Why patients choose paracetamol for self poisoning and their knowledge of its dangers

Adolescent Acetaminophen and Ibuprofen Self-Poisoning, 2017-2022

BACKGROUND

Acetaminophen and ibuprofen are the most common agents involved in adolescent self-poisoning. With increasing suicidality observed during the COVID-19 pandemic, we sought to compare overdose trends, severity, and outcomes for both agents.

METHODS

We performed a retrospective analysis of the National Poison Data System for acetaminophen and ibuprofen single-substance exposures in teenagers 13-19 years of age from 2017-2022. Acetaminophen and ibuprofen overdoses (per 100,000 persons) were plotted by year. Medical outcomes, clinical effects, and therapies were compared to determine if there were differences in overdose severity between the 2 agents.

RESULTS

From 2017 to 2022, US poison centers recorded 50,902 single-substance acetaminophen exposures and 41,674 single-substance ibuprofen exposures in teenagers. Cases peaked in 2021 with 40.0 versus 29.1 cases (per 100,000 persons) for acetaminophen and ibuprofen, respectively. Acetaminophen self-poisoning was significantly more likely to result in death (odds ratio, 13.92; 95% confidence interval, 2.18-581.75; P < 0.001) or inpatient admission (odds ratio, 7.38; 95% confidence interval, 7.10-7.66; P < 0.001) compared with ibuprofen. Abdominal pain and vomiting were the most common clinical effects for both agents, and unsurprisingly, acetaminophen was more likely to cause transaminitis and liver dysfunction, whereas ibuprofen was more likely to cause central nervous system depression and metabolic acidosis. For the acetaminophen group, 19 teenagers underwent organ transplantation.

CONCLUSIONS

Given the increased hospitalization and treatment resources needed for acetaminophen overdoses compared with ibuprofen, it is time to implement acetaminophen packaging policy change to protect US adolescents.

Benzodiazepine exposures among women of reproductive age in the US, 2004-2018

Benzodiazepines, often used to treat anxiety, insomnia, and other conditions, are prescribed more frequently to women than men, and emergency department visits and overdose deaths involving benzodiazepines have increased significantly among women in recent years. This study describes characteristics and trends associated with benzodiazepine exposures among women of reproductive age (15-49 years old) that were reported to United States poison control centers from 2004 through 2018. The National Poison Data System recorded 258,370 first-ranked benzodiazepine exposures among women 15-49 years old during the study period. More than one-half (56.9%) of exposures involved a single-substance and one-third (34.0%) occurred among women 20-29 years old. The majority were categorized as "intentional, suspected suicide" (73.2%) or "intentional" (12.9%). Exposures frequently resulted in admission to a psychiatric facility (20.6%), critical care unit (18.1%), or non-critical care unit (9.3%). Twenty percent of cases resulted in a serious medical outcome, including 205 deaths. The substantial percentage of benzodiazepine exposures among women of reproductive age that were intentional and associated with suicide attempts or suicide deaths indicate that increased prevention efforts are needed to address this issue.

Paracetamol (acetaminophen): A familiar drug with an unexplained mechanism of action

Paracetamol (acetaminophen) is undoubtedly one of the most widely used drugs worldwide. As an over-the-counter medication, paracetamol is the standard and first-line treatment for fever and acute pain and is believed to remain so for many years to come. Despite being in clinical use for over a century, the precise mechanism of action of this familiar drug remains a mystery. The oldest and most prevailing theory on the mechanism of analgesic and antipyretic actions of paracetamol relates to the inhibition of CNS cyclooxygenase (COX) enzyme activities, with conflicting views on the COX isoenzyme/variant targeted by paracetamol and on the nature of the molecular interactions with these enzymes. Paracetamol has been proposed to selectively inhibit COX-2 by working as a reducing agent, despite the fact that in vitro screens demonstrate low potency on the inhibition of COX-1 and COX-2. In vivo data from COX-1 transgenic mice suggest that paracetamol works through inhibition of a COX-1 variant enzyme to mediate its analgesic and particularly thermoregulatory actions (antipyresis and hypothermia). A separate line of research provides evidence on potentiation of the descending inhibitory serotonergic pathway to mediate the analgesic action of paracetamol, but with no evidence of binding to serotonergic molecules. AM404 as a metabolite for paracetamol has been proposed to activate the endocannabinoid and the transient receptor potential vanilloid-1 (TRPV1) systems. The current review gives an update and in some cases challenges the different theories on the pharmacology of paracetamol and raises questions on some of the inadequately explored actions of paracetamol. List of Abbreviations: AM404, N-(4-hydroxyphenyl)-arachidonamide; CB1R, Cannabinoid receptor-1; Cmax, Maximum concentration; CNS, Central nervous system; COX, Cyclooxygenase; CSF, Cerebrospinal fluid; ED50, 50% of maximal effective dose; FAAH, Fatty acid amidohydrolase; IC50, 50% of the maximal inhibitor concentration; LPS, Lipopolysaccharide; NSAIDs, Non-steroidal anti-inflammatory drugs; PGE2, Prostaglandin E2; TRPV1, Transient receptor potential vanilloid-1.

