Age and paracetamol self-poisoning

Assessment of Paracetamol Usage Practices and Perceptions among Caregivers for Children Post-COVID-19 in Saudi Arabia: A Cross-Sectional Analysis

Caregivers often use paracetamol in the management of pediatric illnesses without a clear rationale. This study evaluated the perception and practices of caregivers regarding the use of paracetamol in children in Southwestern Saudi Arabia. This study involved a cross-sectional design involving 373 caregivers of children under twelve. The questionnaire elucidated the reasons, usage frequency, and safe usage practices. Data were analyzed using SPSS, applying Chi-square tests and logistic regression. Most caregivers were in the age range of 31-40 years, and with intermediate education. Paracetamol was mainly used for fever, generalized pain and, diarrhea, with fewer opting for other self-care measures. Caregivers with primary or less education were more likely to perceive paracetamol as safe (AOR = 2.98 (1.3-6.73), p = 0.009) and less inclined to check warning labels (AOR: 0.11 (0.05-0.25), p < 0.001) and expiry dates (AOR: 0.063 (0.027-0.14), p < 0.001). The caregiver's education level significantly influenced the determination of treatment duration (χ2 = 21.58 (4), p < 0.001), dosage (χ2 = 30.70 (4), p < 0.001), and frequency of administration (χ2 = 17.77 (4), p = 0.001). In conclusion, inadequate health literacy can result in a lack of attention towards crucial safety information about pediatric paracetamol use. Hence, counselling initiatives should be undertaken to ensure the safe and effective use of paracetamol in children.

Paracetamol (acetaminophen) poisoning: The early years

Paracetamol (acetaminophen) was marketed in the 1950s as a nonprescription analgesic/antipyretic without any preclinical toxicity studies. It became used increasingly for self-poisoning, particularly in the UK and was belatedly found to cause acute liver damage, which could be fatal. Management of poisoned patients was difficult as maximum abnormalities of liver function were delayed for 3 days or more after an overdose. There was no treatment and the mechanism of hepatotoxicity was not known. The paracetamol half-life was prolonged with liver damage occurring when it exceeded 4 h and the Rumack-Matthew nomogram was an important advance that allowed stratification of patients into separate zones of risk. It is used to guide prognosis and treatment and its predictive value could be increased by combining it with the paracetamol half-life. The problems of a sheep farmer in Australia in the early 1970s led to the discovery of the mechanism of paracetamol hepatotoxicity, and the first effective treatment of overdosage with intravenous (IV) cysteamine. This had unpleasant side effects and administration was difficult. N-acetylcysteine soon became the treatment of choice for paracetamol overdose and given early it was very effective when administered either IV or orally. N-acetylcysteine could cause anaphylactoid reactions, particularly early during IV administration when the concentrations were highest. Simpler and shorter regimes with slower initial rates of infusion have now been introduced with a reduced incidence of these adverse effects. In addition, there has been a move to use larger doses of N-acetylcysteine given over longer periods for patients who are more severely poisoned and those with risk factors. There has been much interest recently in the search for novel biomarkers such as microRNAs, procalcitonin and cyclophilin that promise to have greater specificity and sensitivity than transaminases. Paracetamol-protein adducts predict hepatotoxicity and are specific biomarkers of toxic paracetamol metabolite exposure. Another approach would be measurement of the plasma levels of cysteine and inorganic sulfate. It is 50 years since the first effective treatment for paracetamol poisoning and, apart from liver transplantation, there is still no effective treatment for patients who present late.

Unraveling the effect of intra- and intercellular processes on acetaminophen-induced liver injury

In high dosages, acetaminophen (APAP) can cause severe liver damage, but susceptibility to liver failure varies across individuals and is influenced by factors such as health status. Because APAP-induced liver injury and recovery is regulated by an intricate system of intra- and extracellular molecular signaling, we here aim to quantify the importance of specific modules in determining the outcome after an APAP insult and of potential targets for therapies that mitigate adversity. For this purpose, we integrated hepatocellular acetaminophen metabolism, DNA damage response induction and cell fate into a multiscale mechanistic liver lobule model which involves various cell types, such as hepatocytes, residential Kupffer cells and macrophages. Our model simulations show that zonal differences in metabolism and detoxification efficiency are essential determinants of necrotic damage. Moreover, the extent of senescence, which is regulated by intracellular processes and triggered by extracellular signaling, influences the potential to recover. In silico therapies at early and late time points after APAP insult indicated that prevention of necrotic damage is most beneficial for recovery, whereas interference with regulation of senescence promotes regeneration in a less pronounced way.

Paracetamol dosing in hospital and on discharge for older people who are frail or have low body weight

Aims

To describe paracetamol dosing and liver function test (LFT) monitoring in older hospital inpatients who are frail or have low body weight.

Methods

Retrospective observational study, at a 790‐bed metropolitan public health service in Australia. Patients aged ≥70 years, with body weight <50 kg or frailty index based on laboratory data (FI‐Lab) score ≥0.3, who were administered paracetamol during an admission with length‐of‐stay >72 hours, were included. Data were extracted from electronic medical records. Paracetamol doses administered in hospital, and doses prescribed on discharge, were compared against consensus guidelines that recommended ≤60 mg/kg/d for older people weighing <50 kg, and ≤3000 mg/d for frail older people.

Results

In total, 240 admissions (n = 229 patients, mean age 84.7 years) were analysed. During 150 (62.5%) admissions, higher than recommended paracetamol doses were prescribed. On 138 (57.5%) occasions, patients were prescribed paracetamol on discharge, and 112/138 (81.2%) doses were higher than recommended. Most discharge prescriptions (97/138, 70.3%) were for regular administration. The median daily dose on discharge for patients <50 kg was 83.7 mg/kg (interquartile range 73.6–90.9 mg/kg). For frail patients ≥50 kg, the median daily discharge dose was 3990 mg (interquartile range 3000–4000 mg). LFTs were measured in hospital for 151/200 (75.5%) and 93/166 (56.0%) patients who received paracetamol for >48 hours and >5 days, respectively.

Conclusion

Majority of paracetamol doses prescribed for frail or low‐weight older patients in hospital and on discharge were higher than recommended in consensus guidelines. LFTs were not measured for 44% patients who received paracetamol regularly for >5 days. Further studies are needed to explore long‐term outcomes of this practice.

US Hospital Stays in Children and Adolescents With Acetaminophen Poisoning

OBJECTIVES

Acetaminophen poisoning occurs in all age groups; however, hospital-based outcomes of children with these poisonings were not well characterized. Our objectives were to describe the incidence, characteristics, and outcomes of hospital stays in children with acetaminophen poisoning and evaluate the contribution of intentionality.

