Drug Hepatotoxicity: Newer Agents

MALDI Imaging Mass Spectrometry Visualizes the Distribution of Antidepressant Duloxetine and Its Major Metabolites in Mouse Brain, Liver, Kidney, and Spleen Tissues

Imaging mass spectrometry (IMS) is a powerful tool for mapping the spatial distribution of unlabeled drugs and metabolites that may find application in assessing drug delivery, explaining drug efficacy, and identifying potential toxicity. This study focuses on determining the spatial distribution of the antidepressant duloxetine, which is widely prescribed despite common adverse effects (liver injury, constant headaches) whose mechanisms are not fully understood. We used high-resolution IMS with matrix-assisted laser desorption/ionization to examine the distribution of duloxetine and its major metabolites in four mouse organs where it may contribute to efficacy or toxicity: brain, liver, kidney, and spleen. In none of these tissues is duloxetine or its metabolites homogeneously distributed, which has implications for both efficacy and toxicity. We found duloxetine to be similarly distributed in spleen red pulp and white pulp but differentially distributed in different anatomic regions of the liver, kidney, and brain, with dose-dependent patterns. Comparison with hematoxylin and eosin staining of tissue sections reveals that the ion images of endogenous lipids help delineate anatomic regions in the brain and kidney, while heme ion images assist in differentiating regions within the spleen. These endogenous metabolites may serve as a valuable resource for examining the spatial distribution of other drugs in tissues when staining images are not available. These findings may facilitate future mechanistic studies of the therapeutic and adverse effects of duloxetine. In the current work, we did not perform absolute quantification of duloxetine, which will be reported in due course. SIGNIFICANCE STATEMENT: The study utilized imaging mass spectrometry to examine the spatial distribution of duloxetine and its primary metabolites in mouse brain, liver, kidney, and spleen. These results may pave the way for future investigations into the mechanisms behind duloxetine's therapeutic and adverse effects. Furthermore, the mass spectrometry images of specific endogenous metabolites such as heme could be valuable in analyzing the spatial distribution of other drugs within tissues in scenarios where histological staining images are unavailable.

Effect of direct oral anticoagulant dabigatran on early bone healing: An experimental study in rats

Background

Dabigatran belongs to the new generation of direct oral anticoagulants (DOACs). Its advantages are oral administration and no need for international normalized ratio (INR) monitoring. Although its use has increased, its potential side effects on bone healing and remodeling have not been fully investigated. The present study aimed to evaluate the possible effects of dabigatran on early bone healing.

Methods

Sixteen male Wistar rats were divided into two groups; in group A, 20-mg/kg dabigatran dose was administered orally daily for 15 days, while group B served as a control. Two circular bone defects (d=6 mm) were created on either side of the parietal bones. Two weeks after surgery and euthanasia of the animals, tissue samples (parietal bones that contained the defects) were harvested for histological and histomorphometric analysis. Statistical analysis was performed with a significance level of α=0.5.

Results

No statistically significant differences were found between the two groups regarding the regenerated bone (21.9% vs. 16.3%, P=0.172) or the percentage of bone bridging (63.3% vs. 53.5%, P=0.401).

Conclusion

Dabigatran did not affect bone regeneration, suggesting that it might be a safer drug compared to older anticoagulants known to lead to bone healing delay.

Antioxidant-Based Preventive Effect of Phytochemicals on Anticancer Drug-Induced Hepatotoxicity

Significance: Drug-induced liver injury (DILI) or hepatotoxicity has been a hot issue to overcome on the safety and physiological function of the liver, since it is known to have biochemical, cellular, immunological, and molecular alterations in the liver mainly induced by alcohol, chemicals, drugs, heavy metals, and genetic factors. Recently efficient therapeutic and preventive strategies by some phytochemicals are of interest, targeting oxidative stress-mediated hepatotoxicity alone or in combination with anticancer drugs. Recent Advances: To assess DILI, the variety of in vitro and in vivo animal models has been developed mainly by using carbon tetrachloride, d-galactosamine, acetaminophen, and lipopolysaccharide. Also, the mechanisms on hepatotoxicity by several drugs and herbs have been explored in detail. Recent studies reveal that antioxidants including vitamins and some phytochemicals were reported to prevent against DILI. Critical Issues: Antioxidant therapy with some phytochemicals is noteworthy, since oxidative stress is critically involved in DILI via production of chemically reactive oxygen species or metabolites, impairment of mitochondrial respiratory chain, and induction of redox cycling. Future Directions: For efficient antioxidant therapy, DILI susceptibility, Human Leukocyte Antigen genetic factors, biomarkers, and pathogenesis implicated in hepatotoxicity should be further explored in association with oxidative stress-mediated signaling, while more randomized preclinical and clinical trials are required with optimal safe doses of drugs and/or phytochemicals alone or in combination for efficient clinical practice along with the development of advanced DILI diagnostic tools.

Adverse drug reactions in pregnant women: Do they differ from those in non-pregnant women of childbearing age?

Pharmacoepidemiological research in pregnant women has focused on adverse drug reactions for the course of pregnancy or for the unborn child, but little is known on the risks for the mother. We reported the results of a study that compared adverse drug reactions in pregnant women with non-pregnant women of childbearing age, and investigated whether which types of adverse reactions were more often reported in pregnant women and which drugs were more often involved. This study was carried out in the French pharmacovigilance database (BNPV). We compared adverse drug reactions reported between 1 January 2010 and 31 December 2019 in pregnant women with those reported in of non-pregnant women of childbearing age. We cross-matched each pregnant woman with three non-pregnant women of childbearing age according to geographic area, age and year the adverse reaction was reported. Data analysis revealed that serious adverse reactions were more frequently reported in pregnant women, including anaphylactic reactions. Other adverse reactions including tachycardia, hypotension and hepatic injury were also more frequent in pregnant women than in non-pregnant women of the same age. This could be explained by physiological changes in pregnancy that lead to greater sensitivity to certain adverse reactions. Some drugs, such as phloroglucinol, metoclopramide, iron, atosiban and nifedipine, were more frequently involved in adverse reactions in pregnant women. These drugs are specifically used during pregnancy, which may explain why they are over-represented in adverse reactions. This is the first comparative descriptive study on drug adverse reactions in pregnant women. Specific epidemiological and pharmacokinetic studies are necessary to confirm these results and better understand the differences observed to improve the monitoring of pregnant women exposed to certain drugs.

