Paracetamol intoxications: a retrospective population-based study in Iceland

Acetaminophen overdose: analysis of 2018 US nationwide emergency database

INTRODUCTION

Recognized risk factors for acetaminophen overdose include alcohol, opioids, and mood disorders. The aim of this study is to assess additional risk factors for acetaminophen overdose evaluated in the emergency department (ED).

METHODS

A retrospective study was performed using the 2018 US Nationwide Emergency Department Sample (NEDS). All adult ED visits for acetaminophen overdose were included in the study group and those without it were taken as control. STATA, 16.1 was used to perform multivariable logistic regression analysis and adjusted odds ratios (ORadj) were reported.

RESULTS

We identified 27,792 ED visits for acetaminophen overdose. Relative to non-acetaminophen ED visits, this group was younger (median age 32 vs 47 years; p < 0.0001), more often female (66.1% vs 57.0%; p < 0.0001), had higher ED charges ($3,506 vs $2,714; p < 0.0001), higher proportion of alcohol-related disorders (15.8% vs 3.5%; p < 0.0001), anxiety disorders (30.2% vs 8.3%; p < 0.0001), cannabis use (8.7% vs 1.4%; p < 0.0001), hematology/oncology diagnoses (13.3% vs 10.9%; p < 0.0001), mood disorders (52.4% vs 7.9%; p < 0.0001), opioid-related disorders (4.1% vs 1.0%; p < 0.0001), and suicide attempt/ideation (12.2% vs 1.1%; p < 0.0001). Multivariable analysis showed alcohol-related disorders (ORadj 2.67), anxiety disorders (ORadj 1.24), cannabis (ORadj 1.63), females (ORadj 1.45), Income Q3 (ORadj 1.09), hematology/oncology diagnoses (ORadj 1.40), mood disorders (ORadj 10.07), opioid-related disorders (ORadj 1.20), and suicide attempt/ideation (ORadj 1.68) were associated with acetaminophen overdose.

CONCLUSION

In addition to previously recognized risks, our study demonstrated that cannabis use and hematologic/oncologic comorbidities were more common among acetaminophen-overdose ED visits. These new findings are concerning because of rapid legalization of cannabis and the increasing incidence of cancer worldwide. Additional investigation into these risks should be a priority for clinicians, policymakers, and researchers.

Estimates of Paracetamol Poisoning in Brazil: Analysis of Official Records From 1990s to 2020

Objective: To assess the cases of paracetamol poisoning in Brazil.

METHODS

Analysis of official records of deaths between 1996 and 2019 from the Brazil Mortality Information System (SIM), admissions between 2008 and 2020 from the Hospital Information System (SIH), and cases of poisoning between 2017 and 2020 in health services, reported to the Brazilian Notifiable Diseases Surveillance System (SINAN). In SIM and SIH, records with ICD-10 were included: F55, T39, X40, X60, and Y10. In SINAN, commercial products containing paracetamol were identified. Records were stratified by age, sex, and intentionality. Mean and standard error were calculated for each stratum based on the annual data, by federation unit. Poisoning reports by 1,000,000 inhabitants were calculated from each state and compared to the national average.

RESULTS

In total, 492 deaths, 5,666 hospital admissions, and 17,031 cases of paracetamol poisoning were recorded in the period. Deaths occurred mostly among adults (71.3% ± 3.0) and in suicide attempts (37.3% ± 2.7). Hospital admissions were more frequent in adults (69.7% ± 1.4), women (57.1% ± 2.5), and unintentional poisoning (80.2% ± 4.2). Poisoning reports was more also frequent among adults (71.4% ± 1.2), women (74.2% ± 0.6), and due to accidents (79.6% ± 1.8). The South and Southeast regions of the country presented the highest frequencies in all outcomes, above the national average.

CONCLUSION

Paracetamol exposure is a concern for preventable poisonings, hospital admissions and deaths. More accurate data about paracetamol poisoning are required to support surveillance actions and the development of mechanisms to reduce poisoning, particularly related to adults, women and suicide attempts.

