Trends in emergency department visits attributable to acetaminophen overdoses in the United States: 1993-2007

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.

The Evolution of Circulating Biomarkers for Use in Acetaminophen/Paracetamol-Induced Liver Injury in Humans: A Scoping Review

Acetaminophen (APAP) is a widely used drug, but overdose can cause severe acute liver injury. The first reports of APAP hepatotoxicity in humans were published in 1966, shortly after the development of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as the first biomarkers of liver injury as opposed to liver function. Thus, the field of liver injury biomarkers has evolved alongside the growth in APAP hepatotoxicity incidence. Numerous biomarkers have been proposed for use in the management of APAP overdose patients in the intervening years. Here, we comprehensively review the development of these markers from the 1960s to the present day and briefly discuss possible future directions.

Clinical Characteristics, Outcomes, Disposition, and Acute Care of Children and Adolescents Treated for Acetaminophen Toxicity

OBJECTIVE

Acetaminophen is a common cause of intentional and inadvertent overdoses among children and adolescents worldwide. Little is known about characteristics and clinical outcomes of these youths. The primary goal of this naturalistic study was to describe the psychiatric characteristics, medical management, outcomes, and dispositions of children and adolescents evaluated for excessive acetaminophen exposure.

METHODS

The Rochester Epidemiology Project database was searched for all patients ages 0-18 treated for excessive acetaminophen exposure in Olmsted County, Minnesota, during a 7-year period (2004-2010). Demographic factors, overdose intentionality, medical and psychiatric treatment, mental health and addiction history, and disposition from the emergency department (ED) were documented.

RESULTS

Of 110 cases of acetaminophen overdose (89 female patients and 21 male patients), 97 (88%) were intentional and 13 (12%) were unintentional. Fifteen patients (14%) were discharged from the ED, and 69 (63%) required admission to a medical unit. Sixty-four (59%) received N-acetylcysteine. Ninety-eight (89%) were evaluated by psychiatry, and 80 (73%) were admitted for psychiatric hospitalization. Most had at least one psychiatric diagnosis, most commonly depression (55%); 22 (20%) had a prior suicide attempt. Substance use was common, notably alcohol dependence (N=16, 15%), alcohol abuse (N=18, 16%), and cannabis abuse (N=18, 16%). All survived and recovered without liver transplant.

CONCLUSIONS

Among pediatric patients with acetaminophen overdoses, psychiatric comorbidities and substance use were common. Most received both inpatient medical and psychiatric treatment. Interventions that restrict acetaminophen access are needed for this population, as are suicide risk reduction interventions for delivery in emergency settings.

The Late-Stage Protective Effect of Mito-TEMPO against Acetaminophen-Induced Hepatotoxicity in Mouse and Three-Dimensional Cell Culture Models

An overdose of acetaminophen (APAP), the most common cause of acute liver injury, induces oxidative stress that subsequently causes mitochondrial impairment and hepatic necroptosis. N-acetyl-L-cysteine (NAC), the only recognized drug against APAP hepatotoxicity, is less effective the later it is administered. This study evaluated the protective effect of mitochondria-specific Mito-TEMPO (Mito-T) on APAP-induced acute liver injury in C57BL/6J male mice, and a three dimensional (3D)-cell culture model containing the human hepatoblastoma cell line HepG2. The administration of Mito-T (20 mg/kg, i.p.) 1 h after APAP (400 mg/kg, i.p.) injection markedly attenuated the APAP-induced elevated serum transaminase activity and hepatic necrosis. However, Mito-T treatment did not affect key factors in the development of APAP liver injury including the activation of c-jun N-terminal kinases (JNK), and expression of the transcription factor C/EBP homologous protein (CHOP) in the liver. However, Mito-T significantly reduced the APAP-induced increase in the hepatic oxidative stress marker, nitrotyrosine, and DNA fragmentation. Mito-T markedly attenuated cytotoxicity induced by APAP in the HepG2 3D-cell culture model. Moreover, liver regeneration after APAP hepatotoxicity was not affected by Mito-T, demonstrated by no changes in proliferating cell nuclear antigen formation. Therefore, Mito-T was hepatoprotective at the late-stage of APAP overdose in mice.

Parental Experience of Potential Adverse Drug Reactions Related to Their Oral Administration of Antipyretic Analgesic Medicines in Children in Saudi Arabia

BACKGROUND

Oral antipyretic analgesic medicines are commonly used in children and have the potential for adverse drug reactions (ADRs).

OBJECTIVE

The aim of this study was to explore parental experiences of potential ADRs related to their oral administration of antipyretic analgesics in children in the Kingdom of Saudi Arabia.

METHODS

For this cross-sectional survey, a paper-based questionnaire, consent form and information sheet were handed out to 1000 parents who had administered an oral antipyretic analgesic medicine to their children during the previous 3 months. Data were entered and analyzed using SPSS version 21.0 (IBM-SPSS Inc, Armonk, NY). Simple descriptive and inferential statistics were used. Management and ethical approvals were attained.

