GENERAL ASPECTS OF DRUG-INDUCED LIVER DISEASE

The Unmet Needs of Hepatitis E Virus Diagnosis in Suspected Drug-Induced Liver Injury in Limited Resource Setting

Background: Currently, there are no specific biomarkers for drug-induced liver injury (DILI), and the diagnosis of DILI is based mainly on the exclusion of other causes of liver dysfunction and the recognition of potential causative drugs. Hepatitis E virus (HEV) diagnosis is not routinely enrolled in many countries, and HEV infection could be misdiagnosed as DILI.

Methodology: We retrospectively analyzed plasma samples (n = 80) collected from suspected DILI for HEV markers such as anti-HEV IgM, anti-HEV IgG, and HEV RNA. Anti-HEV antibodies were assessed using commercial ELISA kits. HEV RNA was tested by RT-qPCR targeting HEV ORF2/3, the receiver operating characteristic (ROC) curve was plotted, and a putative threshold for liver function parameters was determined.

Results: Out of 80 samples, 12 samples were positive for anti-HEV IgM and anti-HEV IgG, and HEV RNA was detected in seven samples. The median viral load was 3.46 × 10³ IU/ml, and the isolated viruses belonged to HEV genotype 1. The level of liver enzymes such as alanine transaminase (ALT) and aspartate transaminase (AST), but not alkaline phosphatase (ALP), was significantly higher in HEV confirmed cases than in non-HEV confirmed cases. We identified a plasma ALT level of at least 415.5 U/L and AST level of at least 332 U/L; ALT/ALP ratio of at least 5.08 could be used as a guide for the patients diagnosed as DILI to be tested for HEV infection. The previous liver function parameters showed high sensitivity and good specificity.

Conclusion: Hepatitis E virus was detected in suspected DILI cases. The diagnosis of DILI is not secure until HEV testing is done. Liver function parameters can be used as a guide for HEV testing in suspected DILI cases in countries with limited resources.

Practice Gaps: Drug Reactions

The term "drug reactions" is relevant to dermatology in three categories of reactions: cutaneous drug reactions without systemic features, cutaneous drug reactions with systemic features, and systemic drugs prescribed by the dermatologist with systematic adverse effects. This article uses examples from each of these categories to illustrate several important principles central to drug reaction diagnosis and management. The information presented will help clinicians attain the highest possible level of certainty before making clinical decisions.

Investigation of liver dysfunction: who should we test for hepatitis E?

AIM

Hepatitis E virus (HEV) is endemic in developed countries, but unrecognized infection is common. Many national guidelines now recommend HEV testing in patients with acute hepatitis irrespective of travel history. The biochemical definition of 'hepatitis' that best predicts HEV infection has not been established. This study aimed to determine parameters of liver biochemistry that should prompt testing for acute HEV.

METHODS

This was a retrospective study of serial liver function tests (LFTs) in cases of acute HEV (n=74) and three comparator groups: common bile duct stones (CBD, n=87), drug-induced liver injury (DILI, n=69) and patients testing negative for HEV (n=530). To identify the most discriminating parameters, LFTs from HEV cases, CBD and DILI were compared. Optimal LFT cutoffs for HEV testing were determined from HEV true positives and HEV true negatives using receiver operating characteristic curve analysis.

RESULTS

Compared with CBD and DILI, HEV cases had a significantly higher maximum alanine aminotransferase (ALT) (P<0.001) and ALT/alkaline phosphatase (ALKP) ratio (P<0.001). For HEV cases/patients testing negative for HEV, area under receiver operating characteristic curve was 0.805 for ALT (P<0.001) and 0.749 for the ALT/ALKP ratio (P<0.001). Using an ALT of at least 300 IU/l to prompt HEV testing has a sensitivity of 98.6% and a specificity of 30.3% compared with an ALT/ALKP ratio higher than or equal to 2 (sensitivity 100%, specificity 9.4%).

CONCLUSION

Patients with ALT higher than or equal to 300 IU/l should be tested for HEV. This is simple, detects nearly all cases and requires fewer samples to be tested than an ALT/ALKP ratio higher than or equal to 2. Where clinically indicated, patients with an ALT less than 300 IU/l should also be tested, particularly if HEV-associated neurological injury is suspected.