Plasma Concentration of Taurine Changes following Acetaminophen Overdose in Male Patients during Hospitalization

Changes in plasma concentration of taurine during hospitalization of acetaminophen poisoned patients have not been studied. Hepatotoxicity is a common consequence of acetaminophen overdose that may lead to acute liver failure. Numerous biomarkers for drug-induced liver injury have been explored. All biomarkers are usually obtainable 48 h following acetaminophen overdose. We have already introduced taurine as a non-specific early biomarker of acetaminophen overdose. This study aimed to follow up changes in plasma concentration of taurine during the first three days of acetaminophen overdose. Sixty-four male patients suffering from acetaminophen overdose were selected for the study. Four blood samples were taken from the patients every 12 h. Sixty blood samples were also taken from sixty healthy humans. The plasma concentration of taurine in both groups was analyzed an already developed HPLC method. Analysis of regression showed a significant correlation between means of plasma concentrations of taurine and acetaminophen, aspartate aminotransferase, Alanine aminotransferase, glutathione peroxidase, and prothrombin time during hospitalization. The high plasma concentration of taurine, 6 h or more after acetaminophen overdose, could be a useful early indicator of liver damage.

Paracetamol poisoning: a population-based study from Iceland

OBJECTIVE

To examine the incidence and severity of paracetamol poisoning in a population-based cohort in Iceland. A previous study showed a decrease in the incidence during a financial crisis in Iceland, by approximately half (16/100,000 annually). The aims of the study were to assess the incidence and nature of paracetamol poisoning after economic recovery in Iceland and to compare intentional and accidental poisoning.

METHODS

Paracetamol serum concentrations were used to identify patients in this retrospective study from 2010-2017. A search was undertaken in laboratory databases for patients with serum paracetamol concentrations, which were grouped by <66 µmol/L (below detection limit) and ≥66 µmol/L. Medical records were reviewed and relevant laboratory and clinical information obtained to determine whether paracetamol poisoning had occurred.

RESULTS

Altogether 542 cases of paracetamol poisoning were identified. The mean annual incidence was 27/100,000 (range 22-33). Intentional poisoning was observed in 437/542 (81%) cases, most frequently among females 16-25 years of age. Males ≥65 years were more likely to overdose by accident, which was associated with worse outcomes. Twenty-five (4.6%) patients developed severe paracetamol-induced liver injury and coagulopathy. Overall, six (1.1%) cases were fatal in which paracetamol contributed to the cause of death, with accidental poisoning found in 67% (4/6).

CONCLUSIONS

The incidence of paracetamol poisoning has increased in recent years associated with economic recovery in Iceland. Most patients had favourable outcomes. Intentional overdose was most common in young females, whereas accidental overdose was more common in older males and more frequently associated with a fatal outcome.

A prospective study of the incidence of drug-induced liver injury by the modern volatile anaesthetics sevoflurane and desflurane

BACKGROUND

Volatile anaesthetics are known to cause drug-induced liver injury, a hepatotoxic reaction characterised by antibodies to trifluoroacetylated lipid and protein adducts and cytochrome p450 2E1. The incidence of volatile anaesthetic drug-induced liver injury from older agents has been described, but modern agents have not been prospectively studied.

AIM

To determine prospectively the incidence of volatile anaesthetic drug-induced liver injury from sevoflurane and desflurane.

METHODS

Adult surgical patients with a predicted post-operative stay of at least 4 days were recruited. If volatile anaesthetic was administered, liver biochemistry was performed regularly. Medications, observations and other investigations were documented. Patients with abnormal liver biochemistry were classified as likely volatile anaesthetic drug-induced liver injury or not based on clinical assessment, Roussel Uclaf Causality Assessment Method score, and the absence of other likely pathology. Some patients were also tested for antibodies to both trifluoroacetylated lipid and protein adducts, and cytochrome p450 2E1.

