The patients diagnosed with poisoning were sorted from 2011 to 2016 and included in the study. As the Act was implemented from 2013, the demographic characteristics and clinical outcomes were compared before and after January 2013. A piecewise regression analysis was performed to determine the association between the monthly use of acetaminophen, medication for cold, and nonsteroidal anti-inflammatory drugs (NSAIDs) and the incidence of total poisonings before and after the January 2013.

RESULTS

Among 1 536 277 patients included in the database, 17 523 patients diagnosed with poisoning were enrolled. After the legislative change, the etiology of poisoning did not change, although the frequency of hospitalization from ED was significantly increased. The monthly trend for poisoning due to acetaminophen, cold medications, and NSAIDs showed no significant slope change between before and after the legislative change. The proportional use of acetaminophen and cold medications was significantly decreased, while that of NSAIDs was unchanged before and after the legislative change.

CONCLUSIONS

The change in the Pharmaceutical Affairs Act was not associated with any change in the monthly frequency of medication-related poisoning.

Acute liver failure in Scotland: changes in aetiology and outcomes over time (the Scottish Look-Back Study)

BACKGROUND

Acute liver failure is a rare and devastating clinical condition resulting from sudden loss of hepatic parenchyma and metabolic function. The Scottish Liver Transplant Unit (SLTU) offers specialist management and emergency liver transplantation to patients with acute liver failure from across Scotland.

AIM

To describe temporal changes in number of admissions, aetiology of acute liver failure, severity of disease at presentation and outcomes over a 22-year period.

METHODS

Retrospective analysis of the SLTU database, including all patients admitted with acute liver injury or acute liver failure between November 1992 and March 2014.

RESULTS

There has been no change in the number of patients presenting with acute liver injury or failure secondary to paracetamol overdose, but a reduction in the number of admissions with acute liver injury or failure secondary to non paracetamol causes. Over time, disease severity at presentation has not changed in the paracetamol cohort; those with a non paracetamol aetiology have latterly presented with milder hepatic encephalopathy. Spontaneous survival rates improved significantly over time for those patients with acute liver failure due to paracetamol and non paracetamol aetiologies. The most marked improvement in survival is observed in the sickest patients meeting Kings College Hospital poor prognostic criteria.

CONCLUSIONS

The number of admissions to the SLTU with acute liver failure is decreasing, due to reduced numbers of non paracetamol cases. Outcomes in this condition are improving, due to improvements in intensive care management and use of liver transplantation, and the increase in survival is most marked in patients meeting Kings College Hospital poor prognostic criteria.

The 100 most influential publications in paracetamol poisoning treatment: a bibliometric analysis of human studies

BACKGROUND

Analysis of the most influential publications within paracetamol poisoning treatment can be helpful in recognizing main and novel treatment issues within the field of toxicology. The current study was performed to recognize and describe the most highly cited articles related to paracetamol poisoning treatment.

METHODS

The 100 most highly cited articles in paracetamol poisoning treatment were identified from the Scopus database in November 2015. All eligible articles were read for basic information, including total number of citations, average citations per year, authors' names, journal name, impact factors, document types and countries of authors of publications.

RESULTS

The median number of citations was 75 (interquartile range 56-137). These publications were published between 1974 and 2013. The average number of years since publication was 17.6 years, and 45 of the publications were from the 2000s. A significant, modest positive correlation was found between years since publication and the number of citations among the top 100 cited articles (r = 0.316; p = 0.001). A total of 55 journals published these 100 most cited articles. Nine documents were published in Clinical Toxicology, whereas eight documents were published in Annals of Emergency Medicine. Citations per year since publication for the top 100 most-cited articles ranged from 1.5 to 42.6 and had a mean of 8.5 citations per year and a median of 5.9 with an interquartile range of 3.75-10.35. In relation to the origin of the research publications, they were from 8 countries. The USA had the largest number of articles, 47, followed by the UK and Australia with 38 and nine articles respectively.

CONCLUSIONS

This study is the first bibliometric assessment of the top 100 cited articles in toxicology literature. Interest in paracetamol poisoning as a serious clinical problem continues to grow. Research published in high-impact journals and from high income countries is most likely to be cited in published paracetamol research.

A multicentre programme of clinical and public health research in support of the National Suicide Prevention Strategy for England

Objectives

To carry out a programme of linked research studies aimed at improving the management of self-harm, reducing the incidence of suicide and providing reliable data to evaluate the impact of theNational Suicide Prevention Strategy for England(2002).

Methods

There were four research streams: (1) we studied inquest records from 12 coroners and Ministry of Justice data to assess the accuracy of official suicide statistics; (2) we used Office for National Statistics mortality statistics, data from the Multicentre Study of Self-harm in England, national liver unit data, prescription data and patient interviews to assess (a) the impact of paracetamol (acetaminophen) pack size restrictions (1998), (b) the impact of withdrawal of co-proxamol in 2007 and (c) the relative toxicity in overdose of commonly used antidepressants; (3) we carried out 3-month audits of self-harm management in 32 hospitals to investigate variations between hospitals and the impact of management on repeat self-harm; and (4) we developed and piloted letter-based contact interventions aimed at reducing self-harm.

Key findings

(1) Between 1990 and 2005, the proportion of researcher-defined suicides given a verdict of suicide by the 12 coroners studied decreased by almost 7%, largely because of the increased use of misadventure/accident verdicts for deaths thought, on clinical review, to be suicides. Use of narrative verdicts increased markedly. Coroners who gave more narrative verdicts also gave fewer suicide verdicts, and geographical variations in the use of narrative verdicts appeared to distort reliable assessment of small-area differences in suicide rates. 2(a) UK legislation to reduce pack sizes of paracetamol was followed by a 43% reduction in number of deaths and a 61% reduction in registrations for liver transplantation over the next 11 years. Paracetamol overdoses were often impulsive and some were influenced by media (including the internet); sales outlets appeared mostly to be adhering to sales guidance. Smaller pack sizes of paracetamol for sale in Ireland compared with England did not result in a smaller number of tablets being taken in overdose. There was no clear evidence of an effect of the legislation on prescribing of non-steroidal anti-inflammatory drugs, nor on resulting gastrointestinal bleeds. 2(b) Withdrawal of co-proxamol from use in the UK resulted in approximately 600 fewer deaths than predicted between 2005 and 2010 based on previous trends, with no evidence of substitution by poisoning with other analgesics. 2(c) Of the tricyclic antidepressants, dosulepin and doxepin had the greatest toxicity. Citalopram was more toxic than other selective serotonin reuptake inhibitors. (3) There was marked variation between hospitals in the management of self-harm; effects of this variation on patient outcomes were unclear, although psychosocial assessment may have been associated with reduced repetition. Levels of specialist assessment remained static between 2001–2 and 2010–11, but service quality appeared to improve. (4) Findings of two pilot randomised controlled trials suggested that, although it would be feasible to scale up these interventions to full trials, these interventions might have low generalisability and be of limited benefit to patients.