RESULTS

During March to April 2017, 661 parents agreed to participate, giving a response rate of 66.1%. Of the surveyed sample, 208 parents had observed 1 or more potential ADRs (31.5%, n = 208 out of 661). Parents' (n = 208) most commonly reported potential ADRs (n = 523) were loss of appetite (23%, n = 120 out of 523), stomachache (20.3%, n = 106 out of 523), abdominal colic (13%, n = 68 out of 523), and diarrhea (10.3%, n = 54 out of 523). Parents described severity of the ADRs as slight (71.8%, n = 342 out of 476), annoying to the child (7.9%, n = 85 to of 476), significant and affecting daily tasks (3.6%, n = 17 out of 476) and significant and led to the hospital (6.7%, n = 32 out of 476). Fever was the top-ranked reason for using antipyretic analgesic medicines (41.0%, n = 271 out of 661), followed by toothache (25.0%, n = 165 out of 661) and tonsillitis/laryngitis (24.7%, n = 163 out of 661). Among parents, 34.7% (n = 165 out of 476) did not seek medical attention when a potential ADR occurred, whereas 26.3% (n = 125 out of 476) of parents took their children to hospital clinics.

CONCLUSIONS

Although the majority of parentally reported (but not proven) ADRs were mild, a number of significant ADRs were reported. Future research should consider whether there is a role for physicians and pharmacists in educating parents in Saudi Arabia, and perhaps more widely, about the optimal use of oral antipyretic and analgesic medicines in children. (Curr Ther Res Clin Exp. 2020; 81:XXX-XXX)© 2020 Elsevier HS Journals, Inc.

Recombinant human soluble thrombomodulin ameliorates acetaminophen-induced liver toxicity in mice

Recombinant human soluble thrombomodulin alpha (rhTM) has been developed as an anticoagulant with anti-inflammatory activity. Notably, acetaminophen (APAP) -induced liver disease (AILI) is caused by direct metabolite-induced hepatotoxicity as well as hepatic hyper-coagulation. To evaluate the utility of anticoagulant for the treatment of AILI, rhTM was administered in a mouse AILI model and liver damage was analyzed. AILI was induced in 8-week-old mice by intraperitoneal injection of APAP. rhTM (20 mg/kg) or placebo was injected at the same time as APAP administration. Serum alanine aminotransferase, fibrin degradation products and high-mobility group box 1 levels were significantly decreased in the rhTM-treated group compared with the control group. Furthermore, rhTM reduced the necrotic area and fibrin deposition in liver sections. rhTM suppressed the mRNA expression of heme oxygenase-1, plasminogen activator inhibitor type-1, tissue factors, and inflammatory cytokines compared with the control group. rhTM did not change the hepatic GSH content at 2 h after APAP injection, but restored them at 4 h after the insult. rhTM ameliorated liver damage in mice with AILI, probably via the improvement in liver perfusion induced by it's anticoagulant acitivity, which can lead to the suppression of secondary liver damage.

Visual acuity, literacy, and unintentional misuse of nonprescription medications

PURPOSE

Results of a study of associations between visual acuity and the risk of misuse of nonprescription acetaminophen products in a sample of community-dwelling adults are reported.

METHODS

In a study involving English-speaking adults at 4 primary care clinics, the potential for misuse of nonprescription acetaminophen products was measured via a functional assessment of product self-dosing and by testing patients' understanding of the risks of concomitant use (i.e., taking 2 products at the same time when contraindicated). Vision was assessed using the Rosenbaum vision chart and dichotomized as normal (visual acuity of 20/20-20/25) or low (acuity of 20/30-20/100). Bivariable and multivariable analyses were performed to determine the impact of visual acuity on medication misuse outcomes.

RESULTS

Among the study participants (n = 500), 39% had limited literacy, and 54% were categorized as having low vision. After controlling for age, race, and prior acetaminophen use, low vision was independently associated with an increased risk of self-dosing errors (odds ratio [OR], 1.67; 95% confidence interval [CI], 1.25-2.21; p < 0.001) and misunderstanding of concomitant-use risks (OR, 1.41; 95% CI, 1.00-2.00; p = 0.05). Limited literacy was an independent risk factor for incorrect dosing (OR, 1.71; 95% CI, 1.25-2.35; p = 0.001) and unawareness of concomitant use instructions (OR, 4.14; 95% CI, 2.80-6.12; p < 0.001).

CONCLUSION

Misunderstanding of nonprescription acetaminophen product information was common among study participants and independently associated with both impaired visual acuity and low literacy skills.

Racial disparities in the treatment of acute overdose in the emergency department

OBJECTIVES

Racial and ethnic disparities in the United States continue to exist in many disciplines of medicine, extending to care in the Emergency Department (ED). We sought to examine the relationship between patient race/ethnicity and use of either antidotal therapy or gastrointestinal decontamination for individuals presenting to the ED for acute drug overdose.

METHODS

We completed a secondary analysis of a prospective cohort of patients with suspected acute overdose presenting to two urban tertiary care hospitals between 2009 and 2014. Race was self-identified during ED registration. Antidote administration (primary outcome) and gastrointestinal decontamination (secondary outcome) were reviewed and verified via agreement between two board certified medical toxicologists. Associations between race and outcomes were analyzed using a logistic regression model.

RESULTS

We reviewed 3252 ED patients with acute overdose. Overall, 542 people were treated with an antidote and 234 cases were treated with activated charcoal, either single or multiple dose. Compared to Whites, Blacks and Hispanics were significantly less likely to receive any antidote. The analysis was underpowered to detect racial disparities in the administration of activated charcoal.

