Impact of paracetamol pack size restrictions on poisoning from paracetamol in England and Wales: an observational study

Exploring public knowledge and perceptions regarding per os OTC pain-relieving medications: the case of paracetamol (acetaminophen)

BACKGROUND

Over-the-counter medications (OTC) are safe and effective when patients follow the patient's information leaflet (PIL) instructions and/or the instructions given by healthcare professionals (HCPs). However, OTC medications could be harmful and unsafe when individuals do not follow the given instructions and/or when their understanding about the proper use of OTC medications is incorrect. This study aimed to investigate the knowledge and perceptions of people regarding paracetamol use in the Republic of Cyprus.

METHODS

This cross-sectional study, which belongs to quantitative research methods, included participants visiting community pharmacies in the following three cities of the Republic of Cyprus: Nicosia, Limassol and Larnaca. Participation in the study was voluntary and anonymous. Participants responded to the survey-based questionnaire, which concerned their knowledge and views on paracetamol use. After the data collection, responses were tabulated and analysed statistically.

RESULTS

The original compound was shown to be more well-known compared to generics. A notable percentage of respondents-ranging between 13.0% (N = 49) and 29.8% (N = 112)-answered incorrectly that broadly used non-steroidal anti-inflammatory drugs (NSAIDs) contain paracetamol. Furthermore, a remarkable percentage of respondents (71.5%, N = 269 and 50.3%, N = 189, respectively) falsely believed that two widely used combination products in the market of Cyprus (Paracetamol and Hyoscine-N-butylbromide; Paracetamol and Codeine and Caffeine) did not contain paracetamol. A notable percentage of participants (27.6%, N = 100) believed that paracetamol causes low toxicity. More than a third of the respondents (40.2%, N = 149) drink alcohol together with or slightly after consuming paracetamol products. This viewpoint was linked with the participants' attitude towards consuming paracetamol medications after drinking alcohol (OR for consuming alcohol versus not consuming alcohol 0.100, 95% CI 0.044-0.225, p = 0.000).

CONCLUSIONS

To the best of our knowledge, this is the first study conducted in the Republic of Cyprus on this topic. Paracetamol is frequently consumed by individuals, both in its generic and original forms. However, the study showed that respondents often misperceive NSAIDs and paracetamol-containing medications. In addition, it is identified that there is a lack of education among people about the safe and effective use of paracetamol, namely, indications, potential side effects, maximum daily dose, alcohol consumption, and the potential risks of hepatotoxicity. The study contributed to the current published literature as it showed that there is a significant public health issue, for which appropriate measures can be established by the respective Authorities of Cyprus.

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.

National Poison Center Calls Before vs After Availability of High-Dose Acetaminophen (Paracetamol) Tablets in Switzerland

IMPORTANCE

Acetaminophen (paracetamol) is among the most widely used pain medications worldwide; while safe within the therapeutic range, intake exceeding 4000 mg/d can lead to hepatotoxicity. Prior evidence suggests that limiting the availability of large quantities of acetaminophen is associated with decreased acetaminophen-related poisonings and mortality; in Switzerland, 500-mg tablets are available over-the-counter (OTC) and, as of October 2003, 1000-mg tablets are available with prescription.

OBJECTIVE

To evaluate the association of adding 1000-mg acetaminophen tablets to the Swiss market with utilization and poisonings.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used a quasi-experimental interrupted time series analysis to evaluate 15 790 acetaminophen poison records from January 1, 2000, to December 31, 2018. All calls for acetaminophen-related poisonings identified from the National Swiss Poisons Centre and all sales for oral acetaminophen tablets (prescription and OTC) dispensed between January 2000 and December 2018 were included.

EXPOSURE

October 3, 2003 (Q4 2003), was defined as the intervention date, corresponding to the date of market entry for 1000-mg acetaminophen tablets in Switzerland.

MAIN OUTCOMES AND MEASURES

The primary outcome was the number of quarterly acetaminophen-related poison calls to the National Poison Centre. Additional outcomes included quarterly sales for acetaminophen and change in poisoning circumstances, stratified by preintervention and postintervention periods and by formulation (ie, 500-mg and 1000-mg tablets).

RESULTS

Between 2000 and 2018, 15 790 acetaminophen-related poisoning calls were identified, of which 10 628 (67.3%) were regarding women, and the mean (SD) age of patients was 25.2 (18.2) years. The interrupted time series analysis identified a significant increase in the slope for the number of reported poisonings following the intervention point, particularly for accidental circumstances (z score, -3.62; P < .001). In the preintervention period, 120 of 961 poisonings (15.3%) involved a dose greater than 10 000 mg, while for the postintervention period, 1140 of 5696 (30.6%) had a dose larger than 10 000 mg (P < .001). There was a rapid uptake in 1000-mg acetaminophen sales, while sales of the 500-mg tablet decreased slightly. Since 2012, a mean (SD) of 20.7 million (1.4 million) 1000-mg tablets were dispensed quarterly compared with 2.7 million (0.5 million) 500-mg tablets.

CONCLUSIONS AND RELEVANCE

This study found a significant increase in acetaminophen dispensing and acetaminophen-related poisonings in Switzerland following the approval of 1000-mg tablets in 2003. The availability of 1000-mg acetaminophen should be re-evaluated to minimize the potential for accidental poisonings.

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.

