Changes in paracetamol, antidepressants and opioid poisoning in Scotland during the 1990s

DISTRIBUTION OF DELIBERATE SELF-POISONING BY SOCIO-DEMOGRAPHIC FACTORS, PRECIPITATING EVENTS, TYPE OF SUBSTANCE AND MORTALITY IN POPULATION OF HAZARA DIVISION, PAKISTAN

Background: Deliberate self-poisoning is important cause of deaths in younger population. The objectives of this study were to determine the distribution of deliberate self-poisoning by 12 socio-demographic factors, precipitating events, type of substance and mortality in population of Hazara Division, Pakistan. Materials & Methods: This cross-sectional study was conducted in the Department of Medicine, Ayub Medical College, Abbottabad, Pakistan from October 9, 2017 to December 28, 2018. 102 deliberate self-poisoning patients were selected consecutively from population at risk. Variables were 12 socio-demographic factors, precipitating events, type of substance and mortality. All variables being categorical were described by count and percentage for sample and by confidence intervals for proportion for population at 95% confidence level. RESULTS: Deliberate self-poisoning cases (n=102) were higher in women 80.39%, in age group 18-25 years 54.90%, similar in urban 49.02% and rural 50.98%, higher in non-Pathan 74.51%, in married 57.84%, in joint family 79.41%, in up to matric education 85.29% and in housewives 52.94%, 4.90% with previous history of self-harm, 1.96% with family history of self-harm and higher in lower socioeconomic group 81.37%. The most common precipitating event was interpersonal difficulties with spouse, family members or friends 56.86%, while the most common type of substance was organophosphate 62.75%. Mortality was 3.92%. Conclusion: Deliberate self-poisoning was more prevalent in women, younger age group, married, joint family, educated up to matric, housewives and lower socioeconomic status. Family conflict was most common precipitating factor. Organophosphate was most common type of substance and mortality was high 3.92%.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

LIMITATIONS

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

CONCLUSION

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

Risk markers for fatal and non-fatal prescription drug overdose: a meta-analysis

BACKGROUND

Drug overdose is a public health crisis in the United States, due in part to the unintended consequences of increases in prescribing of opioid analgesics. Many clinicians evaluate risk markers for opioid-related harms when prescribing opioids for chronic pain; however, more data on predictive risk markers are needed. Risk markers are attributes (modifiable and non-modifiable) that are associated with increased probability of an outcome. This review aims to identify risk markers associated with fatal and non-fatal prescription drug overdose by synthesizing findings in the existing peer-reviewed and grey literature. Eligible cohort, case-control, cross-sectional, and case-cohort studies were reviewed and data were extracted for qualitative and quantitative synthesis.

FINDINGS

Summary odds ratios (SOR) were estimated from 29 studies for six risk markers: sex, age, race, psychiatric disorders, substance use disorder (SUD), and urban/rural residence. Heterogeneity was assessed and effect estimates were stratified by study characteristics. Of the six risk markers identified, SUD had the strongest association with drug overdose death (SOR = 5.24, 95% confidence interval (CI) = 3.53 - 7.76), followed by psychiatric disorders (SOR = 3.94, 95% CI = 3.09 - 5.01), white race (SOR = 2.28, 95% CI = 1.93 - 2.70), the 35-44 year age group relative to the 25-34 year reference group (SOR = 1.52, 95% CI = 1.31 - 1.76), and male sex (SOR = 1.33, 95% CI = 1.17 - 1.51).

CONCLUSIONS

This review highlights fatal and non-fatal prescription drug risk markers most frequently assessed in peer-reviewed and grey literature. There is a need to better understand modifiable risk markers and underlying reasons for drug misuse in order to inform interventions that may prevent future drug overdoses.

A retrospective analysis of antidepressant poisonings in the emergency department: 11-year experience

Between 1993 and 2004, patients with antidepressant poisoning admitted to an emergency department (ED) were analysed retrospectively with regard to demographics, clinical findings and treatment attempts. Age, gender, suicide attempts, classification of antidepressants, Glasgow Coma Scale (GCS) score, ECG findings, need for endotracheal intubation, follow-up period and Antidepressant Overdose Risk Assessment (ADORA) criteria were analysed by SPSS software. A total of 356 antidepressant poisoning cases were evaluated. Tricyclic antidepressants (TCA), especially opipramol and amitriptyline, were the most common agents (58.4%). The most frequent ECG finding was sinus tachycardia (40.7%, n=145). Endotracheal intubation was required in 9.6% of cases. Patients with TCA ingestion had a longer observation time in the ED, abnormal ECG findings, abnormal physical examination findings and more ADORA criteria, than patients who ingested selective serotonin re-uptake inhibitors (SSRI) (P=0.008, P=0.008, P<0.001, P<0.001). It was found that the patients who ingested TCA (P=0.001), poisoned with amitriptyline (P=0.001), patients with GCS scores of 8 and less (P=0.001), patients with two or more ADORA criteria (P=0.001), with seizures (P=0.001), with abnormal ECG (P=0.012), and patients with a history of two or more suicide attempts were intubated more frequently. Suicide attempts, classification of the antidepressant, ECG findings, seizure, GCS score and number of detected ADORA criteria affect the need for intubation in patients with antidepressant poisoning.

