Roadmap to DILI research in Europe. A proposal from COST action ProEuroDILINet.

In the current article the aims for a constructive way forward in Drug-Induced Liver Injury (DILI) are to highlight the most important priorities in research and clinical science, therefore supporting a more informed, focused, and better funded future for European DILI research. This Roadmap aims to identify key challenges, define a shared vision across all stakeholders for the opportunities to overcome these challenges and propose a high-quality research program to achieve progress on the prediction, prevention, diagnosis and management of this condition and impact on healthcare practice in the field of DILI. This will involve 1. Creation of a database encompassing optimised case report form for prospectively identified DILI cases with well-characterised controls with competing diagnoses, biological samples, and imaging data; 2. Establishing of preclinical models to improve the assessment and prediction of hepatotoxicity in humans to guide future drug safety testing; 3. Emphasis on implementation science and 4. Enhanced collaboration between drug-developers, clinicians and regulatory scientists. This proposed operational framework will advance DILI research and may bring together basic, applied, translational and clinical research in DILI.

[A 78-year-old female patient with dizziness, apraxia and seizure under proton pump inhibitor therapy]. / 78-jährige Patientin mit Unwohlsein, Schwindel, Apraxie und Krampfanfall unter Protonenpumpeninhibitortherapie.

We report about a female patient with severe hypomagnesemia under therapy with proton pump inhibitors (PPI) who presented with a cerebral seizure. Chronic use of PPIs can cause hypomagnesemia. Because of mostly unspecific symptoms which become symptomatic only with severe deficiency, the disease pattern is underdiagnosed. Hypomagnesemia is currently coming increasingly more to the forefront of medical literature.

Clinical usefulness of electronic drug-drug interaction checking in the care of cardiovascular surgery inpatients.

OBJECTIVES: Drug-related problems (DRPs) are events or circumstances involving drug therapy that actually or potentially interfere with desired health outcomes. This study tested the applicability of clinical decision support software in identifying and managing DRPs among cardiovascular surgery inpatients. METHODS: Two clinical pharmacologists attended ward rounds on a low-dependency cardiovascular surgery ward every 2 weeks over a 7-month period. Three hundred and three patients were assessed. On average, patients received 17 scheduled and 'as required' medicines. DRPs were identified 'manually' via assessment of electronic prescription charts and patient records and 'electronically' using clinical decision support software (Pharmavista). The numbers of alerts for optimizing medication safety generated by the two methods were compared. RESULTS: Manual checking identified 346 DRPs leading to 346 alerts in 201 patients (overall 1.1 alerts/patient). Relevant interactions accounted for 44% of DRPs detected by clinical pharmacologists. Clinical decision support software, which could only report interactions, however, generated 1,370 alerts (average 4.5 alerts/patient). Only 147 (11%) drug-drug interaction alerts were identical to those identified by manual checking; the remaining 89% were considered not clinically relevant. CONCLUSIONS: Compared to identification of DRPs by clinical pharmacologists, the clinical decision support software performed poorly due to over-alerting and inability to assess for problems not caused by drug-drug interactions.

Coprescription of levodopa with antipsychotics in a population of 84,596 psychiatric inpatients from 1994 to 2008.

INTRODUCTION: Patients on levodopa therapy frequently require additional antipsychotic pharmacotherapy. However, consideration must be given to antagonistic interactions on dopamine receptors between levodopa and antipsychotics, and efficacy and safety of such combinations. We therefore aimed to explore the practice and rationale of coprescription between levodopa and antipsychotics in psychiatric patients. METHODS: A descriptive retrospective study based on cross-sectional prescription data repeatedly collected from psychiatric inpatients through the international Drug Safety in Psychiatry (AMSP) program between 1994 and 2008 was undertaken. RESULTS: Within a population of 84 596 psychiatric patients the prevalence of levodopa therapy was 1.0% (n=886). Among those patients on levodopa therapy 59.6% (n=528) also received antipsychotics. Quetiapine coprescription increased after its first marketing in 2000 to 45.9% in 2008. Coprescription of clozapine and olanzapine decreased from up to 25 and 22%, respectively, before to less than 10% after the introduction of quetiapine. Coprescribing of other antipsychotics remained approximately stable with average prevalences between 6 and less than 1%. DISCUSSION: Quetiapine has now replaced clozapine as the most frequently coprescribed neuroleptic in psychiatric patients with levodopa therapy. This is in accordance with recent data indicating a low potential for clinically relevant interactions with levodopa and efficacy against psychosis in levodopa-treated patients. The combined use of antipsychotics other than quetiapine and clozapine with levodopa is less common and generally not supported by appropriate evidence.