Impact of resuscitation fluid bag size availability on volume of fluid administration in the intensive care unit

BACKGROUND

Iatrogenic fluid overload is associated with increased mortality in the intensive care unit (ICU). Decisions on fluid therapy may, at times, be based on other factors than physiological endpoints. We hypothesized that because of psychological factors volume of available fluid bags would affect the amount of resuscitation fluid administered to ICU patients.

METHODS

We performed a prospective intervention cross-over study at 3 Swedish ICUs by replacing the standard resuscitation fluid bag of Ringer's Acetate 1000 mL with 500 mL bags (intervention group) for 5 separate months and then compared it with the standard bag size for 5 months (control group). Primary endpoint was the amount of Ringer's Acetate per patient during ICU stay. Secondary endpoints were differences between the groups in cumulative fluid balance and change in body weight, hemoglobin and creatinine levels, urine output, acute kidney failure (measured as the need for renal replacement therapy, RRT) and 90-day mortality.

RESULTS

Six hundred and thirty-five ICU patients were included (291 in the intervention group, 344 in the control group). There was no difference in the amount of resuscitation fluid per patient during the ICU stay (2200 mL [1000-4500 median IQR] vs 2245 mL [1000-5630 median IQR]), RRT rate (11 vs 9%), 90-day mortality (11 vs 10%) or total fluid balance between the groups. The daily amount of Ringer's acetate administered per day was lower in the intervention group (1040 (280-2000) vs 1520 (460-3000) mL; P = .03).

CONCLUSIONS

The amount of resuscitation fluid administered to ICU patients was not affected by the size of the available fluid bags. However, altering fluid bag size could have influenced fluid prescription behavior.

Measuring the impact of medicines regulatory interventions - Systematic review and methodological considerations

AIMS

Evaluating the public health impact of regulatory interventions is important but there is currently no common methodological approach to guide this evaluation. This systematic review provides a descriptive overview of the analytical methods for impact research.

METHODS

We searched MEDLINE and EMBASE for articles with an empirical analysis evaluating the impact of European Union or non-European Union regulatory actions to safeguard public health published until March 2017. References from systematic reviews and articles from other known sources were added. Regulatory interventions, data sources, outcomes of interest, methodology and key findings were extracted.

RESULTS

From 1246 screened articles, 229 were eligible for full-text review and 153 articles in English language were included in the descriptive analysis. Over a third of articles studied analgesics and antidepressants. Interventions most frequently evaluated are regulatory safety communications (28.8%), black box warnings (23.5%) and direct healthcare professional communications (10.5%); 55% of studies measured changes in drug utilization patterns, 27% evaluated health outcomes, and 18% targeted knowledge, behaviour or changes in clinical practice. Unintended consequences like switching therapies or spill-over effects were rarely evaluated. Two-thirds used before-after time series and 15.7% before-after cross-sectional study designs. Various analytical approaches were applied including interrupted time series regression (31.4%), simple descriptive analysis (28.8%) and descriptive analysis with significance tests (23.5%).

CONCLUSION

Whilst impact evaluation of pharmacovigilance and product-specific regulatory interventions is increasing, the marked heterogeneity in study conduct and reporting highlights the need for scientific guidance to ensure robust methodologies are applied and systematic dissemination of results occurs.

Interventions for paracetamol (acetaminophen) overdose

BACKGROUND

Paracetamol (acetaminophen) is the most widely used non-prescription analgesic in the world. Paracetamol is commonly taken in overdose either deliberately or unintentionally. In high-income countries, paracetamol toxicity is a common cause of acute liver injury. There are various interventions to treat paracetamol poisoning, depending on the clinical status of the person. These interventions include inhibiting the absorption of paracetamol from the gastrointestinal tract (decontamination), removal of paracetamol from the vascular system, and antidotes to prevent the formation of, or to detoxify, metabolites.

OBJECTIVES

To assess the benefits and harms of interventions for paracetamol overdosage irrespective of the cause of the overdose.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register (January 2017), CENTRAL (2016, Issue 11), MEDLINE (1946 to January 2017), Embase (1974 to January 2017), and Science Citation Index Expanded (1900 to January 2017). We also searched the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov database (US National Institute of Health) for any ongoing or completed trials (January 2017). We examined the reference lists of relevant papers identified by the search and other published reviews.

SELECTION CRITERIA

Randomised clinical trials assessing benefits and harms of interventions in people who have ingested a paracetamol overdose. The interventions could have been gastric lavage, ipecacuanha, or activated charcoal, or various extracorporeal treatments, or antidotes. The interventions could have been compared with placebo, no intervention, or to each other in differing regimens.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from the included trials. We used fixed-effect and random-effects Peto odds ratios (OR) with 95% confidence intervals (CI) for analysis of the review outcomes. We used the Cochrane 'Risk of bias' tool to assess the risks of bias (i.e. systematic errors leading to overestimation of benefits and underestimation of harms). We used Trial Sequential Analysis to control risks of random errors (i.e. play of chance) and GRADE to assess the quality of the evidence and constructed 'Summary of findings' tables using GRADE software.

