acyclovir and Chemical-and-Drug-Induced-Liver-Injury

Topics: Chemical and Drug Induced Liver Injury; Databases, Factual; Drug Labeling; Humans; Pharmaceutical Preparations; Risk

Ten patients with chronic type B hepatitis were treated for four weeks with a rapidly tapered dose of oral prednisone (initial dose, 40 mg/d) followed by two weeks of no therapy followed by four weeks of oral acyclovir (600 mg/d). Liver biochemistry, HBsAg, HBeAg, DNA-polymerase and HBV-DNA levels in serum were determined prior to, during and for six months following therapy. The mean age +/- SD of the study population was 33 +/- 15 years (range 18-58). Nine of the patients were male. Four patients were Caucasian and six of Southeast Asian origin. Three patients were homosexual, all HIV antibody negative. The mean ALT level prior to treatment was 89 +/- 62 IU/L (range: 30-214). During the six month post-treatment follow-up period, 5/8 (63%) patients became DNA-P negative and 6/10 (60%) HBV-DNA negative. One responder reverted to DNA-P positive (final response, 50%) and another to HBV-DNA positive (final response, 50%) prior to completion of the study. Patients were more likely to become DNA-P or HBV-DNA negative if they had elevated pre-treatment ALT values and low levels of DNA-P and HBV-DNA. HBeAg became undetectable in 3/10 (30%) individuals, one of whom reverted to positive at the end of the follow-up period (final response, 20%). All patients remained HBsAg positive. Mild fatigue, which occurred in four individuals, was the most common side effect. The results of this study suggest that a controlled clinical trial of oral prednisone/acyclovir is warranted in the treatment of adults with chronic type B hepatitis.

Topics: Acyclovir; Administration, Oral; Adolescent; Adult; Alanine Transaminase; Chemical and Drug Induced Liver Injury; Chronic Disease; DNA-Directed DNA Polymerase; DNA, Viral; Drug Administration Schedule; Female; Hepatitis B; Hepatitis B e Antigens; Hepatitis B Surface Antigens; Hepatitis B virus; Humans; Liver; Male; Middle Aged; Pilot Projects; Prednisone; Substance Withdrawal Syndrome

The bile salt export pump (BSEP) is expressed at the canalicular domain of hepatocytes, where it serves as the primary route of elimination for monovalent bile acids (BAs) into the bile canaliculi. The most compelling evidence linking dysfunction in BA transport with liver injury in humans is found with carriers of mutations that render BSEP nonfunctional. Based on mounting evidence, there appears to be a strong association between drug-induced BSEP interference and liver injury in humans; however, causality has not been established. For this reason, drug-induced BSEP interference is best considered a susceptibility factor for liver injury as other host- or drug-related properties may contribute to the development of hepatotoxicity. To better understand the association between BSEP interference and liver injury in humans, over 600 marketed or withdrawn drugs were evaluated in BSEP expressing membrane vesicles. The example of a compound that failed during phase 1 human trials is also described, AMG 009. AMG 009 showed evidence of liver injury in humans that was not predicted by preclinical safety studies, and BSEP inhibition was implicated. For 109 of the drugs with some effect on in vitro BSEP function, clinical use, associations with hepatotoxicity, pharmacokinetic data, and other information were annotated. A steady state concentration (C(ss)) for each of these annotated drugs was estimated, and a ratio between this value and measured IC₅₀ potency values were calculated in an attempt to relate exposure to in vitro potencies. When factoring for exposure, 95% of the annotated compounds with a C(ss)/BSEP IC₅₀ ratio ≥ 0.1 were associated with some form of liver injury. We then investigated the relationship between clinical evidence of liver injury and effects to multidrug resistance-associated proteins (MRPs) believed to play a role in BA homeostasis. The effect of 600+ drugs on MRP2, MRP3, and MRP4 function was also evaluated in membrane vesicle assays. Drugs with a C(ss)/BSEP IC₅₀ ratio ≥ 0.1 and a C(ss)/MRP IC₅₀ ratio ≥ 0.1 had almost a 100% correlation with some evidence of liver injury in humans. These data suggest that integration of exposure data, and knowledge of an effect to not only BSEP but also one or more of the MRPs, is a useful tool for informing the potential for liver injury due to altered BA transport.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 11; ATP-Binding Cassette Transporters; Biological Transport; Chemical and Drug Induced Liver Injury; Cluster Analysis; Drug-Related Side Effects and Adverse Reactions; Humans; Liver; Male; Multidrug Resistance-Associated Proteins; Pharmacokinetics; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Risk Assessment; Risk Factors; Toxicity Tests