Evaluation of drug interactions in a large sample of psychiatric inpatients: a data interface for mass analysis with clinical decision support software.

In order to improve medication safety, more epidemiological data on the prevalence and clinical relevance of drug interactions are required. We developed an interface for mass analysis using the Clinical Decision Support Software (CDSS) MediQ and a multidimensional classification (Zurich Interaction System (ZHIAS)) incorporating the Operational Classification of Drug Interactions (ORCA). These were applied to 359,207 cross-sectional prescriptions from 84,607 psychiatric inpatients collected through the international AMSP program. MediQ issued 2,308 "high" and 71,112 "average" danger interaction alerts. Among these, after ORCA reclassification, there were 151 contraindicated and 4,099 provisionally contraindicated prescriptions. The ZHIAS provided further detailed categorical information on recommended management and specific increased risks (QTc prolongation being the most frequent one) associated with interactions. We developed a highly efficient solution for the identification and classification of drug interactions in large prescription data sets; this solution may help to reduce the frequency of overalerting and improve acceptance of the efficacy of CDSS in reducing the occurrence of potentially harmful drug interactions.

[Interactions with antiretroviral drugs]. / Arzneimittelinteraktionen mit antiretroviralen Medikamenten.

Drug-drug interactions are frequently encountered in the therapy of HIV-infected patients, since the highly active antiretroviral therapy always contains several drugs. Drugs against opportunistic infections and concomitant diseases are added frequently. All protease inhibitors are inhibitors of CYP3A, which is important in the metabolism of approximately 50% of all drugs, e.g. simvastatin, atorvastatin, sildenafil, and clarithromycin. Among the protease inhibitors, ritonavir is the strongest inhibitor of CYP3A activity. This inhibition is also used to enhance ("boost") the bioavailability of other protease inhibitors. The nonnucleoside reverse transcriptase inhibitors (NNRTI) efavirenz and nevirapine lead to an increase in CYP3A activity during long-term treatment. To prevent interactions, doses of CYP3A substrates have to be adapted in the beginning and at the end of CYP3A activity-modifying treatments. Interactions can also be a result of modifications in the activities of glucuronosyltransferases and of transport proteins. Ritonavir is an inhibitor of P-glycoprotein, which leads to increased expositions towards many antineoplastic drugs.

Ursodeoxycholic acid reduces lipid peroxidation and mucin secretagogue activity in gallbladder bile of patients with cholesterol gallstones.