Stocks of paracetamol products stored in urban New Zealand households: A cross-sectional study

BACKGROUND

Intentional self-harm is a common cause of hospital presentations in New Zealand and across the world, and self-poisoning is the most common method of self-harm. Paracetamol (acetaminophen) is frequently used in impulsive intentional overdoses, where ease of access may determine the choice of substance.

OBJECTIVE

This cross-sectional study aimed to determine how much paracetamol is present and therefore accessible in urban New Zealand households, and sources from where it has been obtained. This information is not currently available through any other means, but could inform New Zealand drug policy on access to paracetamol.

METHODS

Random cluster-sampling of households was performed in major urban areas of two cities in New Zealand, and the paracetamol-containing products, quantities, and sources were recorded. Population estimates of proportions of various types of paracetamol products were calculated.

RESULTS

A total of 174 of the 201 study households (86.6%) had at least one paracetamol product. Study households had mostly prescription products (78.2% of total mass), and a median of 24.0 g paracetamol present per household (inter-quartile range 6.0-54.0 g). Prescribed paracetamol was the main source of large stock. Based on the study findings, 53% of New Zealand households had 30 g or more paracetamol present, and 36% had 30 g or more of prescribed paracetamol, specifically.

CONCLUSIONS

This study highlights the importance of assessing whether and how much paracetamol is truly needed when prescribing and dispensing it. Convenience of appropriate access to therapeutic paracetamol needs to be balanced with preventing unnecessary accumulation of paracetamol stocks in households and inappropriate access to it. Prescribers and pharmacists need to be aware of the risks of such accumulation and assess the therapeutic needs of their patients. Public initiatives should be rolled out at regular intervals to encourage people to return unused or expired medicines to pharmacies for safe disposal.

Substances Involved in Suicidal Poisonings in the United States

OBJECTIVE

This study investigated specific substances most commonly involved in suicidal poisonings, causing severe clinical effects, and leading to intensive treatments.

METHOD

Suicidal poisoning cases for individuals ≥13 years old were obtained from the National Poison Data System for 2011-2015. The most common products involved in single and multiple-product poisonings were identified. Single product cases were used to calculate substances causing the largest numbers of serious clinical effects and leading to intensive treatments.

RESULTS

More than half of reported cases involved only a single product (54.4%), but this frequency was higher at the extremes of age (66.7% in adolescents 13-19 years old and 70.5% in individuals ≥90 years old) and among pregnant women (65.8%). The top three substances involved in single-product poisonings were over-the-counter (OTC) medications, while alcohol and prescription sedatives were most common in multiple-product poisonings. One OTC medication, diphenhydramine, was a frequent cause of several serious clinical effects and intensive treatments.

CONCLUSIONS

Single product suicidal poisonings were more frequent with extremes of age and in pregnancy. OTC products were more frequently used in single product attempts. Products causing serious clinical effects can be targeted for suicide prevention efforts as well as education of health care providers.

Relative toxicity of analgesics commonly used for intentional self-poisoning: A study of case fatality based on fatal and non-fatal overdoses

BACKGROUND

Analgesics are used most frequently in fatal and non-fatal medicinal self-poisonings. Knowledge about their relative toxicity in overdose is important for clinicians and regulatory agencies.

METHODS

Using data for 2005-2012 we investigated case fatality (number of suicides relative to number of non-fatal self-poisonings) of paracetamol, aspirin, codeine, dihydrocodeine, tramadol, paracetamol with codeine (co-codamol), paracetamol with dihydrocodeine (co-dydramol), ibuprofen and co-proxamol (paracetamol plus dextropropoxyphene; withdrawn in the UK in 2008 due to high toxicity). Data on suicides obtained from the Office for National Statistics and on non-fatal self-poisonings from the Multicentre Study of Self-harm in England. Case fatality was estimated for each drug, using paracetamol as the reference category.

RESULTS

Compared to paracetamol and based on single drug deaths the case fatality index of dihydrocodeine was considerably elevated (odds ratio (OR) 12.81, 95% Confidence Interval (CI) 10.19-16.12). Case fatality indices for tramadol (OR 4.05, 95% CI 3.38-4.85) and codeine (OR 2.21, 95% CI 1.81-2.70) were also significantly higher than for paracetamol. The results when multiple drug deaths were included produced similar results. The relative toxicity of co-proxamol far exceeded that of the other analgesics.

LIMITATIONS

Data on fatal self-poisonings were based on national data, whereas those for non-fatal poisonings were based on local data.

CONCLUSIONS

Dihydrocodeine and tramadol are particularly toxic in overdose and codeine is also relatively toxic. They should be prescribed with caution, particularly to individuals at risk of self-harm.

Lack of respiratory depression in paracetamol-codeine combination overdoses

AIMS

Codeine containing analgesics are commonly taken in overdose, but the frequency of respiratory depression is unknown. We investigated whether paracetamol-codeine combination overdoses caused respiratory depression more than paracetamol alone.

