Liver injury related to amoxycillin-clavulanic acid: interlobular bile-duct lesions and extrahepatic manifestations

Role of liver biopsy in the management of idiosyncratic DILI

Drug-induced liver injury (DILI) presents unique challenges in clinical practice. While some types of DILI are mild and resolve quickly after removing the drug, other situations are more complex, with competing aetiologies or underlying liver disease. Guidelines from professional societies agree that the liver biopsy retains a role in understanding and managing DILI in certain situations. Liver biopsy allows characterization of the histological pattern of injury as well as assessment of severity. Inflammatory infiltrates, bile duct injury or loss and vascular injury are all revealed by liver biopsy. Communication between the hepatopathologist and clinical team with clinicopathological correlation of the findings is necessary for the best determination of causality and differentiation from other diseases of exclusion, like autoimmune hepatitis and graft-versus-host disease. This review highlights important aspects of the role of liver biopsy in DILI evaluation.

Ammonium glycyrrhizin counteracts liver injury caused by lipopolysaccharide/amoxicillin-clavulanate potassium

We treated isolated chicken primary hepatocytes with lipopolysaccharide/amoxicillin clavulanate potassium (LPS/AC) to model liver injury and investigate its underlying mechanisms. We also used this model to assess the cytoprotective effects of compound ammonium glycyrrhizin (CAG) in vitro. LPS/AC-induced injury decreased cell viability and increased the activity of serum aspartate transaminase and alanine transaminase. Levels of superoxide dismutase, glutathione, and glutathione peroxidase were lower than control, while levels of the oxidative product malondialdehyde and reactive oxygen species were higher. Treatment with CAG for 24 h ameliorated these changes. Caspase-3 activity assays and flow cytometry revealed increased apoptosis in the model group. However, apoptosis decreased after CAG treatment, as confirmed by Hoechst 33342 staining. We also observed changes in mitochondrial ultrastructure. Real-time PCR and western blot analyses showed that CAG treatment downregulated LPS/AC-induced RNA expression of caspase-3, caspase-9, bax, cytochrome c, and fas, and upregulated the expression of bcl-2. Mitochondrial cytochrome c was released into the cytosol and the inner mitochondrial membrane potential (ΔΨm) was decreased. Our results highlight CAG as a potential therapeutic agent to counteract LPS/AC-induced liver injury.

Drug Hepatotoxicity: Newer Agents

Idiosyncratic hepatotoxicity is one of the most common reasons for an approved drug being restricted. This article focuses on hepatotoxicity of selected and recently introduced agents, such as, tyrosine kinase inhibitors, monoclonal antibodies, novel oral anticoagulants, newer antiplatelets, antibiotics, anti-diabetics, anti-epileptics, anti-depressants, anti-psychotics and anti-retrovirals. Overall, the incidence of clinically relevant hepatotoxicity from newer agents seems to be lower than that of the older agents. Nevertheless, cases of severe hepatotoxicity have been reported due to some of these newer agents, including, trastuzumab, ipilimumab, infliximab, imatinib, bosutinib, dasatinib, gefitinib, erlotinib, sunitinib, ponatinib, lapatinib, vemurafenib, dabigatran, rivaroxaban, felbamate, lamotrigine, levetiracetam, venlafaxine, duloxetine, darunavir, and maraviroc.

Drug-Induced Liver Injury

CONTEXT

Drug-induced liver injury (DILI) represents a diverse set of responses following exposure to any manufactured or naturally occurring chemical compound. Drug-induced liver injury is of major concern owing to the ever increasing number of compounds introduced into the market for treatment of various diseases as well as the increasing popularity of herbals, which lend themselves to self-medication but are not rigorously regulated.

OBJECTIVE

To provide an overview of the prevalence, classification, and diagnosis of DILI with emphasis on pathogenesis and the role of a liver biopsy. To focus on the most common, emerging, and herbal agents that cause DILI with emphasis on the histologic pattern of injury observed.

DATA SOURCES

A review of the literature was drawn from the PubMed (US National Library of Medicine) repository, textbooks, and online databases. All figures were taken from cases seen at our tertiary referral center, which is 1 of 12 participating sites in the National Institutes of Health-funded Drug-Induced Liver Injury Network.

CONCLUSIONS

Drug-induced liver injury due to prescription, over-the-counter, and herbal products is a major cause of liver disease in the United States and around the world. Diagnosis of DILI is challenging because there is no single clinical, laboratory, or histologic feature specific to DILI. Accurate diagnosis requires establishing a causal relationship with the suspected agent and excluding competing causes of liver injury. The liver biopsy is an essential component in the management of DILI by offering clues to the underlying pathogenesis, providing prognostic information, and guiding therapy.

Antibiotic induced liver injury: what about children?

Antimicrobial agents are important causes of drug-induced liver injury. They are responsible for about 45% of cases of drug hepatotoxicity. Hepatic damage mechanisms are intrinsic or idiosyncratic. Usually, antibiotics are responsible for idiosyncratic toxicity. This review summarizes the rate of incidence and clinical features of hepatotoxicity due to antibiotics and chemotherapics, with particular attention to data regarding paediatric population. Liver injury features have been systematically evaluated for the most commonly administered antibiotics and chemotherapics in adults, even though there is little information about other widely used compounds, as cephalosporine or clarithromycin, and about antibiotics active against multi-resistant bacteria, as carbapenems, vancomycin, clindamycin, and linezolid. By contrast, there is an abundance of case reports in paediatrics, but very few structured studies have been carried out in children. Children are an important class of antibiotic users, with specific metabolic characteristics, so more studies on them should be carried out.

Acute cholestatic hepatitis caused by amoxicillin/clavulanate

Amoxicillin/clavulanate is a synthetic penicillin that is currently commonly used, especially for the treatment of respiratory and cutaneous infections. In general, it is a well-tolerated oral antibiotic. However, amoxicillin/clavulanate can cause adverse effects, mainly cutaneous, gastrointestinal, hepatic and hematologic, in some cases. Presented here is a case report of a 63-year-old male patient who developed cholestatic hepatitis after recent use of amoxicillin/clavulanate. After 6 wk of prolonged use of the drug, he began to show signs of cholestatic icterus and developed severe hyperbilirubinemia (total bilirubin > 300 mg/L). Diagnostic investigation was conducted by ultrasonography of the upper abdomen, serum tests for infection history, laboratory screening of autoimmune diseases, nuclear magnetic resonance (NMR) of the abdomen with bile duct-NMR and transcutaneous liver biopsy guided by ultrasound. The duration of disease was approximately 4 mo, with complete resolution of symptoms and laboratory changes at the end of that time period. Specific treatment was not instituted, only a combination of anti-emetic (metoclopramide) and cholestyramine for pruritus.