MAIN RESULTS

We identified 11 randomised clinical trials (of which one acetylcysteine trial was abandoned due to low numbers recruited), assessing several different interventions in 700 participants. The variety of interventions studied included decontamination, extracorporeal measures, and antidotes to detoxify paracetamol's toxic metabolite; which included methionine, cysteamine, dimercaprol, or acetylcysteine. There were no randomised clinical trials of agents that inhibit cytochrome P-450 to decrease the activation of the toxic metabolite N-acetyl-p-benzoquinone imine.Of the 11 trials, only two had two common outcomes, and hence, we could only meta-analyse two comparisons. Each of the remaining comparisons included outcome data from one trial only and hence their results are presented as described in the trials. All trial analyses lack power to access efficacy. Furthermore, all the trials were at high risk of bias. Accordingly, the quality of evidence was low or very low for all comparisons. Interventions that prevent absorption, such as gastric lavage, ipecacuanha, or activated charcoal were compared with placebo or no intervention and with each other in one four-armed randomised clinical trial involving 60 participants with an uncertain randomisation procedure and hence very low quality. The trial presented results on lowering plasma paracetamol levels. Activated charcoal seemed to reduce the absorption of paracetamol, but the clinical benefits were unclear. Activated charcoal seemed to have the best risk:benefit ratio among gastric lavage, ipecacuanha, or supportive treatment if given within four hours of ingestion. There seemed to be no difference between gastric lavage and ipecacuanha, but gastric lavage and ipecacuanha seemed more effective than no treatment (very low quality of evidence). Extracorporeal interventions included charcoal haemoperfusion compared with conventional treatment (supportive care including gastric lavage, intravenous fluids, and fresh frozen plasma) in one trial with 16 participants. The mean cumulative amount of paracetamol removed was 1.4 g. One participant from the haemoperfusion group who had ingested 135 g of paracetamol, died. There were no deaths in the conventional treatment group. Accordingly, we found no benefit of charcoal haemoperfusion (very low quality of evidence). Acetylcysteine appeared superior to placebo and had fewer adverse effects when compared with dimercaprol or cysteamine. Acetylcysteine superiority to methionine was unproven. One small trial (low quality evidence) found that acetylcysteine may reduce mortality in people with fulminant hepatic failure (Peto OR 0.29, 95% CI 0.09 to 0.94). The most recent randomised clinical trials studied different acetylcysteine regimens, with the primary outcome being adverse events. It was unclear which acetylcysteine treatment protocol offered the best efficacy, as most trials were underpowered to look at this outcome. One trial showed that a modified 12-hour acetylcysteine regimen with a two-hour acetylcysteine 100 mg/kg bodyweight loading dose was associated with significantly fewer adverse reactions compared with the traditional three-bag 20.25-hour regimen (low quality of evidence). All Trial Sequential Analyses showed lack of sufficient power. Children were not included in the majority of trials. Hence, the evidence pertains only to adults.

AUTHORS' CONCLUSIONS

These results highlight the paucity of randomised clinical trials comparing different interventions for paracetamol overdose and their routes of administration and the low or very low level quality of the evidence that is available. Evidence from a single trial found activated charcoal seemed the best choice to reduce absorption of paracetamol. Acetylcysteine should be given to people at risk of toxicity including people presenting with liver failure. Further randomised clinical trials with low risk of bias and adequate number of participants are required to determine which regimen results in the fewest adverse effects with the best efficacy. Current management of paracetamol poisoning worldwide involves the administration of intravenous or oral acetylcysteine which is based mainly on observational studies. Results from these observational studies indicate that treatment with acetylcysteine seems to result in a decrease in morbidity and mortality, However, further evidence from randomised clinical trials comparing different treatments are needed.

Should N-Acetylcysteine be Administered Orally or Intravenously for the Treatment of Paracetamol Overdose?

Introduction

Paracetamol is the most commonly used drug in deliberate poisoning. N-acetylcysteine is the standard antidote for significant acute paracetamol overdose, but the route of administration varies between countries. This review aimed to find and appraise those comparative studies which would help answer the following question: in patients who have taken an overdose of paracetamol requiring antidote, is there any difference between intravenous and oral N-acetylcysteine in mortality, hepatotoxicity, adverse drug reactions or cost?

Methods

A literature search was conducted using Medline and other databases. Relevant papers were identified and appraised.

Results

One animal study and seven comparative clinical studies were identified and appraised. The quality of the evidence was generally poor, and there was no clear difference in outcomes between the two routes of administration.

Conclusions

Without evidence of advantage for one route over the other, routine practice should not be changed. However, after 30 years experience, both routes appear to be effective and safe, and in countries where intravenous administration is the standard, it would be reasonable to consider the oral route as an alternative when intravenous access is problematic. There is a need for prospective, randomised trials to determine the relative effectiveness, safety and cost of intravenous and oral formulations of N-acetylcysteine.

Increased availability of paracetamol in Sweden and incidence of paracetamol poisoning: using laboratory data to increase validity of a population-based registry study

PURPOSE

To estimate the incidence trend and outcome of paracetamol poisoning, in relation to increased availability of paracetamol from non-pharmacy outlets in 2009.

METHOD

Patients' serum paracetamol results over 14 years (2000-2013) from 20 (out of 21) regions in Sweden were linked to national registers of hospital care, cause of death, and prescriptions. Paracetamol poisonings were defined by serum paracetamol levels, hospital diagnoses, or cause of death. The change in incidence of poisonings following increased availability of paracetamol was analysed by using segmental regression of time series.

RESULTS

Of the 12 068 paracetamol poisonings, 85% were classified as intentional self-harm. Following increased availability from non-pharmacy outlets, there was a 40.5% increase in the incidence of paracetamol poisoning, from 11.5/100 000 in 2009 to 16.2/100 000 in 2013. Regression analyses indicated a change in the trend (p < 0.0001) but not an immediate jump in the incidence (p = 0.5991) following the increased availability. Adjusting for trends in hospital episodes for self-harm, suicides, and the sales volume of paracetamol did not influence the result. All-cause mortality at 30 days (3.2%) did not change over time.