METHODS

We reviewed deliberate self-poisoning admissions with paracetamol (>2 g) and paracetamol-codeine combinations presenting to a tertiary toxicology unit (1987-2013). Demographic information, clinical effects, treatment (naloxone, length of stay [LOS], mechanical ventilation) were extracted from a prospective database. Primary outcome was naloxone requirement or ventilation for respiratory depression.

RESULTS

From 4488 presentations, 1376 admissions were included with paracetamol alone (929), paracetamol-codeine combinations (346) or paracetamol-codeine-doxylamine combinations (101) without co-ingestants. Median age was 23 years (12-89 years); 1002 (73%) were female. Median dose was 12 g (interquartile range [IQR]: 7.5-20 g). Median LOS was 16 h (IQR: 6.5-27 h) and 564 (41%) were given acetylcysteine. Significantly larger paracetamol doses were ingested and more acetylcysteine given in paracetamol alone versus paracetamol combination overdoses. Seven out of 1376 patients were intubated or received naloxone (0.5%; 95% CI: 0.2-1.1%), three intubated, three given naloxone and one both. Three out of 929 patients ingesting paracetamol alone (0.3%; 95% CI: 0.1-1%) required intubation or naloxone, compared to two out of 346 ingesting paracetamol-codeine combinations (0.6%; 95% CI: 0.1-2.3%; absolute difference, 0.26%; 95% CI: -0.7-1.2%; P = 0.62). Two out of 101 patients ingesting paracetamol-codeine-doxylamine combinations (2%; 95% CI: 0.3-8%) required intubation or naloxone. Four patients were intubated for reasons other than respiratory depression: hepatotoxicity (2), retrieval (1), no data (1). Two out of 929 (0.2%) paracetamol alone overdoses had a Glasgow coma score < 9 compared to three out of 346 (0.9%) in the paracetamol-codeine group.

CONCLUSIONS

Paracetamol-codeine combination overdoses are rarely associated with severe respiratory depression, with only two given naloxone and none intubated for respiratory depression.

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.

Poisons admissions in Edinburgh 1981-2001: agent trends and predictors of hospital readmissions

Self-poisoning is a major public health problem. This study describes patterns of admissions and readmissions from self-poisoning to the Royal Infirmary of Edinburgh from 1981 to 2001. A database on hospital discharges with a diagnosis (ICD-9/10) of poisoning between 1981 and 2001 was used. Annual admissions were described for seven main drug categories, and proportions of patients readmitted within 1-5 years from first admission, were computed for each category. Cox proportional hazards regression was used to evaluate prognostic factors for readmission risk over 1981-2001. For both sexes, admissions increased from the early to mid 1990s, and declined thereafter. The proportion readmitted varied with the drug taken at first admission, from 11.9% (95% CI: 10.8-13%) for non-opiate analgesics, to 17.6% (16.5-18.7%) for benzodiazepines. Deprivation was positively related to readmission risk after first admissions with paracetamol (P<0.001) and benzodiazepines (P<0.001). Timing of first admissions involving paracetamol (P<0.01), benzodiazepines (P<0.001), antidepressants (P<0.001), non-opiate analgesics (P<0.001), and opiates (P<0.05), was inversely associated with readmission risk. In patients admitted for drug overdose, readmission risk is influenced by type of drug taken at first admission. Information on drug type used in self-poisoning may assist in identifying patients at risk for future events, and in reducing hospital read-missions.

Redox-Dependent HMGB1 Isoforms as Pivotal Co-Ordinators of Drug-Induced Liver Injury: Mechanistic Biomarkers and Therapeutic Targets

SIGNIFICANCE

High-mobility group box 1 (HMGB1) is a critical protein in the coordination of the inflammatory response in drug-induced liver injury (DILI). HMGB1 is released from necrotic hepatocytes and activated immune cells. The extracellular function of HMGB1 is dependent upon redox modification of cysteine residues that control chemoattractant and cytokine-inducing properties. Existing biomarkers of DILI such as alanine aminotransferase (ALT) have limitations such as lack of sensitivity and tissue specificity that can adversely affect clinical intervention.

RECENT ADVANCES

HMGB1 isoforms have been shown to be more sensitive biomarkers than ALT for predicting DILI development and the requirement for liver transplant following acetaminophen (APAP) overdose. Hepatocyte-specific conditional knockout of HMGB1 has demonstrated the pivotal role of HMGB1 in DILI and liver disease. Tandem mass spectrometry (MS/MS) enables the characterization and quantification of different mechanism-dependent post-translationally modified isoforms of HMGB1.

CRITICAL ISSUES

HMGB1 shows great promise as a biomarker of DILI. However, current diagnostic assays are either too time-consuming to be clinically applicable (MS/MS) or are unable to distinguish between different redox and acetyl isoforms of HMGB1 (ELISA). Additionally, HMGB1 is not liver specific, so while it outperforms ALT (also not liver specific) as a biomarker for the prediction of DILI development, it should be used in a biomarker panel along with liver-specific markers such as miR-122.