METHODS

We used the 2016 Kids' Inpatient Database and validated International Classification of Diseases, 10th Revision diagnostic codes to identify hospitalizations of children aged 0 to 19 years for acetaminophen poisoning. We used standard survey methods to generate weighted population estimates and describe characteristics and outcomes, both overall and stratified by intentionality.

RESULTS

There were 9935 (95% confidence interval [CI], 9252-10 619) discharges from acute care hospitals for acetaminophen poisoning in U.S. children aged 0 to 19 years during 2016, corresponding to a population rate of 12.1 (95% CI, 11.3-12.9) hospitalizations per 100 000 children. Most hospitalizations for both intentional and unintentional acetaminophen poisoning occurred in females, with a strongly age-related sex distribution. Median length of stay was 2 days (interquartile range, 1-4 days); however, nearly half of discharges were subsequently transferred to another type of facility (eg, psychiatric hospital). Median hospital charges for acute care were $14 379 (interquartile range, $9162-$23 114), totaling $204.7 million (95% CI, $187.4-$221.9) in aggregate. Of 31 632 hospital discharges associated with self-harm medication poisoning in children aged 0 to 19 years, acetaminophen was the single most commonly implicated agent.

CONCLUSIONS

Acetaminophen poisoning was the most common cause of U.S. hospital stays associated with medication self-harm poisoning. More effective acetaminophen poisoning prevention strategies are needed, which may reduce the burden of this common adolescent malady.

Prognostic factors of acetaminophen exposure in the United States: An analysis of 39,000 patients

Acetaminophen is a frequently used over-the-counter or prescribed medication in the United States. Exposure to acetaminophen can lead to acute liver cytolysis, acute liver failure, acute kidney injury, encephalopathy, and coagulopathy. This retrospective cohort study (1/1/2012 to 12/31/2017) investigated the clinical outcomes of intentional and unintentional acetaminophen exposure using the National Poison Data System data. The frequency of outcomes, chronicity, gender, route of exposure, the reasons for exposure, and treatments as described. Binary logistic regression was used to estimate the prognostic factors and odds ratios (OR) with 95% confidence intervals (CI) for outcomes. This study included 39,022 patients with acetaminophen exposure. Our study demonstrated that the likelihood of developing severe outcomes increased by aging (OR = 1.12, 95% CI: 1.08-1.015) and was lower in females (OR = 0.88, 95% CI: 0.78-0.99). Drowsiness/lethargy (OR = 1.48, 95% CI: 1.22-1.82), agitation (OR = 1.66, 95% CI: 1.11-2.50), coma (OR = 23.95, 95% CI: 17.05-33.64), bradycardia (OR = 2.29, 95% CI: 1.22-4.32), rhabdomyolysis (OR = 8.84, 95% CI: 3.71-21.03), hypothermia (OR = 4.1, 95% CI: 1.77-9.51), and hyperthermia 2.10 (OR = 2.10, 95% CI: 1.04-4.22) were likely associated with major outcomes or death. Treatments included intravenous N-acetylcysteine (61%), oral N-acetylcysteine (10%), vasopressor (1%), hemodialysis (0.7%), fomepizole (0.1%), hemoperfusion (0.03%), and liver transplant (0.1%). In conclusion, it is important to consider clinical presentations of patients with acetaminophen toxicity that result in major outcomes and mortality to treat them effectively.

Trimethylamine N-oxide exacerbates acetaminophen-induced liver injury by interfering with macrophage-mediated liver regeneration

Acetaminophen (APAP)-induced acute liver injury (AILI) is the most frequent cause of acute liver failure in developed countries. Trimethylamine N-oxide (TMAO) is a metabolite derived from the gut microbiota and is relatively high in the circulation of the elderly, individuals with diabetes, and heart disease. Herein, we showed that TMAO exacerbates APAP hepatotoxicity. It is possible that delayed liver repair and regeneration that resulted from reduced macrophage accumulation was responsible for this combined hepatotoxicity. Moreover, matrix metalloproteinase 12 (Mmp12), expressed predominantly by macrophages, were reduced by TMAO in vitro and in vivo. This led to the inhibition of macrophage migration and a subsequent decrease in the recruitment of proresolving macrophages to the necrosis area. Furthermore, the administration of recombinant Mmp12 mitigated the enhanced hepatotoxicity in mice cotreated with TMAO and APAP. Overall, this study indicates that TMAO exacerbates APAP-induced hepatotoxicity by hindering macrophage-mediated liver repair, which might stem from the inhibition of Mmp12. These findings imply that liver damage in patients with high levels of circulating TMAO may be more severe in AILI and should exercise caution when treating with NAC.

Risk Factors for Hepatotoxicity Due to Paracetamol Overdose in Adults

Background and Objectives: Over-the-counter availability and a good safety profile make paracetamol one of the most common analgesics in developed countries but also the leading cause of liver failure due to overdose. The objectives of the study were to identify modifiable risk factors for severe hepatotoxicity following paracetamol overdose in adults. Materials and Methods: A retrospective cohort study involved the consecutive adult patients hospitalized in a toxicological center over a period of seven years due to paracetamol overdose. Complete medical datasets of laboratory and anamnestic variables were analyzed and validated by means of logistic regression model. Results: A total of 185 patients entered the study, including 25 individuals who developed severe hepatotoxicity (plasma aminotransferases levels above 1000 UI/L) and 31 individuals with mild to moderate liver injury (plasma aminotransferases levels above upper normal range, but below 1000 UI/L). In the univariable analysis, significant hepatotoxicity risk factors were male gender, alcohol abuse, an ingested paracetamol dose, and a timespan from ingestion to hospital admission. The later one was the only significant risk factor in the multivariable model (adjusted odds ratio 1.08; 95% CI: 1.03-1.12). Conclusions: A delay in hospital admission, resulting in a delayed administration of disease-specific treatment outweighs any other known risk factors of paracetamol-induced hepatotoxicity.

Acute Liver Injury With Therapeutic Doses of Acetaminophen: A Prospective Study

BACKGROUND AND AIMS

Because of the extensive use of this drug, further evaluation of acute liver injury (ALI) with therapeutic doses of acetaminophen (APAP; ≤6 g/d) is required. We characterize ALI with therapeutic doses of APAP and determine the host factors associated with disease severity and the predictors of outcome.