Conclusion

Within the context of the strengths and limitations of the individual studies, this research programme has made significant additions to the evidence base related to suicide and self-harm prevention in the UK.

Study registration

A pilot study of a contact and information based intervention to reduce repeat self-harm; ISRCTN65171515.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Long term effect of reduced pack sizes of paracetamol on poisoning deaths and liver transplant activity in England and Wales: interrupted time series analyses

OBJECTIVE

To assess the long term effect of United Kingdom legislation introduced in September 1998 to restrict pack sizes of paracetamol on deaths from paracetamol poisoning and liver unit activity.

DESIGN

Interrupted time series analyses to assess mean quarterly changes from October 1998 to the end of 2009 relative to projected deaths without the legislation based on pre-legislation trends.

SETTING

Mortality (1993-2009) and liver unit activity (1995-2009) in England and Wales, using information from the Office for National Statistics and NHS Blood and Transplant, respectively.

PARTICIPANTS

Residents of England and Wales.

MAIN OUTCOME MEASURES

Suicide, deaths of undetermined intent, and accidental poisoning deaths involving single drug ingestion of paracetamol and paracetamol compounds in people aged 10 years and over, and liver unit registrations and transplantations for paracetamol induced hepatotoxicity.

RESULTS

Compared with the pre-legislation level, following the legislation there was an estimated average reduction of 17 (95% confidence interval -25 to -9) deaths per quarter in England and Wales involving paracetamol alone (with or without alcohol) that received suicide or undetermined verdicts. This decrease represented a 43% reduction or an estimated 765 fewer deaths over the 11&frac14; years after the legislation. A similar effect was found when accidental poisoning deaths were included, and when a conservative method of analysis was used. This decrease was largely unaltered after controlling for a non-significant reduction in deaths involving other methods of poisoning and also suicides by all methods. There was a 61% reduction in registrations for liver transplantation for paracetamol induced hepatotoxicity (-11 (-20 to -1) registrations per quarter). But no reduction was seen in actual transplantations (-3 (-12 to 6)), nor in registrations after a conservative method of analysis was used.

CONCLUSIONS

UK legislation to reduce pack sizes of paracetamol was followed by significant reductions in deaths due to paracetamol overdose, with some indication of fewer registrations for transplantation at liver units during the 11 years after the legislation. The continuing toll of deaths suggests, however, that further preventive measures should be sought.

What can be done to reduce mortality from paracetamol overdoses? A patient interview study

BACKGROUND

Paracetamol (acetaminophen) is the most common self-poisoning agent in the UK and a leading cause of fatal hepatotoxicity. Following legislation in 1998 to limit pack sizes, beneficial effects on paracetamol-related mortality and morbidity were reported in England. However, there are still over 100 deaths a year and evidence of breaches of sales guidelines.

AIM

To investigate characteristics of people taking larger paracetamol overdoses and compliance with sales guidelines, to inform possible further initiatives to reduce paracetamol fatalities.

DESIGN AND METHODS

Interview study of 60 general hospital patients who took overdoses of over 16 paracetamol tablets (8 g).

RESULTS

Half of all paracetamol overdoses involved over 16 tablets. Patients were predominantly young (three-quarters aged 16-40 years) and female (58.3%); over half (53.3%) had taken a previous paracetamol overdose. Three-quarters said they wanted to die. Half took the overdose within an hour of first thinking of it, half (53.3%) took tablets already in the home and 58.3% bought tablets specifically for the overdose. Ten people tried to buy more than 32 tablets in one transaction; four succeeded. Most knew that a paracetamol overdose could cause death or permanent damage (88.3%) and harm the liver (80.0%) but 70.0% thought they would lose consciousness. Warnings on packs had little deterrent effect. Media and internet influences were identified. Patients chose paracetamol because it was cheap and easily available.

CONCLUSIONS

Further measures to reduce breaches of sales guidelines and the dangers of paracetamol overdose are required. Media and internet site producers should follow guidelines on reporting suicide.

Emergency department visits for overdoses of acetaminophen-containing products

BACKGROUND

Limited national data on the circumstances of acetaminophen overdoses have hindered identification and implementation of prevention strategies.

PURPOSE

To estimate the frequency of and characterize risks for emergency department visits for acetaminophen overdoses that were not related to abuse in the U.S.

METHODS

Data were collected from two components of the National Electronic Injury Surveillance System from January 1, 2006, through December 31, 2007, and analyzed from 2009 to 2010 to estimate the annual number of emergency department visits for non-abuse-related acetaminophen overdose by patient demographics, treatments, and type and amount of acetaminophen-containing product ingested.

RESULTS

There were an estimated 78,414 emergency department visits (95% CI=63655, 93172) annually for non-abuse-related overdoses of acetaminophen-containing products. Most emergency department visits for acetaminophen overdose were for self-directed violence (69.8%, 95% CI=66.4%, 73.2%), with the highest rate among patients aged 15-24 years (46.4 per 100,000 individuals per year). Unsupervised ingestions by children aged <6 years accounted for 13.4% (95% CI=11.0%, 15.9%) of visits for acetaminophen overdoses (42.5 per 100,000 individuals per year). Therapeutic misadventures accounted for 16.7% (95% CI=14.0%, 19.5%) of visits and most involved overuse for medicinal effects (56.1%, 95% CI=50.6%, 61.6%) rather than use of multiple acetaminophen-containing products or dose confusion.