FUTURE DIRECTIONS

A point-of-care test for HMGB1 and the development of redox and acetyl isoform-targeting antibodies will advance clinical utility. Work is ongoing to validate baseline levels of circulating HMGB1 in healthy volunteers.

How well are national guidelines relating to the general sales of aspirin and paracetamol, adhered to by retail stores: a mystery shopper study

OBJECTIVE

To determine whether non-pharmaceutical retail outlets are aboding to the current Medicines and Healthcare products Regulatory Agency (MHRA) national guidelines for over-the-counter (OTC) sales of aspirin and paracetamol.

METHODS

Stages 1 and 2 of the study deployed eight and four medical students, respectively, to undertake a mystery shopper style investigation. Stage 1: eight medical students attempted to buy ≥ 96 tablets/capsules aspirin or paracetamol in one transaction in 62 shops. Stage 2: four medical students attempted to purchase 32 paracetamol 500 mg along with a 'flu remedy preparation also containing paracetamol, in 54 shops.

RESULTS

Stage 1 data revealed that 58% and 57% retailers sold more than the MHRA guidelines recommended for paracetamol and aspirin, respectively. We observed that 23% and 28% retailers were willing to sell ≥ 96 tablets of paracetamol or aspirin with no questions asked. Stage 2 results showed that 57% retailers sold 32 × 500 mg paracetamol in conjunction with a paracetamol-containing 'flu preparation; while 98% shops sold 16 × paracetamol 500 mg along with a paracetamol-containing 'flu remedy, with no questions asked of the shopper or advice given.

DISCUSSION

MHRA national guidelines for OTC medicines sales appear to be poorly adhered to in non-pharmacy shops. Sales of aspirin and paracetamol OTC must be better regulated in the UK to ultimately reduce morbidity and mortality rates of deliberate and accidental overdoses.

Patterns of suicide in Kuwait: a retrospective descriptive study from 2003-2009

Background

Prior to the invasion of Kuwait by Iraq in 1990, suicides were almost unheard of in Kuwait. However, there has been a notable increase in the referrals of suicide cases to the forensic authorities since then. A review of suicide cases was performed to investigate the demographics of this phenomenon and the suicide modalities used and to uncover issues that can be addressed by the region's government.

Methods

The sole source of data was the general department of criminal evidence (GDCE), where cases are referred by police authorities and by hospital investigators from the entire country. All cases signed out by forensic investigators as “suicide” during the time period 2003–2009 were retrieved. A full review of the data from the case files was made. This included demographic data, scene examination, radiographic investigations, autopsies with histo-pathological examination findings and toxicological screening results in each case.

Results

A total of 347 cases were retrieved and studied. Hanging was found to be the most common suicide modality used by subjects (60 %). Non-citizens constituted 87 % of cases, and no significant difference was found between married and single subjects or between Muslims and non-Muslims. Regions that were more populated with an expatriate labour force had the highest suicide prevalence.

Conclusion

The government of Kuwait needs to investigate the dire conditions in which some expatriates live and to improve their situation. More control over the dispensing of certain medications needs to be enforced. Finally, strict firearm control could help reduce the suicide rates in Kuwait.

Characteristics of hospital-treated intentional drug overdose in Ireland and Northern Ireland

OBJECTIVES

This study compared the profile of intentional drug overdoses (IDOs) presenting to emergency departments in Ireland and in the Western Trust Area of Northern Ireland between 2007 and 2012. Specifically the study aimed to compare characteristics of the patients involved, to explore the factors associated with repeated IDO and to report the prescription rates of common drug types in the population.

METHODS

We utilised data from two comparable registries which monitor the incidence of hospital-treated self-harm, recording data from deliberate self-harm presentations involving an IDO to all hospital emergency departments for the period 1 January 2007 to 31 December 2012.

RESULTS

Between 2007 and 2012 the registries recorded 56 494 self-harm presentations involving an IDO. The study showed that hospital-treated IDO was almost twice as common in Northern Ireland than in Ireland (278 vs 156/100 000, respectively).

CONCLUSIONS

Despite the overall difference in the rates of IDO, the profile of such presentations was remarkably similar in both countries. Minor tranquillisers were the drugs most commonly involved in IDOs. National campaigns are required to address the availability and misuse of minor tranquillisers, both prescribed and non-prescribed.

Adolescents with suicidal behaviour: attendance at A&E and six month follow-up

Objectives: To review the clinical presentation, and Accident and Emergency Department clinical response to 14-20 year olds in suicidal crisis in inner city Dublin and to carry out a six month follow up of these young people.

Method: A retrospective review of the case notes of all 14-20 year olds who had attended the Mater Hospital A&E department between June 2001 and May 2002 with suicidal behaviour or ideation was carried out in order to establish socio-demographic information, type of suicidal or self-harming behaviour, intervention in the A&E department, and discharge plan. Active outreach attempts were made to trace, contact and interview these young peoples at least six months after the initial presentation. Quantitative measures of psychological functioning at follow-up included the General Health Questionnaire, The Beck Depression Inventory and The Scale for Suicidal Ideation. A qualitative interview covered their recall of the reasons for their deliberate self harm, their view of their current psychological functioning and personal relationships, reported repetition of deliberate self harm, and their views of what type of services would be useful for young people with suicidal ideation or behaviour.