CONCLUSIONS

The incidence of paracetamol poisoning in Sweden has increased since 2009, contrasting the decreased incidence in the period of 2007-2009. The change in trend was temporally associated with the introduction of availability of paracetamol from non-pharmacy outlets but did not appear to be related to sales volume of paracetamol or general trends in self-harm or suicides. © 2017 Commonwealth of Australia. Pharmacoepidemiology and Drug Safety © 2017 John Wiley & Sons, Ltd.

A study on paracetamol cardiotoxicity

Background

Sri Lanka has a high suicide rate, with more than 40 % of poisoning admissions due to overdose of drugs with Paracetamol being the commonest. Data regarding cardiotoxicity to paracetamol is very minimal though hepatotoxicity following poisoning is well studied. Paracetamol cardiotoxicity has rarely been clinically significant and may have well been overlooked. The possibility that paracetamol overdose might be directly cardiotoxic has been the subject of a few reports. Unexplained deaths and electrocardiographic changes associated with paracetamol poisoning have also been reported in which cardiac origin cannot be clearly ruled out. Although some studies state that paracetamol poisoning has no direct cardiotoxic effect, electrocardiographic changes due to metabolic derangement of hepatotoxicity have been shown in certain studies. Thus, we conducted this study to assess in detail the cardiotoxic effect of paracetamol poisoning.

Methods

This is a cross sectional descriptive study done on those with confirmed paracetamol poisoning. Serum paracetamol levels, Electrocardiogram, Echocardiogram, troponin I, and other basic investigations were done.

Results

Paracetamol ingestion is more common among teenagers and the young population in Sri Lanka. Although several cases of paracetamol poisoning induced cardiotoxicity has been described in the past, this study demonstrated no electrocardiographic, echocardiographic or cardiac biomarkers changes of myocardial toxicity.

Conclusion

Though literature review support cardiotoxicity following paracetamol poisoning, our study does not provide enough evidence for this. Continuous cardiac monitoring, serial troponin and echocaediogram assessment would be voluble adjunct in its management. Further experiments and research in this subject would be useful with a larger number of samples to further evaluate this important problem.

Estimating Consumers' Knowledge and Attitudes Towards Over-The-Counter Analgesic Medication in Greece in the Years of Financial Crisis: The Case of Paracetamol

Introduction

Non-prescription over-the-counter (OTC) drugs are widely used by patients to control aches, pain, and fever. One of the most frequently used OTC medications worldwide is paracetamol (acetaminophen). The aim of the present study was to fill the current knowledge gap regarding the beliefs and attitudes of people in Greece associated with the use of paracetamol during the years of financial crisis.

Methods

The present study employed a sample of individuals visiting community pharmacies in the second largest city of Greece, Thessaloniki. All participants anonymously answered a questionnaire regarding their beliefs and characteristics of paracetamol consumption. Their answers were then statistically analyzed.

Results

The generic paracetamol compound was shown to be more well known than the original. A significant percentage of participants, ranging between 9.9% and 33.7%, falsely believed that certain medications [mainly non-steroidal anti-inflammatory drugs (NSAIDs)] contained paracetamol. Participants’ age, level of education, and gender were shown to be predictive of this false belief. Additionally, 11.1% of participants believed that the maximum allowed daily dose of paracetamol was higher than the correct one. Better educated individuals were less likely to consume alcohol in parallel with paracetamol (odd ratio 0.230, 95% confidence interval 0.058–0.916, P = 0.037).

Conclusion

Paracetamol is commonly used, both in its original and generic forms. However, a significant number of individuals confuse it with NSAIDs. Age, level of education, and gender are important determinants of the characteristics of paracetamol consumption. It seems that patients prefer to take paracetamol on their own decision during the financial crisis.

Electronic supplementary material

The online version of this article (doi:10.1007/s40122-015-0042-x) contains supplementary material, which is available to authorized users.

Tetramine poisoning in China: changes over a decade viewed through the media's eye

Background

Tetramine, or tetramethylenedisulfotetramine, is an internationally banned compound that had been used primarily as a rodenticide. Despite its regulatory status, there are widespread reports of its intentional use in human poisonings, primarily in China, and often in mass poisonings. Enhanced governmental regulations were implemented in 2003 to further reduce the availability of tetramine, though the effects of these regulations, and the current use of tetramine, remains unknown.

Methods

Reports from the website of the China News Agency were collected from 2000 to 2012. Details such as the location, date, and intent of the events were compared before and after the regulations were implemented.

Results

There were a total of 148 events during the study period (95 from 2000 to 2003, and 53 after 2003). There were a total of 3526 victims, including 225 fatalities. The majority of the events were homicidal/terroristic in nature. The incidence of events fell after 2006. More poisoning events occurred in central China, such as Henan and Jiangsu province, and an increase was noted in April and September.

Conclusion

Tetramine poisoning events, as reported in the national Chinese media, fell after the implementation of strict regulation on tetramine. The causal relationship is not known.