CONCLUSIONS

Non-abuse-related overdoses of acetaminophen products lead to many emergency department visits each year, particularly emergency department visits for self-directed violence. Acetaminophen overdose prevention efforts will likely need to be multidimensional.

Detailed analyses of self-poisoning episodes presenting to a large regional teaching hospital in the UK

AIMS

The primary aim of this paper is to provide comprehensive contemporaneous data on the demographics, patterns of presentation and management of all episodes of deliberate self-poisoning presenting to a large regional teaching hospital over a 12 month period.

METHODS

We undertook detailed, retrospective analyses using information from electronic patient records and local patient-tracking, pathology and administrative databases. Statistical analyses were performed using Chi-squared tests, anova and two-tailed t-tests (Graphpad Prism).

RESULTS

One thousand five hundred and ninety-eight episodes of deliberate self-poisoning presented over the year. Demographic data and information on the month, day and time of admission are provided. 70.7% presented to the emergency department (ED) within 4 h of ingestion. 76.3% of patients had only one episode in an extended 29 month follow-up period. A mean of 1.72 drugs were taken per episode with just over half of all episodes involving a single drug only. Paracetamol and ibuprofen were the two most commonly ingested drugs involved in 42.5% and 17.3% of all overdoses respectively. 56.3% of patients taking paracetamol reported ingesting over 8 g (one over the counter packet). Detailed mapping of the patients' pathway through the hospital allowed an estimation of the hospital cost of caring for this patient group at pound 1.6 million pounds per year.

CONCLUSIONS

We present comprehensive and contemporary data on presentations to hospital resulting from deliberate self-poisoning. We include demographic information, presentation patterns, drugs used, a detailed analysis of episodes involving paracetamol and an estimate of the financial burden to hospitals of overdose presentations.

Limiting paracetamol pack size: has it worked in the UK?

INTRODUCTION

Paracetamol poisoning is a major health problem worldwide. Limitation of pack size is an approach increasingly advocated to reduce rates of suicide and serious self-harm from this agent. The United Kingdom adopted such a policy in 1998, restricting non-pharmacy sales to 8 g and pharmacy to pack sizes of 16 g.

METHODS

A literature review was conducted and commentary written on the impact of the change in the United Kingdom on a variety of indices of paracetamol overdose.

RESULTS

Potential markers of effect identified included paracetamol sales, poisons information data, laboratory results, liver unit referrals, and hospital activity and mortality data. Initial reports suggested effects associated with the legislation, but longer term suicide trend analysis has not confirmed these early findings, which were confounded by population trends in self-harm.

CONCLUSION

Paracetamol pack size limitation as applied in the United Kingdom has not reduced paracetamol-related death. Reasons postulated for this failure include patient avoidance of the legislation's intentions, patient confusion, and ineffectiveness of the regulations as conceived and implemented.

Paracetamol (acetaminophen) pack size restrictions and poisoning severity: time trends in enquiries to a UK poisons centre

BACKGROUND AND OBJECTIVE

In September 1998, legislation was introduced in the United Kingdom to limit paracetamol pack sizes to 16 tablets of 500 mg at general sales outlets and 32 tablets of 500 mg at pharmacies. The effect of the regulations on severity of paracetamol poisoning is unclear. The aim of this study was to describe trends in the severity of paracetamol poisoning and to assess the impact of the 1998 Regulations on the enquiries to a UK poisons centre.

METHODS

We extracted data about the age, sex and number of tablets or capsules of paracetamol ingested by patients notified to Guy's and St Thomas' Poisons Unit (London, UK) between 1996 and 2004.

RESULTS AND DISCUSSION

During the study period, there were approximately 140 000 patients with suspected paracetamol poisoning, accounting for around 11% of all patients reported to the poisons unit. The median number of tablets fell from 25 to 20 for males and 20 to 16 for females after 1998. There was also a reduction in the proportion of patients who ingested 17-32 tablets (from 36% to 30%) and 33-100 tablets (from 25% to 19%).

CONCLUSION

Following the 1998 Regulations there was a decline in the severity, but not frequency, of paracetamol poisoning cases reported to Guy's and St Thomas' Poisons Unit. It is unclear whether the decline in severity was a direct consequence of the regulations.

Validation of ICD-9-CM/ICD-10 coding algorithms for the identification of patients with acetaminophen overdose and hepatotoxicity using administrative data

Background

Acetaminophen overdose is the most common cause of acute liver failure (ALF). Our objective was to develop coding algorithms using administrative data for identifying patients with acetaminophen overdose and hepatic complications.

Methods

Patients hospitalized for acetaminophen overdose were identified using population-based administrative data (1995–2004). Coding algorithms for acetaminophen overdose, hepatotoxicity (alanine aminotransferase >1,000 U/L) and ALF (encephalopathy and international normalized ratio >1.5) were derived using chart abstraction data as the reference and logistic regression analyses.

Results

Of 1,776 potential acetaminophen overdose cases, the charts of 181 patients were reviewed; 139 (77%) had confirmed acetaminophen overdose. An algorithm including codes 965.4 (ICD-9-CM) and T39.1 (ICD-10) was highly accurate (sensitivity 90% [95% confidence interval 84–94%], specificity 83% [69–93%], positive predictive value 95% [89–98%], negative predictive value 71% [57–83%], c-statistic 0.87 [0.80–0.93]). Algorithms for hepatotoxicity (including codes for hepatic necrosis, toxic hepatitis and encephalopathy) and ALF (hepatic necrosis and encephalopathy) were also highly predictive (c-statistics = 0.88). The accuracy of the algorithms was not affected by age, gender, or ICD coding system, but the acetaminophen overdose algorithm varied between hospitals (c-statistics 0.84–0.98; P = 0.003).

Conclusion

Administrative databases can be used to identify patients with acetaminophen overdose and hepatic complications. If externally validated, these algorithms will facilitate investigations of the epidemiology and outcomes of acetaminophen overdose.

Legislation restricting paracetamol sales and patterns of self-harm and death from paracetamol-containing preparations in Scotland

AIMS

To describe how changes in legislation to restrict paracetamol sales have affected overdose discharges and death associated with the drug in Scotland.

