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

Gatekeeper training for vendors to reduce pesticide self-poisoning in rural South Asia: a study protocol for a stepped-wedge cluster randomised controlled trial

INTRODUCTION

Pesticide self-poisoning kills an estimated 110 000-168 000 people worldwide annually. Data from South Asia indicate that in 15%-20% of attempted suicides and 30%-50% of completed suicides involving pesticides these are purchased shortly beforehand for this purpose. Individuals who are intoxicated with alcohol and/or non-farmers represent 72% of such customers. We have developed a 'gatekeeper' training programme for vendors to enable them to identify individuals at high risk of self-poisoning (gatekeeper function) and prevent such individuals from accessing pesticides (means restriction). The primary aim of the study is to evaluate the effectiveness of the gatekeeper intervention in preventing pesticide self-poisoning in Sri Lanka. Other aims are to identify method substitution and to assess the cost and cost-effectiveness of the intervention.

METHODS AND ANALYSIS

A stepped-wedge cluster randomised trial of a gatekeeper intervention is being conducted in rural Sri Lanka with a population of approximately 2.7 million. The gatekeeper intervention is being introduced into 70 administrative divisions in random order at each of 30 steps over a 40-month period. The primary outcome is the number of pesticide self-poisoning cases identified from surveillance of hospitals and police stations. Secondary outcomes include: number of self-poisoning cases using pesticides purchased within the previous 24 hours, total number of all forms of self-harm and suicides. Intervention effectiveness will be estimated by comparing outcome measures between the pretraining and post-training periods across the divisions in the study area. The original study protocol has been adapted as necessary in light of the impact of the COVID-19.

ETHICS AND DISSEMINATION

The Ethical Review Committee of the Faculty of Medicine and Allied Sciences, Rajarata University, Sri Lanka (ERC/2018/30), and the ACCORD Medical Research Ethics Committee, Edinburgh University (18-HV-053) approved the study. Results will be disseminated in scientific peer-reviewed journals.

TRIAL REGISTRATION NUMBER

SLCTR/2019/006, U1111-1220-8046.

Acute Liver Failure Secondary to Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is the most common cause of acute liver failure (ALF) in Western countries. Without liver transplantation, the mortality rate for ALF approaches greater than 80%. Acetaminophen-related ALF may be associated with a rapid progression but fortunately has a high chance for spontaneous survival compared with idiosyncratic DILI-related ALF. Several prognostic scoring systems for severe DILI have been developed to aid clinicians in selecting patients who require urgent liver transplantation. Patients who undergo liver transplantation for ALF are at risk for early graft loss and death and should be closely followed.

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.

Vendor-based restrictions on pesticide sales to prevent pesticide self-poisoning - a pilot study

Background

In South Asia, up to 20% of people ingesting pesticides for self-poisoning purchase the pesticide from a shop with the sole intention of self-harm. Individuals who are intoxicated with alcohol and/or non-farmers represent 72% of such high-risk individuals. We aimed to test the feasibility and acceptability of vendor-based restrictions on pesticide sales for such high-risk individuals.

Methods

We conducted a pilot study in 14 (rural = 7, urban = 7) pesticide shops in Anuradhapura District of Sri Lanka. A two-hour training program was delivered to 28 pesticide vendors; the aim of the training was to help vendors recognize and respond to customers at high risk of pesticide self-poisoning. Knowledge and attitudes of vendors towards preventing access to pesticides for self-poisoning at baseline and in a three month follow-up was evaluated by questionnaire. Vendors were interviewed to explore the practice skills taught in the training and their assessment of the program.

Results

The scores of knowledge and attitudes of the vendors significantly increased by 23% (95% CI 15%–32%, p < 0.001) and by 16% (95% CI 9%–23%, p < 0.001) respectively in the follow-up. Fifteen (60%) vendors reported refusing sell pesticides to a high-risk person (non-farmer or intoxicated person) in the follow-up compared to three (12%) at baseline. Vendors reported that they were aware from community feedback that they had prevented at least seven suicide attempts. On four identified occasions, vendors in urban shops had been unable to recognize the self-harming intention of customers who then ingested the pesticide. Only 2 (8%) vendors were dissatisfied with the training and 23 (92%) said they would recommend it to other vendors.