CONCLUSIONS

Blacks and Hispanics are significantly less likely to receive any antidote when presenting to the ED for acute drug overdose. Further studies are needed to determine national prevalence of this apparent disparity in care and to fully characterize how race plays a role in management of acute overdose.

Analgesic-Related Medication Errors Reported to US Poison Control Centers

Objective

This study investigates the characteristics and trends of medication errors involving analgesic medications.

Design and Methods

A retrospective analysis was conducted of analgesic-related medication errors reported to the National Poison Data System (NPDS) from 2000 through 2012.

Results

From 2000 through 2012, the NPDS received 533,763 reports of analgesic-related medication errors, averaging 41,059 medication errors annually. Overall, the rate of analgesic-related medication errors reported to the NPDS increased significantly by 82.6% from 2000 to 2009, followed by a 5.7% nonsignificant decrease from 2009 to 2012. Among the analgesic categories, rates of both acetaminophen-related and opioid-related medication errors reported to the NPDS increased during 2000-2009, but the opioid error rate leveled off during 2009-2012, while the acetaminophen error rate decreased by 17.9%. Analgesic-related medication errors involved nonsteroidal anti-inflammatory drugs (37.0%), acetaminophen (35.5%), and opioids (23.2%). Children five years or younger accounted for 38.8% of analgesics-related medication errors. Most (90.2%) analgesic-related medication errors were managed on-site, rather than at a health care facility; 1.6% were admitted to a hospital, and 1.5% experienced serious medical outcomes, including 145 deaths. The most common type of medication error was inadvertently taking/given the medication twice (26.6%).

Conclusion

Analgesic-related medication errors are common, and although most do not result in clinical consequences, they can have serious adverse outcomes. Initiatives associated with the decrease in acetaminophen-related medication errors among young children merit additional research and potential replication as a model combining government policy and multisectoral collaboration.

Light to moderate drinking and therapeutic doses of acetaminophen: An assessment of risks for renal dysfunction

This study investigated the potential effect of therapeutic doses of acetaminophen (APAP) in combination with light-moderate amounts of alcohol on kidney functions controlling for factors such as hypertension, diabetes and obesity that may predispose the kidney to APAP and/or alcohol toxicity. Secondary analysis of the 2003–2004 National Health and Nutrition Examination Survey data was performed using SAS 9.4. Odds ratios (OR) and 95% confidence intervals (CI) comparing the likelihood that individuals who ingested therapeutic doses of APAP and light-moderate amount of alcohol, compared to those who did not, would have kidney dysfunction were generated from multiple logistics regression models by further controlling for potential predisposing factors namely hypertension, diabetes and obesity. Kidney dysfunction was defined based on self-reports and laboratory examination of serum creatinine (SCr), blood urea nitrogen (BUN), glomerular filtration rate (GFR) and albumin creatinine ratio (ABCR). Statistically significant increased odds of renal dysfunction were noted among respondents who reported use of therapeutic doses of APAP and light-moderate amount of alcohol [OR(95% CI) = 1.64(1.28–2.10) self-report, 2.18(1.81–2.63) SCr, 4.60(3.03–7.00) BUN, 3.14(2.42–4.07) GFR, and 1.71(1.36–2.14) ALBCR)] even after adjusting for hypertension, diabetes and obesity [Adjusted OR (95% CI) = 1.78 (1.22–2.58) self-report, 2.05 (1.07–3.92) GFR]. The toxic effects of APAP and alcohol on the kidney were hypothesized. The threshold doses at which these effects begin to occur are unknown. The findings of this study suggest that even therapeutic doses of APAP and light-moderate amount of alcohol could be health problematic if consumed concomitantly.

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Even therapeutic doses of acetaminophen may be associated with renal dysfunction.

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Light-moderate drinking alone may be protective of renal dysfunction.

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Light-moderate alcohol may enhance effect of therapeutic doses of APAP on kidney.

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Hypertension, obesity & diabetes may strengthen effect of APAP & alcohol on kidney.

Variability in Acetaminophen Labeling Practices: a Missed Opportunity to Enhance Patient Safety

Confusion regarding a drug's active ingredient may lead to simultaneous use of multiple acetaminophen-containing prescriptions and increase the risk of unintentional overdose. The objective of this study was to examine prescription labeling practices for commonly prescribed acetaminophen-containing analgesics, specifically focusing on how active ingredient information and concomitant use warnings were conveyed. Patients with new acetaminophen-containing prescriptions were recruited upon discharge from an emergency department in Chicago or at an outpatient, hospital-based pharmacy in Atlanta. Label information was transcribed from prescription bottles and patients' knowledge of active ingredient was assessed by in-person interviews. Among the 245 acetaminophen-containing prescriptions, hydrocodone was the most common second active ingredient (n = 208, 84.8 %) followed by oxycodone (n = 28, 11.4 %). Acetaminophen was identified by its full name on 6.9 % (n = 17) of labels; various abbreviations were used in 93.1 % of cases. One hundred forty-seven bottles used auxiliary warning labels with the majority of labels (n = 130, 88.4 %) warning about maximum dose and 11.5 % (n = 17) about concomitant use. Most of the study participants (n = 177, 72.2 %) were not able to identify acetaminophen as an active ingredient in their prescription. There was no significant association between the use of unabbreviated labels including warning information and patients' awareness of acetaminophen as an active ingredient (36.4 vs. 27.3 %, p = 0.50). We noted high variability in labeling practices and warning information conveyed to patients receiving acetaminophen-containing prescriptions. Missed opportunities to adequately convey risk information may contribute to the burden of acetaminophen-related liver injury.