APPROACH AND RESULTS

All patients admitted with severe APAP-related ALI in our center were included from 2002 to 2019, either attributable to therapeutic doses or overdose. ALI with therapeutic doses (ALITD) was defined as APAP intake <6 g/d. Overall, 311 of 400 patients with APAP-related ALI had overdose and 89 had taken therapeutic doses. The host factors associated with ALITD were fasting ≥1 day (47.5% of ALITD patients vs. 26% in overdose; P = 0.001), excess drinking (93.3% vs. 48.5%; P < 0.0001), and repeated APAP use (4 vs. 1 day; P < 0.0001). Patients with ALITD were older (44 vs. 30.7 years; P < 0.0001) and had more severe liver injury. In the overall population, the independent predictors of disease severity were older age, longer duration of APAP, and excess drinking. Thirty-day survival was lower in ALITD than in overdose (87.2 ± 3.6% vs. 94.6 ± 1.3%; P = 0.02). Age and the presence of at least one of the King's College Hospital criteria were independent predictors of 30-day survival whereas the pattern of drug intoxication, excess drinking, and bilirubin were not.

CONCLUSIONS

ALI with therapeutic doses of APAP is associated with more severe liver injury than overdose. It only occurs in patients with excess drinking and/or fasting. A warning should be issued about the repeated use of nontoxic doses of APAP in patients with those risk factors.

Sociodemographic and Clinical Features in Patients Presented With Accidental and Deliberate Self-Poisoning: A Comparative Study from Lady Reading Hospital Medical Teaching Institution, Peshawar, Pakistan

Objectives

To evaluate the sociodemographic and clinical characteristics of patients presented with acute self-poisoning at a tertiary care hospital in Pakistan.

Methods and Patients

A comparative study was conducted at Lady Reading Hospital MTI between May 2018 to May 2019 for a duration of 12 months. All patients diagnosed with acute self-poisoning were included in the study. Patients with inconclusive diagnosis, who were dead prior to the arrival to the hospital, or had an incomplete history of poison exposure were excluded from the study. At the time of arrival to the emergency department, the patient was first stabilized. Patients were grouped into two according to the type of exposure, i.e., accidental self-poisoning and deliberate self-poisoning (DSP). Sociodemographic and clinical characteristics of patients were recorded in a preformed proforma. The data were analyzed using Statistical Package for the Social Sciences (SPSS) Version 26 (IBM Corp., Armonk, NY, USA).

Results

The mortality rate in patients with accidental poisoning was 9.62%, whereas it was 26.28% in DSP patients. Data were stratified according to the mode of poisoning, i.e., accidental vs DSP, and variables were assessed in patients who did not survive. It was found that 60% of patients who died in the accidental group were aged 0-15 years. In contrast, only one patient between aged 0-15 years died in the DSP group and the majority of the deaths occurred in those aged 25.1-35 years (31 [75.6%]).

Conclusions

In conclusion, women more often attempted suicide, whereas males suffered accidental poisoning more frequently. Firstly, we found a female predominance in the DSP group, whereas males were more prevalent in with young children experiencing accidental poisoning. Longer time from ingestion of poison to the arrival is associated with poor patient prognosis.

Alcohol consumption is associated with the severity and outcome of acute liver injury/failure

BACKGROUND & AIMS

Non-medical factors which contribute to the severity of acute liver failure (ALF) remain poorly defined. The association of alcohol consumption on the severity of presentation and outcome were determined in patients with ALF and acute liver injury (ALI) in a large, multicentre registry.

METHODS

Alcohol consumption during the 6 months prior to study entry was analysed in 1170 patients enrolled in the ALF Study Group Registry. Consumption was categorized as none/minimal (<3 alcoholic beverages/week) or at least moderate (≥3/week). Clinical characteristics, the severity of liver injury at presentation (ALI or ALF) and outcome were compared.

RESULTS

In patients with acetaminophen (APAP) overdose, at least moderate alcohol consumption was associated with higher peak aminotransferases, bilirubin, creatinine and INR on admission, compared to no/minimal consumption. In patients with non-APAP ALI/ALF, at least moderate alcohol consumption was associated with higher peak aminotransferases and creatinine. In APAP, non-APAP or all aetiologies, at least moderate alcohol consumption was associated with a 75%, 89% and 82% higher odds, respectively, of presenting as ALF rather than ALI (all P < .005). At least moderate alcohol consumption increased the odds of death by 45% (P = .01) across all aetiologies. In multivariate analysis, older age, non-Caucasian race, peak INR, peak bilirubin and at least moderate alcohol consumption were significantly associated with death. Finally, in Kaplan-Meier analysis of patients with all aetiologies, at least moderate alcohol consumption was associated with decreased time-dependent survival (P = .002).

CONCLUSION

Alcohol consumption adversely affects the presentation and outcome of both APAP- and non-APAP-induced ALI/ALF.

Increased risk of congestive heart failure in patients with acetaminophen poisoning: A nationwide cohort study

Acetaminophen poisoning increases cytochrome P450 2E1 expression and reactive oxygen species production, which may lead to maladaptive myocardial remodeling and congestive heart failure (CHF). We conducted a nationwide cohort study to investigate the incidence and risk of CHF in patients with acetaminophen poisoning. We identified a cohort of adult patients with newly diagnosed acetaminophen poisoning in the inpatient claims of the Taiwan National Health Insurance Research Database for the 1998-2011 period. A comparison cohort was frequency matched at a 4:1 ratio for sex, age and index year. All patients were followed up until the occurrence of CHF, withdrawal from the National Health Insurance program, or December 31, 2011. Cox proportional hazards models were employed to calculate the risk of CHF in the acetaminophen poisoning cohort compared with the comparison cohort, and the hazard ratios with 95% confidence intervals are presented. A total of 3546 and 14 184 patients with and without acetaminophen poisoning were followed up for a total of 25 856 and 102 119 person-years, respectively. The overall incidence of CHF was higher in the acetaminophen poisoning cohort than in the comparison cohort (8.12 vs. 5.19 per 10 000 person-years). After adjustment for covariates, the acetaminophen poisoning cohort exhibited a 1.59-fold higher risk of CHF (adjusted hazard ratio = 1.59; 95% confidence interval = 1.43-1.75) than did the comparison cohort. Patients with acetaminophen poisoning exhibited a significantly higher risk of CHF compared with the comparison cohort. Clinicians should follow up heart function in patients with acetaminophen poisoning.