Conclusions

Our study suggests that vendor-based sales restriction in regions with high rates of self-poisoning has the potential to reduce access to pesticides for self-poisoning. A large-scale study of the effectiveness and sustainability of this approach is needed.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5178-2) contains supplementary material, which is available to authorized users.

Oral nonsteroidal anti-inflammatory drugs (NSAIDs) for cancer pain in adults

BACKGROUND

Pain is a common symptom with cancer, and 30% to 50% of all people with cancer will experience moderate to severe pain that can have a major negative impact on their quality of life. Non-opioid drugs are commonly used to treat cancer pain, and are recommended for this purpose in the World Health Organization (WHO) cancer pain treatment ladder, either alone or in combination with opioids.A previous Cochrane review that examined the evidence for nonsteroidal anti-inflammatory drugs (NSAIDs) or paracetamol, alone or combined with opioids, for cancer pain was withdrawn in 2015 because it was out of date; the date of the last search was 2005. This review, and another on paracetamol, updates the evidence.

OBJECTIVES

To assess the efficacy of oral NSAIDs for cancer pain in adults, and the adverse events reported during their use in clinical trials.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase from inception to April 2017, together with reference lists of retrieved papers and reviews, and two online study registries.

SELECTION CRITERIA

We included randomised, double-blind, single-blind, or open-label studies of five days' duration or longer, comparing any oral NSAID alone with placebo or another NSAID, or a combination of NSAID plus opioid with the same dose of the opioid alone, for cancer pain of any pain intensity. The minimum study size was 25 participants per treatment arm at the initial randomisation.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality and potential bias. We did not carry out any pooled analyses. We assessed the quality of the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

Eleven studies satisfied inclusion criteria, lasting one week or longer; 949 participants with mostly moderate or severe pain were randomised initially, but fewer completed treatment or had results of treatment. Eight studies were double-blind, two single-blind, and one open-label. None had a placebo only control; eight compared different NSAIDs, three an NSAID with opioid or opioid combination, and one both. None compared an NSAID plus opioid with the same dose of opioid alone. Most studies were at high risk of bias for blinding, incomplete outcome data, or small size; none was unequivocally at low risk of bias.It was not possible to compare NSAIDs as a group with another treatment, or one NSAID with another NSAID. Results for all NSAIDs are reported as a randomised cohort. We judged results for all outcomes as very low-quality evidence.None of the studies reported our primary outcomes of participants with pain reduction of at least 50%, and at least 30%, from baseline; participants with Patient Global Impression of Change (PGIC) of much improved or very much improved (or equivalent wording). With NSAID, initially moderate or severe pain was reduced to no worse than mild pain after one or two weeks in four studies (415 participants in total), with a range of estimates between 26% and 51% in individual studies.Adverse event and withdrawal reporting was inconsistent. Two serious adverse events were reported with NSAIDs, and 22 deaths, but these were not clearly related to any pain treatment. Common adverse events were thirst/dry mouth (15%), loss of appetite (14%), somnolence (11%), and dyspepsia (11%). Withdrawals were common, mostly because of lack of efficacy (24%) or adverse events (5%).

AUTHORS' CONCLUSIONS

There is no high-quality evidence to support or refute the use of NSAIDs alone or in combination with opioids for the three steps of the three-step WHO cancer pain ladder. There is very low-quality evidence that some people with moderate or severe cancer pain can obtain substantial levels of benefit within one or two weeks.

Risk factors associated with purchasing pesticide from shops for self-poisoning: a protocol for a population-based case-control study

INTRODUCTION

Pesticide self-poisoning is one of the most frequently used methods of suicide worldwide, killing over 300,000 people annually. Around 15-20% of pesticide self-poisonings occur soon after the person has bought the pesticide from a shop. We aim to determine the characteristics of individuals who purchase pesticides directly from shops and how they differ from individuals who access pesticides from other sources such as home, home garden or farmland. This information will help inform possible vendor/shop-based intervention strategies aimed at reducing access to pesticides used for self-harm.