RESULTS

A total of 209 patients were recruited, of which 121 were included for analysis. Post-operative liver biochemistry was abnormal in 62 patients (51.2%); further classified as not volatile anaesthetic drug-induced liver injury in 47 cases (38.8%), and likely volatile anaesthetic-drug induced liver injury in 15 cases (12.4%). Of the likely volatile anaesthetic drug-induced liver injury patients, only one had severe disease with alanine transaminase greater than five times the upper limit of normal, while four cases had moderate disease with alanine transaminase greater than three times the upper limit of normal. Thus, the incidence of clinically significant volatile anaesthetic drug-induced liver injury was 4.1%. No risk factors were identified.

CONCLUSIONS

Volatile anaesthetic drug-induced liver injury from modern agents seems to be as common (4.1%) as previously reported with older agents (3%), and may identify patients at risk of severe acute liver injury with subsequent re-exposure.

Increased acetaminophen related calls to Finnish PIC better reflect acetaminophen sales than serious poisonings

OBJECTIVE

Acetaminophen (APAP) or paracetamol is a commonly encountered medicine in poisonings. We studied the changes in APAP related calls to the Finnish poison information centre (FPIC), and serious intoxications, involving hepatotoxicity or death in 2001-2014. These data were compared with paracetamol sales in Finland.

METHODS

This is a retrospective analysis of the FPIC database calls, national cause of death registry, registries of liver transplantations and molecular adsorbent recycling system (MARS)-treated patients from Helsinki University Hospital together with the National Institute of Health and Welfare registry of patients hospitalized. Data on APAP sales were obtained from the Finnish Medicines Agency.

RESULTS

Between 2001 and 2014, the number of calls/year related to human APAP exposures to the FPIC increased from 227 to 1058. No change in the age distribution of enquiries was seen. Most calls involved minors: 58% (range 52-64%) for children under 6 years old, and 9% (range 6-14%) for children of 6-15 years. In Finland, APAP related fatalities have gradually increased from an average of 7/year (range 4-10) in 2000-2005 to an average of 11/year (range 6-17) in 2010-2013, whereas the number of liver transplantations remained low, average 0.6/year (range 0-2). For patients in need of MARS-treatment, a slight decrease was seen. Total APAP sales increased from 5.6 (47% prescription, 53% OTC) to 29.7 (81% prescription, 19% OTC). DDD/1000 inhabitants/day from 2001 to 2014 is recorded. Best linear relationship (R² = 0.97; p < .001) was observed between total FPIC calls and total sales of APAP in 2001-2014. Fatalities show a weaker relationship with sales (R² = 0.317; p = .045).

CONCLUSIONS

During the study period, we see an increase in FPIC exposure calls accompanied by an increase in APAP sales. Changes in the chosen indicators for serious poisonings show only a weak association. Despite an evident trend between sales and fatalities, the correlation with fatality remains weak due to the small number of fatalities.

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

PURPOSE

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Limited Knowledge of Acetaminophen in Patients with Liver Disease

Background and Aims: Unintentional acetaminophen overdose remains the leading cause of acute liver failure in the United States. Patients with underlying liver disease are at higher risk of poor outcomes from acetaminophen overdose. Limited knowledge of acetaminophen may be a preventable contributor to elevated rates of overdose and thus acute liver failure. The purpose of this study is to assess knowledge of acetaminophen dosing and presence of acetaminophen in common combination products in patients with liver disease. Methods: We performed a cross-sectional study of patients with liver disease at the Pfleger Liver Institute at the University of California, Los Angeles between June 2015 and August 2016. Patients completed a demographic questionnaire and an acetaminophen knowledge survey. Additional information was obtained from the medical record. Results: Of 401 patients with liver disease, 30 (15.7%) were able to correctly identify that people without liver disease can safely take up to 4 g/day of acetaminophen. The majority of patients (79.9%-86.8%) did not know that Norco® (hydrocone/acetaminophen), Vicodin® (hydrocone/acetaminophen) and Percocet® (oxycodone/acetaminophen) contained acetaminophen. Only 45.3% of the patients knew that Tylenol® #3 contained acetaminophen. Conclusions: We conclude that patients with liver disease have critically low levels of knowledge of acetaminophen, putting them at risk both of acetaminophen overdose, as well as undermedication, and inadequate management of chronic pain. We recommend an increase in education efforts regarding acetaminophen dosage and its safety in the setting of liver disease. Increasing education for those at risk of low acetaminophen knowledge is essential to minimizing acetaminophen overdose rates and optimizing pain management.

