Low rates of hepatotoxicity among Asian patients with paracetamol overdose: a review of 1024 cases

Hepatoprotective effects of fruits pulp, seed, and peel against chemical-induced toxicity: Insights from in vivo studies

The liver is a vital organ in human physiology positioned in the upper right quadrant of the peritoneal cavity, which plats a critical role in metabolic processes, detoxification of various substances and overall homeostasis. Along with these critical functions, hepatic diseases impose as significant global health threat. Liver illness is the cause of two million fatalities every year, or 4% of all deaths. Traditionally, healthcare providers have prescribed antibacterial and antiviral medications to address liver illness. Nephrotoxicity is a frequently observed negative reaction to drugs, with the majority of such events happening in individuals who have advanced cirrhosis. Thus, recognizing this gap, there is a dire need of exploration of pharmaceutical alterative for hepatic diseases, with special focus on their efficacy and reduced toxicity. Fruits have long been known to therapeutic impact on human health, thus exploration of fruits components namely pulp, seeds and peels containing phytochemicals have emerged as a promising avenue for hepatoprotective interventions. Thus, review comprehends the information about worldwide burden of chemical induced toxicity and injuries as well as highlight the on-going challenges in hepatic disease management. It also shed light on the valuable contributions fruit parts and their phytocompounds obtained from different components of fruits. Fruit pulp, especially when rich in flavonoids, has demonstrated significant potential in animal model studies. It has been observed to enhance the activity of antioxidant enzymes and reduce the expression of pro-inflammatory markers. The methanolic and ethanolic extracts have demonstrated the most favorable outcomes. Further, this review also discusses about the safety assessments of fruits extracts for their utilization as hepatoprotective agents.

Silymarin Protects against Acute Liver Injury Induced by Acetaminophen by Downregulating the Expression and Activity of the CYP2E1 Enzyme

Previous studies have shown that silymarin protects against various types of drug-induced liver injury, but whether the protective mechanism of silymarin against acetaminophen-induced liver injury is related to the CYP2E1 enzyme remains unclear. In this study, we investigated the effect of silymarin on the activity and expression of CYP2E1 in vitro and in vivo. The results of in vitro studies showed that silymarin not only inhibited the activity of CYP2E1 in human and rat liver microsomes but also reduced the expression of CYP2E1 in HepG2 cells. In vivo studies showed that silymarin pretreatment significantly reduced the conversion of chlorzoxazone to its metabolite 6-OH-CLX and significantly increased the t_1/2, area under the curve (AUC) and mean residence time (MRT) of chlorzoxazone. In addition, silymarin pretreatment significantly inhibited the upregulation of Cyp2e1 expression, reduced the production of 3-cysteinylacetaminophen trifluoroacetic acid salt (APAP-CYS), and restored the liver glutathione level. The results of our study show that silymarin plays an important protective role in the early stage of acetaminophen-induced acute liver injury by reducing the activity and expression of CYP2E1, reducing the generation of toxic metabolites, and alleviating liver injury.

Successful management of delayed presentation of massive paracetamol overdose in a resource‐limited setting: A case report from Nepal

We present a case of self‐poisoning with a massive dose of paracetamol by a young Nepalese female patient who presented late to our emergency department. This report highlights the successful management of the patient with the extended use of N‐acetylcysteine over 4 days and continuous supportive therapy as required. The case is an example of the management of delayed presentation of a massive paracetamol poisoning in a resource‐limited setting, where intensive care units and hemodialysis facilities are not easily available. However, when available, massive poisoning should always be managed in continuous monitoring units under the expertise of a toxicologist.

Probiotics: Evolving as a Potential Therapeutic Option against Acetaminophen-Induced Hepatotoxicity

Acetaminophen (APAP) is the most common prescription medicine around the world for the treatment of pain and fever and is considered to be a safe drug at its therapeutic dose. However, a single overdose or frequent use of APAP can cause severe acute liver injury. APAP hepatotoxicity is a prevalent cause of acute liver disease around the world and the lack of suitable treatment makes it a serious problem. In recent years, there has been a surge in interest in using probiotics and probiotic-derived products, known as postbiotics, as health and disease negotiators. A growing body of evidence revealed that they can be equally effective against APAP hepatotoxicity. Different probiotic bacteria were found to be pre-clinically effective against APAP hepatotoxicity. Different postbiotics have also shown exciting results in preclinical models of APAP hepatotoxicity. This review summarized the protective roles and mechanisms of the different probiotic bacteria and postbiotics against APAP hepatotoxicity, with critical discussion. A brief discussion on potential novel probiotics and postbiotics for oxidative liver injury was also included. This review was written in an attempt to pique the interest of researchers in developing a safe therapeutic option against oxidative liver damage using probiotics and/or postbiotics as dietary supplements.