To describe a case with Brucella-associated meningoencephalitis. In addition, we report drug-induced hepatotoxicity due to acyclovir.. A young woman was admitted with fever and psychosis and neuroimaging findings indicative of meningoencephalitis. Serology was positive for Brucella. She was treated with doxycycline, rifampin, and trimethoprim-sulfamethoxazole.. This case reminds physicians in endemic regions to consider neurobrucellosis as a differential diagnosis in patients with any unexplained neurologic symptoms or atypical psychosis. Early diagnosis and treatment of neurobrucellosis will be helpful in decreasing the sequelae of this complication.

Topics: Acyclovir; Adult; Anti-Bacterial Agents; Brain; Brucella; Chemical and Drug Induced Liver Injury; Drug Therapy, Combination; Female; Fever; Humans; Meningoencephalitis; Organic Chemicals; Psychotic Disorders

Inhibition of the activity of the human bile salt export pump (BSEP: ABCB11) has been proposed to play a role in drug-induced liver injury (DILI). To enhance understanding of the relationship between BSEP inhibition and DILI, inhibition of human BSEP (hBSEP) and its rat ortholog (rBsep) by 85 pharmaceuticals was investigated in vitro. This was explored using assays that quantified inhibition of ATP-dependent [(3)H]taurocholate uptake into inverted plasma membrane vesicles from Sf21 insect cells, which expressed the proteins. Of the pharmaceuticals, 40 exhibited evidence of in vitro transporter inhibition and overall a close correlation was observed between potency values for inhibition of hBSEP and rBsep activity (r(2) = 0.94), although 12 drugs exhibited >2-fold more potent inhibition of hBSEP than rBsep. The median potency of hBSEP inhibition was higher among drugs that caused cholestatic/mixed DILI than among drugs that caused hepatocellular or no DILI, as was the incidence of hBSEP inhibition with IC(50) <300 μM. All drugs with hBSEP IC(50) <300 μM had molecular weight >250, ClogP >1.5, and nonpolar surface area >180Å. A clear distinction was not evident between hBSEP IC(50) or unbound plasma concentration (C(max, u)) of the drugs in humans and whether the drugs caused DILI. However, all 17 of the drugs with hBSEP IC(50) <100 μM and C(max, u) >0.002 μM caused DILI. Overall, these data indicate that inhibition of hBSEP/rBsep correlates with the propensity of numerous pharmaceuticals to cause cholestatic DILI in humans and is associated with several of their physicochemical properties.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily B, Member 11; ATP-Binding Cassette Transporters; Bile Acids and Salts; Cell Line; Chemical and Drug Induced Liver Injury; Cholestasis; Drug-Related Side Effects and Adverse Reactions; Humans; Insecta; Rats; Risk Factors