METHODS AND ANALYSIS

This study will investigate risk factors associated with purchasing pesticides for acts of self-poisoning from pesticide shops, including cases identified over a 9-month period using a population-based case-control group approach. Four interviewer-administered data collection tools will be used for this study: a semistructured questionnaire, Beck Suicidal Intent Scale (SIS), Clinical Interview Schedule-Sinhalese version (CIS-Sn) and Alcohol Use Disorders Identification Test (AUDIT). Each case (expected n=33) will be compared with two groups of individuals: (1) those who have self-poisoned using pesticides from the home, home garden or farmland and (2) those who bought pesticides from the same shops as the above cases, but not did not self-poison. Logistic regression models will be used to identify risk factors of purchasing pesticides for self-poisoning from shops.

ETHICS AND DISSEMINATION

The study has received ethical approval from the Ethical Review Committee of the Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka. A sensitive data collection technique will be used and ethical issues will be considered throughout the study. Results will be disseminated in scientific peer-reviewed articles.

Patient perception and knowledge of acetaminophen in a large family medicine service

The use of acetaminophen is currently under increased scrutiny by the US Food and Drug Administration (FDA) due to the risk of intentional and more concerning, unintentional overdose-related hepatotoxicity. Acetaminophen is responsible for an estimated 48% of all acute liver failure diagnoses. The purpose of this study is to evaluate patient perception and knowledge of the safe use and potential toxicity of acetaminophen-containing products. The authors conducted a descriptive, 2-week study using a convenience sample from a large family medicine clinic waiting room. Survey questions assessed ability to identify acetaminophen, knowledge of the current recommended maximum daily dose, respondent acetaminophen use patterns, common adverse effects associated with acetaminophen, and respondent self-reported alcohol consumption. Acetaminophen safety information was provided to all persons regardless of participation in the study. Of the 102 patients who chose to participate, 79% recognized acetaminophen as a synonym of Tylenol, whereas only 9% identified APAP as a frequently used abbreviation. One third of respondents thought acetaminophen was synonymous with ibuprofen and naproxen. Approximately one fourth of patients correctly identified the then maximum recommended daily acetaminophen dose of 4 g. Seventy-eight percent of patients correctly identified hepatotoxicity as the most common serious adverse effect. We conclude that patient deficiencies in knowledge of acetaminophen recognition, dosing, and toxicity warrant public education by health professionals at all levels of interaction. Current initiatives are promising; however, further efforts are required.

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.

Acetaminophen and asthma

Acetaminophen is a widely used medication for the treatment of pain and fever in children and pregnant women. There is substantial epidemiological evidence in adults and children that acetaminophen use is associated with asthma symptoms. There is also a considerable body of evidence that supports a modest but consistent association of acetaminophen use in pregnancy and early infancy with asthma in later childhood. This relationship is robust to adjustment for a large range of potential confounding factors and, in some studies, shows clear evidence of a dose-dependent association but the possibility of confounding by indication has remained a concern. However, the epidemiological evidence is now compelling and there is a clear need to establish causation so that appropriate advice and interventions can be developed for children at risk of asthma. This requires randomised trials of analgesics and antipyretics, including acetaminophen, in a variety of clinical settings.

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 comparison of self-reported analgesic use and detection of urinary ibuprofen and acetaminophen metabolites by means of metabonomics: the INTERMAP Study

Information on dietary supplements, medications, and other xenobiotics in epidemiologic surveys is usually obtained from questionnaires and is subject to recall and reporting biases. The authors used metabolite data obtained from hydrogen-1 (or proton) nuclear magnetic resonance ((1)H NMR) analysis of human urine specimens from the International Study of Macro-/Micro-Nutrients and Blood Pressure (INTERMAP Study) to validate self-reported analgesic use. Metabolic profiling of two 24-hour urine specimens per individual was carried out for 4,630 participants aged 40-59 years from 17 population samples in Japan, China, the United Kingdom, and the United States (data collection, 1996-1999). (1)H NMR-detected acetaminophen and ibuprofen use was low (∼4%) among East Asian population samples and higher (>16%) in Western population samples. In a comparison of self-reported acetaminophen and ibuprofen use with (1)H NMR-detected acetaminophen and ibuprofen metabolites among 496 participants from Chicago, Illinois, and Belfast, Northern Ireland, the overall rate of concordance was 81%-84%; the rate of underreporting was 15%-17%; and the rate of underdetection was approximately 1%. Comparison of self-reported unspecified analgesic use with (1)H NMR-detected acetaminophen and ibuprofen metabolites among 2,660 Western INTERMAP participants revealed similar levels of concordance and underreporting. Screening for urinary metabolites of acetaminophen and ibuprofen improved the accuracy of exposure information. This approach has the potential to reduce recall bias and other biases in epidemiologic studies for a range of substances, including pharmaceuticals, dietary supplements, and foods.