Caffeic acid attenuated acetaminophen-induced hepatotoxicity by inhibiting ERK1/2-mediated early growth response-1 transcriptional activation

Caffeic acid (CA) is a natural compound abundant in fruits, coffee and plants. This study aims to investigate the involved mechanism of the therapeutic detoxification of CA against acetaminophen (APAP)-induced hepatotoxicity. CA (10, 30 mg/kg) was orally given to mice at 1 h after mice were pre-administrated with APAP (300 mg/kg). The therapeutic detoxification of CA against APAP-induced hepatotoxicity was observed by detecting serum aminotransferases, liver malondialdehyde (MDA) amount and liver histological evaluation in vivo. CA reduced APAP-induced increase in the mRNA expression of early growth response 1 (Egr1) in hepatocytes, and inhibited APAP-induced Egr1 transcriptional activation in vitro and in vivo. CA reduced the increased expression of growth arrest and DNA-damage-inducible protein (Gadd45)α induced by APAP in hepatocytes. Moreover, Egr1 siRNA reduced Gadd45α expression and reversed APAP-induced cytotoxicity in hepatocytes. Further results showed that CA blocked APAP-induced activation of extracellular-regulated protein kinase (ERK1/2) signaling cascade in vivo and in vitro. In addition, the application of ERK1/2 inhibitors (PD98059 and U0126) abrogated the nuclear translocation of Egr1 induced by APAP in hepatocytes. In conclusion, this study demonstrated the therapeutic detoxification of CA against APAP-induced liver injury, and the inhibition of CA on ERK1/2-mediated Egr1 transcriptional activation was involved in this process.

A prospective study on the causes of notably raised alanine aminotransferase (ALT)

OBJECTIVE

High levels of alanine aminotransferase (ALT) can be a marker of severe liver disease with variable aetiologies and prognosis. Very few prospective studies have been undertaken on the aetiology and prognosis of patients with high ALT levels. No population-based prospective study has systematically evaluated drug-induced liver injury (DILI) among these patients. The objective was to determine the aetiology and prognosis of patients with high ALT.

MATERIALS AND METHODS

In a catchment area of 160,000 inhabitants, a population-based prospective study identified all adult patients with serum level of ALT >500 U/L during a 12-month period. All underwent thorough diagnostic work-up and follow-up. In suspected DILI, causality was assessed with Roussel Uclaf Causality Assessment Method.

RESULTS

A total of 155 patients were identified with ALT >500 U/L, 12 children and one with ALT of non-liver-related origin, leaving 142 patients for the analysis: 73 (51%) males, median age 52 (IQR 36-68, range 19-89 years). The most common causes were choledocholithiasis 48/142 (34%), ischaemic hepatitis 26 (18%), viral hepatitis 16 (11%) and DILI 15 (11%), hepatobiliary malignancy (n = 6), surgery/interventions (n = 8) and other aetiologies (n = 23). No specific aetiology was found in 6% of cases. In the total study cohort 99 (70%) required hospitalisation, 78 (55%) had jaundice and 22 (16%) died, liver-related death in 10%, 35% in IH and 7% in DILI.

CONCLUSIONS

The most common cause of notably high ALT was choledocholithiasis. Ischaemic hepatitis was a common aetiology with approximately 35% liver-related mortality. Viral hepatitis and DILI were important aetiologies among these patients.

Characterisation and outcomes of adult patients with paracetamol overdose presenting to a tertiary hospital in Singapore

INTRODUCTION

Paracetamol is the most common pharmaceutical agent implicated in toxic exposure in Singapore. This study aimed to describe the characteristics of paracetamol overdose in the adult population managed at a tertiary healthcare facility in Singapore.

METHODS

Medical records of adult patients hospitalised with a diagnosis of paracetamol overdose at National University Hospital, Singapore, over a three-year period from January 2011 to December 2013 were retrospectively reviewed.