Hepatoprotective effect of Caesalpinia gilliesii and Cajanus cajan proteins against acetoaminophen overdose-induced hepatic damage

This study aims to evaluate two proteins derived from the seeds of the plants Cajanus cajan (Leguminosae) and Caesalpinia gilliesii (Leguminosae) for their abilities to ameliorate the toxic effects of chronic doses of acetoaminphen (APAP) through the determination of certain biochemical parameters including liver marker enzymes: alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and total bilirubin. Also, total protein content and hepatic marker enzyme, lactate dehydrogenase were studied. Moreover, liver antioxidants, glutathione (GSH), nitric oxide, and lipid peroxides were determined in this study. Hepatic adenosine triphosphatase (ATPase), adenylate energy charge (ATP, adenosine diphosphate, adenosine monophosphate, and inorganic phosphate), and phosphate potential, serum interleukin-6, tumor necrosis factor-α, and myeloperoxidase were also examined in the present study. On the other hand, histopathological examination of intoxicated and liver treated with both proteins was taken into consideration. The present results show disturbances in all biochemical parameters and hepatic toxicity signs including mild vascular congestion, moderate inflammatory changes with moderate congested sinusoids, moderate nuclear changes (pyknosis), moderate centrilobular necrosis, fatty changes, nuclear pyknosis vascular congestion, and change in fatty centrilobular necrosis liver. Improvement in all biochemical parameters studied was noticed as a result of treatment intoxicated liver with C. gilliesii and C. cajan proteins either paracetamol with or post paracetamol treatment. These results were documented by the amelioration signs in rat's hepatic architecture. Thus, both plant protein extracts can upregulate and counteract the inflammatory process, minimize damage of the liver, delay disease progression, and reduce its complications.

Therapeutic and protective effects of Caesalpinia gilliesii and Cajanus cajan proteins against acetaminophen overdose-induced renal damage

The present work aims to evaluate the protective and ameliorative effects of two plant-derived proteins obtained from the seeds of Cajanus cajan and Caesalpinia gilliesii(Leguminosae) against the toxic effects of acetaminophen in kidney after chronic dose through determination of certain biochemical markers including total urea, creatinine, and kidney marker enzyme, that is, glyceraldehyde-3-phosphate dehydrogenase (GAPDH). In addition histopathological examination of intoxicated and treated kidney with both proteins was performed. The present results show a significant increase in serum total urea and creatinine, while significant decrease in GAPDH. Improvement in all biochemical parameters studied was demonstrated, which was documented by the amelioration signs in rats kidney architecture. Thus, both plant protein extracts can counteract the nephrotoxic process, minimize damage to the kidney, delay disease progression, and reduce its complications.

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.

High prevalence of medicine-induced attempted suicides among females in Nuuk, Greenland, 2008-2009

Background

The suicide rate in Greenland, especially among men, is among the highest in the world. Attempted suicide rates may be high also. However, the rates of attempted suicide are unknown.

Objective

We aimed to estimate the age- and gender-specific incidence of attempted suicide using medicine in Nuuk in 2008–2009.

Design

An observational retrospective study of consecutive medical records on patients admitted to Dronning Ingrids Hospital in Nuuk in 2008–2009 with possible medicine intoxication.

Results

Seventy-four (60 females and 14 men) cases of attempted suicide using medicine were included. Of those, 43 used paracetamol alone or in combination with other medicine. The incidence of attempted suicide using medicine was higher among females than males (p<0.001). The highest incidence of attempted suicide with paracetamol was found among women aged 20–24 years (0.84%). The highest incidence of suicide with medication (1.31 per 100 inhabitants per year) was among women aged 15–19 years.

Conclusions

The incidence of attempted suicide using medicine was high in Nuuk, Greenland, especially among women. The highest incidence of suicide attempts with medication was observed among women in the age group 15–19 years (1.31%). This may reflect psychosocial vulnerability among young people in Greenland. Initiatives to improve living conditions for children and adolescents are highly recommended to be initiated immediately.

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.

A generalisation of T-optimality for discriminating between competing models with an application to pharmacokinetic studies

The T-optimality criterion is used in optimal design to derive designs for model selection. To set up the method, it is required that one of the models is considered to be true. We term this local T-optimality. In this work, we propose a generalisation of T-optimality (termed robust T-optimality) that relaxes the requirement that one of the candidate models is set as true. We then show an application to a nonlinear mixed effects model with two candidate non-nested models and combine robust T-optimality with robust D-optimality. Optimal design under local T-optimality was found to provide adequate power when the a priori assumed true model was the true model but poor power if the a priori assumed true model was not the true model. The robust T-optimality method provided adequate power irrespective of which model was true. The robust T-optimality method appears to have useful properties for nonlinear models, where both the parameter values and model structure are required to be known a priori, and the most likely model that would be applied to any new experiment is not known with certainty.

Effects of a provincial ban of two toxic organophosphorus insecticides on pesticide poisoning hospital admissions

Background.

Pesticide self-poisoning causes one third of global suicides. Sri Lanka halved its suicide rate by banning WHO Class I organophosphorus (OP) insecticides and then endosulfan. However, poisoning with Class II toxicity OPs, particularly dimethoate and fenthion, remains a problem. We aimed to determine the effect and feasibility of a ban of the two insecticides in one Sri Lankan district.

Methods.

Sale was banned in June 2003 in most of Polonnaruwa District, but not Anuradhapura District. Admissions with pesticide poisoning to the district general hospitals was prospectively recorded from 2002.

Results.

Hospital admissions for dimethoate and fenthion poisoning fell by 43% after the ban in Polonnaruwa, while increasing by 23% in Anuradhapura. The pesticide case fatality fell from 14.4% to 9.0% in Polonnaruwa (odds ratio [OR] 0.59, 95% confidence interval [CI] 0.41–0.84) and 11.3% to 10.6% in Anuradhapura (OR 0.93, 95%CI 0.70–1.25; p = 0.051). This reduction was not sustained, with case fatality in Polonnaruwa rising to 12.1% in 2006–2007. Further data analysis indicated that the fall in case fatality had actually been due to a coincidental reduction in case fatality for pesticide poisoning overall, in particular for paraquat poisoning.