Hepatotoxicity of antibiotics: a review and update for the clinician

Collectively, the various classes of antibiotics are a leading cause of drug-induced liver injury (DILI). However, acute antibiotic-associated DILI can be difficult to diagnose, as the course of therapy is usually brief, and other confounding factors are often present. In addition to the broad clinicopathologic spectrum of hepatotoxicity associated with the antimicrobials, the underlying infectious disease being treated may itself be associated with hepatic dysfunction and jaundice. This review provides summarized information on several classes of antimicrobial agents, highlighting new agents causing DILI and updating information on older agents.

Salvianolic acid B inhibits hepatic stellate cell activation through transforming growth factor beta-1 signal transduction pathway in vivo and in vitro

Salvianolic acid B (Sal B) is a major water soluble component extracted from Radix Salviae miltiorrhizae, a traditional Chinese herb widely used for treating cardiovascular and hepatic diseases. Sal B has been reported to inhibit transforming growth factor (TGF)-β1-stimulated hepatic stellate cells (HSCs) activation and collagen type I expression. In this study, we further investigated the mechanisms of Sal B on liver fibrosis relating to TGF-β/Smads signalling pathway, especially to TGF-β1 receptors. Liver fibrosis model was induced by intraperitoneal injection of dimethylnitrosamine (DMN) for four weeks. Rats were randomly divided into three groups: normal, model, and Sal B groups. Rats in Sal B group were treated by oral administration of Sal B for four weeks from the first day of DMN exposure. Hydroxyproline (Hyp) content in liver tissue was assayed using Jamall's method and collagen deposition was visualized using Sirius red staining. HSCs were isolated from normal rats, and were cultured primarily in uncoated plastics. At day 4 after isolation, cells were stimulated with 2.5 ng/mL TGF-β1, and treated with 1 and 10 µmol/L Sal B and 10 µmol/L SB-431542 (TβR-I inhibitor) for 24 h, respectively. Cell proliferation was examined with 5-ethynyl-2'-deoxyuridine assay. The expressions of alpha smooth muscle actin (α-SMA) and Smad3 were assayed by immunofluorescent stain and Western blotting. The expression of TβR-I was analysed by Western blotting and real-time polymerase chain reaction. The activity of TβR-I kinase was measured by ADP-Glo kinase assay. The results showed that Sal B could inhibit collagen deposition and reduce Hyp content significantly, and decrease expressions of TGF-β1 and TβR-I in fibrotic liver in vivo. Also, Sal B decreased the expressions of α-SMA and TβR-I, inhibited Smad3 nuclear translocation and down-regulated TβR-I kinase activity in vitro. These findings suggested that Sal B could prevent HSCs activation through TGF-β signalling pathway, i.e. inhibiting TGF-β1 expression, activity of TβR-I kinase and Smads phosphorylation.

Differential hepatic expression of CD56 can discriminate biliary atresia from other neonatal cholestatic disorders

OBJECTIVES

The diagnosis of biliary atresia (BA) can be challenging as its histopathologic features overlap with those of other pediatric cholestatic liver diseases. We aimed to study the diagnostic value of hepatic CD56 immunostaining in the differentiation of BA from other causes of neonatal cholestasis.

METHODS

Hepatic CD56 immunostaining was investigated in 30 infants with BA and compared with that in 30 infants with non-BA cholestatic disorders. The expression of positive cells was interpreted semiquantitatively on the basis of the extent (percentage or number) of positive cells on a scale of 0-3.

RESULTS

The occurrence of CD56-positive biliary epithelial cells was significantly higher in the BA (83.3%) than in the non-BA group (6.7%), whereas the occurrence of CD56 natural killer cells in hepatic parenchyma was significantly higher in the non-BA group (76.7%) than in the BA group (6.7%; P<0.0001 for both). In contrast, there was no significant difference between both groups in CD56 natural killer cells in portal tracts (P>0.05). Using this differential expression as a discriminative tool between the BA and the non-BA group, positive biliary epithelial cell staining had high specificity, whereas negative parenchymal staining had high sensitivity (93.3% for both) with an accuracy of 88.3 and 84.65%, respectively. The combination of both parameters improved the accuracy up to 91.65%, with 100% specificity in the diagnosis of BA.

CONCLUSION

CD56 immunostaining of the liver had a diagnostic value; it can be used to differentiate BA from other neonatal cholestatic disorders and might be useful as an additional stain when investigating infants with neonatal cholestasis.

Preparation and evaluation of hepatic stellate cell selective, surface conjugated, peroxisome proliferator-activated receptor-gamma ligand loaded liposomes

Hepatic stellate cells (HSCs) activation leads to major fibrogenic response in liver fibrosis. Selective localization of drug to HSCs can provide effective antifibrotic therapy. Thus, objectives of study were to prepare peroxisome proliferator-activated receptor-γ ligand (rosiglitazone) loaded mannose 6-phosphate modified human serum albumin (M6P-HSA) conjugated liposomes and evaluate pharmacokinetically and pharmacodynamically in rats for application of findings of studies in development of suitable and relevant product for treatment of liver fibrosis. The HSA was derivatized with mannose 6-phosphate and then coupled to optimized liposomes. Drug distribution in liver and other tissues after intravenous administration in carbon tetrachloride-induced liver fibrosis model rats was studied. Histopathological examination, estimation of biochemical markers, and grading of liver fibrosis was performed to evaluate pharmacodynamic efficacy of prepared formulation. The M6P-HSA conjugation to liposomes enhanced rosiglitazone liver uptake significantly (2.61 folds) and disappeared from systemic circulation at double rate. Favorable pharmacokinetics resulted in improved histopathological morphology, biochemical markers level, and decreased fibrosis grade. Hence, critical scrutiny of results suggested preferential and enhanced drug localization in pathogenic cells of liver providing a thinking which may result in development of product that can provide cure or at least prevention to this progressive disease necessitating liver transplant.

Drug-induced cholestasis

Recent progress in understanding the molecular mechanisms of bile formation and cholestasis have led to new insights into the pathogenesis of drug-induced cholestasis. This review summarizes their variable clinical presentations, examines the role of transport proteins in hepatic drug clearance and toxicity, and addresses the increasing importance of genetic determinants, as well as practical aspects of diagnosis and management.