The Art and Science of Diagnosing and Managing Drug-induced Liver Injury in 2015 and Beyond

Drug-induced liver injury (DILI) remains a leading reason why new compounds are dropped from further study or are the subject of product warnings and regulatory actions. Hy's Law of drug-induced hepatocellular jaundice causing a case-fatality rate or need for transplant of 10% or higher has been validated in several large national registries, including the ongoing, prospective U.S. Drug-Induced Liver Injury Network. It serves as the basis for stopping rules in clinical trials and in clinical practice. Because DILI can mimic all known causes of acute and chronic liver disease, establishing causality can be difficult. Histopathologic findings are often nonspecific and rarely, if ever, considered pathognomonic. A daily drug dose >50-100 mg is more likely to be hepatotoxic than does <10 mg, especially if the compound is highly lipophilic or undergoes extensive hepatic metabolism. The quest for a predictive biomarker to replace alanine aminotransferase is ongoing. Markers of necrosis and apoptosis such as microRNA-122 and keratin 18 may prove useful in identifying patients at risk for severe injury when they initially present with a suspected acetaminophen overdose. Although a number of drugs causing idiosyncratic DILI have HLA associations that may allow for pre-prescription testing to prevent hepatotoxicity, the cost and relatively low frequency of injury among affected patients limit the current usefulness of such genome-wide association studies. Alanine aminotransferase monitoring is often recommended but has rarely been shown to be an effective method to prevent serious DILI. Guidelines on the diagnosis and management of DILI have recently been published, although specific therapies remain limited. The LiverTox Web site has been introduced as an interactive online virtual textbook that makes the latest information on more than 650 agents available to clinicians, regulators, and drug developers alike.

Endpoints and clinical trial design for nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease is a common cause of chronic liver disease in the general population. Nonalcoholic steatohepatitis (NASH), the aggressive form of nonalcoholic fatty liver disease, is associated with an increased risk of liver-related mortality and cardiovascular disease. At present, a liver biopsy is the only generally acceptable method for the diagnosis of NASH and assessment of its progression toward cirrhosis. Although several treatments have shown evidence of efficacy in clinical trials of varying design, there are no approved treatments for NASH, and published trials are often too divergent to allow meaningful comparisons. There is thus a lack of established noninvasive, point-of-care diagnostics and approved treatment on one hand and a substantial population burden of disease on the other. These provide the rationale for developing consensus on key endpoints and clinical trial design for NASH.

CONCLUSION

This article summarizes the consensus arrived at a meeting of the American Association for the Study of Liver Diseases on the key endpoints and specific trial design issues that are germane for development of diagnostic biomarkers and treatment trials for NASH.

Suggested guidelines for patient monitoring: hepatic and hematologic toxicity attributable to systemic dermatologic drugs

Hepatic and hematologic toxicity are among the most fearful adverse effects that occasionally occur as a result of systemic drugs in the dermatologist's therapeutic armamentarium. Drugs of greatest interest concerning hepatic toxicity include methotrexate, azathioprine, dapsone, and acitretin. Somewhat overlapping are drugs that have important hematologic toxicities, including methotrexate, azathioprine, dapsone, sulfonamides, cyclophosphamide, and chlorambucil. Laboratory tests most commonly used include (1) hepatic monitoring: transaminases (AST/SGOT and ALT/SGPT) and the ultrasound-guided liver biopsy, and (2) hematologic monitoring: CBC with diff and platelets along with occasional use of the reticulocyte count. Important principles and specific guidelines for monitoring by drug group are highlighted.

Comparison of potentially hepatotoxic drugs among major US drug compendia

BACKGROUND

Although a large number of drugs include warnings or listed adverse reactions that describe reports of associated hepatotoxicity, the hepatotoxic risk is documented with different definitions in major drug compendia.

OBJECTIVES

The purposes of this study were to compare inclusion of potentially hepatotoxic drugs, and analyze the ratings of hepatotoxic risk among major drug compendia.

METHODS

To assess the risk of drug-associated hepatotoxicity, we used current literature of epidemiological studies and developed a 4-level rating scale of hepatotoxic drugs: 3, clear literature evidence of life-threatening hepatotoxicity; 2, multiple case reports or significant liver injuries; 1, no significant liver damage has been reported; and 0, no information. All drugs were evaluated using the 5 major US drug compendia: American Hospital Formulary Service (AHFS), United States Pharmacopeia Drug Information (USPDI), Facts and Comparisons (F&C), Physicians' Desk Reference (PDR), and Clinical Pharmacology (CP). Average rating scores were calculated as the sum of each drug rating score divided by the total number of drugs. One-way analysis of variance and independent t tests were conducted to compare the difference among the rating scores.