Reported hepatotoxicity and hepatotoxicity guidance in the product information of protein kinase inhibitors in oncology registered at the European Medicines Agency

Protein kinase inhibitors (PKIs) used in oncology can induce severe and even fatal hepatotoxicity. Several PKIs are registered within a certain class to target a specific kinase. No systematic comparison of the reported hepatotoxicity and clinical guidance for monitoring and management of hepatotoxic events between the various PKI summaries of product characteristics (SmPC) is yet available. A systematic analysis of data on 21 hepatotoxicity parameters obtained from the SmPCs and European public assessment reports (EPARs) of European Medicines Agency-approved antineoplastic PKIs (n = 55) has been conducted. The median reported incidence (range) of all grades of aspartate aminotransferase (AST) elevations was 16.9% (2.0%-86.4%) for PKI monotherapy, with 2.1% (0.0%-10.3%) being grade 3/4 and for all grades alanine aminotransferase (ALT) elevations 17.6% (2.0%-85.5%), with 3.0% (0.0%-25.0%) being grade 3/4. Fatalities due to hepatotoxicity were reported for 22 out of 47 PKIs (monotherapy) and for 5 out of 8 PKIs (combination therapy). A maximum grade of grade 4 and grade 3 hepatotoxicity was reported for 45% (n = 25) and 6% (n = 3), respectively. Liver parameter monitoring recommendations were present in 47 of the 55 SmPCs. Dose reductions were recommended for 18 PKIs. Discontinuation was recommended for patients meeting Hy's law criteria (16 out of 55 SmPCs). Severe hepatotoxic events are reported in approximately 50% of the analyzed SmPCs and EPARs. Differences in the degree of hepatotoxicity are apparent. Although liver parameter monitoring recommendations are present in the vast majority of the analyzed PKI SmPCs, the clinical guidance for hepatotoxicity was not standardized.

The roles of Cyp1a2 and Cyp2d in pharmacokinetic profiles of serotonin and norepinephrine reuptake inhibitor duloxetine and its metabolites in mice

Duloxetine (DLX) is widely used to treat major depressive disorder. Little is known about the mechanistic basis for DLX-related adverse effects (e.g., liver injury). Human CYP1A2 and CYP2D6 mainly contributes to DLX metabolism, which was proposed to be involved in its adverse effects. Here, we investigated the roles of Cyp1a2 and Cyp2d on DLX pharmacokinetic profile and tissue distribution using a Cyp1a2 knockout (Cyp1a2-KO) mouse model together with a Cyp2d inhibitor (propranolol). Cyp1a2-KO has the few effects on the systematic exposure (area under the plasma concentration-time curve, AUC) and tissue disposition of DLX and its primary metabolites. Propranolol dramatically increased the AUCs of DLX by 3 folds and 1.5 folds in WT and Cyp1a2-KO mice, respectively. Meanwhile, Cyp2d inhibitor decreased the AUC of Cyp2d-involved DLX metabolites (e.g., M16). Mouse tissue distribution revealed that DLX and its major metabolites were the most abundant in kidney, followed by liver and lung with/without Cyp2d inhibitor. Cyp2d inhibitor significantly increased DLX levels in tissues (e.g., liver) in WT and KO mice and decreases the levels of M3, M15, M16 and M17, while it increased the levels of M4, M28 and M29 in tissues. Our findings indicated that Cyp2d play a fundamental role on DLX pharmacokinetic profile and tissue distribution in mice. Clinical studies suggested that CYP1A2 has more effects on DLX systemic exposure than CYP2D6. Further studies in liver humanized mice or clinical studies concerning CYP2D6 inhibitors-DLX interaction study could clarify the roles of CYP2D6 on DLX pharmacokinetics and toxicity in human.

Tyrosine kinase inhibitors can activate the NLRP3 inflammasome in myeloid cells through lysosomal damage and cell lysis

Inflammasomes are intracellular protein complexes that promote an inflammatory host defense in response to pathogens and damaged or neoplastic tissues and are implicated in inflammatory disorders and therapeutic-induced toxicity. We investigated the mechanisms of activation for inflammasomes nucleated by NOD-like receptor (NLR) protiens. A screen of a small-molecule library revealed that several tyrosine kinase inhibitors (TKIs)-including those that are clinically approved (such as imatinib and crizotinib) or are in clinical trials (such as masitinib)-activated the NLRP3 inflammasome. Furthermore, imatinib and masitinib caused lysosomal swelling and damage independently of their kinase target, leading to cathepsin-mediated destabilization of myeloid cell membranes and, ultimately, cell lysis that was accompanied by potassium (K⁺) efflux, which activated NLRP3. This effect was specific to primary myeloid cells (such as peripheral blood mononuclear cells and mouse bone marrow-derived dendritic cells) and did not occur in other primary cell types or various cell lines. TKI-induced lytic cell death and NLRP3 activation, but not lysosomal damage, were prevented by stabilizing cell membranes. Our findings reveal a potential immunological off-target of some TKIs that may contribute to their clinical efficacy or to their adverse effects.

Hepatotoxicity Induced by Azole Antifungal Agents: A Review Study

Context

Fungal infections are very common, and several medications are used to treat them. Azoles are prescribed widely to treat fungal infections. In addition to therapeutic effects, any drug can be accompanied by side effects in patients. One of the most important complications in this regard is liver injury. Therefore, hepatotoxicity induced by azole antifungal drugs were reviewed in this study.

Evidence Acquisition

English scientific papers were evaluated to review the effects of hepatotoxicity by azole antifungal agents, and the related studies' results were summarized using a table. The systematic search was implemented on electronic databases, including PubMed, Google Scholar, and Science Direct. Original articles and review articles that were published before April 1, 2022, were included in the study. Those articles without available full text or non-English articles were excluded. Also, articles that reported pediatric data were excluded.

Results

Most studies have reported the effects of hepatotoxicity by azole antifungal agents, and their mechanisms have been described.

Conclusions

Clinical evaluations regarding the hepatotoxicity of antifungal agents provided in the literature were reviewed. Therefore, it is recommended to prescribe these drugs with caution in high-risk patients suffering from liver diseases, and patients should be monitored for hepatotoxicity. However, more research is needed to evaluate the hepatotoxicity of azole antifungal agents and select appropriate drugs according to cost-effectiveness and the side effects' profiles, relying on lower incidence of this liver complication.

Construction of polysaccharide scaffold-based perfusion bioreactor supporting liver cell aggregates for drug screening

Rebuilding a suitable microenvironment of liver cells is the key challenge to enhancing the expression of hepatic functions for drug screening in vitro. To improve the microenvironment by providing the specific adhesive ligands for hepatocytes in the three-dimensional dynamic culture, a perfusion bioreactor with a pectin/alginate blend porous scaffold was constructed in this study. The galactosyl component in the main chain of pectin was able to be specifically recognized by the asialoglycoprotein receptor on the surface of hepatocytes, and subsequently promoted the adhesion and aggregation of hepatocytes co-cultured with hepatic non-parenchymal cells. The bioreactor was optimized for 4 h of dynamic inoculation followed by perfusion at a flow rate of 2 mL/min, which provided adequate oxygen supply and good mass transfer to the liver cells. During dynamic cultured in the bioreactor for 14 days, more multicellular aggregates were formed and were evenly distributed in the pectin/alginate blend scaffolds. The expressions of intercellular interaction and hepatic functions of the hepatocytes in aggregates were significantly enhanced in the three-dimensional dynamic group. Furthermore, the bioreactor not only markedly upregulated the cell polarity markers expression of hepatocytes but also enhanced their metabolic capacity to acetaminophen, isoniazid, and tolbutamide, which exhibited a significant concentration-dependent manner. Therefore, the pectin/alginate blend scaffold-based perfusion bioreactor appeared to be a promising candidate in the field of drug development and liver regeneration research.