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.

Bilateral ureteric obstruction secondary to renal papillary necrosis

A 2-year-old male presented to hospital with a 5-day history of vomiting and pyrexia. He was initially treated with non-steroidal medication as an anti-pyretic. Initial investigations demonstrated a raised urea and creatinine and he was treated with intravenous fluids. Within 24 h he became anuric with progressive renal insufficiency. Ultrasound scan demonstrated minimal bilateral hydronephrosis with debris in the lower pole calyces. The bladder was empty. Cystoscopy and retrograde contrast imaging revealed bilateral ureteric obstruction. Double J stents were inserted and his renal function returned to normal within 4 days. We believe the aetiology to be renal papillary necrosis and bilateral ureteric obstruction secondary to the administration of ibuprofen in association with dehydration.

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.

Single dose oral ibuprofen for acute postoperative pain in adults

BACKGROUND

This review updates a 1999 Cochrane review showing that ibuprofen at various doses was effective in postoperative pain in single dose studies designed to demonstrate analgesic efficacy. New studies have since been published. Ibuprofen is one of the most widely used non-steroidal anti-inflammatory (NSAID) analgesics both by prescription and as an over-the-counter medicine. Ibuprofen is used for acute and chronic painful conditions.

OBJECTIVES

To assess analgesic efficacy of ibuprofen in single oral doses for moderate and severe postoperative pain in adults.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to May 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered ibuprofen (any formulation) in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number-needed-to-treat-to-benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected.

MAIN RESULTS

Seventy-two studies compared ibuprofen and placebo (9186 participants). Studies were predominantly of high reporting quality, and the bulk of the information concerned ibuprofen 200 mg and 400 mg. For at least 50% pain relief compared with placebo the NNT for ibuprofen 200 mg (2690 participants) was 2.7 (2.5 to 3.0) and for ibuprofen 400 mg (6475 participants) it was 2.5 (2.4 to 2.6). The proportion with at least 50% pain relief was 46% with 200 mg and 54% with 400 mg. Remedication within 6 hours was less frequent with higher doses, with 48% remedicating with 200 mg and 42% with 400 mg. The median time to remedication was 4.7 hours with 200 mg and 5.4 hours with 400 mg. Sensitivity analysis indicated that pain model and ibuprofen formulation may both affect the result, with dental impaction models and soluble ibuprofen salts producing better efficacy estimates. Adverse events were uncommon, and not different from placebo.

AUTHORS' CONCLUSIONS

The very substantial amount of high quality evidence demonstrates that ibuprofen is an effective analgesic in treating postoperative pain. NNTs for 200 mg and 400 mg ibuprofen did not change significantly from the previous review even when a substantial amount of new information was added. New information is provided on remedication.

Acetaminophen-related acute liver failure in the United States

Acetaminophen overdoses are the number one cause of acute liver failure (ALF) in the United States; they account for 50% of all cases of ALF and carry a 30% mortality. Nevertheless, acetaminophen is a highly successful product with sales easily exceeding a billion dollars annually. A narcotic-containing acetaminophen preparation is the number one generic drug sold in the United States. Historically, a strong association was claimed with alcohol as a co-factor and the accidental nature of ingestions was emphasized but the association with alcohol remains a matter of debate. Recently, a very reliable assay has been developed which detects a byproduct of the toxic reaction, acetaminophen-CYS adducts, protein-acetaminophen compounds that are released from damaged hepatocytes in similar fashion to aminotransferases. The US Acute Liver Failure Study Group is a multi-center network established to gather data prospectively on all forms of acute liver failure, a rare but often fatal condition. The group has data on more than 500 acetaminophen cases and described 275 of them in detail in a recent paper. The clinical pattern of presentation is somewhat different in the US compared with the UK, since nearly half are considered to be unintentional, the result of overuse of acetaminophen-containing compounds for pain relief, without suicidal intent. Despite the relatively good prognosis for acetaminophen overdoses, 30% die once acute liver failure occurs and this is the largest cause of death in the entire ALF registry.