RESULTS

In total, 175 different drugs and 3 therapeutic classes with hepatotoxic effects were identified in the compendia, including 59 antineoplastics, 28 anti-infectives, 17 nonsteroidal anti-inflammatory drugs, 17 antipsychotics or phenothiazine derivatives, 9 angiotensin-converting enzyme inhibitors, 6 anticonvulsants, 4 histamine-2 receptor antagonists, and other drugs. Average rating scores were 1.65 for AHFS, 1.10 for USPDI, 1.27 for F&C, 1.34 for PDR, and 1.61 for CP (F=7.93, P<.0001). The risk categories were significantly different among compendia in 4 therapeutic classes of antipsychotics and/or phenothiazines (F=3.471, P=.011), nonsteroidal anti-inflammatory drugs (F=7.866, P<.0001), antineoplastics (F=2.476, P=.044), anti-infectives (F=2.003, P=.098), and angiotensin-converting enzyme inhibitors (F=38.125, P<.0001).

CONCLUSIONS

Rating scores of hepatotoxicity were significantly different among drug compendia. The different compendium put different emphasis on hepatotoxicity severity. Comprehensive evaluations of hepatotoxic-related drugs provide critical information for health practitioners.

Gastrointestinal and hepatic toxicity of selective and non-selective cyclooxygenase-2 inhibitors in pregnant and non-pregnant rats

The aim of the study was to evaluate the toxicity of non-selective (tolmetin, ibuprofen and piroxicam) and selective (DFU) cyclooxygenase-2 inhibitors on pregnant and non-pregnant rats. The drugs were administered orally once (DFU, piroxicam) or three times (tolmetin, ibuprofen) a day from days 8 through 21 of gestation experiment in three doses. The initial dose was similar to the human antiinflammatory one and set as 8.5 mg/kg (tolmetin, ibuprofen), 0.3 mg/kg (piroxicam) and 0.2 mg/kg (DFU). The middle dose was increased 10 times and the highest one 100 times the initial dose. The highest dose for ibuprofen was set at 200mg/kg due to high mortality. On gestation/experimental day 21 animals were sacrificed, blood was collected and abdominal organs were taken for pathological examination. Activity of alanine and asparate aminotransferases and levels of total protein and urea were determined. Stomach, small and large intestines, and liver were grossly and histologically examined. Dose-dependent mortality, signs of gastrointestinal toxicity, and significant changes of biochemical parameters were found in groups exposed to non-selective COX inhibitors in both pregnant and non-pregnant rats. Mild regressive structural hepatic changes were observed. Significant decrease of protein level in non-pregnant rats treated with high DFU dose, and occasionally observed gastrointestinal changes were the only changes noted in groups exposed to the selective COX-2 inhibitor. Tolerability of non-selective COX inhibitors was lower in both pregnant and non-pregnant groups when compared with DFU. Insignificant mortality and histological changes were noted between pregnant and non-pregnant groups.

Differentiation of human hepatoma cells during confluence as revealed by gene expression profiling

Certain human hepatocarcinoma cells undergo differentiation when grown at confluence. In order to understand the basis for this differentiation, we investigated the phenotypic changes occurring during confluent growth of the human hepatoma B16A2 cell line. The global gene expression profile of B16A2 cells grown during confluence for 5 weeks was investigated using microarrays containing complementary sequences corresponding to approximately 10,000 genes, and compared with profiles of adult human liver and HepG2 cells. The major part of gene products detected were shared by all three systems and the hepatoma cell lines expressed surprisingly high levels of liver-enriched transcription factors. During confluence of B16A2 cells, the majority of transcriptional changes monitored were directed towards the phenotype of adult human liver in vivo, although the changes accounted for less than 10% of those necessary to acquire a native hepatic phenotype. Several markers of liver differentiation and regeneration were changed in similar manner as observed in developing liver and during liver regeneration. In conclusion, the data indicate that differentiation in vitro of the B16A2 cell line during confluence partially resembles that of hepatic differentiation and regeneration in vivo, implying a partial normalization of a low differentiated phenotype.