Inhibition of platelet-derived growth factor pathway suppresses tubulointerstitial injury in renal congestion

OBJECTIVE

Increased central venous pressure in congestive heart failure is responsible for renal dysfunction, which is mediated by renal venous congestion. Pericyte detachment from capillaries after renal congestion might trigger renal fibrogenesis via pericyte-myofibroblast transition (PMT). Platelet-derived growth factor receptors (PDGFRs), which are PMT indicators, were upregulated in our recently established renal congestion model. This study was designed to determine whether inhibition of the PDGFR pathway could suppress tubulointerstitial injury after renal congestion.

METHODS

The inferior vena cava between the renal veins was ligated in male Sprague-Dawley rats, inducing congestion only in the left kidney. Imatinib mesylate or vehicle were injected intraperitoneally daily from 1 day before the operation. Three days after the surgery, the effect of imatinib was assessed by physiological, morphological and molecular methods. The inhibition of PDGFRs against transforming growth factor-β1 (TGFB1)-induced fibrosis was also tested in human pericyte cell culture.

RESULTS

Increased kidney weight and renal fibrosis were observed in the congested kidneys. Upstream inferior vena cava (IVC) pressure immediately increased to around 20 mmHg after IVC ligation in both the imatinib and saline groups. Although vasa recta dilatation and pericyte detachment under renal congestion were maintained, imatinib ameliorated the increased kidney weight and suppressed renal fibrosis around the vasa recta. TGFB1-induced elevation of fibrosis markers in human pericytes was suppressed by PDGFR inhibitors at the transcriptional level.

CONCLUSION

The activation of the PDGFR pathway after renal congestion was responsible for renal congestion-induced fibrosis. This mechanism could be a candidate therapeutic target for renoprotection against renal congestion-induced tubulointerstitial injury.

Application of 3D Hepatic Plate-Like Liver Model for Statin-Induced Hepatotoxicity Evaluation

Background: Drug-induced liver injury is one of the main reasons of withdrawals of drugs in postmarketing stages. However, an experimental model(s) which can accurately recapitulates liver functions and reflects the level of drug hepatotoxicity is lack. In this study, we assessed drug hepatotoxicity using a novel three-dimensional hepatic plate-like hydrogel fiber (3D-P) co-culture system.

Methods: During the 28-days culture period, the liver-specific functions, hepatocyte polarity, sensitivity of drug-induced toxicity of 3D-P co-culture system were evaluated with 2D co-culture, collagen sandwich co-culture, 3D hybrid hydrogel fiber co-culture and human primary hepatocytes as controls. High-content imaging and analysis (HCA) methods were used to explore the hepatotoxicity mechanism of five statins.

Results: The 3D-P co-culture system showed enhancing liver-specific functions, cytochrome P450 enzymes (CYPs) metabolic activity and bile excretion, which were considered to result from improved hepatocyte polarity. Three of the statins may cause acute or chronic hepatotoxicity by via different mechanisms, such as cholestatic liver injury.

Conclusion: Our 3D-P co-culture system is characterized by its biomimetic hepatic plate-like structure, long-term stable liver specificity, and prominent bile secretion function, making it applicable for acute/chronic drug hepatotoxicity assessments.

Drug-induced bile duct injury: new agents, new mechanisms

PURPOSE OF REVIEW

Drug-induced bile duct injury can be caused by a long list of agents. In most cases, damage is because of T-cell-mediated idiosyncratic reactions. Recently, a number of new agents, including not only drugs but also herbal supplements, have been incriminated and new mechanisms of bile duct injury have emerged. This review will focus on these new data.

RECENT FINDINGS

New members of drug families already known to be responsible for bile duct injury have been incriminated. New players have been identified, such as herbal supplements, like kratom, and recreational drugs, such as ketamine used outside the medical setting. Anticytokine monoclonal antibodies are rarely involved. In contrast, antineoplastic treatments are of growing concern, especially immune checkpoint inhibitors, which induce immune-related adverse effects because of the excessive stimulation of the immune system and its lack of regulation.

SUMMARY

Two patterns of bile duct injury are recognized. Drug-induced small-duct cholangiopathies target the smaller bile ducts; acute injuries eventually progress to chronic disease in the form of the vanishing bile duct syndrome. Drug-induced sclerosing cholangitis target large bile ducts, with a protracted chronic course; the onset of symptoms may be delayed after drug discontinuation; potentially severe, life-threatening complications can occur.

Imatinib-induced hepatotoxicity via oxidative stress and activation of NLRP3 inflammasome: an in vitro and in vivo study

Imatinib (IM), a milestone drug used in the field of molecular targeted therapy, has been reported to cause serious adverse liver effects, including liver failure and even death. Immune-mediated injury and mitochondrial dysfunction are involved in drug-induced liver injury. However, the mechanism of IM-induced hepatotoxicity remains unclear and warrants further study. In our study, Sprague Dawley rats were administered IM by gavage with 50 mg/kg body weight (BW) once daily for 10 days. Drug-induced liver injury accompanied by inflammatory infiltration was observed in rats following IM exposure, and the expression of NOD-like receptor protein 3 (NLRP3) inflammasome-related proteins was significantly increased compared with that of the control. HepG2 cells were exposed to 0-100 μM IM for 24 h. The results showed that IM decreased cell viability in a dose-dependent manner. Moreover, IM induced a state of obvious oxidative stress and activation of nuclear factor kappa B (NF-κB) in cells, which resulted in the activation of NLRP3 inflammasomes, including caspase 1 cleavage and IL-1β release. These results were significantly reduced after the use of the antioxidants N-acetyl-l-cysteine or the NF-κB inhibitor pyrrolidine di-thio-carbamate. Furthermore, NLRP3 knockdown significantly reduced the release of inflammatory cytokines and improved cell viability. In summary, our data demonstrated that oxidative stress and NLRP3 inflammasome activation are involved in the process of IM-induced hepatotoxicity. The results of this study provide a reference for the prevention and treatment of IM-induced hepatotoxicity.