METHODS

A descriptive analysis of routine death and hospital discharge data for the entire Scottish population between 1995 and 2004. Patients in Scotland participated who were discharged from hospital with a diagnosis of poisoning; deaths in Scotland from diagnosis of poisoning 1995-2003 were also analysed. Outcome measures were changes in mortality and overdose due to poisoning involving paracetamol. A comparison was made of in-hospital and out-of-hospital mortality in fatalities involving paracetamol.

RESULTS

The majority of paracetamol-associated deaths were due to co-proxamol. Deaths associated with paracetamol alone or with ethanol occurred principally in hospital and were a minority of deaths overall. The proportion of in-hospital deaths attributed to paracetamol increased (post/pre ratio 1.347; 95% confidence interval 1.076, 1.639; P = 0.013). Overall numbers of cases discharged with poisoning fell. The proportion of these involving paracetamol in any form increased significantly in all groups except young men aged 10 to <20 years.

CONCLUSIONS

Legislation has not reduced mortality or proportional use of paracetamol in overdose, both of which appear to have increased in Scotland since pack-size limitations. Other approaches are necessary to reduce the death rate from overdoses involving paracetamol.

Impact of Restricting Paracetamol Pack Sizes on Paracetamol Poisoning in the United Kingdom

Paracetamol (acetaminophen) is the most common drug taken in overdose in the UK, accounting for 48% of poisoning admissions to hospital and being involved in an estimated 100-200 deaths per year. In 1998, the UK government introduced legislation that reduced the maximum pack size of all non-effervescent tablets and capsules containing aspirin (acetylsalicylic acid) or paracetamol that can be sold or supplied from outlets other than registered pharmacies from 25 to 16 tablets or capsules. This article reviews the literature to determine the effectiveness of the legislation, focusing specifically on paracetamol poisoning. Seventeen studies on this subject were identified. Three studies found reductions in mortality rates; one study found an increase in mortality rates, while one found an initial reduction followed by an eventual increase; three found no significant difference in mortality rates before and after introduction of the legislation. Five studies found reductions in admissions to liver units, three of these finding a reduction in liver transplantation rates; two further studies found no change in liver function tests and rates of paracetamol-induced acute liver injury or failure. Four studies found a sustained decrease in hospital admissions, while two found an initial decrease followed by an eventual increase. One study found a decline in admissions for paracetamol poisoning and an increase in admissions for non-paracetamol poisoning. Sales data are conflicting, with two studies finding no significant difference in paracetamol sales before and after the introduction of the legislation and one reporting a decline. The severity of overdose appears to have decreased since the maximum permitted packet size was reduced, with five studies reporting a reduction in the number of severe overdoses (measured by numbers of tablets ingested, serum paracetamol concentrations and usage of antidotes). Only two studies reported an increase in the number of severe overdoses.Paracetamol-associated mortality rates, admissions to liver units/liver transplants, hospital admissions and the severity of paracetamol overdose appear to have been decreasing since 1998. However, one study showed that the reductions in mortality and hospital admissions began in 1997; therefore, the contribution of the 1998 legislation to the observed changes is unclear. Most of the studies are based on short-term follow-up so it is difficult to draw any conclusions regarding long-term trends. Many of the studies were also restricted to relatively small areas of the UK; this, combined with a variety of outcome measures, makes it difficult to distinguish any conclusive trends. The studies also suffer from a lack of comparison and control groups. Some studies do not clearly differentiate between the paracetamol preparations covered by the legislation and those not. The limited number of studies to date, combined with a variety of outcome measures, make it difficult to determine with accuracy whether or not the legislation has been a success. More long-term studies are needed to fully assess the impact of the legislation.

How has legislation restricting paracetamol pack size affected patterns of deprivation related inequalities in self-harm in Scotland?

OBJECTIVE

To describe how changes in legislation to control sales and thus restrict the general availability of paracetamol have affected deprivation-related inequalities in deliberate self-harm associated with the drug in Scotland.

DESIGN AND SETTING

A descriptive analysis of routine death and hospital discharge data for the entire Scottish population between 1995 and 2002.

PARTICIPANTS

Patients in Scotland admitted to hospital with a diagnosis of poisoning and deaths in Scotland due to poisoning 1995-2002.

OUTCOME MEASURES

Changes in mortality and overdose rates by deprivation quintile, and case fatality rates due to poisoning involving paracetamol.

RESULTS

Rates of overdose involving paracetamol, while much higher in disadvantaged quintiles, fell in each deprivation quintile following the 1998 legislation. They then returned to levels similar, or above those in the mid 1990s. All quintiles were affected to a similar extent with the relationship between them remaining constant over time. Case fatality rates were significantly higher in more disadvantaged quintiles.

CONCLUSIONS

Marked inequalities exist in paracetamol related harm in Scotland. The most disadvantaged groups (both male and female) have higher overdose and death rates, as well as higher case fatality rates. Following the restrictions all social groups saw similar reductions in paracetamol related harm. This effect has been short-lived and rates have returned to pre-legislation levels. Legislation has not permanently affected overall use of paracetamol in overdose in Scotland or reduced the proportion of patients taking paracetamol as a component of the overdose in the longer term. An important public health policy has failed to achieve its objective and it is not clear why. We need a better understanding of why this measure had only short-term benefits if its full potential is to be achieved.

Prevalence of over-the-counter drug-related overdoses at Accident and Emergency departments in Northern Ireland--a retrospective evaluation

BACKGROUND AND OBJECTIVES

One major concern associated with misuse/abuse of over-the-counter (OTC) products is the potential for over-dosage. The aim of this research study was to evaluate, over a 3-month period, OTC medicine-related overdoses (those involving OTC drugs only and OTC drugs in combination with other drugs) that led to patients presenting at the Accident and Emergency (A & E) departments in four Belfast hospitals.

METHODS

A data collection sheet was designed to capture the information required from the A & E records in each hospital. A retrospective week-by-week data collection, reviewing A & E records, took place over a 3-month period (starting on 1 December 2002). All data related to cases presenting at the A & E departments because of drug overdoses (either accidental or deliberate according to Read Clinical Classification) were included in the study. Data were coded and entered into a custom designed SPSS database for analysis, using Chi square and Fisher exact tests.