Sensitivity of dose-estimations for acute acetaminophen overdose in predicting hepatotoxicity risk using the Rumack-Matthew Nomogram

Timely assessment of acetaminophen concentration in overdose situations is not always available in resource-poor settings. The 150 mg/kg dose-estimate for acetaminophen is widely considered as criterion for acetaminophen overdose. Its sensitivity and specificity when compared to the 150 mg/L treatment line on the Rumack-Matthew Nomogram (150-treatment line) has rarely been evaluated. This is a retrospective chart review of acute acetaminophen overdose patients. We evaluated the sensitivity and specificity of the 150, 200 mg/kg and 8- and 10-g dose-estimates by plotting the serum acetaminophen levels and using 150-treatment line on the Nomogram as the treatment cut-off. A comparison of medical care costs was performed. We enrolled 784 cases for analysis. Median (IQR) age was 23 (20-28) years (81.9% female). There were 545 cases (69.5%) where the estimated ingested acetaminophen dose were ≥150 mg/kg and 406 cases (51.8%) with concentrations ≥150-treatment line. Hepatotoxicity and acute liver injury (ALI) occurred in 7.3% and 23.9%, respectively. The sensitivity and specificity of 150 mg/kg dose-estimate for the 150-treatment line were 92.6% (95% CI 89.6, 94.8) and 55.3% (95% CI 50.3, 60.2). Among patients with dose-estimate below150 mg/kg, none developed hepatotoxicity and 17 (7.1%) develop ALI. The administration of activated charcoal significantly decreased the risk of being above the 150-treatment line by half. In resource-poor setings, the use of 150 mg/kg dose-estimate as a stand-alone criteria for initiation of N-acetylcysteine therapy is satisfactory, especially when combined with decontamination with activated charcoal and follow up of aminotransferase at 24 h.

The Association Between Concurrence of Infection and the Onset of Severe Eruption or Liver Injury in Patients Using Antipyretic Analgesics: A Matched, Nested Case-Control Study

Stevens-Johnson syndrome (SJS) and toxic epidermal necrosis (TEN) or drug-induced liver injury (DILI) are severe drug-induced reactions, known as idiosyncratic drug reactions. It is believed that immune response can lead to these severe adverse drug reactions. Our previous analysis of the Japanese Spontaneous Drug Reaction database suggested that the onset of SJS/TEN and DILI was strongly associated with infection. Hence, we conducted a matched, nested case-control study to elucidate the association between concurrent infection and the onset of SJS/TEN or liver injury in patients prescribed antipyretic analgesics. We extracted 4 112 055 patients who were prescribed antipyretic analgesics between January 2014 and December 2015. Amongst them, 553 (0.01%) were diagnosed with SJS/TEN and 12 606 (0.3%) with liver injury. In a matched, nested case-control study, 131 and 2847 cases matched for SJS/TEN or liver injury, respectively. For each case, 3 controls were randomly matched with the case for age at index date and sex. In the conditional logistic regression analysis, there was a significant association between the combination of infection and antipyretic analgesics and the onset of SJS/TEN or liver injury (SJS/TEN: adjusted OR, 5.59; 95%CI, 2.01-15.51; liver injury: adjusted OR, 2.79; 95%CI, 2.24-3.46). Although it was not possible to distinguish whether the associations were caused by the infection or were a direct consequence of the antibiotic agents, our findings may help to increase awareness of the possibility of the increased onset of idiosyncratic drug reactions (SJS/TEN and liver injury) in antipyretic analgesic users because of infections.

Epidemiological differences of common liver conditions between Asia and the West

Liver diseases form a heterogenous group of acute and chronic disorders of varying etiologies. Not only do they result in significant morbidity and mortality, but they also lead to a marked reduction in quality of life, together with a high socioeconomic burden globally. A better understanding of their global distribution is necessary to curb the massive health-care and socioeconomic burden that they entail. Notable differences and similarities have been described between common liver disease conditions occurring in Asia and the West (Europe and North America), giving rise to the need for an updated collective appraisal of this subject. In this review, the epidemiological differences of common liver conditions, specifically acute liver failure, drug-induced liver injury, acute-on-chronic liver failure, hepatocellular carcinoma, and non-alcoholic fatty liver disease, between Asia and the West are discussed.