Novel Bile Acid-Dependent Mechanisms of Hepatotoxicity Associated with Tyrosine Kinase Inhibitors

Drug-induced liver injury (DILI) is the leading cause of acute liver failure and a major concern in drug development. Altered bile acid homeostasis via inhibition of the bile salt export pump (BSEP) is one mechanism of DILI. Dasatinib, pazopanib, and sorafenib are tyrosine kinase inhibitors (TKIs) that competitively inhibit BSEP and increase serum biomarkers for hepatotoxicity in ∼25-50% of patients. However, the mechanism(s) of hepatotoxicity beyond competitive inhibition of BSEP are poorly understood. This study examined mechanisms of TKI-mediated hepatotoxicity associated with altered bile acid homeostasis. Dasatinib, pazopanib, and sorafenib showed bile acid-dependent toxicity at clinically relevant concentrations, based on the C-DILI assay using sandwich-cultured human hepatocytes (SCHH). Among several bile acid-relevant genes, cytochrome P450 (CYP) 7A1 mRNA was specifically upregulated by 6.2- to 7.8-fold (dasatinib) and 5.7- to 9.3-fold (pazopanib), compared with control, within 8 hours. This was consistent with increased total bile acid concentrations in culture medium up to 2.3-fold, and in SCHH up to 1.4-fold, compared with control, within 24 hours. Additionally, protein abundance of sodium taurocholate co-transporting polypeptide (NTCP) was increased up to 2.0-fold by these three TKIs. The increase in NTCP protein abundance correlated with increased function; dasatinib and pazopanib increased hepatocyte uptake clearance (CL_uptake) of taurocholic acid, a probe bile acid substrate, up to 1.4-fold. In conclusion, upregulation of CYP7A1 and NTCP in SCHH constitute novel mechanisms of TKI-associated hepatotoxicity. SIGNIFICANCE STATEMENT: Understanding the mechanisms of hepatotoxicity associated with tyrosine kinase inhibitors (TKIs) is fundamental to development of effective and safe intervention therapies for various cancers. Data generated in sandwich-cultured human hepatocytes, an in vitro model of drug-induced hepatotoxicity, revealed that TKIs upregulate bile acid synthesis and alter bile acid uptake and excretion. These findings provide novel insights into additional mechanisms of bile acid-mediated drug-induced liver injury, an adverse effect that limits the use and effectiveness of TKI treatment in some cancer patients.

Early intervention of acute liver injury related to venlafaxine: A case report

RATIONALE

Drug-induced liver injury (DILI) is the leading cause of acute liver injury (ALI), market withdrawal of a drug, and rejection of applications for marketing licenses. The incidence of DILI is very low, with a value between 1 and 19 per 100,000 patient years. All antidepressants may induce DILI even at low therapeutic doses. In this report, we present a case of ALI after venlafaxine administration.

PATIENT CONCERNS

A 27-year-old Chinese Han woman was admitted for depression. Several serum liver function indices in this patient were abnormal after antidepressant treatment. The Roussel Uclaf Causality Assessment Method (RUCAM) causality assessment score was 8, and the R value was 31.18.

DIAGNOSES

The patient was diagnosed with hepatocellular ALI, which was derived from venlafaxine-related adverse events.

INTERVENTIONS

First, all medications were stopped to block the progression of DILI. Then, a hepatoprotective strategy and proper psychological treatment were performed to recover the impaired hepatic function.

OUTCOMES

Liver function was fully recovered as indicated by liver function indices and ultrasound imaging.

LESSONS

The possibility of DILI should not be overlooked during the long-term use of antipsychotic drugs. In response, regular liver function monitoring should be performed in a timely manner to avoid missing diagnoses and delayed treatment. Furthermore, the necessary medical treatment needs to be conducted after the occurrence of ALI.

Potential Effects of Coronaviruses on the Liver: An Update

The coronaviruses that cause notable diseases, namely, severe acute respiratory syndrome (SARS), middle east respiratory syndrome (MERS) and coronavirus disease 2019 (COVID-19), exhibit remarkable similarities in genomic components and pathogenetic mechanisms. Although coronaviruses have widely been studied as respiratory tract pathogens, their effects on the hepatobiliary system have seldom been reported. Overall, the manifestations of liver injury caused by coronaviruses typically involve decreased albumin and elevated aminotransferase and bilirubin levels. Several pathophysiological hypotheses have been proposed, including direct damage, immune-mediated injury, ischemia and hypoxia, thrombosis and drug hepatotoxicity. The interaction between pre-existing liver disease and coronavirus infection has been illustrated, whereby coronaviruses influence the occurrence, severity, prognosis and treatment of liver diseases. Drugs and vaccines used for treating and preventing coronavirus infection also have hepatotoxicity. Currently, the establishment of optimized therapy for coronavirus infection and liver disease comorbidity is of significance, warranting further safety tests, animal trials and clinical trials.

Drug-induced liver injury and COVID-19: A review for clinical practice

Coronavirus disease 2019 (COVID-19) consists of a systemic disease that can present many complications. The infection presents broad clinical symptoms and a high rate of transmissibility. In addition to severe acute respiratory syndrome, the patients manifest complications beyond the respiratory system. The frequency of liver damage in COVID-19 patients ranges from 14.8% to 53% of patients. One should pay attention to drug-induced liver injury (DILI) in patients with COVID-19, especially considering the off-label use of drugs in prophylactic and therapeutic regimens applied on large scales. This review aims to present relevant information on the medication used so far in COVID-19 patients and its possible hepatotoxicity. We reviewed liver damage in patients with COVID-19 on PubMed and Virtual Health Library to investigate DILI cases. Four studies were selected, involving the medicines remdesivir, tocilizumab and a pharmacovigilance analysis study. The hepatotoxicity profile of drugs presented in the literature considers use in accordance to usual posology standards for treatment. However, drugs currently used in the management of COVID-19 follow different dosages and posology than those tested by the pharmaceutical industry. The deficiency of uniformity and standardization in the assessment of hepatotoxicity cases hinders the publication of information and the possibility of comparing information among healthcare professionals. It is suggested that severe liver injury in COVID-19 patients should be reported in pharmacovigilance institutions, and physicians should pay attention to any considerable abnormal liver test elevation as it can demonstrate unknown drug hepatotoxicity. Liver disorders in COVID-19 patients and the use of several concomitant off-label medications — with a potential risk of further damaging the liver - should at least be a warning sign for rapid identification and early intervention, thus preventing liver damage from contributing to severe impairment in patients.

Chemotherapy, targeted therapy and immunotherapy: Which drugs can be safely used in the solid organ transplant recipients?