Important elements for the diagnosis of drug-induced liver injury

BACKGROUND & AIMS

Drug-induced liver disease is the leading cause of acute liver failure in the United States. Accurate reporting of drug-induced liver injury is essential for early detection of hepatotoxicity and for developing reliable, interpretable literature. We assessed the extent to which published case reports of drug-induced liver disease include sufficient clinical data for interpreting the cause of toxicity.

METHODS

We developed a list of 42 predetermined, specific minimal elements necessary in evaluating causality of drug-induced liver injury. We then analyzed 97 published case reports or series studies of hepatotoxicity from 6 drugs (from 3 classes): amoxicillin/clavulanic acid (n = 35), troglitazone (n = 32), rosiglitazone (n = 10), pioglitazone (n = 8), zafirlukast (n = 8), and montelukast (n = 4).

RESULTS

Patient age, sex, primary disease, and drug name were reported in most, if not all, published case reports. However, many elements were underreported; some publications did not mention initial bilirubin levels (12%), many did not provide initial alkaline phosphatase levels (58%), and others provided vague descriptions of how certain diagnoses were excluded, that is, tests for hepatitis A, B, and C were negative. Data on abnormal results from serial liver tests frequently were absent. Exclusions of competing viral etiologies were reported in less than 50% of the studies.

CONCLUSIONS

Reports of drug-induced liver diseases often do not provide the data needed to determine the causes of the adverse effects. Efforts to promote and include a list of essential diagnostic elements in research articles could increase the quality and clinical utility of published case reports of drug toxicity.

Amoxicillin and amoxicillin plus clavulanate: a safety review

Despite the considerable number of newer antibacterials made available over the past decades, amoxicillin, alone or in combination with clavulanic acid, still accounts among the most widely used antibacterial agents. Although they are often considered 'twin drugs', they are different both in terms of antibacterial activities and of safety profile. It is well documented that the clavulanate component may cause adverse reactions by itself, thus exposing patients to further, and sometimes undue, risks. Although amoxicillin/clavulanate should be considered as an alternative agent only for the treatment of resistant bacteria, evidence shows that it is often used also when a narrow-spectrum antibiotic would have been just as effective. This prescription habit may have serious consequences in terms of patients' safety, as well as in terms of the development of bacterial resistance.

Drug-related hepatotoxicity and acute liver failure

Drug-induced acute liver failure (ALF) accounts for approximately 20% of ALF in children and a higher percentage of ALF in adults. Although most patients experience milder drug hepatotoxic reactions such as hepatitis, cholestasis, or asymptomatic enzyme elevation, it is important to recognize the potential for progression to ALF. The most common cause of drug-induced ALF in children is acetaminophen (15% of all ALF in children in the United Kingdom and the United States), whereas other drugs such as antituberculous and antiepileptic therapy account for 5%. The pathogenesis of liver injury includes direct hepatotoxicity and idiosyncratic reactions for most drugs, although for others the mechanism of injury is assumed on the basis of clinical presentation and hepatic histological findings. We review the adult and pediatric literature of drug-induced hepatotoxicity and ALF, with special attention to commonly used or offending medications, mechanism of the toxicity, clinical presentation, diagnosis, treatment, and prognosis. Although most of the available information is based on experience in adult patients, we have included that which is applicable to children, or we have cited pediatric examples. Enhanced awareness of the potential hepatotoxicity of commonly prescribed medications may minimize the frequency of serious hepatotoxicity and ALF in pediatric patients.

Mycophenolate mofetil for drug-induced vanishing bile duct syndrome

Amoxicillin/clavulanate is associated with liver injury, mostly of a cholestatic pattern. While outcomes are usually benign, progression to cirrhosis and death has been reported. The role of immunosuppressive therapy for patients with a protracted course is unclear. We report the case of an elderly patient who developed prolonged cholestasis secondary to amoxicillin/clavulanate. Vanishing bile duct syndrome was confirmed by sequential liver biopsies. The patient responded to prednisone treatment, but could not be weaned off corticosteroids, even when azathioprine was added. Complete withdrawal of both prednisone and azathioprine was possible by using mycophenolate mofetil, an inosine monophosphate dehydrogenase inhibitor. Sustained remission has been maintained for more than 3 years with low-dose mycophenolate mofetil.

Hepatotoxicity due to antibiotics

Antimicrobial drugs are important causative agents in idiosyncratic drug-induced liver injury (DILI). As with idiosyncratic DILI in general, antibiotic-induced liver injury is rare but difficult to diagnose and almost impossible to predict. Diagnosis requires awareness of possible causal agents, vigilance in monitoring symptoms and sometimes biochemical tests, attention to careful history taking and establishing temporal association, and exclusion of competing etiologies. In most instances, patients with antibiotic-associated DILI recover if the offending agent is withdrawn in a timely fashion.

Adverse drug reactions related to amoxicillin alone and in association with clavulanic acid: data from spontaneous reporting in Italy

OBJECTIVES

To analyse an Italian database of spontaneous reporting of suspected adverse drug reactions in order to compare the safety profile of amoxicillin and amoxicillin/clavulanic acid.

METHODS

Data were retrieved from the spontaneous reports collected by six Italian regions (the GIF database) from January 1988 to June 2005. Drug utilization data were also available for the two drugs. The comparison between amoxicillin and amoxicillin/clavulanic acid was made using the chi(2) or Student's t-test, when appropriate. Disproportionality in reporting of adverse events was assessed using reporting odds ratio methodology.

RESULTS

Up to June 2005, the GIF database collected 37 906 reports, of which 1088 were related to amoxicillin/clavulanic acid and 1095 to amoxicillin. The percentage of skin reactions was statistically higher for amoxicillin (82%) than for amoxicillin/clavulanic acid (76%); on the contrary, the percentage of gastrointestinal, hepatic and haematological reactions was significantly higher for amoxicillin/clavulanic acid (13%, 4% and 2%, respectively) than for amoxicillin (7%, 1% and 1%, respectively). Amoxicillin/clavulanic acid seems to be associated with a higher risk of Stevens-Johnson syndrome, purpura and hepatitis than amoxicillin alone. In particular, the reporting rate of hepatitis is on average 9-fold higher for amoxicillin/clavulanic acid than for amoxicillin.