Drug-induced cholestasis

Drug-induced cholestasis is a common entity, seen with numerous classes of pharmacological agents. A high index of suspicion is required for the correct diagnosis. Different clinical syndromes may be recognized, with variable degrees of hepatitis in association with cholestasis. The most important aspect of treatment is prompt discontinuation of the offending drug. Several agents have been used for symptomatic relieve of the pruritus associated with cholestasis, including cholestyramine, ursodeoxycholic acid, and opiate antagonists, with limited results. Prognosis is usually good, with few cases of prolonged cholestasis leading to vanishing bile duct syndrome. Liver failure may rarely occur if diagnosis goes unrecognized and the inciting drug is not withdrawn.

Hepatotoxicity and complementary and alternative medicines

Though some herbal medicines have been shown to protect against or treat experimental liver injury in vitro, and many may possess one or a combination of antioxidant, antifibrotic, immunomodulatory, or antiviral activities, they have not been shown effective in human trials. It has been extremely difficult to construct randomized, controlled trials using complementary and alternative medicines because of an incomplete understanding of their modes of action, the lack of standardization in their manufacture, and the complexity of ingredients in any herbal extract. This may become easier once more standardized and broad-based regulatory oversight of marketing and manufacture of these products is achieved. Despite this, the use of complementary and alternative medicines is ever increasing, especially in patients having chronic liver disease. With this growing popularity, it is becoming more apparent that many of these treatments possess the potential for appreciable hepatotoxicity, in some instances resulting in significant morbidity and mortality. Until these products are more closely regulated and their advertising better scrutinized, all physicians and patients should become more familiar with the natural and alternative products that are commonly used, and recognize which can be harmful (Table 4). Better public awareness should be maintained with regard herb and prescription drug interactions.

Acute cholestatic hepatitis associated with celecoxib

OBJECTIVE

To report a case of acute cholestatic hepatitis associated with the selective cyclooxygenase-2 inhibitor celecoxib.

CASE SUMMARY

A 41-year-old white man was hospitalized for jaundice after 2 doses of celecoxib 200 mg for pain associated with right-knee trauma. Laboratory workup showed hyperbilirubinemia, mildly elevated serum transaminase concentrations, and cholestasis. Abdominal imaging showed no dilation of the biliary tree. Histology showed cholestasis, with bile plugs in dilated bile canaliculi and a mild portal infiltrate that are highly suggestive of drug-induced cholestasis.

DISCUSSION

This is the fourth report in the English-language literature describing cholestatic hepatitis temporally related to celecoxib use, the second supported by histologic findings typical of drug-induced cholestasis, and the first in a patient who denied use of alcoholic beverages and was taking no other drugs or herbal products at the time of the reaction. The Naranjo probability scale indicated that celecoxib was a probable cause of acute cholestatic hepatitis in this patient.

CONCLUSIONS

Cholestatic hepatitis is a well-recognized adverse effect of several drugs. Although celecoxib is considered to have a very low potential for hepatic toxicity, well-documented reports of adverse reactions can contribute significantly to the definition of more accurate safety profiles for new drugs introduced into clinical practice.

A new Poisson and Bayesian-based method to assign risk and causality in patients with suspected hepatic adverse drug reactions: a report of two new cases of ticlopidine-induced hepatotoxicity

OBJECTIVE

The diagnosis of drug-induced hepatotoxicity is based on circumstantial evidence and is often inaccurate. We have designed a method based on published data to assign causality to suspected cases of drug-induced hepatotoxicity.

DESIGN

Forty-seven published cases of ticlopidine-induced hepatotoxicity were identified by a Medline-based literature search. Data regarding abnormal liver function in patients receiving ticlopidine were obtained from the only published placebo-ticlopidine clinical trial (the Canadian American Ticlopidine Study; CATS). Thus, we calculated the maximum number of expected hepatotoxicity cases in patients exposed to ticlopidine and those not exposed to the drug by means of the Poisson distribution. The calculated odds ratio was used as a prior odd for subsequent quantification, using a Bayesian-based approach, of individual ticlopidine-induced hepatotoxicity likelihood. Concretely, the prior odd is modified by several separate likelihood ratios: age; sex; AST level; ALT level; alkaline phosphatase level; total bilirubin level; latent period of adverse reaction appearance; and period of remission of adverse reaction. This methodology was applied to two new cases of suspected ticlopidine-induced hepatotoxicity.