In solid organ transplant recipients, cancer is associated with worse prognosis than in the general population. Among the causes of increased cancer‐associated mortality, are the limitations in selecting the optimal anticancer regimen in solid organ transplant recipients, because of the associated risks of graft toxicity and rejection, drug‐to‐drug interactions, reduced kidney or liver function, and patient frailty and comorbid conditions. The advent of immunotherapy has generated further challenges, mainly because checkpoint inhibitors increase the risk of rejection, which may have life‐threatening consequences in recipients of life‐saving organs. In general, there are no safe or unsafe anticancer drugs. Rather, the optimal choice of the anticancer regimen results from a careful risk/benefit assessment, from the awareness of potential pharmacokinetic and pharmacodynamic drug‐to‐drug interactions, and of the risk of drug overexposure in patients with kidney or liver dysfunction. In this review, we summarize general principles that may help the oncologists and transplant physicians in the multidisciplinary management of recipients of solid organ transplantation with cancer who are candidates for chemotherapy, targeted therapy, or immunotherapy.

Safety of treating acute liver injury and failure

INTRODUCTION

Acute liver injury and progression to acute liver failure can be life-threatening conditions that require prompt careful clinical assessment and therapeutic management.

AREAS COVERED

The aim of this article is to review the safety and side effect profile of pharmacological therapies used in the treatment of acute liver injury with specific focus on hepatic toxicity. We performed an extensive literature search with the terms 'acute liver injury,' 'acute liver failure,' 'therapy,' 'safety,' 'adverse reactions' and 'drug induced liver injury.' A thorough discussion of the main drugs and devices used in patients with acute liver injury and acute liver failure, its safety profile and the management of complications associated to therapy of these conditions is presented.

EXPERT OPINION

Several pharmacological approaches are used in acute liver injury and acute liver failure in an empirical basis. Whilst steroids are frequently tried in serious drug-induced liver injury there is concern on a potential harmful effect of these agents because of the higher mortality in patients receiving the drug; hence, statistical approaches such as propensity score matching might help resolve this clinical dilemma. Likewise, properly designed clinical trials using old and new drugs for subjects with serious drug-induced liver injury are clearly needed.

Primary Thromboprophylaxis in Patients with Malignancies: Daily Practice Recommendations by the Hemostasis Working Party of the German Society of Hematology and Medical Oncology (DGHO), the Society of Thrombosis and Hemostasis Research (GTH), and the Austrian Society of Hematology and Oncology (ÖGHO)

Patients with cancer, both hematologic and solid malignancies, are at increased risk for thrombosis and thromboembolism. In addition to general risk factors such as immobility and major surgery, shared by non-cancer patients, cancer patients are exposed to specific thrombotic risk factors. These include, among other factors, cancer-induced hypercoagulation, and chemotherapy-mediated endothelial dysfunction as well as tumor-cell-derived microparticles. After an episode of thrombosis in a cancer patient, secondary thromboprophylaxis to prevent recurrent thromboembolism has long been established and is typically continued as long as the cancer is active or actively treated. On the other hand, primary prophylaxis, even though firmly established in hospitalized cancer patients, has only recently been studied in ambulatory patients. This recent change is mostly due to the emergence of direct oral anticoagulants (DOACs). DOACs have a shorter half-life than vitamin K antagonists (VKA), and they overcome the need for parenteral application, the latter of which is associated with low-molecular-weight heparins (LMWH) and can be difficult for the patient to endure in the long term. Here, first, we discuss the clinical trials of primary thromboprophylaxis in the population of cancer patients in general, including the use of VKA, LMWH, and DOACs, and the potential drug interactions with pre-existing medications that need to be taken into account. Second, we focus on special situations in cancer patients where primary prophylactic anticoagulation should be considered, including myeloma, major surgery, indwelling catheters, or immobilization, concomitant diseases such as renal insufficiency, liver disease, or thrombophilia, as well as situations with a high bleeding risk, particularly thrombocytopenia, and specific drugs that may require primary thromboprophylaxis. We provide a novel algorithm intended to aid specialists but also family practitioners and nurses who care for cancer patients in the decision process of primary thromboprophylaxis in the individual patient.

Mechanism of hepatotoxicity of first-line tyrosine kinase inhibitors: Gefitinib and afatinib

AIMS

Both gefitinib and afatinib are epidermal growth factor tyrosine kinase inhibitors (EGFR-TKI) in the treatment of non-small cell lung cancer (NSCLC). It has been reported that gefitinib and afatinib could cause hepatotoxicity during the clinic treatment, therefore it is critical to investigate their hepatotoxicity systematically. In this study, zebrafish (Danio rerio) were used as model animals to compare the hepatotoxicity and their toxic mechanism.

MAIN METHODS

The zebrafish transgenic line [Tg (fabp10a: dsRed; ela3l:EGFP) was used in this study. After larvae developed at 3 days post fertilization (dpf), they were put into different concentrations of gefitinib and afatinib. At 6 dpf, the viability, liver area, fluorescence intensity, histopathology, apoptosis, transaminase reflecting liver function, the absorption of yolk sac, and the expression of relative genes were observed and analyzed respectively.

KEY FINDINGS

Both gefitinib and afatinib could induce the larvae hepatotoxicity dose-dependently. Based on the liver morphology, histopathology, apoptosis and function assessments, gefitinib showed higher toxicity, causing more serious liver damage. Both gefitinib and afatinib caused abnormal expressions of genes related to endoplasmic reticulum stress (ERS) pathway and apoptosis. For example, jnk, perk, bip, chop, ire1, bid, caspase3 and caspase9 were up-regulated, while xbp1s, grp78, bcl-2/bax, and caspase8 were down-regulated. The hepatotoxicity difference of gefitinib and afatinib might be due to the different expression level of related genes.

A case report of a drug-induced liver injury (DILI) caused by multiple antidepressants with causality established by the updated Roussel Uclaf causality assessment method (RUCAM) and in vitro testing

A 56-year-old female patient was hospitalized because of a lack of response and poor tolerance to multiple antidepressants, which included an episode of DILI. During hospitalization, the patient suffered another episode of DILI. Causality was assessed both by RUCAM and Lymphocyte Transformation Test, allowing to identify a safer medication.

Drug-induced liver injury after switching from tamoxifen to anastrozole in a patient with a history of breast cancer being treated for hypertension and diabetes

Anastrozole is a selective non-steroidal aromatase inhibitor that blocks the conversion of androgens to estrogens in peripheral tissues. It is used as adjuvant therapy for early-stage hormone-sensitive breast cancer in postmenopausal women. Significant side effects of anastrozole include osteoporosis and increased levels of cholesterol. To date, seven case reports on anastrozole hepatotoxicity have been published. We report the case of an 81-year-old woman with a history of breast cancer, arterial hypertension, type 2 diabetes mellitus, hyperlipidemia, and chronic renal insufficiency. Four days after switching hormone therapy from tamoxifen to anastrozole, icterus developed along with a significant increase in liver enzymes (measured in the blood). The patient was admitted to hospital, where a differential diagnosis of jaundice was made and anastrozole was withdrawn. Subsequently, hepatic functions quickly normalized. The observed liver injury was attributed to anastrozole since other possible causes of jaundice were excluded. However, concomitant pharmacotherapy could have contributed to the development of jaundice and hepatotoxicity, after switching from tamoxifen to anastrozole since several the patient’s medications were capable of inhibiting hepatobiliary transport of bilirubin, bile acids, and metabolized drugs through inhibition of ATP-binding cassette proteins. Telmisartan, tamoxifen, and metformin all block bile salt efflux pumps. The efflux function of multidrug resistance protein 2 is known to be reduced by telmisartan and tamoxifen and breast cancer resistance protein is known to be inhibited by telmisartan and amlodipine. Moreover, the activity of P-glycoprotein transporters are known to be decreased by telmisartan, amlodipine, gliquidone, as well as the previously administered tamoxifen. Finally, the role of genetic polymorphisms of cytochrome P450 enzymes and/or drug transporters cannot be ruled out since the patient was not tested for polymorphisms.