CONCLUSIONS

Analysis shows a different safety profile for the two selected drugs. The combination of amoxicillin/clavulanic acid has been increasingly used in Italy and now represents the most frequently antibiotic prescribed by Italian general practitioners. Given the documented level of inappropriate use of beta-lactams in Italy, these results should be taken into account by physicians before prescribing amoxicillin/clavulanic acid to patients.

Protective effect of glycyrrhizin and matrine on acute vanishing bile duct syndrome induced by alpha-naphthylisothiocyanate in rats

AIM

To explore the effects of glycyrrhizin (GL) and matrine (MT) on acute vanishing bile duct syndromes (AVBDS) in rats.

METHODS

AVBDS in rats were induced by alphanaphthylisothiocyanate (ANIT), and the effects of GL and MT on AVBDS were explored and compared with dexamethasone (DEX) by serology determination, histological assessment of liver damage and bile excretion experiments.

RESULTS

The protection of DEX pre-treatment was directed toward cholangiocytes rather than hepatocytes. Rats remedially treated with DEX 3 h after ANIT were not resistant to ANIT toxicity. Notably, remedial treatment with DEX 12 h after ANIT enhanced ANIT toxicity. However, GL and MT attenuated both bile duct and hepatocyte damage induced by ANIT in the initial phase of impairment.

CONCLUSION

The nature products (GL and MT) exhibited better protection against ANIT-induced AVBDS than DEX. In the initial phase of impairment of AVBDS, the protection of GL and MT may be due partially to modifying the metabolism and excretion of ANIT and to their anti-inflammatory effects.

Differential findings for CD14-positive hepatic monocytes/macrophages in primary biliary cirrhosis, chronic hepatitis C and nonalcoholic steatohepatitis

BACKGROUND AND AIMS

Endotoxin-responsive monocytes/macrophages (CD14-positive) are potential sources of profibrogenic factors. The aims of this study were to determine (1) whether hepatic CD14-positive cells are present in various forms of chronic liver disease, and (2) the relationship between CD14-positive cells, myofibroblasts, and fibrosis in these diseases.

METHODS

Liver specimens from control subjects (n = 12) and those with primary biliary cirrhosis (n = 18), chronic hepatitis C (n = 13), or nonalcoholic steatohepatitis (n = 13) were immunostained for CD14, CD68, and alpha-smooth muscle actin (SMA) and the number of cells expressing these antigens was determined. Fibrosis and inflammation were also assessed.

RESULTS

The total number of hepatic CD68-positive cells was similar in diseased and control livers. The number of CD14-positive cells was increased in advanced fibrosis in primary biliary cirrhosis and hepatitis C but not in nonalcoholic steatohepatitis. The number of CD14-positive cells was also increased in hepatitis C specimens with high inflammatory activity. CD14-positive cells were often associated with alpha-SMA-positive myofibroblasts in fibrous septa.

CONCLUSIONS

The number of hepatic CD14-positive cells is increased in advanced fibrosis in subjects with primary biliary cirrhosis and hepatitis C but not in nonalcoholic steatohepatitis. In primary biliary cirrhosis and hepatitis C, CD14-positive macrophages are found in close proximity to fibrous septa and myofibroblasts. In hepatitis C, an increased number of CD14-positive cells are associated with high inflammatory activity.

Increased ADAMTS-13 proteolytic activity in rat hepatic stellate cells upon activation in vitro and in vivo

INTRODUCTION

ADAMTS-13 is a member of A Disintegrin And Metalloprotease with ThromboSpondin type 1 repeats (ADAMTS) family, primarily synthesized in hepatic stellate cells (HSCs), one of the major cell types transdifferentiating into myofibroblasts during liver fibrosis. However, the association between ADAMTS-13 expression and HSC activation or liver fibrosis is not known.

METHODS

In this study, we determined the ADAMTS-13 mRNA, protein, and activity in isolated primary HSCs upon activation on a plastic dish and in liver after administration of carbon tetrachloride (CCl(4)) in rats.

RESULTS

We showed that ADAMTS-13 antigen and proteolytic activity in the activated rat HSCs were dramatically increased, whereas ADAMTS-13 mRNA in these cells was only minimally altered. Similarly, the ADAMTS-13 antigen and proteolytic activity in rat liver after CCl(4) injury were also significantly increased, whereas the ADAMTS-13 mRNAs in these liver tissues were only slightly increased compared with normal. Surprisingly, despite the dramatic up-regulation of ADAMTS-13 protein synthesis in the activated HSCs after CCl(4) administration, the plasma levels of ADAMTS-13 protease in rats did not increase concordantly.

CONCLUSION

We conclude that the up-regulation of ADAMTS-13 protein expression in rat HSCs during activation in vitro and in vivo suggests the possibility of ADAMTS-13 proteolysis, an important part of function of the activated HSCs, perhaps through modulation of liver regeneration or formation of liver fibrosis after various injuries. The data also suggest the minimal contribution of the activated HSCs in regulation of plasma levels of ADAMTS-13 protease.

Hematopoietic Cells Are a Source of Nidogen-1 and Nidogen-2 during Mouse Liver Development

Nidogen-1 and −2 are key components of basement membranes (BMs). Despite the presence of nidogen molecules in the parenchyma of the developing liver, no BMs are formed therein. This suggests that, in the liver, nidogens may also have functions other than BM formation. As a first step toward the elucidation of the possible cell biological functions of nidogens in the developing liver, we aimed to study their cellular origin. We localized expression of nidogen-1 and nidogen-2 on prenatal days 12, 14, and 16 in the developing mouse liver using in situ hybridization at the light and electron microscopic level and light microscopic immunohistochemistry. Our results show that nidogens are produced both in portal anlagen and in the parenchyma during liver development. In the parenchyma, transcripts can be found in hepatocytes, precursors of stellate cells, endothelial cells and, most interestingly, hematopoietic cells. Using real-time PCR, we found that the gene expression for both proteins shows a decrease from day 14 to day 16 concomitant with a decrease in the hepatic hematopoiesis. We suggest that nidogens may, to some extent, take part in the regulation of hepatic hematopoiesis. (J Histochem Cytochem 54:593-604, 2006)

Acute liver failure due to amoxicillin and amoxicillin/clavulanate

The aim of our study is to report upon the presentation of two patients with life-threatening acute liver failure (ALF) due to amoxicillin and amoxicillin/clavulanate. A 59-year-old, Caucasian male presented with ALF 34 days after receiving amoxicillin/clavulanate. Despite aggressive supportive care, he died on hospital day 10. A 42-year-old, Caucasian female presented with ALF 21 days after receiving amoxicillin. She underwent successful liver transplantation on hospital day 19. In both cases, all competing causes of ALF had been excluded, liver pathology was consistent with drug-induced hepatitis, and cases were deemed "definite/highly probable" using causality assessment. Amongst 14 prior ALF/death cases due to amoxicillin/clavulanate, the mean age (62 years), male predominance (57%), and mean delay from drug cessation to presentation (17 days) is similar to what has been reported in patients with self-limited cholestatic hepatitis. Acute liver failure is a rare manifestation of amoxicillin and amoxicillin/clavulanate hepatotoxicity with no obvious clinical features at presentation portending a poor prognosis. Early transfer of patients with severe drug-induced hepatotoxicity (i.e., encephalopathy or coagulopathy) to a transplant center is recommended due to their poor likelihood of recovery.