BACKGROUND: Recently it has been postulated that gallbladder mucin hypersecretion observed in the pathogenesis of cholesterol gallstone disease may be induced by biliary lipid peroxidation. Ursodeoxycholic acid treatment reduces mucin concentration and the formation of cholesterol crystals in the gallbladder bile of patients with cholesterol gallstones and this effect might be mediated by a decrease of biliary lipid peroxidation. MATERIAL AND METHODS: In a double-blind, placebo-controlled trial patients with symptomatic cholesterol gallstones received either ursodeoxycholic acid (750 mg daily) (n = 10) or placebo (n = 12) 10-12 days prior to cholecystectomy. As a marker for lipid peroxidation malondialdehyde was measured in bile together with mucin concentration. In addition, the mucin secretagogue activity of the individual bile samples was assessed in cultured dog gallbladder epithelial cells. RESULTS: Ursodeoxycholic acid therapy resulted in a significant reduction of lipid peroxidation in bile as determined by the biliary malondialdehyde concentration (1.36 +/- 0.28 vs. 2.05 +/- 0.38 micromol L(-1); P < 0.005) and the malondialdehyde (micromol L(-1))/total bile acid (mmol L(-1)) ratio (0.02 +/- 0.005 vs. 0.06 +/- 0.01; P < 0.001). Furthermore, a decrease in mucin concentrations (0.7 +/- 0.3 vs. 1.3 +/- 0.5 mg mL(-1); P < 0.005) and of the mucin secretagogue activity of gallbladder bile (0.9 +/- 0.2 vs. 2.2 +/- 0.3 times control; P < 0.001) was observed. CONCLUSIONS: The reduction of lipid peroxidation and mucin secretagogue activity of gallbladder bile induced by ursodeoxycholic acid treatment may contribute to the beneficial effects of this drug on gallbladder bile composition and symptoms in cholesterol gallstone patients.

Lipid peroxidation and mucin secretagogue activity in bile of gallstone patients.

BACKGROUND: Chronic inflammation of the gallbladder wall and mucin hypersecretion are considered to be important factors in the pathogenesis of cholesterol gallstone disease. The aim of the study was to compare mucin concentration and mucin secretagogue activity with lipid peroxidation in gallbladder bile of patients with cholesterol or pigment stones. MATERIAL AND METHODS: We studied mucin concentration and, as a marker of lipid peroxidation, malondialdehyde concentration in 11 rapid (1 to 3 days) and eight non-nucleating (> 21 days) gallbladder biles of patients with cholesterol or pigment stones. Furthermore, the mucin secretagogue activity of rapid and non-nucleating gallbladder biles, as well as 1-5 micromol L(-1) malondialdehyde on cultured gallbladder epithelial cells, was determined. RESULTS: Our data show an increased malondialdehyde (7.2 +/- 1.8 vs. 3.8 +/- 0.5 micromol L(-1), P = 0.01) and mucin concentration (0.9 +/- 0.09 vs. 0.41 +/- 0.03 mg mL(-1), P = 0.01) and an increased mucin secretagogue activity (2.0 +/- 0.5 vs. 1.1 +/- 0.3 mucin secretion/control, P = 0.04) and cholesterol saturation index (1.2 +/- 0.1 vs. 08 +/- 0.1, P = 0.04) in rapid as compared to non-nucleating gallbladder biles. Malondialdehyde stimulated mucin secretion of cultured gallbladder epithelial cells in a concentration dependent manner. CONCLUSIONS: Our results support a promoting effect of gallbladder mucin hypersecretion by lipid peroxidation leading to rapid formation of cholesterol crystals in gallbladder bile. These findings suggest that besides hypersecretion of cholesterol in bile, chronic inflammation of the gallbladder wall is implicated in the pathogenesis of cholesterol gallstone disease.

Intestinal expression of cytochrome P450 enzymes and ABC transporters and carbamazepine and phenytoin disposition.

OBJECTIVES: Interindividual variability in intestinal absorption and bioavailability might contribute to inadequate control of seizures under treatment with carbamazepine and phenytoin. We therefore correlated intestinal expression levels and genetics of CYP3A4, CYP2C9/19, MDR1 and MRP2 with dose requirement and plasma levels of carbamazepine and phenytoin. MATERIALS AND METHODS: Epileptic patients on carbamazepine (n = 29) or phenytoin (n = 15) were stratified into a 'high'-dose (carbamazepine > or =800 mg/day, phenytoin > or =300 mg/day) and a 'low'-dose group (carbamazepine < or =600 mg/day, phenytoin < or =200 mg/day). Duodenal biopsies and DNA were obtained for Western blotting and genotyping studies. RESULTS: Low carbamazepine plasma levels showed a trend towards higher intestinal MDR1 expression (P = 0.06). Furthermore, carbamazepine dose was positively correlated with MRP2 expression (P = 0.1). Moreover, MDR1 expression and carbamazepine and phenytoin dose requirement was influenced by the genotype in position 2677 and 3435 of the MDR1 gene. CONCLUSION: Differences in intestinal MDR1 and MRP2 expression may influence carbamazepine and phenytoin disposition and may account for interindividual pharmacokinetic variability.