RESULTS

A total of 177 patients had paracetamol overdose. The median age was 25 years, with a significant female predominance (71.2%). Intentional ingestion accounted for the majority (76.8%) of cases. The median dose of paracetamol ingested was 10 (interquartile range 8-15) g. Among patients who reported ingesting more than 10 g, 46.5% perceived the overdose as non-lethal. N-acetylcysteine was administered in 76.3% of patients, among whom 24.4% experienced an anaphylactoid reaction. Of the 10 (5.6%) patients who had severe hepatotoxicity, 2 (1.1%) developed acute liver failure. Most patients had resolving transaminases at discharge and none required liver transplantation. The median length of hospitalisation was three days. There were no fatalities.

CONCLUSION

Paracetamol overdose occurred predominantly in young adults with intentional ingestion, suggesting that preventive measures targeted at promoting public awareness may not suffice. However, the perceived lack of lethality by many patients who ingested potentially toxic amounts of paracetamol reflects a certain knowledge gap. Healthcare providers should proactively educate consumers on the proper use of paracetamol and the consequences of its overdose.

Incidence Rates of Deliberate Self-Harm in Denmark 1994-2011

BACKGROUND

The validity and reliability of suicide statistics have been questioned and few nationwide studies of deliberate self-harm have been presented.

AIM

To calculate rates of deliberate self-harm in Denmark in order to investigate trends and assess the reliability of hospital records.

METHOD

A register study based on all individuals recorded with an episode of deliberate self-harm or probable deliberate self-harm in nationwide registers during 1994-2011.

RESULTS

A substantial difference in the rates of deliberate self-harm and probable deliberate self-harm was noted for both genders. The average incidence rate of deliberate self-harm for women and men was 130.7 (95% CI = 129.6-131.8) per 100,000 and 86.9 (95% CI = 86.0-87.8) per 100,000, respectively. The rates of deliberate self-harm for women increased from 137.6 (95% CI = 132.9-142.3) per 100,000 in 1994 to 152.7 (95% CI = 147.8-157.5) in 2011. For a subgroup of younger women aged 15-24 years, an almost threefold increase was observed, IRR = 2.5 (95% CI = 2.4-2.7). The most frequently used method was self-poisoning.

CONCLUSION

The rates of deliberate self-harm and probable deliberate self-harm differed significantly. An increased incidence of deliberate self-harm among young Danish women was observed, despite detection bias. An improved registration procedure of suicidal behavior is needed.

Scandinavian epidemiological research in gastroenterology and hepatology

In the last decades, a large number of epidemiological studies in gastroenterology and hepatology have originated from the Scandinavian countries. With the help of large health databases, with good validity and other registries related to patient outcomes, researchers from the Scandinavian countries have been able to make some very important contributions to the field. These countries, Sweden, Norway, Finland, Denmark and Iceland, have all universal access to health care and have shown to be ideal for epidemiological research. Population-based studies have been frequent and follow-up studies have been able to describe the temporal trends and changes in phenotypes. Our ability in Scandinavia to follow up defined groups of patients over time has been crucial to learn the natural history of many gastrointestinal and liver diseases and often in a population-based setting. Patient-related outcomes measures will probably gain increasing importance in the future, but Scandinavian gastroenterologists and surgeons are likely to have a better infrastructure for such endeavors compared to most other populations. Thus, there is a bright future for international competitive research within the field of gastrointestinal and liver diseases in Scandinavia.

Hepatotoxicity induced by acute and chronic paracetamol overdose in adults. Where do we stand?