Conclusions.

We found that the insecticides could be effectively banned from agricultural practice, as shown by the fall in hospital admissions, with few negative consequences. However, the ban had only a minor effect on pesticide poisoning deaths because it was too narrow. A study assessing the agricultural and health effects of a more comprehensive ban of highly toxic pesticides is necessary to determine the balance between increased costs of agriculture and reduced health care costs and fewer deaths.

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.

Impact of different pack sizes of paracetamol in the United Kingdom and Ireland on intentional overdoses: a comparative study

Background

In order to reduce fatal self-poisoning legislation was introduced in the UK in 1998 to restrict pack sizes of paracetamol sold in pharmacies (maximum 32 tablets) and non-pharmacy outlets (maximum 16 tablets), and in Ireland in 2001, but with smaller maximum pack sizes (24 and 12 tablets). Our aim was to determine whether this resulted in smaller overdoses of paracetamol in Ireland compared with the UK.

Methods

We used data on general hospital presentations for non-fatal self-harm for 2002 - 2007 from the Multicentre Study of Self-harm in England (six hospitals), and from the National Registry of Deliberate Self-harm in Ireland. We compared sizes of overdoses of paracetamol in the two settings.

Results

There were clear peaks in numbers of non-fatal overdoses, associated with maximum pack sizes of paracetamol in pharmacy and non-pharmacy outlets in both England and Ireland. Significantly more pack equivalents (based on maximum non-pharmacy pack sizes) were used in overdoses in Ireland (mean 2.63, 95% CI 2.57-2.69) compared with England (2.07, 95% CI 2.03-2.10). The overall size of overdoses did not differ significantly between England (median 22, interquartile range (IQR) 15-32) and Ireland (median 24, IQR 12-36).

Conclusions

The difference in paracetamol pack size legislation between England and Ireland does not appear to have resulted in a major difference in sizes of overdoses. This is because more pack equivalents are taken in overdoses in Ireland, possibly reflecting differing enforcement of sales advice. Differences in access to clinical services may also be relevant.

Characterization of acetaminophen overdose-related emergency department visits and hospitalizations in the United States

PURPOSE

To estimate the number of acetaminophen overdose-related emergency department (ED) visits and hospitalizations in the United States, characterize these by intentionality, age, and gender, and compare the strengths and limitations of the utilized databases.

METHODS

We used data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) and the National Electronic Injury Surveillance System (NEISS) to estimate the number of relevant ED visits in the United States between 2000 and 2007, and the National Hospital Discharge Survey (NHDS) to estimate the number of relevant hospitalizations in the United States between 1991 and 2006. National estimates and their standard errors were calculated using information provided in each database. We used the standard United States population in 2000 to calculate age-adjusted rates.

RESULTS

We estimate an annual average of 44,348 (NHAMCS, 2000-2007) or 78,414 (NEISS, 2006-2007) acetaminophen overdose-related ED visits and 33,520 (NHDS, 2000-2006) hospitalizations. For 2000-2006 we calculated an age-adjusted rate of 13.9 acetaminophen overdose-related hospitalizations per 100,000 US population, with the highest rate (15.7) occurring from 2005 to 2006. Between 1991 and 2006, there was no decrease noted in hospitalizations for intentional or unintentional overdoses. The majority of overdoses reported in NEISS (69.8%) and NHDS (74.2%) were classified as intentional (suicides or suicidal gestures), whereas in NHAMCS, intentionality was evenly distributed.

CONCLUSIONS

Our results suggest that acetaminophen overdose, both intentional and unintentional, remains a significant public health concern. With an understanding of their methodological characteristics and limitations, these national databases can be useful tools to characterize acetaminophen overdose-related ED visits and hospitalizations.

Medication errors: pharmacovigilance centres in detection and prevention

1. Detecting medication errors needs collaboration between various organizations, such as patient safety institutions, pharmacovigilance centres, and poison control centres. In order to evaluate the input of pharmacovigilance centres and poison control centres in detecting and evaluating medication errors a pilot project was initiated by the World Alliance for Patient Safety in collaboration with the Uppsala Monitoring Centre; the Moroccan pharmacovigilance centre acted as project coordinator. As part of this project, a questionnaire on detecting medication errors was circulated to pharmacovigilance centres and poison control centres around the world, in order to assess their ability to detect and analyse medication errors. 2. The results showed that through their databases pharmacovigilance centres can detect, identify, analyse, and classify medication errors and carry out root cause analysis, which is an important tool in preventing medication errors. 3. The duties of pharmacovigilance centres in preventing medication errors include informing health-care professionals about the importance of reporting such errors and creating a culture of patient safety. Pharmacovigilance centres aim to prevent medication errors in collaboration with poison control centres. Such collaboration allows improved detection and improved preventive strategies. In addition, collaboration with regulatory authorities is important in finalizing decisions. 4. Collaboration between pharmacovigilance centres and poison control centres should be strengthened and bridges need to be built linking pharmacovigilance centres, poison control centres, and organizations dedicated to patient safety, in order to avoid duplication of workload.

Characteristics of drug-related hospital separations in Australia

BACKGROUND

To examine (a) numbers of alcohol and drug-related hospital separations, 1999-2005; (b) demographics of these separations; (c) principal diagnoses co-occurring with drug-related problems; (d) length of hospital stay.