RESULTS

The prior probability of ticlopidine-induced hepatotoxicity derived from CATS data is 61.29%. This is in contrast with the 28.83% incidence rate of drug-induced liver alterations in the general population. Alkaline phosphatase levels and total bilirubin levels were six times the normal values among individuals with ticlopidine-induced hepatotoxicity than in the general population. They were the most relevant likelihood ratios of the Bayesian model to establish a high level of causality relationship between a hepatotoxicity event and ticlopidine use.

CONCLUSIONS

The proposed method, which links information from clinical trials with the profile of clinical hepatotoxicity of a drug defined from published cases reported after a drug is marketed, can be a useful tool for drug postmarketing surveillance research.

Prospective surveillance of acute serious liver disease unrelated to infectious, obstructive, or metabolic diseases: epidemiological and clinical features, and exposure to drugs

BACKGROUND/AIMS

Acute serious liver disease which is unrelated to infectious, obstructive, or metabolic disease is uncommon. Many drugs have been implicated. Data on its epidemiology are scarce. We performed a population-based prospective study of acute serious liver disease in Catalonia (Spain).

METHODS

A collaborating hospital network was set up. All patients with acute serious liver disease and negative viral hepatitis serological markers, without an obvious cause of liver disease, were included.

RESULTS

The incidence of acute serious liver disease was 7.4 per 10(6) inhabitants per year (95% CI; 6.0-8.8), which increased with age. The incidence of hepatocellular acute serious liver disease (3.84 per 10(6) per year) was greater than that of cholestatic and mixed patterns. The case-fatality ratio was 11.9% and mortality 0.8 per million person-years. The risk of death was similar among patients with hepatocellular and cholestatic patterns. Non-steroidal antiinflammatory drugs, analgesics, and antibacterials were the most frequently used drugs.

CONCLUSIONS

Acute serious liver disease which is unrelated to infectious, obstructive, or metabolic disease is rare. Its incidence increases with age. The prognosis of cholestatic acute serious liver disease does not significantly differ from that of the hepatocellular pattern. Non-steroidal antiinflammatory drugs, analgesics, and antibacterials were the most common drugs likely to be responsible for acute liver disease.

Extrahepatic conditions and hepatic encephalopathy in elderly patients

PURPOSE

Extrahepatic conditions can cause, exacerbate, or mimic hepatic encephalopathy in any patient with advanced liver disease, particularly in older persons. The aim of this study was to characterize the clinical features and frequency of extrahepatic conditions and the effect of therapeutic interventions upon the encephalopathy.

DESIGN

Survey.

SETTING

Inner city community hospital.

METHODS

Retrospective chart review of 294 elderly patients (age 65-97) with liver disease and suspected hepatic encephalopathy, during a 15-year period, that included 188 men and 106 women.

RESULTS

Extrahepatic conditions were found in 64 patients (22%); 29 (10%) patients had > 1 extrahepatic condition. Category and frequency of the extrahepatic conditions found in these 64 patients were as follows: urinary tract infection, 21 (33%); cellulitis/infected pressure ulcers, 16 (25%); pneumonia, 16 (25%); septicemia (with positive blood cultures), 10 (16%); silent myocardial infarction, 10 (16%); drug toxicity (nonsteroidal anti-inflammatory drugs, sedatives, hypnotics, antidiabetics), 6 (9%); meningitis, 6 (9%); head injury, 5 (8%); stroke, 5 (8%); and subdural hematoma, 5 (8%).

CONCLUSION

A significant proportion of elderly patients with liver disease and presumptive diagnosis of hepatic encephalopathy may have extrahepatic condition(s), and the treatment of the latter may improve clinical outcome of such patients. A high index of suspicion, low threshold of diagnostic measures, and prompt treatment of any associated extrahepatic condition are essential to prevent significant morbidity and mortality of these patients.

Non-alcoholic fatty liver disease in an area of southern Italy: main clinical, histological, and pathophysiological aspects

BACKGROUND/AIMS

Studies on non-alcoholic fatty liver disease (NAFLD) have included chronic liver damage attributed to various causes. Our investigation was held to observe the main clinical, histological, and pathophysiological aspects of NAFLD in patients not exposed to any known cause of chronic liver disease.