Drug- and chemical-induced cholestasis

Cholestasis caused by medicinal and chemical agents is an increasingly well-recognized cause of liver disease. Clinical drug-induced cholestatic syndromes producing jaundice and bile duct injury can mimic extrahepatic biliary obstruction, primary biliary cirrhosis, and sclerosing cholangitis, among others. This article updates the various forms of drug-induced cholestasis, focusing on the clinicopathologic features of this form of hepatic injury and on the known or putative mechanisms by which drugs and chemicals lead to cholestasis.

Hepatotoxicity of antibiotics and antifungals

Hepatotoxicity associated with any antibiotic is rare. With the wide-spread use of antimicrobial agents, however, hepatic injury is not an infrequent occurrence. Penicillins remain a widely used class of antimicrobials with a well defined record of low hepatotoxicity. The combination of clavulanate with amoxicillin may be associated with the greatest risk for liver injury from any antimicrobial agent. Significant hepatotoxicity also may occur with sulfamethoxazole/ trimethoprim and combination regimens used to treat tuberculosis. An autoimmune-like hepatitis may result from minocycline or nitrofurantoin exposure and most often resolves with cessation of therapy. Treatment with high doses of tetracycline and oxacillin may be associated with severe hepatotoxicity. Early suspicion of hepatocellular injury in the setting of antimicrobial exposure should prompt cessation of therapy and avoidance of rechallenge.

Conditional tetracycline-regulated expression of TGF-beta1 in liver of transgenic mice leads to reversible intermediary fibrosis

Based on the tetracycline-regulated gene expression system, a double-transgenic mouse model for liver fibrosis was established in which the expression of transforming growth factor beta1 (TGF-beta1) can be regulated deliberately by addition or removal of doxycycline hydrochloride to the drinking water. TGF-beta1 plasma levels in induced double-transgenic mice reached values ranging from 250 to 1,200 ng/mL, being 10 to 30 times above the normal plasma levels. By applying a cyclic induction-deinduction protocol, deleterious effects of the high plasma TGF-beta1 levels were overcome. By using this protocol, liver fibrosis occurred within a few cycles and progressed further to an intermediary fibrosis when cyclic induction was continued. On histochemical staining, a marked perisinusoidal deposition of extracellular matrix was detected accompanied by the activation of hepatic stellate cells as shown by alpha-smooth muscle actin (alpha-SMA) expression. Apoptosis of hepatocytes was prominent in TGF-beta1 high producers, leading to a decreasing number of TGF-beta1-expressing cells with time. No compensatory proliferation of hepatocytes could be detected. In advanced stages, fibrogenesis could be stopped by switching off TGF-beta1 production and reversal of fibrosis could be shown by (immuno)histochemistry within 6 to 21 days. Determination of messenger RNA (mRNA) levels of procollagen I and III, laminin (B1), matrix metalloproteinase (MMP)-2, -9, and -13, and tissue inhibitor of matrix metalloproteinase (TIMP)-1 and -2 by real-time reverse-transcription polymerase chain reaction (RT-PCR) provided insight into some mechanistic details of the fibrogenic process and its reversal. In conclusion, this model will enable the analysis of fibrogenesis at progressive stages and help in elucidating the cellular changes during development and regression of liver fibrosis caused by elevated TGF-beta1 expression.

Bile duct disorders

Drug-induced bile duct injury related prolonged or chronic cholestasis is recognized as a common side effect of treatment with several drugs. The severity and duration of the clinical symptoms suggest that this increase in number of reports is not only related to clinician and pathologists being increasingly aware of the condition, but also may represent a true increase in incidence likely related to a time-related growing experience with newer drugs. This clinical presentation encompasses a wide variety of features that may be the source of diagnostic difficulties, especially in the cases where cholestasis occurs days or weeks after the completion of therapy. Even more puzzling is the initial picture of hepatocholangitis, which may be silent and ensuing bile duct paucity with chronic anicteric cholestasis may be another source of diagnostic difficulties in the long-term. These diagnostic difficulties suggest that some of the cases of the so-called "idiopathic adulthood ductopenia" may originate from overlooked drug induced vanishing bile duct syndrome. The pathogenesis of the syndrome remains largely unknown and the determinants of prognosis and outcome. From reproducible data obtained in different studies investigating HLA-dependent predisposition, one may assume that genetics plays a major role even if other unknown additive factors are also likely involved. Severity of initial hepatocholangitis is likely to represent another important determinant of severity and prognosis, however to be assessed in larger longitudinal studies. Therapy of large bile duct injury mimics that of primary sclerosing cholangitis. Treatment of small bile duct injury remains disappointing. Corticosteroids are invariably ineffective. Ursodeoxycholic acid as been shown to induce improvement of clinical and biochemical cholestasis in some selected cases, its efficacy being however unpredictable. Preliminary data about the natural history of the vanishing bile duct syndrome suggest that therapy might be more effective when initiated early.