Adherence to statin or aspirin or both in patients with established cardiovascular disease: exploring healthy behaviour vs. drug effects and 10-year follow-up of outcome

Aims

To characterize adherence in patients with established cardiovascular disease taking statins and aspirin and to estimate the effects of adherence due to health behaviour, a lack of beneficial drug effect, or both on recurrence of cardiovascular disease or all-cause mortality over 10 years.

Methods

A population-based cohort study using a record-linkage database in Tayside, Scotland. Subjects with cardiovascular disease (n = 7657; 4185 aspirin-alone cohort, 671 statin-alone cohort and 2801 combination use cohort) were studied between 1993 and 2003. The effects of adherence on recurrence of cardiovascular disease or mortality were assessed using Poisson regression model.

Results

In subjects taking both aspirin and statins, those adherent to statins but not aspirin had a lower risk of recurrence [adjusted risk ratio (RR) 0.64; 95% confidence interval 0.49, 0.82], but those adherent to aspirin but not statins has no such effect (adjusted RR 0.91; 0.72, 1.15), suggesting that adherence behaviour alone was not responsible for the beneficial effect. Within the group adherent to aspirin, ≥80% adherence to statins was associated with reduced recurrence compared with those poorly adherent (adjusted RR 0.76; 0.62, 0.94), but no such effect of aspirin was seen in those adherent to statins. Similar results were found for all-cause mortality.

Conclusions

Poor health behaviour is not a sufficient explanation of adverse outcome in poorly adherent patients. Adverse outcome is more likely to be driven by foregone drug benefits.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Aspirin and statins are widely-used drugs in patients with cardiovascular disease.

There is less information on healthy behaviour vs. drug effects.

WHAT THIS STUDY ADDS

Long-term adherence to aspirin and statin treatments in patients with established cardiovascular disease has been investigated.

Poor health behaviour is not a sufficient explanation of adverse outcome in poorly adherent patients.

Etiologies of acute liver failure

PURPOSE OF REVIEW

Acute liver failure remains a unique syndrome that results from massive loss of hepatocytes or hepatocyte function due to a variety of etiologies: viruses, drugs, toxins and other genetic and autoimmune conditions. The resulting clinical picture is remarkably similar across the different etiologies, reflecting common patterns of response of the innate immune system and the resulting inflammatory response. This review highlights developments in the delineation of etiologies of this relatively rare condition.

RECENT FINDINGS

The contribution of different etiologies to the overall picture varies by country. Europe and North America demonstrate a large proportion of cases due to acetaminophen and to idiosyncratic drug reactions, whereas reports from emerging countries in Asia and Africa are more likely to feature viral illnesses, particularly hepatitis B and E. Recent studies have suggested ever more exotic etiologies, new drugs and viruses.

SUMMARY

A careful search for the cause of acute liver failure in each case is of value in determining whether there are specific antidotes available and what the prognosis might be.

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.

Emergency department management of the salicylate-poisoned patient

Salicylate toxicity continues to be encountered commonly in emergency medicine. This article portrays the signs and symptoms of salicylate toxicity, reviews the erratic absorption and elimination kinetics, describes the devastating physiologic effects of overdose, and illustrates the potentially subtle manifestations of chronic aspirin toxicity.

Hospitalizations for acetaminophen overdose: a Canadian population-based study from 1995 to 2004

BACKGROUND

Acetaminophen overdose (AO) is the most common cause of acute liver failure. We examined temporal trends and sociodemographic risk factors for AO in a large Canadian health region.

METHODS

1,543 patients hospitalized for AO in the Calgary Health Region (population ~1.1 million) between 1995 and 2004 were identified using administrative data.