METHODS

We evaluated, in 84 in-patients (male/female, 66/18; median age, 36 years), the clinical and biochemical characteristics of NAFLD, and particularly its association with diabetes, dyslipidemia, hyperinsulinemia and/or with the increase of parameters of oxidative stress (blood levels of malonyldialdehyde, 4-hydroxynonenal and total plasma antioxidant capacity).

RESULTS

Ninety percent of patients had an increased body mass index (BMI), 35% had dyslipidemia, 40% had sub-clinical diabetes (only 3% had overt diabetes), 60% had hyperinsulinemia, and more than 90% had enhanced levels of lipid peroxidation markers. In 48 patients who had consented to liver biopsy, we found: 14 with simple steatosis, 32 with steatohepatitis, and two with cirrhosis.

CONCLUSIONS

Our data indicate that in our country, NAFLD may occur in young males with an increased BMI, with or without hyperinsulinemia, dyslipidemia and diabetes, generally associated with disorders of redox status, and that it may be differentiated from steatosis to steatohepatitis or cirrhosis only with a liver biopsy.

Antifungal activities and cytotoxicity studies of six new azasordarins

GW 471552, GW 471558, GW 479821, GW 515716, GW 570009, and GW 587270 are members of a new family of sordarin derivatives called azasordarins. The in vitro activities of these compounds were evaluated against clinical isolates of yeasts, including Candida albicans, Candida non-albicans, and Cryptococcus neoformans strains. Activities against Pneumocystis carinii, Aspergillus spp., less common molds, and dermatophytes were also investigated. Azasordarin derivatives displayed significant activities against the most clinically important Candida species, with the exception of C. krusei. Against C. albicans, including fluconazole-resistant strains, MICs at which 90% of the isolates tested are inhibited (MIC(90)s) were 0.002 microg/ml with GW 479821, 0.015 microg/ml with GW 515716 and GW 587270, and 0.06 microg/ml with GW 471552, GW 471558, and GW 570009. The MIC(90)s of GW 471552, GW 471558, GW 479821, GW 515716, GW 570009, and GW 587270 were 0.12, 0.12, 0.03, 0.06, 0.12, and 0.06 microg/ml, respectively, against C. tropicalis and 4, 0.25, 0.06, 0.25, 0.5, and 0.5 microg/ml, respectively, against C. glabrata. In addition, some azasordarin derivatives (GW 479821, GW 515716, GW 570009, and GW 58720) were active against C. parapsilosis, with MIC(90)s of 2, 4, 4, and 1 microg/ml, respectively. The compounds were extremely potent against P. carinii, showing 50% inhibitory concentrations of <or=0.001 microg/ml. However Cryptococcus neoformans was resistant to all compounds tested (MIC > 16 microg/ml). These azasordarin derivatives also showed significant activity against emerging fungal pathogens, which affect immunocompromised patients, such as Rhizopus arrhizus, Blastoschizomyces capitatus, and Geotrichum clavatum. Against these organisms, the MICs of GW 587270 ranged from 0.12 to 1 microg/ml, those of GW 479821 and GW 515716 ranged from 0.12 to 2 microg/ml, and those of GW 570009 ranged from 0.12 to 4 microg/ml. Against Fusarium oxysporum, Scedosporium apiospermum, Absidia corymbifera, Cunninghamella bertholletiae, and dermatophytes, GW 587270 was the most active compound, with MICs ranging from 4 to 16 microg/ml. Against Aspergillus spp., the MICs of the compounds tested were higher than 16 microg/ml. The in vitro selectivity of azasordarins was investigated by cytotoxicity studies performed with five cell lines and primary hepatocytes. Concentrations of compound required to achieve 50% inhibition of the parameter considered (Tox(50)s) of GW 570009, GW 587270, GW 479281, and GW 515716 in the cell lines ranged from 60 to 96, 49 to 62, 24 to 36, and 16 to 38 microg/ml, respectively. The cytotoxicity values of GW 471552 and GW 471558 were >100 microg/ml for all cell lines tested. Tox(50)s on hepatocytes were in the following order: GW 471558 > GW 471552 > GW 570009 > GW 587270 > GW 515716 > GW 479821, with values ranging from higher than 100 microg/ml to 23 microg/ml. The cytotoxicity results obtained with fully metabolizing rat hepatocytes were in total agreement with those obtained with cell lines. In summary, the in vitro activities against important pathogenic fungi and the selectivity demonstrated in mammalian cell lines justify additional studies to determine the clinical usefulness of azasordarins.