RESULTS

OTC drug-related overdoses comprised 40.1% of all overdoses, of which 24.0% were OTC-only overdoses. Those who overdosed on OTC drugs (solely or combined with other drugs) were mainly female (62.3%) and in the age category 31-50 years (44.9%; P <0.05). The majority (n=215) of OTC-related overdoses were intentional, whereas only 28 were accidental. Of those who attended the A & E departments and had an overdose history, one-third overdosed on OTC-related products and two-thirds overdosed on OTC drugs only.

CONCLUSIONS

OTC drugs accounted for a significant proportion of overdose presentations at the A & E departments in Northern Ireland. Higher awareness of the potential of OTC product use in overdose cases (intentional or accidental) is recommended for both the public and health care professionals.

UK legislation on analgesic packs: before and after study of long term effect on poisonings

OBJECTIVE

To evaluate the long term effect of legislation limiting the size of packs of analgesics sold over the counter.

DESIGN

Before and after study.

SETTING

Suicides in England and Wales, data from six liver units in England and Scotland and five general hospitals in England, and UK data on sales of analgesics, between September 1993 and September 2002.

DATA SOURCES

Office for National Statistics; six liver units in England and Scotland; monitoring systems in general hospitals in Oxford, Manchester, and Derby; and Intercontinental Medical Statistics Health UK.

MAIN OUTCOME MEASURES

Deaths by suicidal overdose with paracetamol, salicylates, or ibuprofen; numbers of patients admitted to liver units, listed for liver transplant, and undergoing transplantations for paracetamol induced hepatotoxicity; non-fatal self poisonings with analgesics and numbers of tablets taken; and sales figures for analgesics.

RESULTS

Suicidal deaths from paracetamol and salicylates were reduced by 22% (95% confidence interval 11% to 32%) in the year after the change in legislation on 16 September 1998, and this reduction persisted in the next two years. Liver unit admissions and liver transplants for paracetamol induced hepatotoxicity were reduced by around 30% in the four years after the legislation. Numbers of paracetamol and salicylate tablets in non-fatal overdoses were reduced in the three years after the legislation. Large overdoses were reduced by 20% (9% to 29%) for paracetamol and by 39% (14% to 57%) for salicylates in the second and third years after the legislation. Ibuprofen overdoses increased after the legislation, but with little or no effect on deaths.

CONCLUSION

Legislation restricting pack sizes of analgesics in the United Kingdom has been beneficial. A further reduction in pack sizes could prevent more deaths.

Acetaminophen Availability Increases in Canada with No Increase in the Incidence of Reports of Inpatient Hospitalizations with Acetaminophen Overdose and Acute Liver Toxicity

In September 1999, several Canadian provinces had place-of-sale restrictions lifted that had limited the sale of acetaminophen >325 mg and packages >24 tablets (any strength) to pharmacies only. This allowed the sale of all strengths of immediate-release acetaminophen in all package sizes in nonpharmacy locations. This study's purpose was to explore the effect that lifting restrictions on acetaminophen place of sale may have had on reported hospitalizations in Canada related to acetaminophen overdose toxicity. Using hospital discharge data, provinces with no preexisting restrictions on place of sale were compared with those in which restrictions were lifted in September 1999. Cases of reported APAP overdose included ICD-9/9-CM code 965.4, ICD-9 code E850.2, or ICD-9-CM code E850.4. Cases with reported acute liver toxicity included ICD-9/9-CM codes 570, 572.2, 572.4, V42.7, or procedure code 50.5. There were no significant differences between the 1.5-year periods pre- and post-September 1999 in annual incidence rates per 100,000 persons ages >/=12 years of hospitalizations reported with acetaminophen overdose, either overall or limited to those with death as an outcome, or in hospitalization reports with both acetaminophen overdose and acute liver toxicity, either overall (provinces with no restrictions: pre = 0.70, post = 0.80, P = 0.6328; provinces with restrictions lifted in September 1999: pre = 0.49, post = 0.47, P = 0.8649) or limited to those with death as an outcome (provinces with no restrictions: pre = 0.22, post = 0.12, P = 0.3030; provinces with restrictions lifted in September 1999: pre = 0.13, post = 0.09, P = 0.3589). In conclusion, the decision to lift Canadian place-of-sale restrictions increased acetaminophen availability and did not increase the rate of reported hospitalizations related to acetaminophen overdose toxicity.

Acetylcysteine treatment for non-acetaminophen-induced acute liver failure

OBJECTIVE

To evaluate the effectiveness of intravenous acetylcysteine in the treatment of non-acetaminophen-induced acute liver failure (ALF).

DATA SOURCES

A search of MEDLINE (1966-March 2003), International Pharmaceutical Abstracts (1970-2003), and Cochrane Library (2003, issue 3) databases was conducted, using the search terms acetylcysteine, non-acetaminophen-induced hepatic failure, liver failure, intravenous, and treatment.

DATA SYNTHESIS

All of the studies found were small and do not provide conclusive evidence that acetylcysteine benefits this subgroup of patients. Microvascular regional benefits were seen, but clinical outcomes have not been studied.

CONCLUSIONS

Intravenous acetylcysteine should not be used routinely for treatment of non-acetaminophen-induced ALF. Further large-scale studies are needed to evaluate clinical outcomes.

The epidemiology of self-poisoning in the UK

Self-poisoning by ingestion or inhalation is common, and it is important to study its various epidemiological manifestations with clear definitions. Data on fatal self-poisonings are recorded nationally within the UK and are codified according to the International Classification of Diseases (ICD) revision relevant at the time. Most fatal self-poisonings are codified as suicides, accidental deaths or undetermined deaths ('open verdicts'). Non-fatal self-poisoning data, whether accidental or as a manifestation of deliberate self-harm, are recorded through hospital discharge information nationally but are not routinely published in the same way as mortality data. The bulk of the UK's published epidemiological information on nonfatal self-poisoning episodes is largely based on individual hospitals' admission or discharge records ('special studies'). After establishing definitions for different self-poisoning categories we discuss the published data on self-poisoning as they relate to suicide, accidental self-poisoning and deliberate self-harm in the UK.