Acetaminophen Poisoning May Increase Coronary Artery Disease Risk: A Nationwide Cohort Study

The purpose of this nationwide cohort study was to investigate the incidence and risk of coronary artery disease (CAD) in patients with acetaminophen (APAP) poisoning. We identified the patients with APAP poisoning and randomly selected comparison patients according to a 1:4 ratio, matching them by age, sex, and the index year using data from the National Health Insurance Research Database from 2000 to 2010. We traced both cohorts until a diagnosis of CAD, loss to follow-up, or the end of 2011. In total, 2723 patients with APAP poisoning and 10,892 comparison patients have followed. The incidence rate of CAD was higher in the APAP poisoning cohort than in the non-APAP poisoning cohort (1.53 vs 0.87 per 1000 patient-years). The APAP poisoning cohort exhibited a 1.85-fold higher risk of CAD than did the non-APAP poisoning cohort (adjusted hazard ratio [aHR] 1.85; 95% confidence interval [CI] 1.16-2.94). Male sex, advanced age, and hypertension were independently associated with CAD risk. The risk of CAD was considerably higher within 3 years following APAP poisoning (aHR 2.73; 95% CI 1.31-5.69). This study indicated that APAP poisoning may increase risk of CAD development.

Are some people at increased risk of paracetamol-induced liver injury? A critical review of the literature

Purpose

Paracetamol is one of the world’s most commonly used drugs. In overdose, it is well established to be hepatotoxic. The aim of this review was to identify factors that have been, or actually are, associated with the development of liver injury after paracetamol exposure in humans.

Method

Google Scholar and PubMed were searched on various dates between December 2016 and March 2017. Papers identified had their references analysed for further studies that might be relevant.

Results

At the time of writing, there was little good quality clinical evidence—from studies of paracetamol overdose or therapeutic use—to suggest that any groups of people are relatively protected from, or are at greater risk of, liver injury. The factors that were historically used to indicate higher risk in the UK have no good quality clinical evidence to support their re-introduction into clinical practice. The safe (and still effective) oral dose of paracetamol in patients weighing less than 50 kg has not been established.

Conclusion

There is no patient group that is unequivocally at elevated risk of paracetamol-induced liver toxicity. We propose two clinical scenarios that warrant further research. Firstly, there is a need to establish whether the dose of paracetamol should be reduced in patients with low body weight. Secondly, if or when genomic information regarding individual patients becomes readily available to inform prescribing, we propose the contribution of the genome to paracetamol toxicity should be re-investigated with robustly designed studies. Such studies could enhance the safe use of one of the most frequently taken drugs.

Electronic supplementary material

The online version of this article (10.1007/s00228-017-2356-6) contains supplementary material, which is available to authorized users.

Student-selected component in the medical curriculum: investigations and psychiatric referral for paracetamol overdose in an accident and emergency department

BACKGROUND

A student-selected component (SSC) of the medical curriculum requires the student to be self-directed in locating and undertaking a placement in a clinical specialty of their choosing and completing a project. The clinical area for experience was an accident and emergency department, and our topic was a focused audit on the investigations and referral for paracetamol overdose. The purpose of this paper is twofold: to reflect on the education value to medical students of an SSC in a medical curriculum, and to highlight learning and understanding through completion of an audit.

MATERIALS AND METHODS

An audit approach was applied. The aim of the project study was to investigate the level of compliance with best-practice guidelines for investigations and psychiatric referral in paracetamol overdose.

RESULTS

A total of 40 cases meeting the inclusion criteria were randomly selected. The sample had a mean age of 27 years, of whom 70.5% were female, and the ingested dose of paracetamol ranged from 0.864 to 80 g. Paracetamol abuse may present as intentional and unintentional overdose. In our study, 85% of cases were identified as intentional overdose and 76% had a history of psychiatric illness. Generally, medical management was compliant with guidelines, with some minor irregularities. The international normalized ratio was the most underperformed test.

CONCLUSION

Our choice of topic, paracetamol overdose, contributed to our understanding of the breadth of factors to be considered in the emergency medical management of a patient. In this regard, we had the benefit of understanding how the diagnostic and therapeutic factors, when applied in accordance with best-practice guidelines, work very effectively. The SSC impacted positively on our cognitive, personal, and professional development. In facilitating the student with choice, the SSC encouraged self-direction and proactivity. We gained experience in the discipline of research and acquired some skills in independent thinking and analysis.

Massive paracetamol overdose: an observational study of the effect of activated charcoal and increased acetylcysteine dose (ATOM-2)

CONTEXT

Paracetamol is commonly taken in overdose, with increasing concerns that those taking "massive" overdoses have higher rates of hepatotoxicity and may require higher doses of acetylcysteine. The objective was to describe the clinical characteristics and outcomes of "massive" (≥ 40 g) paracetamol overdoses.

METHODS

Patients were identified through the Australian Paracetamol Project, a prospective observational study through Poisons Information Centres in NSW and Queensland, over 3 and 1.5 years, respectively, and retrospectively from three clinical toxicology unit databases (over 2.5 to 20 years). Included were immediate-release paracetamol overdoses ≥ 40 g ingested over ≤ 8 h. Outcomes measured included paracetamol ratio[defined as the ratio of the first paracetamol concentration taken 4-16 h post-ingestion to the standard (150 mg/L at 4 h) nomogram line at that time] and hepatotoxicity (ALT >1000 U/L).

RESULTS

Two hundred paracetamol overdoses were analysed, reported median dose ingested was 50 g (interquartile range (IQR): 45-60 g) and median paracetamol ratio 1.9 (IQR: 1.4-2.9, n = 173). One hundred and ninety-three received acetylcysteine at median time of 6.3 h (IQR: 4-9.3 h) post-ingestion. Twenty-eight (14%) developed hepatotoxicity, including six treated within 8 h of ingestion. Activated charcoal was administered to 49(25%), at median of 2 h post-ingestion (IQR:1.5-5 h). Those receiving activated charcoal (within 4 h of ingestion), had significantly lower paracetamol ratio versus those who did not: 1.4 (n = 33, IQR: 1.1-1.6) versus 2.2 (n = 140, IQR: 1.5-3.0) (p < .0001) (paracetamol concentration measured ≥ 1 h after charcoal). Furthermore, they had lower rates of hepatotoxicity [unadjusted OR: 0.12 (95% CI: <0.001-0.91); adjusted for time to acetylcysteine OR: 0.20 (95%CI: 0.002-1.74)]. Seventy-nine had a paracetamol ratio ≥2, 43 received an increased dose of acetylcysteine in the first 21 h; most commonly a double dose in the last bag (100 to 200 mg/kg/16 h). Those receiving increased acetylcysteine had a significant decrease risk of hepatotoxicity [OR:0.27 (95% CI: 0.08-0.94)]. The OR remained similar after adjustment for time to acetylcysteine and paracetamol ratio.

CONCLUSION

Massive paracetamol overdose can result in hepatotoxicity despite early treatment. Paracetamol concentrations were markedly reduced in those receiving activated charcoal within 4 h. In those with high paracetamol concentrations, treatment with increased acetylcysteine dose within 21 h was associated with a significant reduction in hepatotoxicity.