Serotonergic and non-serotonergic targets in the pharmacotherapy of visceral hypersensitivity.

Visceral hypersensitivity is considered a key mechanism in the pathogenesis of functional gastrointestinal (GI) disorders. Targeting visceral hypersensitivity seems an attractive approach to the development of drugs for functional GI disorders. This review summarizes current knowledge on targets for the treatment of visceral hypersensitivity, and the status of current and future drug and probiotic treatment development, and the role of pharmacogenomic factors.

Cholestasis protects the liver from ischaemic injury and post-ischaemic inflammation in the mouse.

BACKGROUND AND HYPOTHESIS: Cholestasis is associated with high morbidity and mortality in patients undergoing major liver surgery, but the mechanisms responsible remain elusive. Increased ischaemic liver injury and inflammation may contribute to the poor outcome. METHODS: Common bile duct ligation (biliary obstruction with hyperbilirubinaemia) or selective ligation of the left hepatic duct (biliary obstruction without hyperbilirubinaemia) was performed in C57BL/6 mice before 1 h of hepatic ischaemia and 1, 4 or 24 h of reperfusion. Infection with the intracellular hepatic pathogen Listeria monocytogenes for 12 and 48 h was used to study ischaemia-independent hepatic inflammation. RESULTS: Cholestatic mice showed considerable protection from ischaemic liver injury as determined by transaminase release, histological liver injury and neutrophil infiltration. In cholestatic mice, reduced injury correlated with a failure to activate nuclear factor kappaB (NFkappaB) and tumour necrosis factor alpha (TNFalpha) mRNA synthesis, two key mediators of post-ischaemic liver inflammation. After selective bile duct ligation, both the ligated and the non-ligated lobes showed blocked activation of NFkappaB as well as reduced induction of TNFalpha mRNA synthesis and neutrophil infiltration. By contrast, infection with L monocytogenes showed comparable activation of NFkappaB and hepatic recruitment of neutrophils 12 h after infection. CONCLUSION: Cholestasis does not increase but rather dramatically protects the liver from ischaemic injury and inflammation. This effect is mediated by a systemic factor, but not bilirubin, and is associated with a preserved capacity to trigger an inflammatory response to other stimuli such as a bacterial pathogen.

Thiopurine S-methyltransferase polymorphisms: efficient screening method for patients considering taking thiopurine drugs.

OBJECTIVE: More than 11% of the Caucasian population are heterozygous or homozygous carriers of thiopurine S-methyltransferase (TPMT) mutants and are at risk for toxic side effects when treated with thiopurine drugs. Therefore, screening for TPMT polymorphisms in a patient prior to prescribing these agents is recommended. The goal of this study was to determine a cut-off concentration of the TPMT activity assay beyond which genotyping of the TPMT gene should be performed. METHODS: The TPMT activity of 240 unrelated Caucasian subjects was measured using high-performance liquid chromatography. Genotyping for the most frequent allelic variants, TPMT*2, *3A, *3B, *3C and *7 was performed by LightCycler technology and sequencing. RESULTS: The inter-individual TPMT activity showed a range from 23 nmol MTG/g*Hb*h(-1) to 97 nmol MTG/g*Hb*h(-1) with a median of 56 nmol MTG/g*Hb*h(-1). Using a cut-off concentration of 45.5 nmol MTG/g*Hb*h(-1), a test sensitivity of 100% and a specificity of 89% were reached for heterozygous carriers of a TPMT mutation. We identified 1 carrier of TPMT*2, 14 carriers of TPMT*3A and 3 carriers of TPMT*3C, resulting in a TPMT heterozygosity prevalence of 7.5%. CONCLUSIONS: This study defines the cut-off value for the TPMT phenotyping assay at 45.5 nmol/g*Hb*h(-1), beyond which additional genotyping elucidates the individual risk for drug therapy. Using this cut-off concentration, the number of genotyping assays could be reduced by about 60%.