Hyperbilirubinemia during quinupristin-dalfopristin therapy in liver transplant recipients: correlation with available liver biopsy results

STUDY OBJECTIVE

To review the liver histopathology in transplant recipients who developed hyperbilirubinemia during therapy with quinupristin-dalfopristin, a new streptogramin antibiotic, and to ascertain whether objective histologic evidence of adverse drug effect could be correlated to serum bilirubin levels.

DESIGN

Retrospective analysis.

SETTING

University of Pittsburgh Medical Center.

PATIENTS

From a database of 34 liver recipients who received quinupristin-dalfopristin for vancomycin-resistant Enterococcus faecium infection who were prospectively enrolled in a multicenter, open-label, emergency-use protocol, the data for a subset of 25 patients who underwent one or more liver biopsies during therapy were reviewed for this study.

INTERVENTIONS

Quinupristin-dalfopristin was administered intravenously at 7.5 mg/kg every 8 hours. Available serum bilirubin levels from before, during, and 1 week after therapy were tabulated. Liver biopsy results obtained within 1 week before and during therapy were retrospectively reviewed. Histopathologic results were characterized and correlated to bilirubin level.

MEASUREMENTS AND MAIN RESULTS

Cholestatic changes were already present in 15 of 17 patients who underwent biopsy before therapy. During therapy, the most common findings from 40 biopsies (25 patients) were cholestasis (33 biopsies), acute rejection (10), and periportal inflammation (8). There was no evidence of drug-specific histopathologic injury.

CONCLUSION

Hyperbilirubinemia in these patients was likely multifactorial and most frequently due to sepsis and prior graft injury.

Relevance of liver enzyme elevations with four different neuroleptics: a retrospective review of 7,263 treatment courses

Data on liver enzyme elevations were collected in a retrospective study of 7,263 treatment courses with haloperidol, clozapine, perphenazine, and perazine. Charts of 233 patients hospitalized between 1980 and 1992 at Tübingen University Psychiatric Clinic were selected because clinically relevant increases of liver enzymes had been detected during monotherapy with one of the four examined neuroleptics. At least one hepatic enzyme (mostly alanine aminotransferase [ALAT]) exceeded the established reference range of 3-fold elevations of ALAT, aspartate aminotransferase, gamma-glutamyl transpeptidase, and glutamate dehydrogenase and 2-fold elevations of alkaline phosphatase (AP) during monotherapy with clozapine in 15%, perazine in 7.6%, perphenazine in 4%, and haloperidol in 2.4% of the cases. If all liver enzyme abnormalities with any elevation greater than the conventional upper limits are considered, incidences were as follows: clozapine, 78%; perphenazine, 62%; perazine, 59%; and haloperidol, 50%. Testing for overall differences within the four neuroleptics resulted in significantly different incidences of liver enzyme elevations (chi2 test,p < 0.0001). Threefold increases of AP (>540 U/L) were seen in three patients receiving haloperidol (0.3%) only. Twofold increases of AP (>360 U/L) were distributed as follows: clozapine, 1%; haloperidol, 0.8%; perazine, 0.3%; and perphenazine, 0.1%. Only in the group with 1-fold elevations of AP (>180 U/L) were the differences within the drug regimens significant (clozapine, 40.3%; haloperidol, 33.2%; perphenazine, 23.4%; and perazine, 23.1%; chi2 test, p < 0.0001). In the period under study, no instance of icterus occurred.

The efficacy and safety of comfrey

Herbal medication has gathered increasing recognition in recent years with regard to both treatment options and health hazards. Pyrrolizidine alkaloids have been associated with substantial toxicity after their ingestion as tea and in the setting of contaminated cereals have led to endemic outbreaks in Jamaica, India and Afghanistan. In Western Europe, comfrey has been applied for inflammatory disorders such as arthritis, thrombophlebitis and gout and as a treatment for diarrhoea. Only recently was the use of comfrey leaves recognized as a substantial health hazard with hepatic toxicity in humans and carcinogenic potential in rodents. These effects are most likely due to various hepatotoxic pyrrolizidine alkaloids such as lasiocarpine and symphytine, and their related N-oxides. The mechanisms by which toxicity and mutagenicity are conveyed are still not fully understood, but seem to be mediated through a toxic mechanism related to the biotransformation of alkaloids by hepatic microsomal enzymes. This produces highly reactive pyrroles which act as powerful alkylating agents. The main liver injury caused by comfrey (Symphytum officinale) is veno-occlusive disease, a non-thrombotic obliteration of small hepatic veins leading to cirrhosis and eventually liver failure. Patients may present with either acute or chronic clinical signs with portal hypertension, hepatomegaly and abdominal pain as the main features. Therapeutic approaches include avoiding intake and, if hepatic failure is imminent, liver transplantation. In view of the known serious hazards and the ban on distributing comfrey in Germany and Canada, it is difficult to understand why comfrey is still freely available in the United States.