Smads 2 and 3 are differentially activated by transforming growth factor-beta (TGF-beta ) in quiescent and activated hepatic stellate cells. Constitutive nuclear localization of Smads in activated cells is TGF-beta-independent

Hepatic stellate cells are the primary cell type responsible for matrix deposition in liver fibrosis, undergoing a process of transdifferentiation into fibrogenic myofibroblasts. These cells, which undergo a similar transdifferentiation process when cultured in vitro, are a major target of the profibrogenic agent transforming growth factor-beta (TGF-beta). We have studied activation of the TGF-beta downstream signaling molecules Smads 2, 3, and 4 in hepatic stellate cells (HSC) cultured in vitro for 1, 4, and 7 days, with quiescent, intermediate, and fully transdifferentiated phenotypes, respectively. Total levels of Smad4, common to multiple TGF-beta superfamily signaling pathways, do not change as HSC transdifferentiate, and the protein is found in both nucleus and cytoplasm, independent of treatment with TGF-beta or the nuclear export inhibitor leptomycin B. TGF-beta mediates activation of Smad2 primarily in early cultured cells and that of Smad3 primarily in transdifferentiated cells. The linker protein SARA, which is required for Smad2 signaling, disappears with transdifferentiation. Additionally, day 7 cells demonstrate constitutive phosphorylation and nuclear localization of Smad 2, which is not affected by pretreatment with TGF-beta-neutralizing antibodies, a type I TGF-beta receptor kinase inhibitor, or activin-neutralizing antibodies. These results demonstrate essential differences between TGF-beta-mediated signaling pathways in quiescent and in vitro transdifferentiated hepatic stellate cells.

The myofibroblastic conversion of peribiliary fibrogenic cells distinct from hepatic stellate cells is stimulated by platelet-derived growth factor during liver fibrogenesis

The origin of myofibroblasts and the factors promoting their differentiation during liver fibrogenesis remain uncertain. During biliary-type fibrogenesis, the proliferation and chemoattraction of hepatic stellate cells (HSC) toward bile ducts is mediated by platelet-derived growth factor (PDGF), while myofibroblastic conversion of peribiliary cells distinct from HSC also occurs. We herein examined the phenotype of these peribiliary myofibroblasts as compared with myofibroblastic HSC and tested whether their differentiation was affected by PDGF. Biliary-type liver fibrogenesis was induced by common bile duct ligation in rats. After 48 hours, periductular fibrosis in portal tracts colocalized with smooth muscle alpha-actin-immunoreactive myofibroblasts, the majority of which were desmin negative. Simultaneously, in sinusoids, desmin immunoreactivity was induced in a large number of HSC, which were smooth muscle alpha-actin negative. Cultures of peribiliary myofibroblasts were expanded from isolated bile duct segments and compared with myofibroblastic HSC. Peribiliary myofibroblasts outgrowing from bile duct segments expressed smooth muscle alpha-actin, alpha1 (I) collagen mRNA, and PDGF receptor-beta subunit. Desmin immunoreactivity gradually decreased in cultured peribiliary myofibroblasts, contrasting with constant labeling of all myofibroblastic HSC. In addition, IL-6 expression in peribiliary myofibroblasts was up to 100-fold lower than in myofibroblastic HSC, whereas the expression of the complement-activating protease P100 in both cell types showed little difference and that of the extracellular matrix component fibulin 2 was similar. The expression of smooth muscle alpha-actin protein in cultured peribiliary myofibroblasts was stimulated by PDGF-BB and inhibited by STI571, a PDGF receptor tyrosine kinase inhibitor, whereas in bile duct-ligated rats, the administration of STI571 caused a significant decrease in peribiliary smooth muscle alpha-actin immunoreactivity, and to a lesser extent, a decrease in peribiliary fibrosis. These results indicate that peribiliary cells distinct from HSC undergo a PDGF-mediated conversion into myofibroblasts expressing IL-6 at lower levels than myofibroblastic HSC and contribute to the initial formation of biliary-type liver fibrosis.

Hepatitis associated with amoxicillin/clavulanic acid and/or ciprofloxacin

We describe an elderly patient with normal pre-existing liver functions who was treated with amoxicillin/clavulanic acid and later ciprofloxacin for acute bronchitis. He developed a pattern of liver dysfunction consistent with hepatocellular injury, with clinical features of a hypersensitivity reaction, which may be attributable to either or both of the antimicrobial agents used. This gradually resolved over a 4-week time period, with conservative management. A review of the relevant literature on drug-induced hepatotoxicity is also presented.

[Amoxicillin-clavulanic acid induced hepatotoxicity with progression to cirrhosis]

Amoxicillin-clavulanic acid is a commonly used antibiotic in clinical practice. It is usually prescribed on an empirical basis and several cases of hepatotoxicity with cholestasis have been described. We report the case of a 42-year-old man who developed an acute hepatocellular lesion with progression to cirrhosis. The patient received amoxicillin-clavulanic acid twice with an interval of four months. Other causes of hepatic failure were excluded. Although amoxicillin-clavulanic acid-induced hepatotoxicity has been widely documented, there are no other reports describing its progression to cirrhosis in an adult.

Anti-oxidant ebselen causes the resolution of experimentally induced hepatic fibrosis in rats

BACKGROUND

Hepatic fibrosis occurs because of injury to the liver parenchyma and biliary system. We have investigated the effect of an organic selenium anti-oxidant, ebselen, in the resolution of experimentally induced hepatic fibrosis, and evaluated its effect on various paradigms involved in hepatic fibrosis.

METHODS

Following pretreatment with phenobarbitone, liver fibrosis was induced in male Fischer 344 rats by using carbon tetrachloride treatment for 10 weeks. Carbon tetrachloride-treated rats were randomly assigned into two groups: (i) no ebselen; and (ii) ebselen administered for 3 weeks following a 10-week carbon tetrachloride treatment period. Normal controls were: (i) neither carbon tetrachloride nor ebselen treated; or (ii) ebselen treated for 13 weeks. Liver sections were stained with hematoxylin and eosin, Masson trichrome and stained for reticulin by using silver impregnation. Reverse transcription-polymerase chain reaction was used to analyze the steady-state levels of gene(s) involved in: (i) hepatic fibrosis, namely, transforming growth factor-beta1, procollagen I and III, tissue inhibitor of metalloproteinase-1 and matrix metalloproteinase-13; (ii) oxidative stress, namely, cytochrome P4502E1; and (iii) preneoplastic liver foci, namely, the placental form of glutathione-S-transferase.

RESULTS

Histological staining showed that ebselen resolves carbon tetrachloride-induced hepatic fibrosis. Treatment with ebselen reduced steady-state levels of transforming growth factor-beta1, procollagen I and III, tissue inhibitor of metalloproteinase-1, cytochrome P4502E1 and placental form glutathione-S-transferase transcripts, and increased transcripts of matrix metalloproteinase-13.

CONCLUSION

These findings provide evidence that ebselen significantly causes the resolution of carbon tetrachloride-induced hepatic fibrosis in rats.