The human bile salt export pump (BSEP) is a membrane protein expressed on the canalicular plasma membrane domain of hepatocytes, which mediates active transport of unconjugated and conjugated bile salts from liver cells into bile. BSEP activity therefore plays an important role in bile flow. In humans, genetically inherited defects in BSEP expression or activity cause cholestatic liver injury, and many drugs that cause cholestatic drug-induced liver injury (DILI) in humans have been shown to inhibit BSEP activity in vitro and in vivo. These findings suggest that inhibition of BSEP activity by drugs could be one of the mechanisms that initiate human DILI. To gain insight into the chemical features responsible for BSEP inhibition, we have used a recently described in vitro membrane vesicle BSEP inhibition assay to quantify transporter inhibition for a set of 624 compounds. The relationship between BSEP inhibition and molecular physicochemical properties was investigated, and our results show that lipophilicity and molecular size are significantly correlated with BSEP inhibition. This data set was further used to build predictive BSEP classification models through multiple quantitative structure-activity relationship modeling approaches. The highest level of predictive accuracy was provided by a support vector machine model (accuracy = 0.87, κ = 0.74). These analyses highlight the potential value that can be gained by combining computational methods with experimental efforts in early stages of drug discovery projects to minimize the propensity of drug candidates to inhibit BSEP.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily B, Member 11; ATP-Binding Cassette Transporters; Bile Acids and Salts; Cell Line; Chemical and Drug Induced Liver Injury; Humans; Quantitative Structure-Activity Relationship

Cecropia glaziovii Snethl. (Cecropiaceae), commonly known as "embaúba-vermelha", is widely distributed throughout Latin America and has been reported in Brazilian folk medicine to treat cough, asthma, high blood pressure and inflammation.. Investigate the hepatoprotective properties of crude hydroethanolic extract of C. glaziovii as well as its in vitro antioxidant and antiviral (HSV-1 acyclovir resistant strain) activities.. The hepatoprotective effect, the antioxidant properties and antiviral activity of crude hydroethanol extract (RCE40) from C. glaziovii leaves were evaluated by carbon-tetrachloride (CCl(4))-induced hepatotoxicity, by TBARS (thiobarbituric acid reactive species) and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assays, respectively.. The RCE40 extract (20 mg/kg) inhibited lipid peroxidation on liver in post injury treatment and decreased serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). In addition, in this protocol the RCE40 (20 mg/kg) enhanced the activity of hepatic enzymes (SOD/CAT) which are involved in combating reactive oxygen species (ROS), suggesting that it possesses the capacity to attenuate the CCl(4)-induced liver damage. Moreover the RCE40 (20 mg/kg) inhibited TBARS formation induced by several different inductors of oxidative stress showing significant antioxidant activity, including physiologically relevant concentration, as low as 2 µg/mL. Concerning antiviral activity, the RCE40 was effective against herpes simplex virus type 1 replication (29R acyclovir resistant strain) with EC(50) = 40 µg/mL and selective index (SI) = 50.. These results indicate that C. glaziovii could be a good source of antioxidant and anti-HSV-1 lead compounds.

Topics: Acyclovir; Animals; Cecropia Plant; Chemical and Drug Induced Liver Injury; Chlorocebus aethiops; Drug Resistance, Viral; Herpesvirus 1, Human; Male; Plant Extracts; Plant Leaves; Rats; Rats, Wistar; Vero Cells

Drug-induced liver injury (DILI) is a leading cause of drugs failing during clinical trials and being withdrawn from the market. Comparative analysis of drugs based on their DILI potential is an effective approach to discover key DILI mechanisms and risk factors. However, assessing the DILI potential of a drug is a challenge with no existing consensus methods. We proposed a systematic classification scheme using FDA-approved drug labeling to assess the DILI potential of drugs, which yielded a benchmark dataset with 287 drugs representing a wide range of therapeutic categories and daily dosage amounts. The method is transparent and reproducible with a potential to serve as a common practice to study the DILI of marketed drugs for supporting drug discovery and biomarker development.