Paracetamol (Acetaminophen) poisoning data can reveal the potential deficiencies of paracetamol poisoning management guidelines. We conducted a retrospective cohort study of patients >18years who were attended in the emergency department (ED) of a Spanish tertiary hospital, from 2005 to 2010 for suspected paracetamol overdose and who had measurable paracetamol concentrations. 208 patients suspected of paracetamol poisoning were identified. The annual incidence in the ED increased from 2.0 (95%-CI: 0.2-7.2) cases per 10,000 patients in 2005 to 3.4 (95%-CI: 1.1-8.8) in 2010. Only 7 of 98 patients (7.14%) with acute poisoning at toxic doses showed hepatotoxicity signs, 4 (57.1%) of whom presented acute liver failure (ALF) criteria, while 8 of 10 patients (80%) with chronic paracetamol poisoning at toxic doses presented hepatotoxicity and 3 (37.5%) with ALF criteria. The time required to find medical care was 9.0h for acute poisoning and 49.6h for chronic poisoning (p<0.001). We conclude that the incidence of suspected cases of paracetamol poisoning at our hospital is increasing. The majority of toxicity cases, including ALF, associated with the ingestion of paracetamol were due to chronic poisoning. This finding constitutes an important warning regarding paracetamol chronic poisoning, and clinicians should have a higher index of clinical suspicion for this entity.

Female gender in the setting of liver transplantation

The evolution of liver diseases to end-stage liver disease or to acute hepatic failure, the evaluation process for liver transplantation, the organ allocation decision-making, as well as the post-transplant outcomes are different between female and male genders. Women’s access to liver transplantation is hampered by the use of model for end-stage liver disease (MELD) score, in which creatinine values exert a systematic bias against women due to their lower values even in the presence of variable degrees of renal dysfunction. Furthermore, even when correcting MELD score for gender-appropriate creatinine determination, a quantifiable uneven access to transplant prevails, demonstrating that other factors are also involved. While some of the differences can be explained from the epidemiological point of view, hormonal status plays an important role. Moreover, the pre-menopausal and post-menopausal stages imply profound differences in a woman’s physiology, including not only the passage from the fertile age to the non-fertile stage, but also the loss of estrogens and their potentially protective role in delaying liver fibrosis progression, amongst others. With menopause, the tendency to gain weight may contribute to the development of or worsening of pre-existing metabolic syndrome. As an increasing number of patients are transplanted for non-alcoholic steatohepatitis, and as the average age at transplant increases, clinicians must be prepared for the management of this particular condition, especially in post-menopausal women, who are at particular risk of developing metabolic complications after menopause.

Lower susceptibility of female mice to acetaminophen hepatotoxicity: Role of mitochondrial glutathione, oxidant stress and c-jun N-terminal kinase

Acetaminophen (APAP) overdose causes severe hepatotoxicity in animals and humans. However, the mechanisms underlying the gender differences in susceptibility to APAP overdose in mice have not been clarified. In our study, APAP (300mg/kg) caused severe liver injury in male mice but 69-77% lower injury in females. No gender difference in metabolic activation of APAP was found. Hepatic glutathione (GSH) was rapidly depleted in both genders, while GSH recovery in female mice was 2.6 fold higher in the mitochondria at 4h, and 2.5 and 3.3 fold higher in the total liver at 4h and 6h, respectively. This faster recovery of GSH, which correlated with greater induction of glutamate-cysteine ligase, attenuated mitochondrial oxidative stress in female mice, as suggested by a lower GSSG/GSH ratio at 6h (3.8% in males vs. 1.4% in females) and minimal centrilobular nitrotyrosine staining. While c-jun N-terminal kinase (JNK) activation was similar at 2 and 4h post-APAP, it was 3.1 fold lower at 6h in female mice. However, female mice were still protected by the JNK inhibitor SP600125. 17β-Estradiol pretreatment moderately decreased liver injury and oxidative stress in male mice without affecting GSH recovery.

CONCLUSION

The lower susceptibility of female mice is achieved by the improved detoxification of reactive oxygen due to accelerated recovery of mitochondrial GSH levels, which attenuates late JNK activation and liver injury. However, even the reduced injury in female mice was still dependent on JNK. While 17β-estradiol partially protects male mice, it does not affect hepatic GSH recovery.

Overdose with modified-release paracetamol (Panadol Osteo®) presenting to a metropolitan emergency medicine network: a case series

BACKGROUND

There are currently no large cases series documenting poisoning with paracetamol modified-release (Panadol Osteo®, GlaxoSmithKline, Sydney, NSW, Australia). Management guidelines recommend at least two serum paracetamol concentrations 4 h apart and initiating treatment with N-acetylcysteine (NAC) if more than 10 g is ingested.