The effect of recalling paracetamol on hospital admissions for poisoning in Western Australia

OBJECTIVES

To assess the effect of two recalls of paracetamol products on rates of intentional and unintentional overdoses of paracetamol in all age groups, as well as any effect on poisoning by other agents.

DESIGN

A before-and-after epidemiological study using data from the Western Australian Health Services Research Linked Database, which records all admissions to public and private hospitals throughout the State.

MAIN OUTCOME MEASURES

Hospital admissions in Western Australia for poisonings with all agents, including paracetamol and other over-the-counter analgesics.

RESULTS

There were 11 752 admissions for poisoning from 1996 to 2001. Paracetamol was the primary poisoning agent in 2266 (19.3%) admissions, aspirin in 120 (1%) and ibuprofen in 277 (2%). There was a significant decrease in the admission rate for paracetamol poisoning when sales were restricted in 2000 (rate ratio, 0.82; 95% CI, 0.68-0.99) compared with the same period in other years. There was no increase in poisoning with other agents at this time. However, admissions for paracetamol overdose also showed a large random variation that tended to obscure any effect.

CONCLUSIONS

Our study highlights the need to control for random as well as seasonal fluctuations in admission rates, and for restrictions on paracetamol sales to last for several months across all retail outlets. Limiting access to paracetamol may reduce paracetamol poisonings without a coincident increase in the use of other agents

The Esperance primary prevention of suicide project

BACKGROUND

Suicide has been a major community concern in Esperance, a geographically isolated port on the south coast of Western Australia.

AIMS

To evaluate the effect of three evidence-based initiatives for the primary prevention of suicide: (i) providing suicide awareness sessions for staff members in health, education and social services; (ii) limiting the sale of over the counter analgesics (aspirin and paracetamol) to packets containing less than the minimum lethal dose; and (iii) implementing Commonwealth media guidelines in the reporting of suicides by media.

METHODS

Changes in knowledge, awareness, attitudes, comfort and use, before and after each intervention were assessed using standardized instruments and pro forma derived from previous work, such as the Youth Suicide Prevention Training Manual and Suicide Intervention Beliefs Scale. Percentage changes in the number of retail outlets selling over the counter analgesics to less than potentially lethal quantities (less than 8 g of paracetamol or aspirin) were also measured. Media representatives were interviewed to gain their perceptions of Commonwealth Guidelines for the reporting of suicide, and encouraged to consult the project team before reporting suicide related issues.

RESULTS

The baseline survey illustrated that mental health staff and general practitioners were more aware of suicide issues, risk factors for suicide and awareness of professional and ethical responses than staff from other services, and were more willing to raise the issue with a person at risk. Thirty-three subjects participated in suicide awareness training of whom 21 (66%) returned questionnaires. There were significant increases in awareness of suicide-related issues and risk factors, as well as reported levels of knowledge of professional and ethical responses and comfort, competence and confidence levels when assisting a person at risk. Only three media representatives were aware of the Commonwealth Health Department Guidelines for reporting suicide and only one believed that the guidelines influenced their reporting. The local newspapers subsequently contacted the researchers to check that their reporting met the guidelines. As regards access to analgesics, one out of seven retailers agreed to implement the strategy (pending agreement from other retailers), another claimed increased awareness of the danger of analgesics, and three maintained that they would attempt to monitor excessive amounts sold to one individual.

CONCLUSIONS

Local initiatives can improve the awareness and knowledge of staff in the assessment of suicide risk, as well as of local media. These need to be complemented by initiatives at State or Commonwealth level to produce change in statewide media, or sales of over the counter analgesics.

Paracetamol-related deaths in Scotland, 1994-2000

AIMS

To investigate the death rate due to paracetamol poisoning in Scotland and what effect the reduction in over-the-counter paracetamol pack sizes in 1998 had on the death rate.

METHODS

Records from 1994 to 2000 were examined to identify the number and annual incidence of paracetamol-related deaths. Numbers of deaths before and after the pack size reduction were compared.

RESULTS

No significant differences were shown due to the pack size reduction. The Scottish paracetamol-related death rate was twice as high as in England and Wales.

CONCLUSIONS

Further measures to reduce paracetamol-related morbidity and mortality in Scotland should be considered.

Ease of access is a principal factor in the frequency of paracetamol overdose

BACKGROUND

In Ireland, 30% of non-fatal overdoses involve paracetamol.

AIMS

To determine how and where patients obtained paracetamol, to assess awareness of toxicity and examine the relationship between dose and suicidal intent.

METHODS

A prospective study of patients admitted following a paracetamol overdose recording their reasons for using paracetamol, their knowledge of its toxicity and their suicidal intent scale (SIS).

RESULTS

Of 100 patients, 66% obtained paracetamol in non-pharmacy outlets, 82% cited ease of availability as the reason, 55% were aware of its toxicity, 31% of liver damage and 68% did not read the warning on packets. The mean number of tablets taken was 51.3 for males and 37.2 for females (p < 0.01). Males presented later than females for medical attention (12.5 versus seven hours [p < 0.02]) and more males than females took alcohol (p < 0.03). The mean SIS score was 14.71 for males and 12.38 for females. There was a significant correlation between the SIS and the amount of paracetamol consumed (r = 0.28; p < 0.01).

CONCLUSION

The majority obtained paracetamol in local shops or at home. Knowledge of toxicity and the need for early antidote was poor. There was a significant relationship between suicidal intent and number of tablets consumed. Limiting availability could reduce number of overdoses.

Paracetamol pack size restriction: the impact on paracetamol poisoning and the over-the-counter supply of paracetamol, aspirin and ibuprofen

PURPOSE

Self-poisoning occurs with over-the-counter (OTC) drugs, particularly paracetamol (acetaminophen). In 1998, OTC pack sizes of paracetamol were reduced. We have studied the effect of this pack size restriction on OTC supply of paracetamol, aspirin and ibuprofen.

METHODS

IMS Health UK provided data on the UK sales of paracetamol, aspirin and ibuprofen. The total mass and number of packs of each drug supplied were compared for the years 1998, 1999 and 2000.

RESULTS

The mass of aspirin and paracetamol sold fell, that of ibuprofen increased. The number of paracetamol packs sold was unchanged, the analgesic dose of aspirin fell and ibuprofen supply increased.