Results: A total of 89 young people aged 14-20 years (male: female ratio = 2:3) presented to the Mater A&E department between June 2001 and May 2002 with deliberate self-harm, deliberate self-poisoning and/or suicidal ideation, and accounted for 108 presentations. They showed high levels of psychosocial disadvantage. Almost half had a history of previous contact with mental health services, while the same proportion had a history of previous deliberate self-harm. Drug overdose using paracetamol was the most common method used. Psychiatric assessment was documented in 66% of cases, and documented follow up recommendations were made in 60% of cases. Two thirds of the 89 young people who formed the study population were traced. Half of those contacted agreed to be interviewed and half refused. The majority of those interviewed described themselves as functioning better psychologically than at the time of the index attendance at the A&E department The quantitative measures supported this. One third of those interviewed reported repeated deliberate self-harm since their index attendance, for which most did not seek medical intervention. Many of the young people had clear views about the importance of talking to someone when in crisis. They described a service, which was informal, accessible on a 24-hour basis, and staffed by people with experience of mental health, alcohol and drug related disorders.

Conclusions: This is a particularly vulnerable group of patients from a socio-demographic and mental health perspective. Their attendance at the A&E department provides a unique opportunity for an in-depth psychosocial assessment, which should be recorded in a systematic way to assist clinical audit, facilitate strategic mental health planning and may confer some therapeutic clinical benefit to at risk young people. An easily accessible, active DSH team specifically tailored for young people in the A&E department could provide assessment and short-term follow-up. This is the approach recommended by young people in suicidal crisis, whose views need to be heard.

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

Objectives

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

Methods

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

Key findings

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

Conclusion

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

Study registration

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

Funding

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

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

OBJECTIVE

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

DESIGN

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

SETTING

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

PARTICIPANTS

Residents of England and Wales.

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

Evaluation of paracetamol distribution and stability in case of acute intoxication in rats

Effects of different storing conditions on paracetamol concentration in biological samples of acute intoxicated rats were investigated. The stability and distribution of paracetamol was observed in postmortem serum, liver, kidney and brain tissues. The serum samples were stored for 30 days and daily changes were evaluated for paracetamol. A significant difference ( p = 0.05) was noticed on the 30th experimental day. Paracetamol serum levels changed as much as 66.30% and 33.78% for 4°C and −20°C, respectively. The stability of paracetamol in liver stored at −20°C was also evaluated for 30 days. The paracetamol concentration levels taken from liver samples dramatically decreased from 30.36% on the 1st day to 94.97% on the 30th day. The paracetamol distribution in organs was as 2.68 , 1.11 and 0.68 mg/g in liver, kidney and brain samples, respectively. Meaningful difference in paracetamol in serum and liver samples was in observed in 30th day values ( p = 0.05).

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.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Factors associated with choice of psychotropic drugs used for intentional drug overdose

INTRODUCTION

Knowledge of the factors influencing the choice of drugs used for intentional drug overdose (IDO) may allow the reduction of IDO lethality.

OBJECTIVES

To assess with which frequency subjects with intentional overdose of psychotropic drugs ingest their own psychotropic drug treatment, and whether prescription of a drug may be a factor influencing the choice of drugs used for the IDO.

METHODS

Demographic characteristics, psychiatric history, and currently prescribed psychotropic drug treatment were collected for all the patients (n = 1,654) admitted to an emergency department (ED) for IDO with psychotropic drugs (anxiolytics, hypnotics, antidepressants, neuroleptics and mood stabilizers) over a period of 18 months. Drugs ingested for the IDO were compared in subjects who had ingested at least one psychotropic drug that was prescribed for them and subjects who had ingested psychotropic drugs not prescribed for them using multivariate logistic regression.

RESULTS

Two-thirds of the patients ingested during the IDO at least one of their own prescribed psychotropic drugs. Compared with the subjects who had ingested psychotropic drugs not prescribed for them, they were more likely to have a history of psychiatric hospitalization (OR 4.2; 95%CI 3.1-5.5), of being a psychiatric outpatient (OR 3.9; 95%CI 3.0-5.1), of parasuicide (OR 2.5; 95%CI 1.9-3.3) and a serious IDO (OR 2; 95%CI 1.4-2.9). Independently from age and psychiatric hospitalization history, they ingested during the IDO more often antidepressants (OR 4.4; 95%CI 3.0-6.4), antipsychotics (OR 2.9; 95%CI 1.7-4.8) and mood stabilizers (OR 4.1; 95%CI 1.6-10.7). No association was found with prescription for overdose of hypnotic (OR 1.1; 95%CI 0.8-1.5), anxiolytic (OR 1.2; 95%CI 0.9-1.7) or paracetamol (OR 1.0; 95%CI 0.5-2.1).