Targeted metabolomic profiling indicates structure-based perturbations in serum phospholipids in children with acetaminophen overdose

Phospholipids are an important class of lipids that act as building blocks of biological cell membranes and participate in a variety of vital cellular functions including cell signaling. Previous studies have reported alterations in phosphatidylcholine (PC) and lysophosphatidylcholine (lysoPC) metabolism in acetaminophen (APAP)-treated animals or cell cultures. However, little is known about phospholipid perturbations in humans with APAP toxicity. In the current study, targeted metabolomic analysis of 180 different metabolites including 14 lysoPCs and 73 PCs was performed in serum samples from children and adolescents hospitalized for APAP overdose. Metabolite profiles in the overdose group were compared to those of healthy controls and hospitalized children receiving low dose APAP for treatment of pain or fever (therapeutic group). PCs and lysoPCs with very long chain fatty acids (VLCFAs) were significantly decreased in the overdose group, while those with comparatively shorter chain lengths were increased in the overdose group compared to the therapeutic and control groups. All ether linked PCs were decreased in the overdose group compared to the controls. LysoPC-C26:1 was highly reduced in the overdose group and could discriminate between the overdose and control groups with 100% sensitivity and specificity. The PCs and lysoPCs with VLCFAs showed significant associations with changes in clinical indicators of drug metabolism (APAP protein adducts) and liver injury (alanine aminotransferase, or ALT). Thus, a structure-dependent reduction in PCs and lysoPCs was observed in the APAP-overdose group, which may suggest a structure-activity relationship in inhibition of enzymes involved in phospholipid metabolism in APAP toxicity.

Acetaminophen hepatotoxicity in mice: Effect of age, frailty and exposure type

Acetaminophen is a commonly used analgesic that can cause severe hepatotoxicity in overdose. Despite old age and frailty being associated with extensive and long-term utilization of acetaminophen and a high prevalence of adverse drug reactions, there is limited information on the risks of toxicity from acetaminophen in old age and frailty. This study aimed to assess changes in the risk and mechanisms of hepatotoxicity from acute, chronic and sub-acute acetaminophen exposure with old age and frailty in mice. Young and old male C57BL/6 mice were exposed to either acute (300 mg/kg via oral gavage), chronic (100 mg/kg/day in diet for six weeks) or sub-acute (250 mg/kg, t.i.d., for three days) acetaminophen, or saline control. Pre-dosing mice were scored for the mouse clinical frailty index, and after dosing serum and liver tissue were collected for assessment of toxicity and mechanisms. There were no differences with old age or frailty in the degree of hepatotoxicity induced by acute, chronic or subacute acetaminophen exposure as assessed by serum liver enzymes and histology. Age-related changes in the acetaminophen toxicity pathways included increased liver GSH concentrations, increased NQO1 activity and an increased pro- and anti-inflammatory response to acetaminophen in old age. Frailty-related changes included a negative correlation between frailty index and serum protein, albumin and ALP concentrations for some mouse groups. In conclusion, although there were changes in some pathways that would be expected to influence susceptibility to acetaminophen toxicity, there was no overall increase in acetaminophen hepatotoxicity with old age or frailty in mice.

Drug-induced liver injury in older adults

Drug-induced liver injury (DILI) is an important cause of hospitalisation and of medication deregistration. In old age, susceptibility to DILI is affected by changes in physiology and increased interindividual variability, compounded by an increased prevalence of disease and the frailty syndrome. While dose-related or predictable DILI reactions are often detected in preclinical trials, the occurrence of rare hypersensitivity or idiosyncratic reactions cannot be reliably predicted from preclinical studies or even by clinical trials. The limited participation of older adults in clinical trials means that the susceptibility of this population to DILI is largely unknown. Vigilance during clinical trials and postmarketing surveillance must be universally practised. A systematic approach should be taken to determine not only which medicines are hepatotoxic and should be removed from the market, but also the hepatotoxicity risks from marketed drugs to consumers with different characteristics, many of whom are older people.

Hepatoprotective activity of methanolic extract of Syzygium jambos (Linn.) leaf against paracetamol intoxicated Wistar albino rats

Hepatoprotective activity of methanolic extract of Syzygium jambos (Alston) (Linn.) leaves against Paracetamol-induced hepatic damage in Wistar albino rats was observed at two different doses, 100 and 200 mg/kg body weight. The healthy control, disease control, and standard drug Silymarin-treated groups were also maintained for the comparison. The liver marker enzymes SGOT, SGPT, ALKP, Serum Bilirubin and other metabolic parameters like total cholesterol, HDL-cholesterol were evaluated in all the experimental groups. The changes in liver function parameters were significant in comparison to disease control group and the observed efficacy was comparable to standard drug. The efficacy of the extract was found to be dose dependent. The histopathology study of liver also supports the presence of hepatoprotective activity in S. jambos by showing improved cytoarchitecture of liver cells in the treated groups. The results obtained in this study indicate necessity for further research on isolation and characterization of functional molecules from the extract.

The effect of aging on acetaminophen pharmacokinetics, toxicity and Nrf2 in Fischer 344 rats

We investigated the effect of aging on hepatic pharmacokinetics and the degree of hepatotoxicity following a toxic dose of acetaminophen. Young and old male Fischer 344 rats were treated with 800 mg/kg acetaminophen (young n = 8, old n = 5) or saline (young n = 9, old n = 9). Serum measurements showed old rats treated with acetaminophen had significantly lower serum alanine aminotransferase and higher acetaminophen and acetaminophen glucuronide levels and creatinine, compared with acetaminophen treated young rats (p < .05). Immunoblotting and activity assays showed old saline-treated rats had twofold lower cytochrome P450 2E1 activity and threefold higher NAD(P)H quinone oxireductase 1 protein expression and activity than young saline-treated rats (p < .05), although Nrf2, glutathione cysteine ligase-modulatory subunit, glutathione cysteine ligase-catalytic subunit, and cytochrome P450 2E1 protein expressions were unchanged. Primary hepatocytes isolated from young rats treated with 10 mM acetaminophen had lower survival than those from old rats (52.4% ± 5.8%, young; 83.6% ± 1.7%, old, p < .05). The pharmacokinetic changes described may decrease susceptibility to acetaminophen-induced hepatotoxicity but may increase risk of nephrotoxicity in old age.