Acetylcholinesterase Inhibitors for Alzheimer's Disease Treatment Ameliorate Acetaminophen-Induced Liver Injury in Mice via Central Cholinergic System Regulation

Acetaminophen (APAP) is widely used as an analgesic and antipyretic agent, but it may induce acute liver injury at high doses. Alzheimer's disease patients, while treated with acetylcholinesterase inhibitor (AChEI), may take APAP when they suffer from cold or pain. It is generally recognized that inhibiting acetylcholinesterase activity may also result in liver injury. To clarify whether AChEI could deteriorate or attenuate APAP hepatotoxicity, the effects of AChEI on APAP hepatotoxicity were investigated. Male C57BL/6J mice were administrated with the muscarinic acetylcholine receptor (mAChR) blocker atropine (Atr), or classic α7 nicotine acetylcholine receptor (α7nAChR) antagonist methyllycaconitine (MLA) 1 hour before administration of AChEIs-donepezil (4 mg/kg), rivastigmine (2 mg/kg), huperzine A (0.2 mg/kg), or neostigmine (0.15 mg/kg)-followed by APAP (300 mg/kg). Eight hours later, the mice were euthanized for histopathologic examination and biochemical assay. The results demonstrated that the tested AChEIs, excluding neostigmine, could attenuate APAP-induced liver injury, accompanied by reduced reactive oxygen species formation, adenosine triphosphate and cytochrome C loss, c-Jun N-terminal kinase 2 (JNK2) phosphorylation, and cytokines. However, Atr or MLA significantly weakened the protective effect of AChEI by affecting mitochondrial function or JNK2 phosphorylation and inflammation response. These results suggest that central mAChR and α7nAChR, which are activated by accumulated acetylcholine resulting from AChEI, were responsible for the protective effect of AChEIs on APAP-induced liver injury. This indicates that Alzheimer's patients treated with AChEI could take APAP, as AChEI is unlikely to deteriorate the hepatotoxicity of APAP.

Acetaminophen administration in pediatric age: an observational prospective cross-sectional study

Background

Parents often do not consider fever as an important physiological response and mechanism of defense against infections that leads to inappropriate use of antipyretics and potentially dangerous side effects. This study is designed to evaluate the appropriateness of antipyretics dosages generally administered to children with fever, and to identify factors that may influence dosage accuracy.

Results

In this cross-sectional study we analyzed the clinical records of 1397 children aged >1 month and < 16 years, requiring a primary care (ambulatory) outpatient visit due to fever. We evaluated the number of children who had received >90 mg/kg/day of acetaminophen, the prescriber, the medication formula and the educational level of the caregiver who administered acetaminophen. Among those children included in our study, 74 % were administered acetaminophen for body temperature ≤ 38.4 °C. 24.12 % of children received >90 mg/kg/day of acetaminophen. Parents with university qualifications most commonly self-administered acetaminophen to their children, in a higher than standard dose. Self medication was also described in 60 % of children, whose acetaminophen was administered for temperatures < 38 °C. Acetaminophen over-dosage was also favored by the use of drug formulations as drops or syrup.

Conclusions

Our study shows that preventive action should be taken regarding the use of acetaminophen as antipyretic drug in children in order to reduce the fever phobia and self-prescription, especially of caregivers with higher educational levels. It is also necessary to promote a more appropriate use of acetaminophen in those parents using drops or syrup formulations.

Risk Factors, Clinical Presentation, and Outcomes in Overdose With Acetaminophen Alone or With Combination Products: Results From the Acute Liver Failure Study Group

BACKGROUND AND AIMS

Acetaminophen (APAP) is the most common cause of acute liver failure (ALF) in the west. It is unknown if APAP overdose in combination with diphenhydramine or opioids confers a different clinical presentation or prognosis. Study objectives were to compare (1) baseline patient characteristics; (2) initial clinical presentation; and (3) clinical outcomes among patients with ALF due to APAP alone or in combination with diphenhydramine or opioids.

METHODS

We analyzed 666 cases of APAP-related liver failure using the Acute Liver Failure Study Group database from 1998 to 2012. The database contains detailed demographic, laboratory, and clinical outcome data, including hemodialysis, transplantation, and death and in-hospital complications such as arrhythmia and infection.

RESULTS

The final sample included 666 patients with APAP liver injury. A total 30.3% of patients were overdosed with APAP alone, 14.1% with APAP/diphenhydramine, and 56.6% with APAP/opioids. Patients taking APAP with opioids were older, had more comorbidities, and were more likely to have unintentional overdose (all P<0.0001). On presentation, 58% in the APAP/opioid group had advanced encephalopathy as compared with 43% with APAP alone (P=0.001) The APAP/diphenhydramine group presented with the highest serum aminotransferase levels, no differences in laboratory values were noted at 3 days postenrollment. No significant differences were observed in clinical outcomes among the groups.