Multikinase inhibitor-induced liver injury in patients with cancer: A review for clinicians

BACKGROUND

Multikinase inhibitors (MKI) are targeted molecular agents that have revolutionized cancer management. However, there is a paucity of data concerning MKI-related liver injury risk and clinical guidelines for the management of liver toxicity in patients receiving MKI for cancer are scarce.

DESIGN

We conducted a PubMed search of articles in English published from January 2000 to December 2018 related to hepatotoxicity of the 29 FDA-approved MKIs at doses used in clinical practice. The search terms were the international non-proprietary name of each agent cross-referenced with «hepatotoxicity», «hepatitis», «hepatic adverse event», or «liver failure», and «phase II clinical trial», «phase III clinical trial», or «case report».

RESULTS

Following this search, 140 relevant studies and 99 case reports were considered. Although asymptomatic elevation of aminotransferase levels has been frequently observed in MKI clinical trials, clinically significant hepatotoxicity is a rare event. In most cases, the interval between treatment initiation and the onset of liver injury is between one week and two months. Liver toxicity is often hepatocellular and less frequently mixed. Life-threatening MKI-induced hepatic injury has been described, involving fulminant liver failure or death. Starting from existing data, a description of MKI-related liver events, grading of hepatotoxicity risk, and recommendations for management are also given for various MKI molecules.

CONCLUSION

All MKIs can potentially cause liver injury, which is sometimes irreversible. As there is still no strategy available to prevent MKI-related hepatotoxicity, early detection remains crucial. The surveillance of liver function during treatment may help in the early detection of hepatotoxicity. Furthermore, the exclusion of potential causes of hepatic injury is essential to avoid unnecessary MKI withdrawal.

What have we learned from animal models of idiosyncratic, drug-induced liver injury?

INTRODUCTION

Idiosyncratic, drug-induced liver injury (IDILI) continues to plague patients and restrict the use of drugs that are pharmacologically effective. Mechanisms of IDILI are incompletely understood, and a better understanding would reduce speculation and could help to identify safer drug candidates preclinically. Animal models have the potential to enhance knowledge of mechanisms of IDILI.

AREAS COVERED

Numerous hypotheses have emerged to explain IDILI pathogenesis, many of which center on the roles of the innate and/or adaptive immune systems. Animal models based on these hypotheses are reviewed in the context of their contributions to understanding of IDILI and their limitations.

EXPERT OPINION

Animal models of IDILI based on an activated adaptive immune system have to date failed to reproduce major liver injury that is of most concern clinically. The only models that have so far resulted in pronounced liver injury are based on the multiple determinant hypothesis or the inflammatory stress hypothesis. The liver pathogenesis in IDILI animal models involves various leukocytes and immune mediators such as cytokines. Insights from animal models are changing the way we view IDILI pathogenesis and are leading to better approaches to preclinical prediction of IDILI potential of new drug candidates.

Ginsenoside Rk1 induces apoptosis and downregulates the expression of PD-L1 by targeting the NF-κB pathway in lung adenocarcinoma

Ginsenoside Rk1 can function as an antitumor modulator that induces apoptosis in lung adenocarcinoma cells by inhibiting NF-κB transcription and triggering cell cycle arrest.

Three case reports: Temporal association between tyrosine-kinase inhibitor-induced hepatitis and immune checkpoint inhibitors in renal cell carcinoma

RATIONALE

Hepatotoxicity is a well-known adverse effect of vascular endothelial growth factor receptor (VEGFR) tyrosine-kinase inhibitors (TKIs), usually employed for the treatment of metastatic renal cell carcinoma (mRCC). Immune checkpoint inhibitors (ICIs) have been shown to improve survival in specific patients with mRCC, but concerns have arisen over their safety profile, particularly as regards the risk of liver damage in those patients receiving TKIs sequentially or concurrently with these new drugs. Here, we report three cases of hepatitis presentation in patients receiving TKIs after ICIs that should potentially be considered in current clinical practice, where a combination of these hepatotoxic drugs is becoming increasingly used.

PATIENTS CONCERNS

All three patients were receiving TKIs therapy and presented with nonspecific clinical deterioration and liver enzyme elevation in different time frames according to the start of treatment. All were previously treated with ICIs.

DIAGNOSES

After performing imaging techniques and complementary laboratory tests for the differential diagnosis of hepatic injury, the diagnosis of potentially TKI-induced hepatitis was assumed in all these cases. Hepatic biopsy was performed only in the first case in order to confirm the diagnosis.

INTERVENTIONS

Potential toxic drugs were interrupted and steroids course with slow reduction regimen was administered in all these cases because of the previous use of ICIs.

OUTCOMES

The patients described improved with this conservative treatment without complications during the following weeks. Only one case presented a new episode of mild hepatic alteration while on treatment with following treatment.

LESSONS

Taking into account this new therapeutic context, stricter monitoring for potentially increased/altered adverse events should be indicated. Adequate patient selection and consideration of the safety profile of the different drugs used could help to optimize treatment in the near future.

Pharmacologic Management of Portal Hypertension

Terlipressin, somatostatin, or octreotide are recommended as pharmacologic treatment of acute variceal hemorrhage. Nonselective β-blockers decrease the risk of variceal hemorrhage and hepatic decompensation, particularly in those 30% to 40% of patients with good hemodynamic response. Carvedilol, statins, and anticoagulants are promising agents in the management of portal hypertension. Recent advances in the pharmacologic treatment of portal hypertension have mainly focused on modifying an increased intrahepatic resistance through nitric oxide and/or modulation of vasoactive substances. Several novel pharmacologic agents for portal hypertension are being evaluated in humans.

Generation of hepatic spheroids using human hepatocyte-derived liver progenitor-like cells for hepatotoxicity screening

Rationale: The idiosyncratic drug-induced liver injury (iDILI) is a major cause of acute liver injury and a key challenge in late-stage drug development. Individual heterogeneity is considered to be an essential factor of iDILI. However, few in vitro model can predict heterogeneity in iDILI. We have previously shown that mouse and human hepatocytes can be converted to expandable liver progenitor-like cells in vitro (HepLPCs). However, the limited proliferation potential of human HepLPCs confines its industrial application. Here, we reported the generation of a novel hepatocyte model not only to provide unlimited cell sources for human hepatocytes but also to establish a tool for studying iDILI in vitro.