Cholangiopathy after short-term administration of piperacillin and imipenem/cilastatin

We describe a patient who suffered from intestinal perforation after abdominal trauma. Perioperatively, he was treated with a single dose of piperacillin and 9 doses of imipenem/cilastatin over 3 days. The patient was discharged 5 days after surgery in good clinical condition and with normal liver values except for a marginal elevation of alanine aminotransferase. Two weeks after discharge, he developed fatigue, fever and pruritus, necessitating rehospitalization. He was jaundiced and had elevated alkaline phosphatase and transaminases. After exclusion of an intra-abdominal fluid collection, a vascular problem, and infectious or autoimmune liver disease, a liver biopsy was performed. The biopsy revealed centrizonal bilirubinostasis, a portal infiltrate rich in eosinophils and cholangitis. Lymphocyte transformation tests for piperacillin and imipenem/cilastatin were positive, suggesting an immunological mechanism for the observed hepatopathy. Cholestasis gradually decreased but was detectable for several weeks. The patient had a full clinical and biochemical recovery after 3 months. We conclude that short-term therapy with piperacillin, imipenem/cilastatin or the combination of these drugs can lead to the same type of hepatopathy as described for amoxycillin/clavulanic acid or antistaphylococcal penicillins. Liver biopsy and positive lymphocyte transformation are compatible with an immunological mechanism.

Transforming growth factor beta-1 stimulates invasivity of hepatic stellate cells by engagement of the cell-associated fibrinolytic system

The activation of hepatic stellate cells (HSC) during liver fibrogenesis has been shown to be mediated by paracrine and autocrine loops involving transforming growth factor-beta1 (TGF-beta1) as the main fibrogenic mediator secreted by activated macrophages, endothelial cells and liberated by disintegrated platelets. The cell-associated plasminogen activation system regulates extracellular matrix (ECM) catabolism and cell movement. We have studied whether TGF-beta1 could modulate the plasminogen activation system in human HSC and the role of such protease system in the activity of TGF-beta1 on HSC. Urokinase plasminogen activator receptors (u-PAR), u-PA and plasminogen activator inhibitor type 1 (PAI-1) were determined by immunoassay and RNase protection assay. Cell migration, evaluated either as chemotaxis or as chemoinvasion, was studied in Boyden chambers after addition of TGF-beta1, and inhibition with anti-u-PA and anti-u-PAR antagonists [antibodies against u-PA and u-PAR and antisense oligonucleotides (aODN) against u-PAR mRNA]. We have shown that TGF-beta1 is not mitogenic for HSC, while it is a powerful motogen either in chemotaxis or chemoinvasion assays. TGF-beta1 up-regulates the synthesis and expression of PAI-1, as well as u-PAR expression and exposure at the cell membrane, while it does not affect u-PA levels. TGF-beta1-dependent chemoinvasion of reconstituted basement membrane exploits the cell-associated plasminogen activation system, since it is blocked by monoclonal antibodies against u-PA and against various u-PAR domains, as well as by anti-u-PAR aODN. We have also observed a cumulative effect of TGF-beta1, b-FGF and PDGF in the invasion assay of HSC: in the presence of low amounts of TGF-beta1 the chemoinvasive activity of PDGF and bFGF is dramatically increased. Also this cooperation requires u-PAR and is inhibited by monoclonal antibodies against u-PAR domains I, II and III.

Drug-induced liver disease

The incidence of drug-induced liver disease appears to be increasing, reflecting the increasing number of new agents that have been introduced into clinical use over the past several decades. Among the topics covered, the author discusses incidence, diagnosis, risk factors, clinical presentations, hepatitis, and vascular injury. The author also reviews the hepatic injury seen with commonly prescribed drugs, emphasizing newer developments in the field and recent publications and reports.

Rapidly progressive cholestasis: An unusual reaction to amoxicillin/clavulanic acid therapy in a child

Hepatotoxity associated with amoxicillin/clavulanic acid is usually a self-limited disease with complete recovery. We report a rapidly progressing liver disease with ductopenia and portal fibrosis in a 3-year-old boy treated with Augmentin.

HLA association of amoxicillin-clavulanate--induced hepatitis

BACKGROUND & AIMS

Drug-induced immunoallergic hepatitis typically affects a minority of patients exposed to a particular drug. Its rarity is believed to be due to metabolic or immunologic idiosyncrasy. The presence of an immunologic idiosyncrasy might imply an HLA association. Previous studies reporting an HLA association of drug-induced hepatitis included only small numbers of patients and used serological HLA typing.

METHODS

We studied 35 patients with biopsy-documented amoxicillin-clavulanate-induced hepatitis. HLA-A and -B were typed using alloantisera and compared with those of 300 controls (volunteer bone marrow donors). HLA-DRB and -DWB were typed by polymerase chain reaction-line probe assay, with 60 volunteer bone marrow donors serving as controls.

RESULTS

The study group was characterized by a higher frequency of DRB1*1501-DRB5*0101-DQB1*0602 haplotype (57.1% vs. 11.7% in controls, P < 0.000005; after correction for the large number of comparisons, P < 0.0002). Patients with DRB1*1501-DRB5*0101-DQB1*0602 haplotype were more likely than patients without it to have a cholestatic (70% vs. 60%) or mixed (30% vs. 13%) than a hepatocellular pattern of hepatitis (0% vs. 27%) (P < 0.05).

CONCLUSIONS

Amoxicillin-clavulanate-induced hepatitis is associated with the DRB1*1501-DRB5*0101-DQB1*0602 haplotype. The data support the view that an immunologic idiosyncrasy, mediated through HLA class II antigens, plays a role in the pathogenesis of drug-induced immunoallergic hepatitis. HLA association has a limited impact on the expression of hepatitis.

Drug- and chemical-induced cholestasis

Cholestasis resulting from drugs is an increasingly recognized cause of liver disease. It produces a broad clinical-pathologic spectrum of injury that includes simple jaundice, cholestatic hepatitis, and bile duct injury that can mimic extrahepatic biliary obstruction, primary biliary cirrhosis, and sclerosing cholangitis. Although the risk of drug-induced cholestasis leading to a fatal outcome is quite rare, knowledge and recognition of the various forms of cholestatic injury assumes an importance whenever clinicians are confronted with jaundice or other manifestations of liver disease in patients receiving medicinal or chemical agents.