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.

Epidemiology of poisonings, fractures and burns among 0-24 year olds in England using linked health and mortality data

BACKGROUND

Understanding patterns of injury in England is challenging due to a lack of national injury surveillance data. Through recent linkage of a large primary care research database to hospitalization and mortality data, we describe the epidemiology of poisonings, fractures and burns over a 14-year period.

METHODS

We used linked English primary care, hospitalisation and mortality data from the Clinical Practice Research Datalink, Hospital Episode Statistics and Office for National Statistics between 1998 and 2011 to establish a cohort of 2,106,420 0-24 year olds. Incidence rates, per 10 000 person-years (PY) were estimated by age, sex, calendar year and socioeconomic status. Using Poisson regression we estimated incidence rate ratios, adjusting for age and sex.

RESULTS

Age patterns of injury incidence varied by injury type, with peaks at age 2 (74.3/10 000 PY) and 18 (74.7/10 000 PY) for poisonings, age 13 for fractures (305.1/10 000 PY) and age 1 for burns (116.8/10 000 PY). Over time, fracture incidence increased, whereas poisoning incidence increased only among 15-24 year olds and burns incidence reduced. Poisoning and burns incidence increased with deprivation, with the steepest socioeconomic gradient for poisonings among 20-24 year olds (IRR 2.63, 95% confidence interval 2.24-3.09).

CONCLUSION

Differing patterns according to age and injury type reflect differences in underlying injury mechanisms, highlighting the importance of developing tailored preventative interventions across the life course. Inequalities in injury occurrences support the targeting of preventative interventions to children and young people living in the most deprived areas.

Emergency department visits for acetaminophen overdose: a Canadian population-based epidemiologic study (1997–2002)

Objective:

We describe the epidemiology of emergency department (ED) visits for acetaminophen overdose in a large Canadian health region, with a focus on sociodemographic risk factors and temporal trends.

Methods:

Patients presenting to an ED in the Calgary Health Region (population ~ 1.1 million) for acetaminophen overdose between 1997 and 2002 were identified using regional administrative data.

Results:

A total of 2699 patients made 3015 ED visits for acetaminophen overdose between 1997 and 2002, corresponding to an age- and sex-adjusted incidence of 45.7 per 100 000 population. Alcohol-related disorders were common (19%) and overdose rates were higher in females, younger patients, Aboriginals and social assistance recipients. The incidence decreased from 52.6 per 100 000 in 1997 to 35.1 per 100 000 in 2002 (34% relative reduction;p&lt; 0.0005). When classified according to suicidal intent, the rates of intentional and unintentional overdose (69% and 25% of all overdoses, respectively) showed similar temporal trends. A marked seasonality was observed, with a peak in spring and early summer.

Conclusions:

ED visit rates for acetaminophen overdose fell between 1997 and 2002. High-risk groups, including young females and marginalized populations, may benefit from preventive and educational initiatives.

Paracetamol overdose in Victoria remains a significant health-care burden

BACKGROUND AND AIM

Paracetamol is the most frequently used analgesic in Australia and can be purchased without a prescription. We aimed to investigate the epidemiology and outcome of paracetamol overdoses occurring in Victoria, Australia.

METHODS

The Victorian admitted episode dataset was examined for all patients who had a diagnosis of paracetamol poisoning (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification [ICD-10-AM]: T39.1) or paracetamol adverse effect in therapeutic use (Y45.5) from July 1, 2000 to June 30, 2007. Data extracted included all ICD-10 codes related to their admissions, gender, age range, date of admission, and cause of death (if applicable).

RESULTS

Over 7 years, there was a total of 14,662 hospital admissions for paracetamol overdose with a mean of 2095 cases per year. Accidental overdoses comprised 15% (n = 2149) of cases. The overdose rate fell from 46 cases per 100,000 in 2001 to 39 cases per 100,000 in 2006 (P < 0.001). Most overdoses occurred in women (71%), and patients between 15 and 50 years old comprised 78% of all cases. Complications and mortality were relatively uncommon, with only 26 deaths directly attributable to paracetamol overdose over the 7 years. No child under 15 years old died from their overdose.