Characteristics and Outcomes of Acetaminophen Overdose and Hepatotoxicity in Thailand

Background and Aims: Acetaminophen (APAP) is the leading cause of drug overdose and hepatotoxicity worldwide, including in Thailand. Patterns of overdose and hospital management are known to have significant impacts on the outcomes of APAP overdose, and these factors vary from country to country. Therefore, this study aimed to analyze clinical characteristics of Thai patients with APAP overdose in terms of overdose patterns, clinical presentation, treatment and outcomes. Methods: In this retrospective analytical study, medical records of adult patients hospitalized with a diagnosis of APAP overdose at Rajavithi Hospital, Bangkok, between January 2013 and December 2017 were reviewed. Results: A total of 184 patients diagnosed with APAP overdose were included. The median age was 22 (15-76) years and the majority were female (79.9%). Most overdoses were intended self-poisoning ingestion (90.8%) with a median dose of 10.5 g (4.5-50). A total of 121 patients were treated with N-acetylcysteine with a median visit-to-N-acetylcysteine time of 2 (0.5-15) h. Overall, 15.6% developed mild hepatotoxicity (aspartate aminotransferase or alanine aminotransferase >3 times the upper limit of normal), 6.4% developed severe hepatotoxicity (aspartate aminotransferase or alanine aminotransferase >10 times the upper limit of normal and international normalized ratio >2.0) and 3 patients developed acute liver failure (1 patient resolved spontaneously and 2 patients, neither of whom had a liver transplant, died). Significant predictors for hepatotoxicity included older age, chronic alcohol drinking, repeated taking of medication for more than 8 h (staggered ingestion), long duration between ingestion and hospital visit, alcohol coingestion, abdominal pain symptoms, and acute kidney injury. Conclusions: Most cases of APAP overdose in Thailand appear to be young women with intentional ingestion. With prompt management, most patients (76.4%) did not develop significant hepatotoxicity; nevertheless, despite N-acetylcysteine therapy, hepatotoxicity including acute liver failure was observed in a small proportion of patients, particularly those with unintentional overdose and chronic alcohol drinking.

Genetic Association of Single Nucleotide Polymorphisms with Acetaminophen-Induced Hepatotoxicity

Acetaminophen is commonly used to reduce pain and fever. Unfortunately, overdose of acetaminophen is a leading cause of acute liver injury and failure in many developed countries. The majority of acetaminophen is safely metabolized in the liver and excreted in the urine; however, a small percentage is converted to the highly reactive N-acetyl-p-benzoquinone imine (NAPQI). At therapeutic doses, NAPQI is inactivated by glutathione S-transferases, but at toxic levels, excess NAPQI forms reactive protein adducts that lead to hepatotoxicity. Individual variability in the response to both therapeutic and toxic levels of acetaminophen suggests a genetic component is involved in acetaminophen metabolism. In this review, we evaluate the genetic association studies that have identified 147 single nucleotide polymorphisms linked to acetaminophen-induced hepatotoxicity. The identification of novel genetic markers for acetaminophen-induced hepatotoxicity provides a rich resource for further evaluation and may lead to improved prognosis, prevention, and treatment.

Endogenous Antioxidant and LOX-Mediated Systems Contribute to the Hepatoprotective Activity of Aqueous Partition of Methanol Extract of Muntingia calabura L. Leaves against Paracetamol Intoxication

Methanol extract of Muntingia calabura L. (family Muntingiaceae) leaf has been reported to exert various pharmacological activities including hepatoprotection. The present study was carried out to identify the most effective hepatoprotective partition derived from the extract and to determine the mechanisms of action involved. The extract was partitioned using solvents with different polarity to yield petroleum ether (PEMC), ethyl acetate (EAMC), and aqueous (AQMC) extracts. Each extract, at 250 mg/kg, was subjected to the paracetamol (PCM)-induced hepatotoxic assay and several parameters such as liver weight, liver/body weight ratio, serum liver enzymes' level, and histopathological examinations were determined. Each partition was also tested for their antioxidant and anti-inflammatory potentials. The most effective extract (AQMC) was prepared in additional dose of 50 and 500 mg/kg, and then subjected to the same liver toxicity test in addition to the endogenous antioxidant enzymes assay. Moreover, AQMC was also subjected to the phytochemical screening and HPLC analysis. Overall, from the results obtained: AQMC exerted significant (p < 0.05): (i) antioxidant activity when assessed using the DPPH, SOD and ORAC assays with high TPC detected; (ii) anti-inflammatory activity via LOX, but not XO pathway; (iii) hepatoprotective activity indicated by its ability to reverse the effect of PCM on the liver weight and liver/body weight ratio, the level of serum liver enzymes (ALT, AST, and ALP), and activity of several endogenous antioxidant enzymes (SOD and CAT). Phytochemicals analyses demonstrated the presence of several flavonoid-based bioactive compounds such as gallic acid and quercetin, which were reported to possess hepatoprotective activity. In conclusion, AQMC exerts hepatoprotective activity against the PCM-induced toxicity possibly by having a remarkable antioxidant potential and ability to activate the endogenous antioxidant system possibly via the synergistic action of its phytoconstituents.