CONCLUSIONS

Most patients with APAP-induced ALF were taking APAP combination products. There were significant differences in patient characteristics and clinical presentation based on the type of product ingested, however, there were no differences noted in delayed hepatotoxicity or clinical outcomes.

Trends in rates of acetaminophen-related adverse events in the United States

PURPOSE

The goal of this study is to summarize trends in rates of adverse events attributable to acetaminophen use, including hepatotoxicity and mortality.

METHODS

A comprehensive analysis of data from three national surveillance systems estimated rates of acetaminophen-related events identified in different settings, including calls to poison centers (2008-2012), emergency department visits (2004-2012), and inpatient hospitalizations (1998-2011). Rates of acetaminophen-related events were calculated per setting, census population, and distributed drug units.

RESULTS

Rates of poison center calls with acetaminophen-related exposures decreased from 49.5/1000 calls in 2009 to 43.5/1000 calls in 2012. Rates of emergency department visits for unintentional acetaminophen-related adverse events decreased from 58.0/1000 emergency department visits for adverse drug events in 2009 to 50.2/1000 emergency department visits in 2012. Rates of hospital inpatient discharges with acetaminophen-related poisoning decreased from 119.8/100 000 hospitalizations in 2009 to 108.6/100 000 hospitalizations in 2011. After 2009, population rates of acetaminophen-related events per 1 million census population decreased for poison center calls and hospitalizations, while emergency department visit rates remained stable. However, when accounting for drug sales, the rate of acetaminophen-related events (per 1 million distributed drug units) increased after 2009. Prior to 2009, the rates of acetaminophen-related hospitalizations had been slowly increasing (p-trend = 0.001).

CONCLUSIONS

Acetaminophen-related adverse events continue to be a public health burden. Future studies with additional time points are necessary to confirm trends and determine whether recent risk mitigation efforts had a beneficial impact on acetaminophen-related adverse events. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Clinical and economic characteristics of emergency department visits due to acetaminophen toxicity in the USA

OBJECTIVES

To estimate the number of acetaminophen (APAP) toxicity-related emergency department (ED) visits, and to assess their associated clinical and economic burden in the USA from 2006 to 2010.

DESIGN

Cross-sectional, retrospective, large-scale database study.

SETTING

Non-federal, non-rehabilitation, community EDs in the USA.

PARTICIPANTS

Inclusion criteria included any listed diagnosis identifying poisoning by aromatic analgesics paracetamol/APAP or associated supplementary code. Generalised linear models were used to investigate the association between outcomes of inpatient admission, mortality, requirement of invasive mechanical ventilation, charges and inpatient lengths of stay based on patient, hospital and clinical characteristics.

RESULTS

Across the 625.2 million ED visits in the USA from 2006 to 2010, 411,811 APAP-related toxicity ED visits were observed, with 45.5% resulting in inpatient admission, 4.7% requiring invasive mechanical ventilation and 0.6% involving death. Overall, the incidence proportion was 27.10 per 100,000 US population, exceeding 70 per 100,000 at age 2 years and ages 16-18 years. The total national bill was $1.06 billion per year (US$ 2014), and predominantly involved females (65.5%) and intentional self-harm (58.4%), which were notably higher within the 12-20 years age category (female(12-20 years)=74.8%, intentional self-harm(12-20 years)=71.4%). Behavioural and mental health comorbidities were relatively common and associated with an increased relative risk of admission and likelihood of charges almost entirely across all age categories of ≥12 years within the multivariable analyses. The number of ED visits did not appreciably change over time, decreasing by <2% from 2006 to 2010 (n=1351). Multivariable results also suggested no consistent change in outcomes across the study's time horizon.

CONCLUSIONS

A substantial public health impact of APAP toxicity-related cases was observed in the US from 2006 to 2010, with incidence proportions peaking at age 2 years and ages 16-18 years. After controlling for numerous factors, no consistent change was observed over the 5-year time horizon concerning outcomes of admission, mortality, invasive mechanical ventilation, charges or length of stay.

Characteristics and trends of emergency patients with drug overdose in Osaka

Aim

Drug overdose is an important issue in emergency medicine. However, studies covering overdose patients transported by ambulance have not been sufficiently carried out. We attempted to clarify problems of suspected drug overdose patients transported by ambulance.

Methods

This is a prospective population-based cohort study. Data were collected by emergency medical service crews in Osaka City, Japan, between January 1998 and December 2010.

Results

Drug overdose cases increased annually from 1,136 in 1998 to 1,822 in 2010 (P < 0.0001 for trend). In these cases, the dominant age range was between 16 and 40 years and the age distribution did not change over time. The age of non-overdose cases increased (P < 0.0001 for trend), with patients aged ≥66 years becoming most common in recent years, reflecting the aging of society. Males comprised most non-overdose patients, but the percentage of females increased annually (P < 0.0001 in trend). Females comprised approximately 70% in overdose cases annually throughout the study period. The duration from the emergency call to the arrival at the hospital for overdose patients has increased markedly in recent years. It also takes more time to obtain acceptance from hospitals to care for patients of suspected overdose.

Conclusion

The characteristics of drug overdose patients are clearly different from those of non-overdose patients. Recent trends of drug overdose patients indicate the accelerated burden on emergency medical services system.