Methods: Human primary hepatocytes were isolated by modified two-step perfusion technique. The chemical reprogramming culture condition together with gene-transfer were then used to generate the immortalized HepLPC cell lines (iHepLPCs). Growth curve, doubling time, and karyotype were analyzed to evaluate the proliferation characteristics of iHepLPCs. Modified Hepatocyte Maturation Medium and 3D spheroid culture were applied to re-differentiate iHepLPCs.

Results: iHepLPCs exhibited efficient expansion for at least 40 population doublings, with a stable proliferative ability. They could easily differentiate back into metabolically functional hepatocytes in vitro within 10 days. Furthermore, under three-dimensional culture conditions, the formed hepatic spheroids showed multiple liver functions and toxicity profiles close to those of primary human hepatocytes. Importantly, we established a hepatocyte bank by generating a specific number of such cell lines. Screening for population heterogeneity allowed us to analyze the in vitro heterogeneous responses to hepatotoxicity induced by molecular targeted drugs.

Conclusions: In light of the proliferative capacity and the heterogeneity they represented, these iHepLPCs cell lines may offer assistance in studying xenobiotic metabolism as well as liver diseases in vitro.

HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity: a systematic review and meta-analysis

Associations between HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity have been reported. To consolidate the results from all available reports in scientific databases, systematic review and meta-analysis techniques were used to quantify these associations. Studies investigating associations between HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity were systematically searched in PubMed, Human Genome Epidemiology Network, and the Cochrane Library. Primary outcomes were the associations between HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity. Overall odds ratios (ORs) with the corresponding 95%CIs were calculated using a random-effect model to determine the associations between HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity. A clear association between HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity was identified in our analyses. The summary OR was 6.23 (95%CI = 4.11-9.45). Similar associations were also found in the subgroup analyses by lapatinib treatment regimens. ORs were 10.04 (95%CI = 6.15-16.39), 8.65 (95%CI = 4.52-16.58), and 3.88 (95%CI = 2.20-6.82) in the lapatinib group, lapatinib + trastuzumab group, and lapatinib + chemotherapy or lapatinib + trastuzumab + chemotherapy group, respectively. Since HLA-DRB1*07:01 is associated with lapatinib-induced hepatotoxicity, genetic screening of HLA-DRB1*07:01 in breast cancer patients prior to lapatinib therapy is warranted for patient safety. In addition, further studies should define the risk of HLA-DRB1*07:01 and lapatinib-induced hepatotoxicity in specific ethnicities.

A case of late presentation of darunavir-related cholestatic hepatitis

We report a case of darunavir-induced cholestatic hepatitis in a human immunodeficiency virus (HIV)-infected patient in the third year of his combined antiretroviral therapy. During the patient's monthly follow-up with regard to his HIV infection, elevated transaminase levels were detected. The patient was subsequently hospitalised at the AIDS and gastroenterology departments. All tested viral hepatitis markers were negative. A diagnosis of autoimmune hepatitis was also ruled out. The liver biopsy revealed cholestatic hepatitis. Darunavir withdrawal resulted in a progressive decrease in liver enzyme levels. We highlight the importance of recognising late development of liver injury secondary to the use of darunavir, and the importance of monitoring liver function in patients undergoing prolonged treatment involving darunavir.

Acute severe hepatitis with alemtuzumab and rechallenge after a year

Alemtuzumab is a monoclonal antibody used as a disease modifying agent in relapsing and remitting multiple sclerosis. It has not previously been associated with drug induced liver injury. Here we present a case of a 49 year old female developing drug induced liver injury secondary to alemtuzumab, confirmed upon rechallenge. Our patient developed severe hepatitis within two days of starting alemtuzumab, both initially and upon rechallenge. The alanine aminotransferase peaked at 577 units per litre and 426 units per litre after initial dose of alemtuzumab and rechallenge respectively. The patient's liver function tests improved significantly between doses of alemtuzumab and again normalised within three months of the second dose, with no clinical manifestations of acute hepatic failure. A full hepatitis screen ruled out alternative causes of hepatitis, including autoimmune hepatitis and hepatotoxicity relating to other medications. Deliberate rechallenge with a medication thought to be associated with drug induced liver injury is uncommonly performed but provides substantial evidence for causality in the appropriate clinical context. The Roussel Uclaf Causality Assessment Method score was calculated as nine, indicating that drug induced liver injury due to alemtuzumab is highly probable. Drug induced liver injury is a potentially serious condition that should be monitored for during alemtuzumab treatment of relapsing and remitting multiple sclerosis. The role of a rechallenge should be weighed up on a case by case basis.

Hepatotoxicity of Inflammatory Bowel Disease Medications

Various medications used to treat inflammatory bowel diseases have been implicated to cause hepatotoxicity. These include sulfasalazine, 5-aminosalicylic acids, fluoroquinolones, metronidazole, thiopurines, methotrexate, anti-tumor necrosis factor agents, and alpha-4 integrin inhibitors. Various types of liver injury have been reported in association with these medications including hypersensitivity reaction, hepatocellular or cholestatic disease, nodular regenerative hyperplasia, liver fibrosis/cirrhosis, portal hypertension and autoimmune liver injury. The revised Roussel Uclaf Causality Assessment Method (RUCAM) provides a scoring system to determine the likelihood of whether a drug caused liver injury. Unfortunately some of the reported liver injuries in association with these treatments have not undergone RUCAM assessment. Therefore, although some of the reports used in this review article show an association between a medication and the reported liver injury, they may not necessarily show causation. In this article, we address methods of monitoring to detect these injuries. We also discuss the prognosis and recommended management plans when liver injury occurs.

Ultra-performance LC–MS/MS study of the pharmacokinetic interaction of imatinib with selected vitamin preparations in rats

Aim: The growing interest of cancerous patients in using vitamins, while on imatinib (IMA) therapy, increased the risk of their pharmacokinetic interactions. Methodology: Ultra-performance LC–MS/MS method was developed and validated for the determination of IMA following oral administration of selected vitamin preparations (vitamin A, E, D3 and C) in rat plasma using a hybrid sample preparation technique of protein precipitation followed by SPE. Results: The method showed good linear response for IMA over the concentration range 1–500 ng/ml. Co-administered vitamin preparations could affect IMA pharmacokinetic profiling through either an increase (vitamin A and E) or a decrease (vitamin C) in IMA bioavailability. Vitamin D3 produced no significant effect on IMA bioavailability. Conclusion: Particular concern should be paid when vitamin preparations are administered with IMA.