Human ileal bile acid transporter gene ASBT (SLC10A2) is transactivated by the glucocorticoid receptor.

BACKGROUND: Patients with Crohn's disease suffer from intestinal bile acid malabsorption. Intestinal bile acid absorption is mediated by the apical sodium dependent bile acid transporter ASBT/IBAT (SLC10A2). In rats, ASBT is induced by glucocorticoids. AIMS: To study whether human ASBT is activated by glucocorticoids and to elucidate the mechanism of regulation. PATIENTS AND METHODS: ASBT expression in ileal biopsies from patients with Crohn's disease and from healthy subjects was quantified by western blot. ASBT promoter function was studied in luciferase assays and by electrophoretic mobility shift assay. RESULTS: In 16 patients with Crohn's disease, ASBT expression was reduced to 69 (7.5)% compared with healthy controls (mean (SEM); p = 0.01). In 10 healthy male volunteers, ASBT protein expression was increased 1.34 (0.11)-fold (mean (SEM); p<0.05) after 21 days' intake of budesonide (9 mg/day) whereas expression of the peptide transporter 1 was unaffected. Reporter constructs of the human ASBT promoter were activated 15-20-fold by coexpression of the glucocorticoid receptor (GR) and exposure to the GR ligands dexamethasone or budesonide. Two glucocorticoid response elements in the ASBT promoter, arranged as inverted hexanucleotide repeats (IR3 elements), conferred inducibility by GR and dexamethasone in a heterologous promoter context and were shown to bind GR in mobility shift assays. CONCLUSIONS: Human ASBT is induced by glucocorticoids in vitro and in vivo. Induction of ASBT by glucocorticoids could be beneficial in patients with Crohn's disease who exhibit reduced ASBT expression. This study identifies ASBT as a novel target of glucocorticoid controlled gene regulation in the human intestine.

Constitutive rat multidrug-resistance protein 2 gene transcription is down-regulated by Y-box protein 1.

BACKGROUND/AIMS: Molecular mechanisms underlying transcriptional rat multidrug-resistance protein 2 (Mrp2, Abcc2) gene regulation are mostly unclear. Given the presence of putative binding sites for the Y-box binding protein YB-1 in the regulatory sequence, its trans-regulatory influence was analyzed. METHODS: Reporter assays in HepG2 cells with various Mrp2 deletion constructs in the absence and presence of co-transfected YB-1 were performed. DNA binding studies with recombinant YB-1 protein and nuclear extracts obtained from HepG2 cells and rat liver tissue were carried out. RESULTS: The minimal promoter sequence was confined to the proximal 186 bp. A YB-1 responsive element, Mrp2 YRE-1, was mapped at -186/-157, which exhibits specific YB-1 binding. YB-1 acts as a potent repressor of Mrp2 promoter activity in vitro. CONCLUSIONS: Constitutive Mrp2 gene expression is conferred through the proximal -186 bp. YB-1 acts as a repressor in vitro by specific binding to a defined element in the proximal promoter sequence.

[Management of ulcerative colitis]. / Management der Colitis ulcerosa.