Functions of the fibrinolytic system in human Ito cells and its control by basic fibroblast and platelet-derived growth factor

During liver fibrogenesis, hepatic stellate cells (HSC) proliferate and migrate under the influence of growth factors, including platelet-derived growth factor (PDGF) and basic-fibroblast growth factor (b-FGF). The plasminogen activation system regulates extracellular matrix (ECM) catabolism and cell movement. We evaluated the expression and biological functions of the plasminogen activation system in human HSC and its interaction with PDGF and b-FGF. Urokinase-plasminogen activator receptors (u-PAR) were measured by radioligand binding, cell cross-linking, immunoassay, and RNAse protection assay. u-PA and plasminogen activator inhibitors (PAIs) expression and activities were analyzed by zymography, immunoassay, and RNase protection assay. Cell migration and proliferation, studied in Boyden chambers and by microscopic counting, were evaluated after the addition of PDGF, b-FGF, and blockade with anti-u-PA, anti-u-PAR antibodies, and antisense oligodeoxynucleotides (aODN) against u-PAR mRNA. We have shown that HSC produce u-PAR, u-PA, and PAI-1. PDGF and b-FGF up-regulate u-PA and u-PAR, but not PAI-1, and exogenous addition of u-PA stimulates HSC proliferation, chemotaxis, and chemoinvasion. Inhibition of u-PA/u-PAR with antibodies against u-PA or u-PAR and with u-PAR aODN inhibit the proliferative, chemotactic, and chemoinvasive activity of PDGF and b-FGF. These findings indicate that u-PA and u-PAR are required for the mitogenic and chemoinvasive activity of PDGF and b-FGF on HSC.

An unusual case of amoxicillin/clavulanic acid-related hepatotoxicity

Amoxicillin/clavulanic acid is a widely used antibiotic. Hepatic dysfunction is a rare adverse reaction associated with this combination antibiotic. We report the case of a 40-yr-old woman with a somewhat unusual presentation of amoxicillin/clavulanate-related cholestatic hepatotoxicity and multiple duodenal erosions whose diagnosis was delayed until inadvertent rechallenge with the antibiotic combination. The relevant literature is also reviewed and discussed. The diagnosis may be missed because the onset of signs/symptoms may occur several weeks after the cessation of therapy. The hepatic dysfunction, which may be severe and is more prevalent in elderly patients, is usually reversible, although chronic liver disease and deaths have been reported. Immunological hypersensitivity is considered to be the most likely mechanism resulting in liver injury. Amoxicillin/clavulanate should be used with caution in patients with underlying liver disease and in the elderly.

Overview of chronic cholestatic conditions in adults: terminology and definitions

The cholangiopathies represent diseases and syndromes affecting the biliary system at any site between the canals of Hering and the ampulla of Vater. Hepato-canalicular cholestasis reflects biliary secretory failure of the hepatocyte caused by disturbances of intracellular organelles or damage to the bile canalicular excretory functions. Drug reactions are related especially to antibiotics, phenothiazine derivates and carbamazepine. Immune-mediated cholangiopathies cause destruction and reduction of interlobular bile ducts, and are sometimes called vanishing bile duct diseases. They include primary biliary cirrhosis, primary sclerosing cholangitis, autoimmune cholangitis, chronic hepatic allograft rejection, graft-versus-host disease and chronic cholestatic sarcoidosis. Ischemic (vascular) cholangiopathies include traumatic, hepatic arteritis and mechanical causes. Infectious cholangiopathies usually are associated with the immunosuppressed patient.

Idiopathic biliary ductopenia in adults without symptoms of liver disease

BACKGROUND

Idiopathic adulthood ductopenia is a severe cholestatic liver disease of unknown cause characterized by loss of the interlobular bile ducts in more than 50 percent of the portal tracts. In most reported cases, cirrhosis and liver failure develop.

METHODS

We studied 24 adults with abnormal results on liver-function tests but no symptoms of liver disease. All had liver biopsies that showed a lack of bile ducts in many of the portal tracts.

RESULTS

The 17 women and 7 men had a mean age of 41 years (range, 27 to 57). All were asymptomatic and had high serum gamma-glutamyltransferase concentrations (mean [+/-SD], 179 +/- 84 U per liter); 75 percent also had abnormal serum alanine aminotransferase concentrations. The proportion of portal tracts that had bile ducts was 62 +/- 7 percent (range, 55 to 78 percent). Three patients had a second liver biopsy three to nine years after the first; there were no changes over time. In four of the five patients treated with 600 to 900 mg of ursodiol two to three times daily, results of liver-function tests returned to normal.

CONCLUSIONS

Idiopathic biliary ductopenia, with an apparently nonprogressive clinical course, can occur in adults who have no symptoms of biliary disease.

Antibiotic-associated hepatitis: update from 1990

OBJECTIVE

To review the literature on the recent available evidence of antibiotic-associated acute liver injury.

DATA SOURCES

All published articles from January 1990 to July 1995 were extracted from the monthly updated HEPATOX database. Additional articles were found using MEDLINE, EMBASE, and PASCAL searches. Hepatic injuries associated with antituberculous, antimycotic, antiviral, antiprotozoal, and antiseptic compounds were excluded form this review.

STUDY SELECTION

As the amount of literature was large, only case reports, series and epidemiologic data were used. Results from clinical trials were reviewed only when other information was available.

DATA EXTRACTION

Original articles were reviewed to select relevant material. Information regarding the clinical description, histologic features, severity, outcome, and possible risk factors was extracted. Data on incidence were provided by epidemiologic studies or spontaneous reporting to regulatory agencies.

DATA SYNTHESIS

Antibiotic-associated acute injury is rare, with an incidence not exceeding 1 case 10,000 users for most drugs. Among beta-lactams, amoxicillin/clavulanic acid and penicillinase-resistant penicillins are associated with predominant and sometimes protracted cholestasis. The hepatotoxic potential of all available erythromycin salts is confirmed, and recent evidence suggests that roxithromycin could be added to the list of antibiotic-induced liver injury. Among fluoroquinolones, only ciprofloxacin has been associated with serious hepatitis. Trimethoprim/sulfamethoxazole-induced hepatitis often reported, but trimethoprim alone also appears as a possible cause of acute liver injury. Finally, acute bile duct injuries and ductopenia have been described with several antibiotics.

CONCLUSIONS

The most important recent information is the possibility of protracted liver cholestasis with bile duct injuries induced by several antibiotics, particularly penicillinase-resistant penicillins, and the identification of new potentially hepatotoxic antibiotics, namely, roxithromycin, ciprofloxacin, and trimethoprim.