CONCLUSIONS

It seems that the paracetamol pack size reduction has not achieved as large an overdose rate reduction as might have been expected. Instead, a shift to the use of ibuprofen may lead to an increase in gastrointestinal adverse events and continue the burden on healthcare resources.

Over-the-counter analgesics: a toxicology perspective

The decision to use any analgesic is a balance of benefit and risk. In the case of analgesics, it is important to balance the therapeutic benefit against both the risk in therapeutic use and the risk (and ease of treatment) in overdose. Paracetamol in therapeutic dose carries little risk of adverse events. Less than 0.1% of the estimated 30 million paracetamol users in the United Kingdom attend hospital with a paracetamol overdose each year, and approximately 200 people die, most of whom presented late or did not receive antidote, N-acetylcysteine, within 12 hours. Nonsteriodal anti-inflammatory drugs (NSAIDs) have greater adverse effects in therapeutic use than paracetamol but also have a lower incidence of severe features or death in overdose. There is no antidote available for NSAID poisoning. Aspirin carries both significant adverse effects in therapeutic dose and a substantial risk in overdose, for which there is no antidote. Its risk-benefit profile is probably the poorest of all analgesics currently available over-the-counter (OTC); this is reflected in current trends both in analgesic use and overdose figures. Although a number of options to reduce deaths from poisoning by OTC analgesics have been considered, few are practical, and all must take account of the public health benefits provided by these drugs. A perspective should be retained that the vast majority of the population in Australia, the United States, the United Kingdom, and Denmark derive therapeutic benefit from OTC analgesics and do not take them in overdose. The majority of those who do take overdoses come to little or no harm. Management of serious poisoning by paracetamol, aspirin, or NSAIDs remains a medical challenge.

Alcohol exposure and paracetamol-induced hepatotoxicity

Most instances of hepatotoxicity due to paracetamol in the United Kingdom and Australia are the result of large overdoses of the drug taken with suicidal or parasuicidal intent. In contrast, serious hepatotoxicity at recommended or near-recommended doses for therapeutic purposes has been reported, mainly from the United States and in association with chronic alcohol use, leading to the widely held belief that chronic alcoholics are predisposed to paracetamol-related toxicity at relatively low doses. Yet the effects of alcohol on paracetamol metabolism are complex. Studies performed in both experimental animals and humans indicate that chronic alcohol use leads to a short-term, two- to threefold increase in hepatic content of cytochrome P4502E1, the major isoform responsible for the generation of the toxic metabolite from paracetamol, although increased oxidative metabolism of paracetamol at recommended doses has not been demonstrated clinically. A reduced hepatic content of glutathione, required to detoxify the reactive metabolite, has been documented in chronic alcoholics, due probably to associated fasting and malnutrition, providing a metabolic basis for any possible predisposition of this group to hepatotoxicity at relatively low paracetamol doses. Simultaneous alcohol and paracetamol ingestion reduces oxidative metabolism of paracetamol in both rodents and humans, predominantly as a consequence of depletion in cytosol of free NADPH. The possibilities that chronic alcohol use may predispose to paracetamol-related hepatotoxicity and that alcohol taken with paracetamol may protect against it, based on these metabolic observations, are examined in this review.

Paracetamol recall: a natural experiment influencing analgesic poisoning

OBJECTIVES

To determine whether the occurrence of paracetamol and non-paracetamol analgesic deliberate self-poisoning (DSP) and accidental paediatric poisoning was affected by two periods of recall of paracetamol products.

DESIGN

Retrospective, observational audit of proportions of poisonings with tablet and capsule formulations of paracetamol, ibuprofen and aspirin products during two recall periods compared with the number of poisonings during the same periods of the previous three years.

SETTING

A national poisons information centre and a regional toxicology service.

MAIN OUTCOME MEASURES

Rates of DSP and accidental paediatric poisoning with paracetamol, ibuprofen and aspirin.

RESULTS

During the two recall periods, there was a significant increase in ibuprofen DSP calls to the poisons information centre (RR, 1.86; 95% Cl, 1.41-2.44; P = 0.001). There was no significant change in paracetamol or aspirin DSP calls over the two recall periods. However, there was a non-significant reduction in DSP calls with paracetamol in the first recall period alone (P = 0.057). There was a significant increase in the proportion of aspirin DSP presentations for the toxicology service (RR, 3.33; 95% CI, 0.97-11.4; P = 0.043), but no significant changes in paracetamol and ibuprofen DSP presentations. For accidental paediatric ingestions there was a significant increase in the proportion of ibuprofen calls (RR, 2.35; 95% CI, 1.85-2.98; P = 0.001), but no significant change in paracetamol or aspirin calls.

CONCLUSIONS

Reduced paracetamol availability increased poisoning with alternative analgesics, but had little effect on the incidence of paracetamol poisoning. Restriction of paracetamol-containing products may inadvertently increase poisoning with potentially more toxic agents.

A NO-releasing derivative of acetaminophen spares the liver by acting at several checkpoints in the Fas pathway

NCX-701 is a nitric oxide (NO)-releasing acetaminophen (APAP) derivative. In the present study we demonstrated that NCX-701 is as effective as APAP in controlling body temperature in a rat model of endotoxin-induced fever. Liver toxicity is a major complication of APAP overdosing. To investigate whether NCX-701 is hepatotoxic, BALB/C mice were injected with 100 - 500 mg kg(-1) APAP or NCX-701 alone or in combination (i.e. 500 mg kg(-1) of both compounds). Our results demonstrated that although APAP caused a dose-dependent liver injury, NCX-701 was completely devoid of liver toxicity. At the dose of 500 mg kg(-1) APAP caused an approximately 40 fold increase of AST plasma levels and extensive centrilobular necrosis. APAP and NCX-701 share the same metabolic pathway as demonstrated by the time-course of APAP-glucuronide concentrations in plasma and liver. NCX-701 was safe in mice with pre-existing chronic liver disease. Indeed, while C57BL6 transgenic mice expressing the hepatitis B virus (HBV) at the age of 8 months were significantly more susceptible to liver damage induced by APAP (500 mg kg(-1)) than their congenic littermates, treating HBV-transgenic mice with NCX-701, 500 mg kg(-1), caused no damage. Co-administration of NCX-701 at the dose 500 mg kg(-1) to mice treated with APAP, 500 mg kg(-1), completely protected against liver damage induced by APAP. APAP, but not NCX-701, upregulated liver Fas and Fas Ligand mRNA expression in vivo. Incubating mouse hepatocytes with APAP, but not with NCX-701, increased cell surface Fas expression and sensitized hepatocytes to death induced by challenge with a Fas-agonistic antibody. Collectively, these observations suggest that APAP toxicity is Fas mediated and that NCX-701 spares the liver by acting at several checkpoints in the Fas pathway.