Unintended Consequences of Systemic and Ablative Oncologic Therapy in the Abdomen and Pelvis

Human cancers are genetically complex and diverse. Although advances in oncologic therapy aim to define and target unique steps in carcinogenesis, oncologists often rely on less discriminate anticancer therapies that have consequences for normal tissues. Even many of the so-called targeted therapies currently employed can adversely affect normal cells, leading to complications that necessitate dose reductions or cessation of specific therapies. This article explores the unintended consequences of currently employed systemic and ablative anticancer therapies that might manifest at imaging examinations of the abdomen and pelvis, including cytotoxic, molecular targeted, and immunologic agents; ablation; and hematopoietic stem cell transplant. Each of these treatments can have both major and minor unintended effects in the targeted organ(s), in local or adjacent structures, or at distant sites. Timely detection and reporting of adverse consequences of anticancer therapies by the astute imager can result in critical treatment modifications and/or lifesaving interventions; therefore, knowledge of these unintended effects is paramount for radiologists interpreting the results of imaging examinations in cancer patients. ^©RSNA, 2018.

Noninvasive Imaging of Drug-Induced Liver Injury with 18F-DFA PET

Drug-induced liver failure is a significant indication for a liver transplant, and unexpected liver toxicity is a major reason that otherwise effective therapies are removed from the market. Various methods exist for monitoring liver injury but are often inadequate to predict liver failure. New diagnostic tools are needed. Methods: We evaluate in a preclinical model whether ¹⁸F-2-deoxy-2-fluoroarabinose (¹⁸F-DFA), a PET radiotracer that measures the ribose salvage pathway, can be used to monitor acetaminophen-induced liver injury and failure. Mice treated with vehicle, 100, 300, or 500 mg/kg acetaminophen for 7 or 21 h were imaged with ¹⁸F-FDG and ¹⁸F-DFA PET. Hepatic radiotracer accumulation was correlated to survival and percentage of nonnecrotic tissue in the liver. Mice treated with acetaminophen and vehicle or N-acetylcysteine were imaged with ¹⁸F-DFA PET. ¹⁸F-DFA accumulation was evaluated in human hepatocytes engrafted into the mouse liver. Results: We show that hepatic ¹⁸F-DFA accumulation is 49%-52% lower in mice treated with high-dose acetaminophen than in mice treated with low-dose acetaminophen or vehicle. Under these same conditions, hepatic ¹⁸F-FDG accumulation was unaffected. At 21 h after acetaminophen treatment, hepatic ¹⁸F-DFA accumulation can distinguish mice that will succumb to the liver injury from those that will survive it (6.2 vs. 9.7 signal to background, respectively). Hepatic ¹⁸F-DFA accumulation in this model provides a tomographic representation of hepatocyte density in the liver, with a R² between hepatic ¹⁸F-DFA accumulation and percentage of nonnecrotic tissue of 0.70. PET imaging with ¹⁸F-DFA can be used to distinguish effective from ineffective resolution of acetaminophen-induced liver injury with N-acetylcysteine (15.6 vs. 6.2 signal to background, respectively). Human hepatocytes, in culture or engrafted into a mouse liver, have levels of ribose salvage activity similar to those of mouse hepatocytes. Conclusion: Our findings suggest that PET imaging with ¹⁸F-DFA can be used to visualize and quantify drug-induced acute liver injury and may provide information on the progression from liver injury to hepatic failure.

Cholestatic liver injury as a side-effect of dabigatran and the use of coagulation tests in dabigatran intoxication and after reversal by idarucizumab in bleeding and sepsis

Idarucizumab, an antidote specific for dabigatran, became available recently. Dabigatran is not associated with increased risk of hepatotoxicity in comparison with warfarin, but it is seen as a rare side-effect. Cases of cholestatic liver injury due to dabigatran have not been reported previously. We present a case of severe gastro-intestinal bleeding with underlying dabigatran intoxication in a patient with renal failure and the effect of reversal of dabigatran using idaruzicumab on coagulation assays. International normalized ratio (INR) and activated partial thromboplastin time (APTT) results were elevated in a setting of sepsis, possibly due to liver failure. INR and APTT can be elevated if sepsis is complicated by disseminated intravascular coagulation (DIC) or liver failure, making it challenging to determine dabigatrans contribution to their prolongation. A rebound effect after administration of idarucizumab and slow elimination of dabigatran due to reduced kidney function could be detected using the Hemoclot^® diluted thrombin time (dTT) in this situation, in contrast to with non-dilutional assays. Before admission, cholestatic liver injury started shortly after initiation of dabigatran etexilate therapy. As no other cause was found, this liver injury was likely to be drug-induced. Bleeding cessated promptly after administration of idarucizumab in dabigatran intoxication. In conclusion, the anticoagulant effect of dabigatran can be measured by Hemoclot^® dTT in sepsis and cholestatic liver injury was seen as a possible rare side-effect of dabigatran treatment.

Acute Liver Failure

Acute liver failure (ALF) is a life-threatening condition of heterogeneous etiology. Outcomes are better with early recognition and prompt initiation of etiology-specific therapy, intensive care protocols, and liver transplantation (LT). Prognostic scoring systems include the King's College Criteria and Model for End-stage Liver Disease score. Cerebral edema and intracranial hypertension are reasons for high morbidity and mortality; hypertonic saline is suggested for patients with a high risk for developing intracranial hypertension, and when it does, mannitol is recommended as first-line therapy. Extracorporeal liver support system may serve as a bridge to LT and may increase LT-free survival in select cases.

Imaging of hepatic toxicity of systemic therapy in a tertiary cancer centre: chemotherapy, haematopoietic stem cell transplantation, molecular targeted therapies, and immune checkpoint inhibitors

The purpose of this review is to familiarise radiologists with the spectrum of hepatic toxicity seen in the oncology setting, in view of the different systemic therapies used in cancer patients. Drug-induced liver injury can manifest in various forms, and anti-neoplastic agents are associated with different types of hepatotoxicity. Although chemotherapy-induced liver injury can present as hepatitis, steatosis, sinusoidal obstruction syndrome, and chronic parenchymal damages, molecular targeted therapy-associated liver toxicity ranges from mild liver function test elevation to fulminant life-threatening acute liver failure. The recent arrival of immune checkpoint inhibitors in oncology has introduced a new range of immune-related adverse events, with differing mechanisms of liver toxicity and varied imaging presentation of liver injury. High-dose chemotherapy regimens for haematopoietic stem cell transplantation are associated with sinusoidal obstruction syndrome. Management of hepatic toxicity depends on the clinical scenario, the drug in use, and the severity of the findings. In this article, we will (1) present the most common types of oncological drugs associated with hepatic toxicity and associated liver injuries; (2) illustrate imaging findings of hepatic toxicities and the possible differential diagnosis; and (3) provide a guide for management of these conditions.