Protection afforded by pre- or post-treatment with 4-phenylbutyrate against liver injury induced by acetaminophen overdose in mice

Acetaminophen (paracetamol, N-acetyl-p-aminophenol; APAP) is a widely used analgesic/antipyretic drug with few adverse effects at therapeutic doses; suicidal or unintentional overdose of APAP frequently induces severe hepatotoxicity. To explore a new and effective antidote for APAP hepatotoxicity, this study examined the effects of sodium 4-phenylbutyrate (4-PBA) on liver injury induced by APAP overdose in mice. Liver injury was induced in C57BL/6 male mice by intraperitoneal injection of APAP (400mg/kg). The effects of 4-PBA (100-200mg/kg) treatment at 1h before the APAP injection were evaluated with serum alanine aminotransferase (ALT) and blood ammonia levels, hepatic pathological changes, including histopathology, DNA damage, nitrotyrosine formation, and mRNA or protein expression involved in the development of hepatotoxicity, such as X-box binding protein-1 (XBP1), c-Jun N-terminal kinase (JNK), C/EBP homologous protein (CHOP) and B-cell lymphoma 2 interacting mediator of cell death (Bim). In addition, glutathione depletion and CYP2E1 protein expression, which are measures of the metabolic conversion of APAP to a toxic metabolite, were examined. Furthermore, we examined the effects of post-treatment with 4-PBA against APAP-induced hepatotoxicity in mice. When administered at 1h before APAP injection, 4-PBA significantly prevented the increase in serum ALT and blood ammonia levels, centrilobular necrosis of hepatocytes, DNA fragmentation, and nitrotyrosine formation induced by APAP in mice. 4-PBA also inhibited hepatic Xbp1 mRNA splicing and JNK phosphorylation induced by APAP, but did not suppress CHOP and Bim mRNA and protein expression. In addition, 4-PBA had little effect on hepatic glutathione depletion and CYP2E1 expression, parameters of toxic APAP metabolite production. Post-treatment with 4-PBA administration at 1 or 2h after APAP injection also attenuated the increase in serum ALT and blood ammonia levels and hepatic pathological changes in APAP-induced hepatotoxicity in mice. Although post-treatment with 4-PBA did not show any effects on hepatic Xbp1 mRNA splicing and JNK phosphorylation, it drastically attenuated the DNA fragmentation induced by APAP. The precise molecular mechanisms of the protection afforded by 4-PBA against APAP hepatotoxicity in mice are unclear, but they seem to involve inhibition of hepatocellular DNA fragmentation. We suggest that 4-PBA is a promising candidate as an antidote against APAP-induced liver injury.

Negative predictive value of acetaminophen concentrations within four hours of ingestion

OBJECTIVES

The objective was to ascertain whether acetaminophen (APAP) concentrations less than 100 μg/mL obtained between 1 and 4 hours after acute ingestion accurately predict a nontoxic 4-hour concentration.

METHODS

The authors performed a multicenter, prospective cohort study involving five emergency departments (EDs) participating in the ToxIC Research Network. Data were collected from May 2009 to December 2011. Patients with APAP concentrations <100 μg/mL drawn between 1 and 4 hours after acute ingestions, and concentrations drawn 4 or more hours after ingestions, were included in the study. Exclusion criteria included initial concentration >100 μg/mL, initial APAP concentration drawn prior to 1 hour, two undetectable APAP concentrations, the second concentration drawn prior to 4 hours, and unknown time of ingestion. Toxic concentrations 4 or more hours after ingestion were defined as concentrations that plotted above the 150 μg/mL line on the Rumack-Matthew nomogram.

RESULTS

Data were collected on 83 patients who met inclusion criteria. Of the 83 patients with APAP concentrations <100 μg/mL between 1 and 4 hours, one patient (1.2%) had a ≥ 4-hour toxic concentration. Negative predictive value (NPV) for an APAP concentration <100 μg/mL obtained between 1 and 4 hours after an acute ingestion was 98.8% (95% confidence interval [CI] = 93.5% to 99.8%).

CONCLUSIONS

An APAP concentration of <100 μg/mL obtained between 1 and 4 hours after ingestion has a high NPV for excluding toxic ingestion. We do not recommend reliance on concentrations obtained between 1 and 4 hours to exclude toxicity, because of a potential false-negative rate of 6.5%.

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.

Ozagrel hydrochloride, a selective thromboxane A₂ synthase inhibitor, alleviates liver injury induced by acetaminophen overdose in mice

Background

Overdosed acetaminophen (paracetamol, N-acetyl-p-aminophenol; APAP) causes severe liver injury. We examined the effects of ozagrel, a selective thromboxane A₂ (TXA₂) synthase inhibitor, on liver injury induced by APAP overdose in mice.

Methods

Hepatotoxicity was induced to ICR male mice by an intraperitoneal injection with APAP (330 mg/kg). The effects of ozagrel (200 mg/kg) treatment 30 min after the APAP injection were evaluated with mortality, serum alanine aminotransferase (ALT) levels and hepatic changes, including histopathology, DNA fragmentation, mRNA expression and total glutathione contents. The impact of ozagrel (0.001-1 mg/mL) on cytochrome P450 2E1 (CYP2E1) activity in mouse hepatic microsome was examined. RLC-16 cells, a rat hepatocytes cell line, were exposed to 0.25 mM N-acetyl-p-benzoquinone imine (NAPQI), a hepatotoxic metabolite of APAP. In this model, the cytoprotective effects of ozagrel (1–100 muM) were evaluated by the WST-1 cell viability assay.