Topics: Animals; Benchmarking; Biomarkers, Pharmacological; Chemical and Drug Induced Liver Injury; Drug Design; Drug Labeling; Drug-Related Side Effects and Adverse Reactions; Humans; Pharmaceutical Preparations; Reproducibility of Results; United States; United States Food and Drug Administration

Drug-induced liver injury (DILI) is a significant concern in drug development due to the poor concordance between preclinical and clinical findings of liver toxicity. We hypothesized that the DILI types (hepatotoxic side effects) seen in the clinic can be translated into the development of predictive in silico models for use in the drug discovery phase. We identified 13 hepatotoxic side effects with high accuracy for classifying marketed drugs for their DILI potential. We then developed in silico predictive models for each of these 13 side effects, which were further combined to construct a DILI prediction system (DILIps). The DILIps yielded 60-70% prediction accuracy for three independent validation sets. To enhance the confidence for identification of drugs that cause severe DILI in humans, the "Rule of Three" was developed in DILIps by using a consensus strategy based on 13 models. This gave high positive predictive value (91%) when applied to an external dataset containing 206 drugs from three independent literature datasets. Using the DILIps, we screened all the drugs in DrugBank and investigated their DILI potential in terms of protein targets and therapeutic categories through network modeling. We demonstrated that two therapeutic categories, anti-infectives for systemic use and musculoskeletal system drugs, were enriched for DILI, which is consistent with current knowledge. We also identified protein targets and pathways that are related to drugs that cause DILI by using pathway analysis and co-occurrence text mining. While marketed drugs were the focus of this study, the DILIps has a potential as an evaluation tool to screen and prioritize new drug candidates or chemicals, such as environmental chemicals, to avoid those that might cause liver toxicity. We expect that the methodology can be also applied to other drug safety endpoints, such as renal or cardiovascular toxicity.

Topics: Animals; Anti-Infective Agents; Anti-Inflammatory Agents; Chemical and Drug Induced Liver Injury; Databases, Factual; Drug-Related Side Effects and Adverse Reactions; Humans; Liver; Models, Biological; Predictive Value of Tests

Drug-induced liver injury is one of the main causes of drug attrition. The ability to predict the liver effects of drug candidates from their chemical structures is critical to help guide experimental drug discovery projects toward safer medicines. In this study, we have compiled a data set of 951 compounds reported to produce a wide range of effects in the liver in different species, comprising humans, rodents, and nonrodents. The liver effects for this data set were obtained as assertional metadata, generated from MEDLINE abstracts using a unique combination of lexical and linguistic methods and ontological rules. We have analyzed this data set using conventional cheminformatics approaches and addressed several questions pertaining to cross-species concordance of liver effects, chemical determinants of liver effects in humans, and the prediction of whether a given compound is likely to cause a liver effect in humans. We found that the concordance of liver effects was relatively low (ca. 39-44%) between different species, raising the possibility that species specificity could depend on specific features of chemical structure. Compounds were clustered by their chemical similarity, and similar compounds were examined for the expected similarity of their species-dependent liver effect profiles. In most cases, similar profiles were observed for members of the same cluster, but some compounds appeared as outliers. The outliers were the subject of focused assertion regeneration from MEDLINE as well as other data sources. In some cases, additional biological assertions were identified, which were in line with expectations based on compounds' chemical similarities. The assertions were further converted to binary annotations of underlying chemicals (i.e., liver effect vs no liver effect), and binary quantitative structure-activity relationship (QSAR) models were generated to predict whether a compound would be expected to produce liver effects in humans. Despite the apparent heterogeneity of data, models have shown good predictive power assessed by external 5-fold cross-validation procedures. The external predictive power of binary QSAR models was further confirmed by their application to compounds that were retrieved or studied after the model was developed. To the best of our knowledge, this is the first study for chemical toxicity prediction that applied QSAR modeling and other cheminformatics techniques to observational data generated by the means of automate

Topics: Animals; Chemical and Drug Induced Liver Injury; Cluster Analysis; Databases, Factual; Humans; MEDLINE; Mice; Models, Chemical; Molecular Conformation; Quantitative Structure-Activity Relationship