CONCLUSION

Prescription of the psychotropic drugs plays an important role in the choice of the drugs ingested for the IDO. It might make potentially "dangerous" drugs available for the patient. Physicians have always to balance the benefit of the treatment against the risk of drug overdose.

Etiology and outcome of patients presenting for poisoning to the emergency department in Taiwan: a prospective study

Poisoning is one of the most common reasons for visiting the emergency department in many countries, and the pattern varies from countries to countries and time to time. To compare the etiology and outcome of poisoning patients in different gender and age groups, we conducted a prospective study at the emergency departments of two medical centers in southern Taiwan between January 2001 and December 2002. All cases of poisoning, excluding patients diagnosed as cases of alcohol or food poisoning, were included, and relevant information was collected. There were 1512 cases of poisoning observed with a male to female ratio of 1:1.2 (684/828). Overall, drugs (49.9%) were the main agents involved, and a suicidal attempt (66.1%) was the predominant etiology. A total of 63 fatalities (4.2%) were observed and pesticides, especially paraquat, resulted in most fatalities. Patients aged 19–30 years constituted the most cases, and significant differences in exposure agents, causes, and fatality rates were found among different age and gender groups. The results are compatible with the trend reported by other Asian countries. This study also shows important differences existing in poisoning patients of different age and gender groups. Therefore, different poisoning-prevention strategies should be applied to different groups.

Acute liver failure: Summary of a workshop

Acute liver failure (ALF) is a rare but challenging clinical syndrome with multiple causes; a specific etiology cannot be identified in 15% of adult and 50% of pediatric cases. The course of ALF is variable and the mortality rate is high. Liver transplantation is the only therapy of proven benefit, but the rapidity of progression and the variable course of ALF limit its use. Currently in the United States, spontaneous survival occurs in approximately 45%, liver transplantation in 25%, and death without transplantation in 30% of adults with ALF. Higher rates of spontaneous recovery (56%) and transplantation (31%) with lower rates of death (13%) occur in children. The outcome of ALF varies by etiology, favorable prognoses being found with acetaminophen overdose, hepatitis A, and ischemia (approximately 60% spontaneous survival), and poor prognoses with drug-induced ALF, hepatitis B, and indeterminate cases (approximately 25% spontaneous survival). Excellent intensive care is critical in management of patients with ALF. Nonspecific therapies are of unproven benefit. Future possible therapeutic approaches include N-acetylcysteine, hypothermia, liver assist devices, and hepatocyte transplantation. Advances in stem cell research may allow provision of cells for bioartificial liver support. ALF presents many challenging opportunities in both clinical and basic research.

Increased use of medicinal drugs in self-harm in urban areas in Sri Lanka

Previous research has identified pesticides as the commonest substance used in poisoning in Sri Lanka. The aim of the study is to describe substances used in overdose and the characteristics of patients admitted with medicinal drug overdose in an urban tertiary care hospital in Colombo. A descriptive study of one hundred and ninety one patients admitted with intentional self poisoning to National Hospital of Sri Lanka, Colombo was carried out. Medicinal drugs were the commonest substance used in overdose (68%). Those who used medicinal drugs were mainly female (72.3%) and were aged between 15-24 years (76.2%). In Colombo medicinal drugs were the commonest substance used in intentional self poisoning in contrast to findings in rural areas.

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.

Self-poisoning by the older person: a review

Suicide is a major health issue worldwide and is among the top ten causes of death in many countries. Much research, media attention and public health initiatives are focused on reducing the suicide rate among adolescents and young adults. In many countries, however, it is the elderly population with the greatest number of suicides, the majority of which die by drug overdose. This is commonly explained by an increased suicidal intent among older people due to co-morbidity and social isolation. The physical vulnerability of elderly people to potential toxins however is also likely to play an important role. This review examines the epidemiology of elderly suicide, considers commonly implicated drugs, and discusses associated risk factors in this complex and multifactorial problem.

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.

Restricting Access to Methods of Suicide

Abstract. Restriction of access to means for suicidal behavior, especially dangerous methods, is a key element in most national suicide prevention strategies. In this paper the rationale for this is discussed, including the fact that suicidal impulses are often brief, that availability of a method may influence both the occurrence and outcome of a suicidal act, and that if a favored means becomes less available it does not always result in substitution by another method. Examples of evidence for the effectiveness of restricting availability of suicidal methods on subsequent suicidal behavior are presented, plus the supporting findings from studies of long-term survivors of serious suicide attempts in which only a minority have gone on to die in subsequent suicide attempts. Finally, factors likely to determine the effectiveness of modifying access to means for suicide are considered, together with the main elements that need to be addressed in evaluation.

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.

Choice of poison for intentional self-poisoning in rural Sri Lanka

BACKGROUND

Although intentional self-poisoning is a major public health problem in rural parts of the Asia-Pacific region, relatively little is known of its epidemiology. We aimed to determine why Sri Lankan self-poisoning patients choose particular poisons, and whether acts of self-harm with highly dangerous poisons were associated with more premeditation and effort.

METHODS

We interviewed 268 self-poisoning patients presenting to two district general hospitals in rural Sri Lanka.