Opioid utilization patterns among medicare patients with diabetic peripheral neuropathy

BACKGROUND

Diabetic peripheral neuropathy (DPN) affects a large percentage of patients with type 2 diabetes and is associated with moderate-to-severe pain. Patients with DPN bear a substantial economic burden as a result of increased overall healthcare utilization. The reported costs of treating DPN are nearly $11 billion, with elderly (aged ≥65 years) patients with type 2 diabetes accounting for 93.1% ($10.2 billion) of the total costs.

OBJECTIVES

To describe the real-world utilization patterns of long-acting opioids (LAOs) and chronic short-acting opioids (SAOs) use in a sample of Medicare enrollees (aged ≥65 years) with painful DPN, and to identify potential areas for improvement in the management of elderly patients with painful DPN who are treated with opioids.

METHODS

In this retrospective pharmacy claims analysis, the Chronic Opioid Medication Use Evaluation (MUE) software was used to import and analyze individual plan, retrospective pharmacy utilization claims data from the MarketScan claims databases. Patients aged ≥65 years who had painful DPN as identified by ≥2 International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes for painful DPN (250.6X or 357.2) in at least 2 quarters in 2009, and who had ≥1 claims for LAO and/or chronic use of SAO (≥60 days of continuous therapy), were selected for analysis. Pharmacy claim data were extracted for 12 months, and various opioid utilization measures were reported.

RESULTS

A total of 1448 unique Medicare patients with painful DPN were identified who had 11,740 claims for an LAO and/or chronic use of an SAO. Of the 1448 patients, 62% had chronic use of an SAO, and of these, 89% had no concurrent claim for LAO (minimum, 60-day overlap). The most frequently filled LAOs were fentanyl transdermal (38%), oxycodone controlled release (CR; 26%), and morphine CR/extended release (ER)/sustained release (SR; 20%). The daily average consumptions for fentanyl transdermal, oxycodone CR, and morphine CR/ER/SR were 0.3, 2.5, and 2.4, respectively. Among the study population, 15.2% of the patients filled an LAO or SAO prescription at ≥2 pharmacies. Furthermore, these elderly patients with painful DPN used greater doses of LAOs than what is recommended in the package insert, and 1.6% of patients used high doses of acetaminophen and 15.2% utilized multiple pharmacies to obtain their opioid prescriptions. Moreover, this population had prevalent concomitant use of opioids and prescribed gastrointestinal (GI) medications.

CONCLUSION

Results from our retrospective pharmacy claims analysis demonstrated that elderly patients with painful DPN use doses of LAOs above those recommended in the package insert, with some patients using high doses of acetaminophen and utilizing multiple pharmacies to obtain their opioid prescriptions. In addition, this population had prevalent concomitant use of opioids and prescription GI medications. The use of software, such as the Opioid MUE, to monitor opioid drug utilization trends and examine other utilization measures can assist healthcare decision makers and payers in their utilization reviews to appropriately manage this population.

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.

Staggered overdose pattern and delay to hospital presentation are associated with adverse outcomes following paracetamol-induced hepatotoxicity

AIMS

Paracetamol (acetaminophen) poisoning remains the major cause of severe acute hepatotoxicity in the UK. In this large single centre cohort study we examined the clinical impact of staggered overdoses and delayed presentation following paracetamol overdose.

RESULTS

Between 1992 and 2008, 663 patients were admitted with paracetamol-induced severe liver injury, of whom 161 (24.3%) had taken a staggered overdose. Staggered overdose patients were significantly older and more likely to abuse alcohol than single time point overdose patients. Relief of pain (58.2%) was the commonest rationale for repeated supratherapeutic ingestion. Despite lower total ingested paracetamol doses and lower admission serum alanine aminotransferase concentrations, staggered overdose patients were more likely to be encephalopathic on admission, require renal replacement therapy or mechanical ventilation and had higher mortality rates compared with single time point overdoses (37.3% vs. 27.8%, P= 0.025), although this overdose pattern did not independently predict death. The King's College poor prognostic criteria had reduced sensitivity (77.6, 95% CI 70.8, 81.5) for this pattern of overdose. Of the 396/450 (88.0%) single time point overdoses in whom accurate timings could be obtained, 178 (44.9%) presented to medical services >24 h following overdose. Delayed presentation beyond 24 h post overdose was independently associated with death/liver transplantation (OR 2.25, 95% CI 1.23, 4.12, P= 0.009).

CONCLUSIONS

Both delayed presentation and staggered overdose pattern are associated with adverse outcomes following paracetamol overdose. These patients are at increased risk of developing multi-organ failure and should be considered for early transfer to specialist liver centres.

Age-related changes in the hepatic pharmacology and toxicology of paracetamol

Optimal pharmacotherapy is determined when the pharmacokinetics and pharmacodynamics of the drug are understood. However, the age-related changes in pharmacokinetics and pharmacodynamics, as well as the increased interindividual variation mean optimal dose selection are a challenge for prescribing in older adults. Poor understanding of how hepatic clearance and toxicity are different with age results in suboptimal dose selection, poor efficacy, and/or increased toxicity. Of particular concern is the analgesic paracetamol which has been in use for more than 50 years and is consumed by a large proportion of older adults. Paracetamol is considered to be a relatively safe drug; however, caution must be taken because of its potential for toxicity. Paracetamol-induced liver injury from accidental overdose accounts for up to 55% of cases in older adults. Better understanding of how age affects the hepatic clearance and toxicity of drugs will contribute to evidence-based prescribing for older people, leading to fewer adverse drug reactions without loss of benefit.

Overdose pattern and outcome in paracetamol-induced acute severe hepatotoxicity

AIMS

Paracetamol (acetaminophen) hepatotoxicity is the commonest cause of acute liver failure (ALF) in the UK. Conflicting data regarding the outcomes of paracetamol-induced ALF resulting from different overdose patterns are reported.

METHODS

Using prospectively defined criteria, we have analysed the impact of overdose pattern upon outcome in a cohort of 938 acute severe liver injury patients admitted to the Scottish Liver Transplantation Unit.

RESULTS

Between 1992 and 2008, 663 patients were admitted with paracetamol-induced acute severe liver injury. Of these patients, 500 (75.4%) had taken an intentional paracetamol overdose, whilst 110 (16.6%) had taken an unintentional overdose. No clear overdose pattern could be determined in 53 (8.0%). Unintentional overdose patients were significantly older, more likely to abuse alcohol, and more commonly overdosed on compound narcotic/paracetamol analgesics compared with intentional overdose patients. Unintentional overdoses had significantly lower admission paracetamol and alanine aminotransferase concentrations compared with intentional overdoses. However, unintentional overdoses had greater organ dysfunction at admission, and subsequently higher mortality (unintentional 42/110 (38.2%), intentional 128/500 (25.6%), P < 0.001). The King's College poor prognostic criteria had reduced sensitivity in unintentional overdoses (77.8%, 95% confidence intervals (CI) 62.9, 88.8) compared with intentional overdoses (89.9%, 95% CI 83.4, 94.5). Unintentional overdose was independently predictive of death or liver transplantation on multivariate analysis (odds ratio 1.91 (95% CI 1.07, 3.43), P = 0.032).