METHODS

Data from the National Hospital Morbidity Database (NHMD) were analysed. Hospital separations where alcohol, opioids, amphetamine, cannabis, cocaine, other drugs (such as sedatives and hypnotics) and pharmaceutical poisoning were mentioned were examined.

RESULTS

Numbers per million persons were highest for alcohol, followed by other drugs, particularly sedatives and hypnotics. Alcohol and opioid-related problems were prominent among older age groups, whereas cannabis and pharmaceutical poisoning problems had greater proportions among 15-24 year olds. Opioid-related separations were relatively high in number within the context of prevalence of use, and often accompanied by principal diagnoses of physical or general health problems. Almost half of amphetamine and cannabis-related separations were accompanied by principal diagnoses of mental health problems.

CONCLUSIONS

This research highlights the complexities of drug-related hospital presentations, indicating the need for thorough assessment of physical and mental problems, as well as a drug use history at the time of admission. Continued development of integrated models of care, targeting both mental health and drug use are essential. Consistent with the international literature, many of these separations are preventable, particularly those for pharmaceutical poisoning. Finally, ongoing efforts to reduce the significantly greater harms related to opioid use, as well as increasing treatment opportunities for opioid-dependent people in Australia is an important public health priority.

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.

Reasons for the use of mild analgesics among English students

OBJECTIVE

Mild analgesics such as paracetamol and ibuprofen are amongst the most commonly used over-the-counter (OTC) drugs. However, little is known about what beliefs people hold about them. The present paper examines: (a) the patterns of mild analgesic usage in a sample of university students, (b) their beliefs about the associated risks and the necessity of taking mild analgesics, and (c) the association between beliefs about analgesics and self-reports of their use.

SETTING

A convenience sample of 333 students studying at a large English University were approached on the University campus. Of these, 291 agreed to participate, yielding an 87% response rate.

METHOD

This study employed a cross-sectional design, with all participants completing the same questionnaire concerning their use of mild painkillers, such as paracetamol and ibuprofen, and beliefs about their use.

MAIN OUTCOME MEASURE

Four questions asked about their patterns of mild analgesic use in the past month, specifically (a) have they taken analgesics, (b) how often did they take analgesics when they had symptoms, (c) did they take more than a single dose of 1-2 tablets at one time, and (d) did they exceed the maximum dose.

RESULTS

Almost all of the 291 participants reported symptoms in the past month, with over two thirds treating with mild analgesics, and one sixth exceeding the maximum dose. Only 17% indicated that there were short-term risks of using mild analgesics, although half indicated that there were long-term risks. The risks that were identified generally did not conform with current medical thinking. Perceptions of risks were not generally associated with self-reports of analgesic usage. Rather, respondents who thought analgesics were more necessary were more likely to report taking analgesics, report taking more analgesics, and report exceeding the maximum dose.

CONCLUSION

These results indicate the need for caution in current moves to encourage self-medication. If people are unaware of the risks of drugs such as paracetamol or ibuprofen, then they may only contact health professionals after they experience adverse effects.

Interrupted time-series analysis of regulations to reduce paracetamol (acetaminophen) poisoning

BACKGROUND

Paracetamol (acetaminophen) poisoning is the leading cause of acute liver failure in Great Britain and the United States. Successful interventions to reduced harm from paracetamol poisoning are needed. To achieve this, the government of the United Kingdom introduced legislation in 1998 limiting the pack size of paracetamol sold in shops. Several studies have reported recent decreases in fatal poisonings involving paracetamol. We use interrupted time-series analysis to evaluate whether the recent fall in the number of paracetamol deaths is different to trends in fatal poisoning involving aspirin, paracetamol compounds, antidepressants, or nondrug poisoning suicide.

METHODS AND FINDINGS

We calculated directly age-standardised mortality rates for paracetamol poisoning in England and Wales from 1993 to 2004. We used an ordinary least-squares regression model divided into pre- and postintervention segments at 1999. The model included a term for autocorrelation within the time series. We tested for changes in the level and slope between the pre- and postintervention segments. To assess whether observed changes in the time series were unique to paracetamol, we compared against poisoning deaths involving compound paracetamol (not covered by the regulations), aspirin, antidepressants, and nonpoisoning suicide deaths. We did this comparison by calculating a ratio of each comparison series with paracetamol and applying a segmented regression model to the ratios. No change in the ratio level or slope indicated no difference compared to the control series. There were about 2,200 deaths involving paracetamol. The age-standardised mortality rate rose from 8.1 per million in 1993 to 8.8 per million in 1997, subsequently falling to about 5.3 per million in 2004. After the regulations were introduced, deaths dropped by 2.69 per million (p = 0.003). Trends in the age-standardised mortality rate for paracetamol compounds, aspirin, and antidepressants were broadly similar to paracetamol, increasing until 1997 and then declining. Nondrug poisoning suicide also declined during the study period, but was highest in 1993. The segmented regression models showed that the age-standardised mortality rate for compound paracetamol dropped less after the regulations (p = 0.012) but declined more rapidly afterward (p = 0.031). However, age-standardised rates for aspirin and antidepressants fell in a similar way to paracetamol after the regulations. Nondrug poisoning suicide declined at a similar rate to paracetamol after the regulations were introduced.