RESULTS

Eighty-five percent of patients cited easy availability as the basis for their choice of poison. There was little premeditation: more than 50% ingested the poison less than 30 minutes after deciding to self-harm. Patients had little knowledge about treatment options or lethality of the poison chosen. We found no difference in reasons for choice of poison between people ingesting different poisons, despite marked differences in toxicity, and between people who died and those who survived.

CONCLUSIONS

Poisons were chosen on the basis of availability, often at short notice. There was no evidence that people using highly toxic poisons made a more serious or premeditated attempt. Restrictions on availability of highly toxic poisons in rural communities must be considered in strategies to reduce the number of intentional self-poisoning deaths in the Asia Pacific region.

Deliberate self-poisoning with acetaminophen: a comparison with other medications

BACKGROUND

Acetaminophen is the most common drug employed in deliberate self-poisoning (DSP) in many countries and can lead to acute liver failure. The purpose of the present study was to compare DSP with acetaminophen with DSP with other medications.

METHODS

From January 2001 to December 2002, all patients admitted after DSP to Soroka University Hospital in Beer-Sheva, Israel, were identified. Demographic data and medical history were obtained retrospectively.

RESULTS

There were 282 incidences of DSP in the study period. The mean age of 94 patients with an acetaminophen overdose was lower than that of patients who had attempted DSP with other medications (24.8 vs. 34.6 years, p<0.001). There was no gender or ethnic difference between the groups. Patients with DSP with acetaminophen were less likely to make recurrent attempts (23.4% vs. 39.9% p=0.006), less likely to have psychiatric disorders (32% vs. 59% p<0.001), and had a shorter hospital stay (1.7 vs. 2.1 days, p=0.05). The acetaminophen group had less of an impairment in level of consciousness (84% vs. 52.1% p<0.001) and had less need for ICU care (6.4% vs. 14.9%, p=0.04). Serum levels were checked in 68 (72.3%) of the patients in the acetaminophen group and they were found to be high in 6 (8.8%) of them (95% CI 2.1-15.5%).

CONCLUSION

Taking an overdose of acetaminophen is a common method of DSP, with patients tending to have a more benign presentation and shorter hospital stay than those who attempt DSP with other medications. Further research on the optimal care of these patients and multi-disciplinary approaches to DSP prevention are needed.

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.

Co-proxamol and suicide: preventing the continuing toll of overdose deaths

Restricting means for suicide is a key element in suicide prevention strategies of all countries where these have been introduced. Preventing deaths from analgesic overdoses is highlighted in the National Suicide Prevention Strategy for England. The problem of self-poisoning with the prescription-only drug co-proxamol (dextropropoxyphene plus paracetamol) has received attention in several countries. We have conducted a review of the international literature related to possible strategies to tackle this problem. In England and Wales in 1997-1999, 18% of drug-related suicides involved co-proxamol; these constituted 5% of all suicides. Death usually results from the toxic effects of dextropropoxyphene on respiration or cardiac function. Death from co-proxamol overdose may occur rapidly, the lethal dose can be relatively low, and the effects are potentiated by alcohol and other CNS depressants. The majority of co-proxamol overdose deaths occur before hospital treatment can be received. The risk can extend to others in the household of the person for whom the drug is prescribed. While there is limited evidence that educational strategies have been effective in reducing deaths from co-proxamol poisoning, initiatives in Scandinavia, Australia and the UK to restrict availability of co-proxamol have produced promising results. Given the paucity of evidence for superior therapeutic efficacy of co-proxamol over other less toxic analgesics, there are good reasons to question whether it should continue to be prescribed.

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.

Paracetamol poisoning--impact of pack size restrictions

BACKGROUND

Pack sizes of paracetamol available to the public were reduced by legislation in 1998.

OBJECTIVE

To study the effect of the legislation on paracetamol poisoning related admissions to an accident and emergency department and to a tertiary referral liver unit.

METHOD

Data were obtained from the University Hospitals, Birmingham, UK (UHB) Trust Information Service and the Queen Elizabeth Hospital liver unit records on (a) the number of patients admitted to hospital because of paracetamol overdose and (b) the number of patients admitted to the liver unit with parcetamol-induced hepatotoxicity.

RESULTS

Prior to legislation, an average of 360 people a year were admitted to UHB. However, following the change in legislation the number of admissions has fallen to an average of 250 people per year. This represents a reduction of 31%. Prior to legislation, an average of 76 people per year were admitted to the liver unit. Post-legislation this number has dropped to an average of 38 per year representing a reduction of 50%.

CONCLUSION

Legislation restricting paracetamol pack-size reduced the incidence and severity of poisoning.

Co-proxamol and suicide: a study of national mortality statistics and local non-fatal self poisonings

OBJECTIVES

To examine the incidence of suicides due to co-proxamol compared with tricyclic antidepressants and paracetamol, and to compare fatality rates for self poisonings with these drugs.

DESIGN

Analysis of routinely collected national and local data on suicides and self poisonings.