The bile salt export pump (BSEP) is an efflux transporter, driving the elimination of endobiotic and xenobiotic substrates from hepatocytes into the bile. More specifically, it is responsible for the elimination of monovalent, conjugated bile salts, with little or no assistance from other apical transporters. Disruption of BSEP activity through genetic disorders is known to manifest in clinical liver injury such as progressive familial intrahepatic cholestasis type 2. Drug-induced disruption of BSEP is hypothesized to play a role in the development of liver injury for several marketed or withdrawn therapeutics. Unfortunately, preclinical animal models have been poor predictors of the liver injury associated with BSEP interference observed for humans, possibly because of interspecies differences in bile acid composition, differences in hepatobiliary transporter modulation or constitutive expression, as well as other mechanisms. Thus, a BSEP-mediated liver liability may go undetected until the later stages of drug development, such as during clinical trials or even postlicensing. In the absence of a relevant preclinical test system for BSEP-mediated liver injury, the toxicological relevance of available in vitro models to human health rely on the use of benchmark compounds with known clinical outcomes, such as marketed or withdrawn drugs. In this study, membrane vesicles harvested from BSEP-transfected insect cells were used to assess the activity of more than 200 benchmark compounds to thoroughly investigate the relationship between interference with BSEP function and liver injury. The data suggest a relatively strong association between the pharmacological interference with BSEP function and human hepatotoxicity. Although the most accurate translation of risk would incorporate pharmacological potency, pharmacokinetics, clearance mechanisms, tissue distribution, physicochemical properties, indication, and other drug attributes, the additional understanding of a compound's potency for BSEP interference should help to limit or avoid BSEP-related liver liabilities in humans that are not often detected by standard preclinical animal models.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily B, Member 11; ATP-Binding Cassette Transporters; Biological Assay; Biological Transport; Cell Line; Cell Membrane; Chemical and Drug Induced Liver Injury; Cytoplasmic Vesicles; Drug Evaluation, Preclinical; Humans; Liver; Rats; Reproducibility of Results; Spodoptera; Transfection; Xenobiotics

The antiviral effect of azidothymidine (AZT) can be potentiated by acyclovir (ACV), and this drug association has been used in the management of HIV-infected patients. In the present study we examined the effects of this association on the livers and kidneys of both pregnant rats and their concepts. Previous data from this laboratory suggested that the deleterious effects of ACV on rat pregnancy are due to its extraplacental actions and these are, at least in part, counteracted by concomitant treatment with AZT. Kidneys and livers of pregnant rats were noticed to be much more sensitive to the toxic action of the drugs than those of their concepts, ACV eliciting much more evident morphological alterations than did AZT. Contrary to what was expected, in the group of rats treated with both drugs AZT was not able to diminish the severity of the alterations evoked by ACV. The proposed "protective" action of AZT against the abortive effect of ACV on rat pregnancy does not seem to be exerted through a renal or hepatic pathway.

Topics: Abortion, Spontaneous; Acyclovir; Animals; Antiviral Agents; Chemical and Drug Induced Liver Injury; Drug Synergism; Female; Kidney; Kidney Diseases; Liver; Liver Diseases; Pregnancy; Pregnancy Complications; Rats; Rats, Wistar; Zidovudine

A 33-year-old male with acquired immunodeficiency syndrome received ganciclovir for presumed cytomegalovirus retinitis. Although results of baseline liver function tests were abnormal, marked elevations of transaminases and alkaline phosphatase occurred when the drug was first instituted, as well as after rechallenge. These elevated laboratory values declined on each occasion that the drug was withdrawn. As no other toxic or infectious insults could clearly be incriminated in these acute, self-limited episodes of hepatic function abnormalities, ganciclovir was most likely responsible for the toxicity observed in this patient.

Topics: Acquired Immunodeficiency Syndrome; Acyclovir; Adult; Antiviral Agents; Chemical and Drug Induced Liver Injury; Cytomegalovirus Infections; Ganciclovir; Humans; Liver Function Tests; Male; Time Factors