CONCLUSIONS

Introduction of regulations to limit availability of paracetamol coincided with a decrease in paracetamol-poisoning mortality. However, fatal poisoning involving aspirin, antidepressants, and to a lesser degree, paracetamol compounds, also showed similar trends. This raises the question whether the decline in paracetamol deaths was due to the regulations or was part of a wider trend in decreasing drug-poisoning mortality. We found little evidence to support the hypothesis that the 1998 regulations limiting pack size resulted in a greater reduction in poisoning deaths involving paracetamol than occurred for other drugs or nondrug poisoning suicide.

Does restricting pack size of paracetamol (acetaminophen) reduce suicides?

The authors discuss a new study that examined the change in deaths attributed to paracetamol poisoning in England and Wales in the six years before and after a legislated reduction in the maximum pack size.

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.

Paracetamol availability and recent changes in paracetamol poisoning: is the 1998 legislation limiting availability of paracetamol being followed?

OBJECTIVE

To determine the degree of adherence to legislation introduced in 1998 restricting the availability of over the counter paracetamol.

DESIGN

A prospective observational study.

SETTING

An emergency department in an inner city London teaching hospital. Pharmacy and non-pharmacy outlets in south London.

MAIN OUTCOME MEASURES

(1) The source of paracetamol ingested by 107 patients presenting with an acute paracetamol overdose (2001-2003) and (2) the ability to purchase paracetamol from pharmacy and non-pharmacy outlets in a manner contravening paracetamol pack size legislation (2004).

RESULTS

Potentially toxic amounts of paracetamol in excess of pack size restrictions were purchased in 70% (17 of 24) of outlets. Forty six per cent of patients who had ingested a potentially toxic dose of paracetamol obtained the tablets in a manner contravening the 1998 legislation.

CONCLUSION

Legislation limiting the availability of over the counter paracetamol is not being adhered to in south London. A significant number of patients ingesting a potentially toxic dose of paracetamol report purchasing the tablets in a manner contravening the legislation. Studies that attempt to assess the impact of the legislation need to be interpreted in the context of these results. Measures to enforce current legislation may help to reduce the severity of paracetamol poisoning in the UK.

Drug-induced liver disease

PURPOSE OF REVIEW

To summarize the pertinent case reports, case series and clinical studies that described clinical, histological, epidemiological and mechanistic features of drug-induced liver disease in 2005.

RECENT FINDINGS

Acetaminophen, highly active antiretroviral therapy and drugs for tuberculosis retained their preeminent position as the most commonly reported agents causing drug-induced liver disease, with acetaminophen continuing to be the leading cause of acute liver failure in the USA. While the frequency of drug-induced liver disease remains low, a large case-series of acute drug-induced liver disease from Spain and Sweden supported the observation that acute hepatocellular jaundice from a drug is associated with death or the need for transplant in at least 10% (known as Hy's Law). With respect to using potentially hepatotoxic medications in patients with underlying liver disease, statins and second-generation thiazolidinediones were shown to be safe when used in patients with elevated baseline alanine aminotransferase or aspartate aminotransferase levels.

SUMMARY

Drug-induced liver disease remains an important cause of acute liver failure, and research efforts by the National Institutes of Health and others are underway to better determine the risk factors and other host susceptibilities that will allow for the safer use of drugs in the future.

Interventions for paracetamol (acetaminophen) overdose

BACKGROUND

Poisoning with paracetamol (acetaminophen) is a common cause of hepatotoxicity in the Western World. Inhibition of absorption, removal from the vascular system, antidotes, and liver transplantation are interventions for paracetamol poisoning.

OBJECTIVES

To assess the benefits and harms of interventions for paracetamol overdose.

SEARCH STRATEGY

We identified trials through electronic databases, manual searches of bibliographies and journals, authors of trials, and pharmaceutical companies until December 2005.

SELECTION CRITERIA

Randomised clinical trials and observational studies were included.

DATA COLLECTION AND ANALYSIS

The primary outcome measure was all-cause mortality plus liver transplantation. Secondary outcome measures were clinical symptoms, (eg, hepatic encephalopathy, fulminant hepatic failure), hepatotoxicity, adverse events, and plasma paracetamol concentration. We used Peto odds ratios and odds ratios with 95% confidence intervals (CI) for analysis of outcomes. Random- and fixed-effects meta-analyses were performed.

MAIN RESULTS

Ten small and low-methodological quality randomised trials, one quasi-randomised study, and 48 observational studies were identified. It was not possible to perform relevant meta-analyses of randomised trials that have addressed our outcome measures. Activated charcoal, gastric lavage, and ipecacuanha are able to reduce the absorption of paracetamol, but the clinical benefit is unclear. Of these, activated charcoal seems to have the best risk-benefit ratio. N-acetylcysteine seems preferable to placebo/supportive treatment, dimercaprol, and cysteamine, but N-acetylcysteine's superiority to methionine is unproven. It is not clear which N-acetylcysteine treatment protocol offers the best efficacy. No strong evidence supports other interventions for paracetamol overdose. N-acetylcysteine may reduce mortality in patients with fulminant hepatic failure (Peto OR 0.26, 95% CI 0.09 to 0.94, one trial). Liver transplantation has the potential to be life saving in fulminant hepatic failure, but refinement of selection criteria for transplantation and long-term outcome reporting are required.

AUTHORS' CONCLUSIONS

Our results highlight a paucity of randomised trials on interventions for paracetamol overdose. Activated charcoal seems the best choice to reduce absorption. N-acetylcysteine should be given to patients with overdose but the selection criteria are not clear. No N-acetylcysteine regime has been shown to be more effective than any other. It is a delicate balance when to proceed to liver transplantation, which may be life-saving for patients with poor prognosis.