OBJECTIVE

To describe a cohort of Panadol Osteo® poisoning and determine if the management of identified cases was consistent with existing guidelines.

METHOD

Descriptive retrospective case series presenting to a metropolitan hospital network with paracetamol poisoning from October 2009 to September 2013.

RESULTS

There were 42 cases of Panadol Osteo® poisoning identified. Twenty-nine patients (median ingested dose 19 950 mg) were treated with NAC, of which 27 were acute single ingestions. Of NAC-treated patients, 85% (23/27) had an initial serum paracetamol concentration that was above the nomogram line. However, 15% (4/27) had an initial non-toxic concentration that later increased above the line. In 14 untreated patients (median ingested dose 7980 mg), one was an unrecognised late line-crosser with initial non-toxic serum paracetamol concentration. Only 43% (6/14) had a repeat paracetamol concentration measured. Three patients had a 4 h paracetamol >500 μmol/L. Late line-crossing was seen in the NAC-treated group at this level. In two untreated patients, NAC should have been commenced on the reported dose.

CONCLUSION

Most patients presenting with Panadol Osteo® poisoning requiring NAC treatment had an initial serum paracetamol concentration indicating need for treatment. A small number of late treatment nomogram line-crossers was seen on repeat paracetamol estimation. The current guideline for Panadol Osteo® poisoning would have detected all cases requiring NAC treatment.

Female gender as a susceptibility factor for drug-induced liver injury

Adverse drug reactions (ADRs) can involve all tissues and organs, but liver injuries are considered among the most serious. A number of prospective, multicenter studies have confirmed a higher risk of ADRs in general among female subjects compared to a male cohort. Although drug-induced liver injury (DILI) is infrequently encountered, the preponderance of evidence suggests that women appear to be more susceptible than men to fulminate hepatic/acute liver failure especially in response to some anti-infective drugs and to autoimmune-like hepatitis following exposure to certain other therapeutic drugs. A number of hypotheses have been proposed to explain this sex difference in susceptibility to DILI. Collectively, these hypotheses suggest three basic sex-dependent mechanisms that include differences in various aspects of drug pharmacokinetics (PK) or pharmacodynamics following the administration of certain drugs; specific hormonal effects or interactions with immunomodulating agents or signaling molecules; and differences in the adverse response of the immune system to some drugs, reactive drug metabolites, or drug-protein adducts. At the preclinical drug safety stage, there is a need for more research on hormonal effects on drug PK and for additional research on gender differences in aberrant immune responses that may lead to idiosyncratic DILI in some female patients. Because the detection of rare but serious hepatic ADRs requires the exposure of very large patient populations, pharmacovigilance networks will continue to play a key role in the postmarketing surveillance for their detection and reporting.

Impact of amending the acetylcysteine marketing authorisation on treatment of paracetamol overdose

In September 2012, the Medicines and Healthcare products Regulatory Agency (MHRA) substantially amended the Marketing Authorisation for acetylcysteine following an extensive review. The present study examined the impact of this license change on patterns of acetylcysteine use in patients presenting to hospital after paracetamol (acetaminophen) overdose. Between September 2011 and April 2013, 785 consecutive patients presented to York Hospital due to paracetamol overdose, and a before-after analysis was used to compare outcomes. There were 483 patients before and 302 patients after the license amendment, and age, gender, acute or staggered overdose pattern, and dose were similar in both groups. In the patients with paracetamol concentrations between the "100-line" and "200-line," a significantly higher proportion received acetylcysteine treatment (51% before versus 98% after, P = 0.0029), as expected. A modest increase was also observed in relation to late or staggered overdose or cases where the time of ingestion was uncertain (53% versus 74%, P = 0.0430). The median duration of hospital stay increased across the entire study population, from 15 to 24 hours (P = 0.0159) due to the increased proportion of patients requiring acetylcysteine treatment. The findings indicate that the MHRA amendment is a financially costly intervention, and further studies are needed to examine clinical outcomes so that its cost effectiveness might be addressed.