Ulcerative colitis is a chronic inflammatory bowel disease. The disease is diagnosed on the basis of clinical parameters and endoscopic-histologic evaluation. 5-aminosalicylic acid (5-ASA, mesalamine) represents the first-line treatment of choice. For patients with distal and left-sided disease the use of rectal preparations is effective. Most patients respond to 5-ASA suppositories or to topic steroids such as budesonide suppositories or hydrocortisone foam. For patients with extended disease, oral medications are mandatory. In case of low- to moderate-grade inflammation, 5-ASA preparations should be implemented. In the case of severe disease treatment with steroids is required. Following induction of remission, prophylactic treatment with 5-ASA (1.5 g/d) should be maintained. For patients with frequent or severe relapses, immunosuppressive therapy with azathioprine or 6-mercaptopurine is indicated. In case of a fulminant course of disease, treatment with intravenous cyclosporine is required in patients who have not responded to high-dose intravenous steroids. When all conservative treatment options fail, proctocolectomy with construction of an ileoanal pouch should be performed. New therapeutic strategies such as infliximab and interferons are being evaluated in clinical trials. The long-term complications of ulcerative colitis include steroid-induced osteoporosis and anemia and should be treated adequately. Finally, the risk for development of colorectal cancer increases steadily with disease duration and dysplasia should be screened for by endoscopic surveillance programs.

First clinical experience with Molecular Adsorbent Recirculating System (MARS) in six patients with severe acute on chronic liver failure.

UNLABELLED: Despite recent advances in general supportive care, the mortality rate of patients with severe liver insufficiency remains high. Recently a new artificial liver support system MARS has been used for selective removal of albumin-bound toxins. AIM: To assess the safety and efficacy of MARS treatment in patients with acute on chronic liver disease (n = 5) or liver failure after extended hepatic resection (n = 1). DESIGN/PATIENTS: Six patients, aged 34-58 years, with severe liver insufficiency (mean MELD-score 31 (range 24-35)) were treated one to 16 times with the MARS system. At baseline three patients were intubated, three were encephalopathic (HE) and three had multifactorial kidney failure requiring kidney replacement therapy. RESULTS AND CONCLUSION: In all the patients MARS treatment significantly reduced the serum bilirubin levels. In three patients encephalopathy improved. In two patients the extracorporeal treatment precipitated a disseminated intravascular coagulation with clinically significant bleeding. Bridging to liver transplantation was possible in one patient, the other five patients died 30 days (2-74 days) after starting MARS therapy. Our case series shows that MARS treatment in general can be safely performed in patients with severe liver disease. However, in patients with an activated clotting system severe bleeding complication can be triggered and MARS treatment should be used very cautiously in these situations. MARS seems to be a promising new treatment option for patients with acute on chronic liver failure. However, carefully conducted randomized controlled trials are necessary to define its potential place in the treatment of patients with severe liver disease.

Hepatic uptake of cholecystokinin octapeptide by organic anion-transporting polypeptides OATP4 and OATP8 of rat and human liver.

BACKGROUND & AIMS: Cholecystokinin (CCK) is a major gastrointestinal peptide hormone that is released postprandially from the small intestine and exerts marked effects on gallbladder and gastrointestinal motility. The smaller isoforms CCK-8 and CCK-4 are rapidly taken up into hepatocytes, metabolized, and excreted into bile. Our aim was to identify and characterize the hepatocellular CCK-8 uptake system. METHODS: CCK-8 uptake was measured in Xenopus laevis oocytes expressing the organic anion-transporting polypeptides of rat liver (Oatp1, Oatp2, Oatp3, or Oatp4) and of human liver (OATP-A, OATP-B, OATP-C, or OATP8) and in primary cultured rat hepatocytes. RESULTS: Rat Oatp4 and human OATP8 efficiently mediated CCK-8 uptake in oocytes, with Michaelis constant (Km) values of 14.9 +/- 2.9 micromol/L and 11.1 +/- 2.9 micromol/L, respectively. CCK-8 uptake by hepatocytes was also saturable, with a Km of 6.7 +/- 2.1 micromol/L. The Km value in rat hepatocytes is consistent with Oatp4-mediated transport. CONCLUSIONS: CCK-8 is selectively transported by rat Oatp4 and human OATP8, both of which are exclusively expressed at the basolateral membrane of hepatocytes. These 2 transporters are the first and probably the predominant hepatic uptake systems for CCK-8 and may be critical for the rapid clearance of this hormone from the circulation.