Hepatotoxicity of botanicals

OBJECTIVE

Hepatic impairment resulting from the use of conventional drugs is widely acknowledged, but there is less awareness of the potential hepatotoxicity of herbal preparations and other botanicals, many of which are believed to be harmless and are commonly used for self-medication without supervision. The aim of this paper is to examine the evidence for hepatotoxicity of botanicals and draw conclusions regarding their pathology, safety and applications.

DESIGN

Current literature on the hepatotoxicity of herbal drugs and other botanicals is reviewed. The aetiology, clinical picture and treatment of mushroom (Amanita) poisoning are described.

RESULTS

Hepatotoxic effects have been reported for some Chinese herbal medicines (such as Jin Bu Huan, Ma-Huang and Sho-saiko-to), pyrrolizidine alkaloid-containing plants, germander (Teucrium chamaedrys), chaparral (Larrea tridentata), Atractylis gummifera, Callilepsis laureola, and others. The frequency with which botanicals cause hepatic damage is unclear. There is a lack of controlled treatment trials and the few studies published to date do not clarify the incidence of adverse effects. Many plant products do not seem to lead to toxic effects in everyone taking them, and they commonly lack a strict dose-dependency. For some products, such as Sho-saiko-to, the picture is confused further by demonstrations of hepatoprotective properties for some components. Mushroom poisoning is mostly due to the accidental consumption of Amanita species. Treatment with silymarin, thioctic acid, penicillin and liver transplantation have been shown to be effective but require early diagnosis.

CONCLUSIONS

Severe liver injury, including acute and chronic abnormalities and even cirrhotic transformation and liver failure, has been described after the ingestion of a wide range of herbal products and other botanical ingredients, such as mushrooms. It is concluded that in certain situations herbal products may be just as harmful as conventional drugs.

The Long Evans Cinnamon (LEC) rat develops hepatocellular damage in the absence of antimicrosomal antibodies

Long Evans Cinnamon (LEC) rats are an inbred strain with a mutation affecting a copper transporter. As a result, hepatic copper levels rise and the rats spontaneously develop hepatitis that is fatal in about 40% of the rats. The rats that die have been reported to develop anti-microsomal antibodies, most frequently against protein disulfide isomerase (PDI), prior to the onset of liver damage. The association between the presence of antibodies and death of the LEC rats, along with the detection of antibodies prior to the detection of liver damage suggested that the antibodies may have a role in the pathogenesis of liver damage. The objective of this study was to more clearly delineate the temporal relationship between antibody production and the onset of liver damage and copper accumulation. Serum was screened for the presence of anti-microsomal antibodies by immunoblotting. Liver damage was assessed by serum biochemistry and histological examination on rats between 6 and 12 weeks of age (four per group). Copper accumulation in the liver was determined by biochemistry and histological examination. Evidence of liver damage was detectable by serum biochemistry and histopathology by 11.5 weeks. Copper was rarely detected in hepatocytes, although it was detected in macrophages. Sera from only one of seven rats with evidence of liver damage had detectable anti-microsomal protein antibodies. The protein recognized was not PDI. The development of anti-microsomal autoantibodies did not precede the development of significant liver damage, suggesting that they play only a secondary role, if any, in the pathogenesis of hepatitis in this rat strain.

Hepatitis

Hepatitis is a diagnosis that can easily be missed by the physician. The morbidity of this disease is significant when one takes into account all the cases that either do not have a typical presentation or are misdiagnosed. The emergency physician bears substantial responsibility in the diagnosis and intervention of patients with hepatitis, and needs to develop a systematic way of approaching the patient with a viral syndrome or other vague complaints that will allow appropriate consideration of this diagnosis.