Results

Ozagel treatment significantly attenuated higher mortality, elevated serum alanine aminotransferase levels, excessive hepatic centrilobular necrosis, hemorrhaging and DNA fragmentation, as well as increase in plasma 2,3-dinor thromboxane B₂ levels induced by APAP injection. Ozagrel also inhibited the hepatic expression of cell death-related mRNAs induced by APAP, such as jun oncogene, FBJ osteosarcoma oncogene (fos) and C/EBP homologous protein (chop), but did not suppress B-cell lymphoma 2-like protein11 (bim) expression and hepatic total glutathione depletion. These results show ozagrel can inhibit not all hepatic changes but can reduce the hepatic necrosis. Ozagrel had little impact on CYP2E1 activity involving the NAPQI production. In addition, ozagrel significantly attenuated cell injury induced by NAPQI in RLC-16.

Conclusions

We demonstrate that the TXA₂ synthase inhibitor, ozagrel, dramatically alleviates liver injury induced by APAP in mice, and suggest that it is a promising therapeutic candidate for the treatment of APAP-induced liver injury.

Adverse effects of analgesics commonly used by older adults with osteoarthritis: focus on non-opioid and opioid analgesics

BACKGROUND

Osteoarthritis (OA) is the most common cause of disability in older adults, and although analgesic use can be helpful, it can also result in adverse drug events.

OBJECTIVE

To review the recent literature to describe potential adverse drug events associated with analgesics commonly used by older adults with OA.

METHODS

To identify articles for this review, a systematic search of the English-language literature from January 2001 to June 2012 was conducted using PubMed, MEDLINE, EBSCO, and the Cochrane Database of Systematic Reviews for publications related to the medical management of OA. Search terms used were "analgesics," "acetaminophen," "nonsteroidal anti-inflammatory drugs" (NSAIDs), "opioids," "pharmacokinetics," "pharmacodynamics," and "adverse drug events." The search was restricted to those articles that concerned humans aged ≥65 years. A manual search of the reference lists from identified articles and the authors' article files, book chapters, and recent reviews was conducted to identify additional articles. From these, the authors identified those studies that examined analgesic use in older adults.

RESULTS

There are limited data to suggest that non-frail elders are more likely than their younger counterparts to develop acetaminophen-induced hepatotoxicity. However, decreased hepatic phase II metabolism in frail elders may result in increased risk of hepatotoxicity. It is now well established that older adults are at higher risk of NSAID-induced gastrointestinal toxicity and renal insufficiency. Insofar as opioids, the data that suggest an increased risk of falls, fractures, or delirium need to be tempered by the potential risk of inadequately treating severe chronic OA-related pain.

CONCLUSIONS

Acetaminophen is the mainstay frontline analgesic for treating OA-related pain in older adults. NSAIDs should be limited to short-term use only, and for moderate to severe OA-related pain, opioids may be preferable in individuals without substance abuse or dependence issues.

Risk of unintentional overdose with non-prescription acetaminophen products

BACKGROUND

There is increasing concern over the risk of consumer unintentional misuse of non-prescription (a.k.a. 'over-the-counter') medications containing acetaminophen, which could lead to acute liver failure.

OBJECTIVE

To determine the prevalence of potential misuse and overdose of over-the-counter medications containing acetaminophen, either alone or in combination.

DESIGN

Cross-sectional, structured interviews with literacy assessment.

SETTING

One academic and one community-based general internal medicine practice in Chicago, IL, and one academic general internal medicine practice and a public hospital clinic in Atlanta, GA.

PATIENTS

Five hundred adults seeking primary care, ages 18-80.

MEASUREMENT

Demonstration of how and when patients would take over-the-counter medications containing acetaminophen, alone or in combination with one another, over a 24-hour period.

RESULTS

Overall, 23.8 % of participants demonstrated they would overdose on a single over-the-counter acetaminophen product by exceeding a dose of four grams in a 24-hour period; 5.2 % made serious errors by dosing out more than six grams. In addition, 45.6 % of adults demonstrated they would overdose by 'double-dipping' with two acetaminophen-containing products. In multivariable analyses, limited literacy (Relative Risk Ratio (RR) 1.65, 95 % Confidence Interval (CI) 1.03-2.66) and heavy acetaminophen use in the past six months (RR 1.70, 95 % CI 1.10-2.64) were independently associated with overdosing over-the-counter products.

CONCLUSION

Misunderstanding of the active ingredient and proper instructions for over-the-counter medications containing acetaminophen is common. The potential for errors and adverse events associated with unintentional misuse of these products is substantial, particularly among heavy users of acetaminophen and those with limited literacy.

Paracetamol intoxications: a retrospective population-based study in Iceland

OBJECTIVE

Paracetamol is the most common cause of acute liver failure (ALF) in many countries. Much data on paracetamol toxicity originate from liver transplant centers and tertiary referral institutions. The authors analyzed the population-based annual incidence of paracetamol overdoses and ALF, and described the risk factors for hepatotoxicity.