Referral patterns and social deprivation in paracetamol-induced liver injury in Scotland

Paracetamol overdose is the commonest cause of acute liver failure in the UK, which has led to measures to restrict its sale. We aimed to establish whether changes in the referral of patients with paracetamol-induced acute liver failure have occurred since the introduction of legislation. We compared data from patients admitted to the Scottish Liver Transplantation Unit in 1992-98 with those admitted in 1998-2001. The incidence of paracetamol-induced liver failure, severity of patients' illness, and outcome did not differ between the groups. Patients with paracetamol-induced acute liver failure had higher Carstairs scores (1.99 [95% CI 1.33-2.65]; n=190) than patients with non-paracetamol acute liver failure (0.02 [-0.79 to 0.84]; n=68). We have shown an association between paracetamol-induced acute liver failure and social deprivation.

Effects of legislation restricting pack sizes of paracetamol and salicylate on self poisoning in the United Kingdom: before and after study

OBJECTIVE

To evaluate the effects on suicidal behaviour of legislation limiting the size of packs of paracetamol and salicylates sold over the counter.

DESIGN

Before and after study.

SETTING

UK population, with detailed monitoring of data from five liver units and seven general hospitals, between September 1996 and September 1999.

SUBJECTS

People who died by suicidal or accidental overdose with paracetamol or salicylates or who died of undetermined causes; patients admitted to liver units with hepatic paracetamol poisoning; patients presenting to general hospitals with self poisoning after taking paracetamol or salicylates.

MAIN OUTCOME MEASURES

Mortality from paracetamol or salicylate overdose; numbers of patients referred to liver units or listed for liver transplant; numbers of transplantations; numbers of overdoses and tablets taken; blood concentrations of the drugs; prothrombin times; sales to pharmacies and other outlets of paracetamol and salicylates.

RESULTS

Numbers of tablets per pack of paracetamol and salicylates decreased markedly in the year after the change in legislation on 16 September 1998. The annual number of deaths from paracetamol poisoning decreased by 21% (95% confidence interval 5% to 34%) and the number from salicylates decreased by 48% (11% to 70%). Liver transplant rates after paracetamol poisoning decreased by 66% (55% to 74%). The rate of non-fatal self poisoning with paracetamol in any form decreased by 11% (5% to 16%), mainly because of a 15% (8% to 21%) reduction in overdoses of paracetamol in non-compound form. The average number of tablets taken in paracetamol overdoses decreased by 7% (0% to 12%), and the proportion involving >32 tablets decreased by 17% (4% to 28%). The average number of tablets taken in salicylate overdoses did not decrease, but 34% fewer (2% to 56%) salicylate overdoses involved >32 tablets. After the legislation mean blood concentrations of salicylates after overdose decreased, as did prothrombin times; mean blood concentrations of paracetamol did not change.

CONCLUSION

Legislation restricting pack sizes of paracetamol and salicylates in the United Kingdom has had substantial beneficial effects on mortality and morbidity associated with self poisoning using these drugs.

Drug-induced liver disease

This year's review is divided into several sections: the first describes drug withdrawals and new general reviews of drug-induced liver disease (DILD), including a review of a classification of drug injury. We review agents newly described as causing DILD, and new reports of DILD from established agents appearing in the year 2000. New aspects regarding the treatment of acetaminophen toxicity are included, and in the final section we deal with prevention of DILD as well as issues surrounding the use of potentially hepatotoxic medications in patients with underlying chronic disease.

Acute liver failure

Worldwide, viral hepatitis is the leading cause of acute liver failure, whereas acetaminophen hepatotoxicity is the most commonly identified cause in Western countries. Restricting the quantity of acetaminophen tablets dispensed has been shown to reduce morbidity and mortality in countries with a high incidence of acetaminophen overdose. Troglitazone and bromfenac are two recently approved medications that were withdrawn from the market due to an unacceptably high incidence of severe hepatotoxicity. In addition, trovafloxacin, nefazodone, and ritonavir were reported to be associated with severe hepatitis and acute liver failure. Moderate hypothermia is a simple and potentially effective means of reducing intracranial pressure in patients with acute liver failure and cerebral edema. However, controlled clinical trials are needed to determine proper patient selection and optimize treatment. Extracorporeal bioartificial liver support devices remain an exciting but as yet unproven means of supporting acute liver failure patients with advanced encephalopathy. Living donor liver transplantation has recently been reported for adults and children with acute liver failure. However, ethical concerns regarding donor safety and the ability to obtain informed consent without coercion have been raised. Lastly, advances in the identification and isolation of pluripotent liver stem cells in human bone marrow provides hope for a simple and effective means of enhancing native liver regeneration.

Management of drug-induced liver disease

The treatment and prevention of drug-induced liver injury starts with the recognition of hepatotoxicity at the earliest possible time so that the suspected drug can be discontinued expeditiously. Both liver enzyme monitoring and vigilance for signs of hypersensitivity involving the liver are useful strategies for many agents known to cause hepatocellular necrosis leading to liver failure. Specific antidotes to prevent or limit hepatic damage exist for only a few drugs, the most important being N-acetylcysteine for the treatment of acetaminophen hepatotoxicity. Corticosteroids are of unproven benefit in the setting of fulminant failure. Ursodiol may be helpful in instances of cholestatic injury. For other agents, supportive measures and the increasing use of liver-assist devices as well as emergency liver transplantation are available when drug injury evolves into irreversible liver failure. It is hoped that a better understanding of hepatotoxicity mechanisms will lead to the development of more specific and effective forms of therapy in the near future.