SETTING

Records of suicides in England and Wales 1997-9; non-fatal self poisonings in Oxford District 1997-9.

DATA SOURCES

Office for National Statistics and Oxford monitoring system for attempted suicide.

MAIN OUTCOME MEASURES

Incidence of suicides with co-proxamol or tricyclic antidepressants or paracetamol. Ratios of fatal to non-fatal self poisonings.

RESULTS

Co-proxamol alone accounted for 5% of all suicides. Of 4162 drug related suicides, 18% (766) involved co-proxamol alone, 22% (927) tricyclic antidepressants alone, and 9% (368) paracetamol alone. A higher proportion of suicides in the 10-24 year age group were due to co-proxamol than in the other age groups. The odds of dying after overdose with co-proxamol was 2.3 times (95% confidence interval 2.1 to 2.5) that for tricyclic antidepressants and 28.1 times (24.9 to 32.9) that for paracetamol.

CONCLUSIONS

Self poisoning with co-proxamol is particularly dangerous and contributes substantially to drug related suicides. Restricting availability of co-proxamol could have an important role in suicide prevention.

Valproate overdose: a comparative cohort study of self poisonings

AIMS

Based on individual case reports of massive overdoses, valproate is often regarded as having significant toxicity. This study aimed to describe the epidemiology of valproate poisoning and the spectrum of its clinical effects.

METHODS

Consecutive valproate poisonings were identified and compared with other anticonvulsant overdoses and all other poisonings, from a prospective database of poisoning admissions presenting to a regional toxicology service. National prescription data for the same period were obtained.

RESULTS

There were 79 patients with valproate poisoning from January 1991 to November 2001, 15 cases with valproate alone. Of the 15 cases, drowsiness occurred in two patients (both taking> 200 mg kg-1), vomiting occurred in four and tachycardia in five. In patients co-ingesting other medications, moderate to severe effects were consistent with the co-ingestants. There was one death not directly related to valproate. One patient had metabolic acidosis and thrombocytopaenia consistent with severe valproate toxicity. Comparison of valproate, carbamazepine, phenytoin and control groups showed that length of stay for both phenytoin and carbamazepine was significantly longer than for valproate (P < 0.0001), and there was a significantly increased risk of intensive care unit admission for carbamazepine vs valproate (OR 2.73; 95% CI 1.22, 6.28; P = 0.015). Although valproate prescriptions increased over the 10 years, there was relatively greater increase in the incidence of valproate poisoning. The odds of a valproate overdose in 1992 compared with carbamazepine were 0.29 (95% CI 0.07, 1.28; P = 0.141), but in 2001 were 2.73 (95% CI 1.38, 5.39; P = 0.004).

CONCLUSIONS

Valproate causes mild toxicity in the majority of cases. Massive overdoses of greater than 400 mg kg-1 can cause severe toxicity, but these are uncommon. The older anticonvulsants phenytoin and carbamazepine remain a greater problem than valproate in overdose.

United Kingdom legislation on pack sizes of analgesics: background, rationale, and effects on suicide and deliberate self-harm

Following increasing concern in the UK about the mortality and morbidity associated with self-poisoning with analgesics, especially paracetamol (Tylenol, acetaminophen), legislation was introduced in 1998 to modify packs sold over-the-counter. The most important change was a reduction in the maximum size of packs. In this paper the background to the legislation, the rationale behind it, and its early impact are reviewed. The changes have had significant positive initial benefits on the mortality and morbidity associated with self-poisoning with analgesics.

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

BACKGROUND

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Trends in suicide from drug overdose in the elderly in England and Wales, 1993-1999

BACKGROUND

Drug overdose is a common method of suicide in the elderly. Hence, an understanding of current trends in epidemiology of these deaths is important when considering measures to decrease suicide rates.

METHODS

Analysis of the Office for National Statistics (ONS) database of deaths from overdose and poisoning. Suicide and undetermined deaths from drug overdose between 1993-1999 in the over 65 year olds were studied. Socio-demographic data from the four drug groups most commonly used in overdose were extracted, and age and sex specific mortality rates calculated. Enumeration districts were ranked into five quintiles based on their Carstairs scores, and death rates in each quintile for men and women calculated.

RESULTS

There were 1864 deaths from drug overdose during the study period. Suicide and undetermined death rates from drug overdose remained stable between 1993-1999. Drugs most commonly used in overdose were (in order) paracetamol (and related compounds), benzodiazepines, antidepressants, and opiates. Women comprised 62% of deaths. Death rates increased with age, with highest rates in men over 75 (37.7 deaths per million). Benzodiazepines showed the most marked increase with age. Co-proxamol comprised 32% of deaths from paracetamol compounds, and 95% of antidepressant deaths were due to tricyclic antidepressants. There was no association in women between Carstairs area deprivation and suicide rates; in men rates were highest in the most deprived areas.

CONCLUSION

Suicides in the over 65 year olds may be decreased by changes in prescription practice. Paracetamol, co-proxamol, tricyclic antidepressants and benzodiazepines should be prescribed with caution to the elderly with depression or at high risk of depression.