METHODS

A search was undertaken for the diagnosis of paracetamol overdoses in the diagnoses registry of the National University Hospital of Iceland from 2004 to 2009 serving a population of 219,249 inhabitants. Relevant information was collected from medical records.

RESULTS

A total of 1913 drug-related poisoning episodes were identified and reviewed, 352 (18%) involved paracetamol overdoses. The annual incidence of paracetamol overdoses declined from 30.0 (2004) to 16.0/100,000 per year (2009) (p < 0.05). The female/male ratio was 3.0 and the largest age group was 16-25 years. After the initial examination, 26% were discharged home. Hospitalized index visits were 182 with accidental overdoses constituting 16 (9%) with no gender difference. Compared with intentional overdose the accidental group had higher aminotransferases (p < 0.005). ALF occurred in 3.8% (7/182) of the index visits and the incidence was 0.7/100,000 per year. In the intentional group, 1.2% (2/163) developed ALF versus 25% (4/16) of the accidental group (p = 0.001). Only one patient died from ALF and none underwent liver transplantation.

CONCLUSION

The annual incidence of paracetamol overdoses was high in this population-based study but declined. Young females with intentional overdose accounted for most of the cases, whereas accidental overdoses were more common in older patients. The occurrence of ALF was low and mostly associated with accidental overdose.

Population prevalence of high dose paracetamol in dispensed paracetamol/opioid prescription combinations: an observational study

Background

Paracetamol (acetaminophen) is generally considered a safe medication, but is associated with hepatotoxicity at doses above doses of 4.0 g/day, and even below this daily dose in certain populations.

Methods

The Nova Scotia Prescription Monitoring Program (NSPMP) in the Canadian province of Nova Scotia is a legislated organization that collects dispensing information on all out-of-hospital prescription controlled drugs dispensed for all Nova Scotia residents. The NSPMP provided data to track all paracetamol/opioids redeemed by adults in Nova Scotia, from July 1, 2005 to June 30, 2010. Trends in the number of adults dispensed these prescriptions and the numbers of prescriptions and tablets dispensed over this period were determined. The numbers and proportions of adults who filled prescriptions exceeding 4.0 g/day and 3.25 g/day were determined for the one-year period July 1, 2009 to June 30, 2010. Data were stratified by sex and age (<65 versus 65+).

Results

Both the number of prescriptions filled and the number of tablets dispensed increased over the study period, although the proportion of the adult population who filled at least one paracetamol/opioid prescription was lower in each successive one-year period. From July 2009 to June 2010, one in 12 adults (n = 59,197) filled prescriptions for over 13 million paracetamol/opioid tablets. Six percent (n = 3,786) filled prescriptions that exceeded 4.0 g/day and 18.6% (n = 11,008) exceeded 3.25 g/day of paracetamol at least once. These findings exclude non-prescription paracetamol and paracetamol–only prescribed medications.

Conclusions

A substantial number of individuals who redeem prescriptions for paracetamol/opioid combinations may be at risk of paracetamol-related hepatotoxicity. Healthcare professionals must be vigilant when prescribing and dispensing these medications in order to reduce the associated risks.

Acute and chronic acetaminophen use and renal disease: a case-control study using pharmacy and medical claims

BACKGROUND

Studies have examined the association between acetaminophen (APAP) use and renal disease; however, their interpretation is limited by a number of methodological issues.

OBJECTIVE

To study the association between acute and chronic prescription-acquired APAP use and renal disease.

METHODS

This was a retrospective case-control study of medical and pharmacy claims of a 10% random sample of the enrollees from the IMS LifeLink Health Plans commercial claims dataset for dates of service from January 1, 1997, through December 31, 2009. Subjects were continuously enrolled and aged 18 years or older. Cases had at least 1 incident claim of renal disease defined by ICD-9-CM codes in the primary diagnosis field. Controls were randomly selected from individuals without evidence of renal disease, liver disease, or asthma in medical claims and matched to cases in a 3-to-1 ratio based on 3 variables (age, gender, and geographic region). APAP exposure, dosage, and duration of use were measured in the 7 and 30 days (acute) and in the 1-year (chronic) look-back periods. Multivariable conditional logistic regression was used to estimate the risk of APAP exposure adjusted for comorbidities, use of other nephrotoxic drugs, and health system factors.

RESULTS

There were 4,724 cases and 14,172 controls with a mean (SD) age of 60.8 (17.8) years, and 52.6% were males; 10.9% of cases and 4.2% of controls had APAP exposure in the 30 days pre-index with mean potential maximum daily dosages of 3,846.5 mg and 3,190.8 mg, respectively. Acute APAP exposure was significantly associated with renal disease, and the risk decreased with longer look-back periods (7 days: adjusted odds ratio [OR] = 1.93, 95% CI = 1.61-2.30); 30 days: OR = 1.71, 95% CI = 1.48-1.97). Cumulative APAP dosage greater than 1 kg and APAP use for longer than 30 days in the pre-index year were not significantly associated with an increased risk of renal disease (both P values = 0.900).

CONCLUSIONS

Acute prescription-acquired APAP use was associated with renal disease, while chronic use was not. Because this study assessed APAP use in pharmacy claims, further research accounting for over-the-counter APAP use is warranted before the safety of chronic APAP consumption can be firmly established.