RESULTS

The age/sex-adjusted hospitalization rate decreased by 41% from 19.6 per 100,000 population in 1995 to 12.1 per 100,000 in 2004 (P < 0.0005). This decline was greater in females than males (46% vs. 29%). Whereas rates fell 46% in individuals under 50 years, a 50% increase was seen in those >/= 50 years. Hospitalization rates for intentional overdoses fell from 16.6 per 100,000 in 1995 to 8.6 per 100,000 in 2004 (2004 vs. 1995: rate ratio [RR] 0.49; P < 0.0005). Accidental overdoses decreased between 1995 and 2002, but increased to above baseline levels by 2004 (2004 vs. 1995: RR 1.24;P < 0.0005). Risk factors for AO included female sex (RR 2.19; P < 0.0005), Aboriginal status (RR 4.04; P < 0.0005), and receipt of social assistance (RR 5.15; P < 0.0005).

CONCLUSION

Hospitalization rates for AO, particularly intentional ingestions, have fallen in our Canadian health region between 1995 and 2004. Young patients, especially females, Aboriginals, and recipients of social assistance, are at highest risk.

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.

Acute liver failure: a review

Since publication of the first descriptions of acute liver failure (ALF) as a distinct clinical entity in the 1950's, the understanding of the pathophysiologic mechanisms involved and the management options have increased substantially. ALF still represents a major challenge for todays hepatologists, because it can rapidly lead to multiorgan failure and death that may be preventable with appropriate intervention. This article summarizes the basic patho-physiology underlying ALF, compares epidemiologic trends in the United States, the United Kingdom, and the Far East, and reviews prognostic markers and treatment options for ALF.

Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study

Severe acetaminophen hepatotoxicity frequently leads to acute liver failure (ALF). We determined the incidence, risk factors, and outcomes of acetaminophen-induced ALF at 22 tertiary care centers in the United States. Detailed prospective data were gathered on 662 consecutive patients over a 6-year period fulfilling standard criteria for ALF (coagulopathy and encephalopathy), from which 275 (42%) were determined to result from acetaminophen liver injury. The annual percentage of acetaminophen-related ALF rose during the study from 28% in 1998 to 51% in 2003. Median dose ingested was 24 g (equivalent to 48 extra-strength tablets). Unintentional overdoses accounted for 131 (48%) cases, intentional (suicide attempts) 122 (44%), and 22 (8%) were of unknown intent. In the unintentional group, 38% took two or more acetaminophen preparations simultaneously, and 63% used narcotic-containing compounds. Eighty-one percent of unintentional patients reported taking acetaminophen and/or other analgesics for acute or chronic pain syndromes. Overall, 178 subjects (65%) survived, 74 (27%) died without transplantation, and 23 subjects (8%) underwent liver transplantation; 71% were alive at 3 weeks. Transplant-free survival rate and rate of liver transplantation were similar between intentional and unintentional groups. In conclusion, acetaminophen hepatotoxicity far exceeds other causes of acute liver failure in the United States. Susceptible patients have concomitant depression, chronic pain, alcohol or narcotic use, and/or take several preparations simultaneously. Education of patients, physicians, and pharmacies to limit high-risk use settings is recommended.

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.

Change in profile of acute self drug-poisonings over a 10-year period

All acute, deliberate, drug-poisoning-related emergency department visits over two periods of one year, 1992-1993 (P1) and 2001-2002 (P2), were reviewed to investigate trends in substances used for acute self drug-poisonings over a 10-year period. For P1 and P2 respectively, 804 and 830 episodes of acute self drug-poisonings were compared. For the two studied periods, psycholeptic drugs predominated (78 and 77%); however, benzodiazepines declined (67 to 55%; P <0.01) and antidepressants increased (9.5 to 15%; P <0.01). Moreover, the type of antidepressant changed markedly with a decrease of the imipraminic antidepressants (48.4 to 10.7%) and an increase of selective serotonin reuptake inhibitors (31.2 to 74%). The proportion of benzodiazepine-related drugs increased with time (7.9 to 14.1%). The proportion of analgesics was 5.4% for P1 and 7.3% for P2; paracetamol, alone or associated to other compounds, remained the most incriminated. Nevertheless, opioids were more often mentioned during the later period (11.6 to 24.5%). The trend of the different pharmacological families used in acute self drug-poisonings is not fundamentally different over a 10-year period. However, there are some qualitative modifications, which are important for readjusting the emergency physician's toxicological knowledge and public health actions.