CONCLUSIONS

Unintentional paracetamol overdose is associated with increased mortality compared with intentional paracetamol overdose, despite lower admission paracetamol concentrations. Alternative prognostic criteria may be required for unintentional paracetamol overdoses.

Long-term prognosis for transplant-free survivors of paracetamol-induced acute liver failure

BACKGROUND

The prognosis for transplant-free survivors of paracetamol-induced acute liver failure remains unknown.

AIM

To examine whether paracetamol-induced acute liver failure increases long-term mortality.

METHODS

We followed up all transplant-free survivors of paracetamol-induced acute liver injury, hospitalized in a Danish national referral centre during 1984-2004. We compared age-specific mortality rates from 1 year post-discharge through 2008 between those in whom the liver injury led to an acute liver failure and those in whom it did not.

RESULTS

We included 641 patients. On average, age-specific mortality rates were slightly higher for the 101 patients whose paracetamol-induced liver injury had caused an acute liver failure (adjusted mortality rate ratio = 1.70, 95% CI 1.02-2.85), but the association was age-dependent, and no survivors of acute liver failure died of liver disease, whereas suicides were frequent in both groups. These observations speak against long-term effects of acute liver failure. More likely, the elevated mortality rate ratio resulted from incomplete adjustment for the greater prevalence of substance abuse among survivors of acute liver failure.

CONCLUSIONS

Paracetamol-induced acute liver failure did not affect long-term mortality. Clinical follow-up may be justified by the cause of the liver failure, but not by the liver failure itself.

A cross-sectional observation of the factors associated with deliberate self-poisoning with acetaminophen: impact of gender differences and psychiatric intervention

OBJECTIVES

The objectives of this study were to determine the risk factors and life stressors that are prevalent among the acetaminophen deliberate self-poisoning (DSP) cases, to identify gender differences in the associated factors, and to determine the prevalence of psychiatric diagnosis and the patterns and types of psychotherapeutic interventions provided by psychiatrists.

METHODS

This is a cross-sectional study, a retrospective descriptive case review of hospital admissions for acetaminophen DSP.

RESULTS

There were 177 incidences of DSP during the study period. The mean age of the cases was 23.1 +/- 7.3 years and 84.1% of them were females. The risk factors were more significantly associated with males: chronic ethanol intake (p = 0.04), higher reported dose ingested (p = 0.01), higher latency time (p = 0.04) and longer hospital stay (p = 0.03). The most commonly reported psychotherapeutic interventions used by psychiatrists were psychoeducation of the patient, followed by referral to a psychiatric clinic, family psychoeducation and psychotropic medication. Sertraline (SSRI) was the most frequently prescribed antidepressant.

CONCLUSIONS

Males have been shown to use more toxic doses and to delay treatment due to high latency time. Most DSP patients have different life stressors and psychiatric diagnoses that may be associated with varying degrees of suicidal intent. All patients presenting following DSP need to be carefully screened for psychiatric illness. Randomized controlled studies need to be conducted on DSP patients with psychiatric illness to determine which treatments are effective.

Outcome of acute liver failure in the elderly

Older age is considered a poor prognostic factor in acute liver failure (ALF) and may still be considered a relative contraindication for liver transplantation for ALF. We aimed to evaluate the impact of older age, defined as age > or = 60 years, on outcomes in patients with ALF. One thousand one hundred twenty-six consecutive prospective patients from the US Acute Liver Failure Study Group registry were studied. The median age was 38 years (range, 15-81 years). One thousand sixteen patients (90.2%) were younger than 60 years (group 1), and 499 (49.1%) of these had acetaminophen-induced ALF; this rate of acetaminophen-induced ALF was significantly higher than that in patients > or = 60 years (group 2; n = 110; 23.6% with acetaminophen-induced ALF, P < 0.001). The overall survival rate was 72.7% in group 1 and 60.0% in group 2 (not significant) for acetaminophen patients and 67.9% in group 1 and 48.2% in group 2 for non-acetaminophen patients (P < 0.001). The spontaneous survival rate (ie, survival without liver transplantation) was 64.9% in group 1 and 60.0% in group 2 (not significant) for acetaminophen patients and 30.8% in group 1 and 24.7% in group 2 for non-acetaminophen patients (P = 0.27). Age was not a significant predictor of spontaneous survival in multiple logistic regression analyses. Group 2 patients were listed for liver transplantation significantly less than group 1 patients. Age was listed as a contraindication for transplantation in 5 patients. In conclusion, in contrast to previous studies, we have demonstrated a relatively good spontaneous survival rate for older patients with ALF when it is corrected for etiology. However, overall survival was better for younger non-acetaminophen patients. Fewer older patients were listed for transplantation.

Treatment of chronic non-malignant pain in the elderly: safety considerations

Non-malignant pain in the elderly is frequently under-treated, with physicians appearing to be uncertain concerning how best to achieve optimum management of this common problem in individual cases. The aim of this review is to provide a brief overview and discuss the variety of interacting factors that contribute to the continuing under-treatment of chronic non-malignant pain in the older population. The central objective is to encourage safer and more effective pain management in a population that is highly vulnerable to painful conditions and to the consequences of poorly treated pain. Under-treatment of pain as experienced by the elderly is largely a consequence of uncertainties that arise within a complex environment that is underscored and exacerbated by the progressive and rapid aging of the global population. Uncertainties include the optimum management of pain in geriatric syndromes, frailty and dementia, and their impact on diagnosis, pain assessment and choices of treatment modalities. There is an inadequate evidence base for pharmacological interventions in older persons with respect to pharmacokinetic and pharmacodynamic changes that occur with aging. In this review, the prevalence of chronic pain and the incidence of adverse drug reactions are identified as factors that encourage conservatism in prescribing, as are major predictors of adverse drug reactions, i.e. aging, inappropriate combinations of medications and polypharmacy. The major classes of analgesic drugs are summarized with reference to their mechanisms of action, analgesic properties and known adverse effects. Although all medications have associated risks, the use of analgesics in managing persistent pain in elderly people is widely supported and guided on the basis of clinical experience and consensus among specialists in geriatrics and pain management. It is concluded that the absence of trial data, specific to the elderly, is substantially offset by information based on clinical experience and expert consensus statements. Used appropriately, analgesic and adjuvant treatments can and should be employed to relieve persistent pain in the expanding elderly population.