CONCLUSION

Admission to Victorian hospitals with paracetamol overdose presents an enormous and in many cases preventable health-care burden. Fortunately, there has been a gradual fall in admissions, and most cases appear relatively benign. Further reductions in overdose could be achieved with increased awareness by physicians and the general public regarding the potential for accidental overdose, and increasing funding for mental health initiatives.

Scottish and Newcastle antiemetic pre-treatment for paracetamol poisoning study (SNAP)

Background

Paracetamol (acetaminophen) poisoning remains the commonest cause of acute liver injury in Europe and North America. The intravenous (IV) N-acetylcysteine (NAC) regimen introduced in the 1970s has continued effectively unchanged. This involves 3 different infusion regimens (dose and time) lasting over 20 hours. The same weight-related dose of NAC is used irrespective of paracetamol dose. Complications include frequent nausea and vomiting, anaphylactoid reactions and dosing errors. We designed a randomised controlled study investigating the efficacy of antiemetic pre-treatment (ondansetron) using standard NAC and a modified, shorter, regimen.

Methods/Design

We designed a double-blind trial using a 2 × 2 factorial design involving four parallel groups. Pre-treatment with ondansetron 4 mg IV was compared against placebo on nausea and vomiting following the standard (20.25 h) regimen, or a novel 12 h NAC regimen in paracetamol poisoning. Each delivered 300 mg/kg bodyweight NAC. Randomisation was stratified on: paracetamol dose, perceived risk factors, and time to presentation. The primary outcome was the incidence of nausea and vomiting following NAC. In addition the frequency of anaphylactoid reactions and end of treatment liver function documented. Where clinically necessary further doses of NAC were administered as per standard UK protocols at the end of the first antidote course.

Discussion

This study is primarily designed to test the efficacy of prophylactic anti-emetic therapy with ondansetron, but is the first attempt to formally examine new methods of administering IV NAC in paracetamol overdose. We anticipate, from volunteer studies, that nausea and vomiting will be less frequent with the new NAC regimen. In addition as anaphylactoid response appears related to plasma concentrations of both NAC and paracetamol anaphylactoid reactions should be less likely. This study is not powered to assess the relative efficacy of the two NAC regimens, however it will give useful information to power future studies. As the first formal randomised clinical trial in this patient group in over 30 years this study will also provide information to support further studies in patients in paracetamol overdose, particularly, when linked with modern novel biomarkers of liver damage, patients at different toxicity risk.

Trial registration

EudraCT number 2009-017800-10, ClinicalTrials.gov IdentifierNCT01050270

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The epidemiology of childhood poisonings in Cyprus

Information on childhood poisonings in Cyprus is limited. Our objective was to examine the epidemiology of poisonings among children in Cyprus. All children up to 15 years of age admitted for poisoning to the Archbishop Makarios Hospital in Nicosia, Cyprus between 2005 and 2008 were included in our study. All hospital poisoning records were reviewed. A total of 257 children were admitted for poisoning. The mean age of children was 3.1 years, of which 83.7% were below the age of 5 years old, while 53% were boys. The poisoning hospitalizations accounted for about 3% of all admissions to the pediatric department during the study period (4 years). The annual cumulative incidence of childhood poisoning hospitalizations was 116 per 100,000 children. Medications accounted for 46.1% of all poisonings, the most frequent cause being paracetamol (9.8%), cardiovascular medications (5.3%), antitussive medications (4.5%), and other painkillers (4.1%). Another 37.6% of hospitalizations involved household products such as household cleaning products (11.8%), petroleum products (11.0%), and rodenticides (5.7%). Among children who ingested petroleum distillates, 55.6% developed clinical symptomatology. The vast majority of cases were accidental (93.8%). Suicidal cases involved children 8-14 years old, mainly girls, and the most frequent poisoning ingested was paracetamol (46.7%). Poisoning hospitalizations represent an important cause of morbidity among children in Cyprus. Preventive strategies should include the education of caregivers on the handling of medications and household products as well as legislation requiring child-resistant packaging for all medications and household products including petroleum distillates.

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.

Over the counter medicines: proceed with caution

Robin Ferner and Keith Beard caution that the risks of increasing people’s access to over the counter medicines may outweigh the benefits

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

Background

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

Methods

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

Results

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

Conclusion

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

Acute child poisonings in Oslo: a 2-year prospective study

AIM

To study the current epidemiology, clinical course and outcome of poisonings among children in Oslo and compare findings to a similar study from 1980.

METHODS

Observational study with prospective inclusion of all children (<15 years of age) with a main diagnosis of acute poisoning treated in hospital or outpatient clinic in Oslo for 2 years.