A Study on the Medication Errors in the Administration of N-Acetylcysteine for Paracetamol Overdose Patients in Malaysia

Introduction

N-Acetylcysteine (NAC) has been used to treat paracetamol overdose for four decades. But the administration of NAC regimens is complicated. Therefore, medication errors are an ongoing issue in the acute-care setting and directly impact the safety of patients.

Objective

To evaluate the rate of NAC-related medication errors during the management of paracetamol overdose at a teaching hospital in Malaysia.

Methods

This clinical audit study was performed retrospectively between June 2008 and June 2011. Patients who presented to the adult emergency department with paracetamol overdose and had received at least the loading dose of intravenous NAC were eligible. Children below the age of 12 years old were not included. Also, patients displaying chronic excessive paracetamol usage or recurrent paracetamol overdose were excluded. We determined the type and frequency of medication errors during intravenous NAC administration.

Results

The study population ranged from 13 to 87 years old (mean age: 25.06; median: 23) and was predominantly female. The overall prevalence of intravenous NAC-related medication errors was found to be 84.3%. Moreover, the following frequencies were observed based on error type: 5.9% wrong dose, 37.3% incorrect infusion rate, 8.5% interruption during treatment, and 66.5% unnecessary administration.

Conclusion

We observe a surprisingly high prevalence of medication errors related to the administration of intravenous NAC. Thus, this emerging issue needs be addressed in order to ensure patient safety as well as to prevent unnecessary hospital admissions and/or burdening treatment costs. (Hong Kong j.emerg.med. 2014;21: 361-367)

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Acetaminophen-Induced Hepatotoxicity: a Comprehensive Update

Hepatic injury and subsequent hepatic failure due to both intentional and non-intentional overdose of acetaminophen (APAP) has affected patients for decades, and involves the cornerstone metabolic pathways which take place in the microsomes within hepatocytes. APAP hepatotoxicity remains a global issue; in the United States, in particular, it accounts for more than 50% of overdose-related acute liver failure and approximately 20% of the liver transplant cases. The pathophysiology, disease course and management of acute liver failure secondary to APAP toxicity remain to be precisely elucidated, and adverse patient outcomes with increased morbidity and mortality continue to occur. Although APAP hepatotoxicity follows a predictable timeline of hepatic failure, its clinical presentation might vary. N-acetylcysteine (NAC) therapy is considered as the mainstay therapy, but liver transplantation might represent a life-saving procedure for selected patients. Future research focus in this field may benefit from shifting towards obtaining antidotal knowledge at the molecular level, with focus on the underlying molecular signaling pathways.

Pharmacogenetics of analgesic drugs

• Individual variability in pain perception and differences in the efficacy of analgesic drugs are complex phenomena and are partly genetically predetermined.

• Analgesics act in various ways on the peripheral and central pain pathways and are regarded as one of the most valuable but equally dangerous groups of medications.

• While pharmacokinetic properties of drugs, metabolism in particular, have been scrutinised by genotype–phenotype correlation studies, the clinical significance of inherited variants in genes governing pharmacodynamics of analgesics remains largely unexplored (apart from the µ-opioid receptor).

• Lack of replication of the findings from one study to another makes meaningful personalised analgesic regime still a distant future.

• This narrative review will focus on findings related to pharmacogenetics of commonly used analgesic medications and highlight authors’ views on future clinical implications of pharmacogenetics in the context of pharmacological treatment of chronic pain.

Pathways involved in acetaminophen hepatotoxicity with specific targets for inhibition/downregulation

Insights on molecular/immunological mechanisms involve in APAP hepatotoxicity and pave way for researchers/clinicians/pharma bodies to identify novel biomarkers, effective bioactive candidates and fruitful therapy against APAP hepatotoxicity.

Pharmacogenomics of acetaminophen in pediatric populations: a moving target

Acetaminophen (APAP) is widely used as an over-the-counter fever reducer and pain reliever. However, the current therapeutic use of APAP is not optimal. The inter-patient variability in both efficacy and toxicity limits the use of this drug. This is particularly an issue in pediatric populations, where tools for predicting drug efficacy and developmental toxicity are not well established. Variability in toxicity between age groups may be accounted for by differences in metabolism, transport, and the genetics behind those differences. While pharmacogenomics has been revolutionizing the paradigm of pharmacotherapy for many drugs, its application in pediatric populations faces significant challenges given the dynamic ontogenic changes in cellular and systems physiology. In this review we focused on the ontogenesis of the regulatory pathways involved in the disposition of APAP and on the variability between pediatric, adolescent, and adult patients. We also summarize important polymorphisms of the pharmacogenes associated with APAP metabolism. Pharmacogenetic studies in pediatric APAP treatment are also reviewed. We conclude that while a consensus in pharmacogenetic management of APAP in pediatric populations has not been achieved, a systems biology based strategy for comprehensively understanding the ontogenic regulatory pathway as well as the interaction between age and genetic variations are particularly necessary in order to address this question.