Acetaminophen hepatotoxicity and acute liver failure

Acetaminophen-induced hepatotoxicity is a common consequence of acetaminophen overdose and may lead to acute liver failure (ALF). Currently acetaminophen is the most common cause of ALF in both United States and United Kingdom, with a trend to increasing incidence in the United States. N-acetylcysteine is the most effective drug to prevent progression to liver failure with acetaminophen hepatotoxicity. Liver transplantation is the only definitive therapy that will significantly increase the chances of survival for advanced ALF. This communication reviews current information regarding causes and management of acetaminophen-induced hepatotoxicity and ALF.

Acetaminophen usage patterns and concentrations of glutathione and gamma-glutamyl transferase in alcoholic subjects

STUDY OBJECTIVES

To determine if subjects with chronic alcoholism are predisposed to acetaminophen-induced hepatotoxicity, and to determine the contributing factors.

DESIGN

Prospective cohort study.

SETTING

Community-based crisis intervention center.

SUBJECTS

One hundred eighty-eight subjects who answered "yes" to at least one of the four questions on the CAGE (Cut down-Annoyed-Guilty-Eye-opener) questionnaire for identifying alcoholism, and 10 healthy volunteers (controls).

INTERVENTION

A history, physical examination, urine toxicologic analysis, ethanol and drug therapy history, and venous blood samples were collected on all subjects.

MEASUREMENTS AND MAIN RESULTS

Venous blood was analyzed for a liver profile, prothrombin time, and total and oxidized glutathione concentrations. A significantly higher proportion of daily drinkers were regular daily users (29.2% [45/154] vs 11.8% [4/34], p=0.0497) as well as abusers (35.7% [55/154] vs 14.7% [5/34], p=0.0237) of acetaminophen compared with non daily drinkers. Alcoholic subjects with elevated gamma-glutamyl transferase (GGT >or= 51 U/L) levels had significantly lower median plasma glutathione concentrations (2.33 micromol/L, 95% confidence interval [CI] 1.74-2.69 micromol/L) compared with those of alcoholic subjects with normal GGT concentrations (5.97 micromol/L, 95% CI 4.39-7.03 micromol/L, p<0.0001) and healthy volunteers (6.59 micromol/L, 95% CI 4.79-9.65 micromol/L, p=0.0002). A significant inverse correlation was also noted between the GGT concentration and the plasma total glutathione concentration (r = -0.62, p<0.0001). None of the 188 subjects met all preset criteria for hepatotoxicity.

CONCLUSIONS

Daily drinkers were more than twice as likely as non daily drinkers to be regular daily acetaminophen users and abusers. Alcoholic subjects with elevated GGT concentrations had significantly lower plasma total glutathione concentrations, and plasma total glutathione concentrations inversely correlated with GGT concentrations. Elevated GGT concentrations may be a clinical marker of depleted glutathione in alcoholic subjects. Acetaminophen-induced hepatotoxicity appears to be uncommon in alcoholic subjects, despite the 31.9% (60/188 patients) who took doses that are potentially hepatotoxic.

Safety and efficacy of intravenous N-acetylcysteine for acetaminophen overdose: analysis of the Hunter Area Toxicology Service (HATS) database

BACKGROUND

Acetaminophen (N-acetyl-p-aminophenyl; APAP) is the leading drug used in self-poisoning and frequently causes hepatotoxicity, including acute liver failure.

OBJECTIVE

To provide descriptive data on the safety and efficacy of intravenous N-acetylcysteine (IV-NAC) in the treatment of APAP toxicity, based on information in the Hunter Area Toxicology Service (HATS) database involving residents of the Greater Newcastle Area of New South Wales, Australia.

METHODS

This was a retrospective analysis of all APAP overdoses from January 1987 to January 2003. Data were collected prospectively according to a published protocol and included patient characteristics, exposures to APAP and other potential toxins, treatments, and outcomes. Primary safety/tolerability endpoints included the mortality rate and incidence of adverse drug reactions, while efficacy endpoints included alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels.

RESULTS

Of 1749 patients, 399 (22.8%) were treated with IV-NAC. Of these, 37 (9.3%) had an adverse drug reaction to IV-NAC, of which seven (1.8% of total) were anaphylactoid. There were five deaths in hospital (mortality rate = 0.3%), including two attributed to APAP (0.1%) and none to IV-NAC. Of 64 patients who were treated with IV-NAC within 8 hours after APAP ingestion and had available ALT/AST data, two (3.1%) developed hepatotoxicity (AST/ALT > 1000 IU/L) compared with 32 (25%) of 128 patients receiving IV-NAC > 8 hours after APAP ingestion (p = 0.0002). A total of 26 patients (15.6%) receiving IV-NAC treatment within 8 hours after APAP ingestion had hospitalization stays > 48 hours compared with 70 (33.3%) receiving IV-NAC > 8 hours after ingestion (p < 0.0001).

CONCLUSIONS

For patients with APAP overdose seen in the HATS database of New South Wales, Australia, in-hospital death was infrequent (< 1%) and hepatotoxicity was significantly less likely when IV-NAC was administered within 8 hours after APAP ingestion compared with longer intervals (p < 0.01). As a descriptive retrospective database analysis, this study could not exclude certain sources of bias, including temporal changes over the 16-year course of data collection in the use of IV-NAC and low ascertainment of mild, self-limiting reactions to IV-NAC.

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.

Drug-induced liver disease

PURPOSE OF REVIEW

To summarize the pertinent case reports, case series and clinical studies that described clinical, histological, epidemiological and mechanistic features of drug-induced liver disease in 2005.

RECENT FINDINGS

Acetaminophen, highly active antiretroviral therapy and drugs for tuberculosis retained their preeminent position as the most commonly reported agents causing drug-induced liver disease, with acetaminophen continuing to be the leading cause of acute liver failure in the USA. While the frequency of drug-induced liver disease remains low, a large case-series of acute drug-induced liver disease from Spain and Sweden supported the observation that acute hepatocellular jaundice from a drug is associated with death or the need for transplant in at least 10% (known as Hy's Law). With respect to using potentially hepatotoxic medications in patients with underlying liver disease, statins and second-generation thiazolidinediones were shown to be safe when used in patients with elevated baseline alanine aminotransferase or aspartate aminotransferase levels.

SUMMARY

Drug-induced liver disease remains an important cause of acute liver failure, and research efforts by the National Institutes of Health and others are underway to better determine the risk factors and other host susceptibilities that will allow for the safer use of drugs in the future.