RESULTS

One hundred seventy-five episodes of acute poisoning were included at the outpatient clinic only (n = 65), the paediatric department only (n = 82) or both (n = 28 referrals). Annual incidence was 97 per 100 000, significantly lower than in 1980 (230 per 100 000). Highest incidence was in 1-year-old males (576 per 100 000). In children <8 years of age, the most common toxic agents were pharmaceuticals (39%) and household products (32%); children > or = 8 years ingested mainly ethanol (46%) or pharmaceuticals (36%). Five percent of all children were comatose, and complications were seen in 13%. All children survived without sequelae. Half of the admissions needed treatment; most commonly used treatments were activated charcoal (33%), gastric lavage (9%) and emetics (9%).

CONCLUSION

The incidence of child poisonings in Oslo has significantly reduced since 1980. Only half of the poisonings needed treatment, most of the poisonings were mild and the clinical outcome was good.

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.

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.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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

OBJECTIVE

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

DESIGN AND SETTING

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

PARTICIPANTS

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

OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

Naloxone in opioid poisoning: walking the tightrope

Acute opioid intoxication and overdose are common causes of presentation to emergency departments. Although naloxone, a pure opioid antagonist, has been available for many years, there is still confusion over the appropriate dose and route of administration. This article looks at the reasons for this uncertainty and undertakes a literature review from which a treatment algorithm is presented.

Are selective serotonin re-uptake inhibitors associated with an increased risk of self-harm by antidepressant overdose?

OBJECTIVE

To investigate likelihood of self-harm by overdose with antidepressant drugs of different types by examining hospital admission data and poisons inquiries and relating them to prescribing.

DESIGN

Retrospective analysis of prospectively collected data on overdose admissions, poisons inquiries and prescribing of antidepressants in Edinburgh and Scotland.

SETTING

Poisons treatment unit of the Royal Infirmary of Edinburgh and its surrounding catchment for overdose cases and Scotland for poisons inquiries.

PARTICIPANTS

All patients admitted to the Royal Infirmary of Edinburgh between 1 January 2000 and 31 December 2002 with an overdose involving an antidepressant.

MAIN OUTCOME MEASURES

Overdose admissions (patients) in relation to prescribing in Edinburgh and poisons inquiries in relation to prescription rates in Scotland.

RESULTS

There were 1656 admissions involving 1343 patients. The likelihood of admission for an individual patient in relation to volume of prescribing (likelihood ratio: 95%CI) in the catchment was somewhat smaller for amitriptyline (0.83:0.74-0.92) and sertraline (0.79:0.63-0.99), and somewhat greater for mirtazapine (1.99:1.57-2.51), trazadone (1.30:1.09-1.54) and venlafaxine (0.97:1.81-1.16) [corrected] For poisons inquiries in Scotland, the excess for venlafaxine and mirtazapine was confirmed and likelihood of an inquiry lowest for selective serotonin re-uptake inhibitors (SSRIs).

CONCLUSIONS

There was no evidence of an excess likelihood of presentation with overdose with SSRIs, and the likelihood was reduced with sertraline. There was a small excess of both admissions and poisons inquiries for mirtazapine and venlafaxine. This is a concern in view of the increased toxicity of venlafaxine in overdose in comparison with SSRIs.

Hospital discharges and 30-day case fatality for drug poisoning: a Danish population-based study from 1979 to 2002 with special emphasis on paracetamol

OBJECTIVE

To examine the number of hospital discharges and 30-day case fatalities due to drug poisoning based on data from a Danish County Hospital Discharge Registry from 1979 to 2002.

METHODS

All patients with a hospital discharge diagnosis of drug poisoning were identified and separated into groups taking: (1) opioid analgesics; (2) non-opioid analgesics; (3) anxiolytics; (4) antidepressants; (5) antipsychotics; or (6) non-specified. Paracetamol and salicylate were analysed separately. From 1994 to 2001, the total amount of drugs sold in the county was identified from a national drug database.

RESULTS

A total of 13,432 patients with a median age 41.5 years at discharge of whom 59% were females accounted for 20,249 discharges for drug poisoning. The overall number of discharges remained essentially stable around 170 discharges per 100,000 inhabitants per year. From the mid-1990's, paracetamol became the most frequently used drug in poisoning with the largest increase in female teenagers. Thirty-day case fatality in poisoning with opioids was 3.6% compared with around 1% in other drug categories. For most drug categories, a sale of around 80,000 defined daily doses was associated with one hospital discharge due to drug poisoning.

CONCLUSION

The overall number of hospital discharges remained stable and seems primarily related to amount of drugs available. With almost 10 years delay, the easier access to paracetamol was followed by an increase in hospitalisation due to poisoning with paracetamol. However, although the majority of hospitalisations were found in the younger age group, the highest mortality was seen among the elderly.

The epidemiology of self-poisoning in the UK

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