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 and the U.S. Acute Liver Failure Study Group: lowering the risks of hepatic failure

Acetaminophen overdose is the leading cause for calls to Poison Control Centers (>100,000/year) and accounts for more than 56,000 emergency room visits, 2,600 hospitalizations, and an estimated 458 deaths due to acute liver failure each year. Data from the U.S. Acute Liver Failure Study Group registry of more than 700 patients with acute liver failure across the United States implicates acetaminophen poisoning in nearly 50% of all acute liver failure in this country. Available in many single or combination products, acetaminophen produces more than 1 billion US dollars in annual sales for Tylenol products alone. It is heavily marketed for its safety compared to nonsteroidal analgesics. By enabling self-diagnosis and treatment of minor aches and pains, its benefits are said by the Food and Drug Administration to outweigh its risks. It still must be asked: Is this amount of injury and death really acceptable for an over-the-counter pain reliever?

Cardiovascular prophylaxis with aspirin: costs of supply and management of upper gastrointestinal and renal toxicity

AIMS

To determine the cost to the NHS of prescribed low-dose aspirin.

METHODS

This was a population based observational cohort study. Patients from Tayside Scotland (17 244 new users of dispensed aspirin each with 10 matched comparators) were included. A pragmatic analysis totalled costs from the start to end of the study and compared these with a matched cohort of aspirin nonusers to estimate excess costs. Fastidious analyses were done of subjects with no prior history of upper gastrointestinal (UGI) or renal disease where the cost that occurred during aspirin exposure, the 30 days following aspirin exposure and subsequent nonexposure was calculated adjusting for risk factors in each period.

RESULTS

Subjects took aspirin for only 1.18 of the 2.53 years follow-up (47% compliance). Aspirin use cost an additional 49.86 UK pounds per year (pragmatic analysis) made up of 1.96 UK pounds for aspirin tablets (4%), 5.49 UK pounds for dispensing costs (11%), 24.60 UK pounds for UGI complications (49%) and 17.81 UK pounds for renal complications (36%). The costs for managing complications were substantially lower in the fastidious analysis (2.66 UK pounds for UGI complications and 2.92 UK pounds for renal complications). Assuming that the antiplatelet trial meta-analysis is an accurate assessment of the benefits of aspirin, the costs of preventing one vascular event lay between 62 500 UK pounds (primary prevention, pragmatic analysis) and 867 UK pounds (secondary prevention, fastidious analysis). These costs may be underestimates due to the low compliance observed.

CONCLUSIONS

Compliance with aspirin was poor. Serious adverse events were uncommon but despite this aspirin cost the NHS between 6 and 25 times the cost of aspirin tablets due to dispensing costs and the cost of managing adverse effects.

Hepatocellular damage from non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for the management of rheumatological disorders, and as analgesics and antipyretics. Hepatotoxicity is an uncommon, but potentially lethal complication, which usually occurs within 12 weeks of starting therapy. It can occur with all NSAIDs, but appears to be more common with diclofenac and particularly sulindac. Female patients aged >50 years, with autoimmune disease, and those on other potentially hepatotoxic drugs, appear to be particularly susceptible. Liver function test abnormalities generally settle within 4-6 weeks of stopping the causative drug. However, some patients may develop acute liver failure and successful orthotopic liver transplantation may be undertaken in such patients. Recent in vitro animal studies have shown that the mechanism of diclofenac toxicity relates both to impairment of ATP synthesis by mitochondria, and to production of active metabolites, particularly n,5-dihydroxydiclofenac, which causes direct cytotoxicity. Mitochondrial permeability transition (MPT) has also been shown to be important in diclofenac-induced liver injury, resulting in generation of reactive oxygen species, mitochondrial swelling and oxidation of NADP and protein thiols. Physicians and hepatologists must be vigilant to the hepatotoxic potential of any NSAID, as increased awareness, surveillance and reporting of these events will lead to a better understanding of the risk factors and the pathophysiology of NSAID-related hepatotoxicity.