[Nutrition and IBD-Consensus of the Austrian Working Group of IBD (Inflammatory Bowel Diseases) of the ÖGGH]. / Ernährung und chronisch entzündliche Darmerkrankungen - ein Konsensus der Arbeitsgruppe chronisch entzündliche Darmerkrankungen der Österreichischen Gesellschaft für Gastroenterologie und Hepatologie (Austrian Guidelines for nutrition in IBD).

This is a consensus of the Austrian working group of IBD (inflammatory bowel diseases) of the ÖGGH on nutrition in IBD. Malnutrition should be assessed in case of IBD (in 20 - 70 % of Crohn's patients) and weight loss(> 5 % within 3 months) or nutritional deficiencies or after extensive bowel resection and afterwards also treated. Malnutrition should be treated with medical therapy of IBD and also adequate - as far as possible - with oral nutritional therapy particularly because of reduced life quality, risk of opportunistic infections, osteopenia/osteoporosis, longer hospitalisations and higher mortality. Iron homeostasis, serum levels of Vitamin B12- and folic acid, 25-hydroxyvitamin D and zinc should be checked. Therapy with enteral liquid diets is only indicated as therapy of first choice in children and adolescents, but only in rare situations in adults with IBD. There is - up to now - no proven oral diet for maintenance of remission in IBD. Probiotics as E. coli Nissle could be used as alternative to mesalazine for maintenance of remission in patients with ulcerative colitis. A specific dietary counselling is mandatory in patients with ileostoma or short bowel syndrome. Malnutrition of short bowel patients is particularly dependent on the function and length of the remaining bowel, therefore the most effective medical therapy should be administered.

[Colorectal cancer: screening and surveillance in inflammatory bowel diseases - consensus of the working group for inflammatory bowel diseases of the Austrian Society of Gastroenterology and Hepatology]. / Kolorektales Karzinom: Screening und Surveillance bei chronisch entzündlichen Darmerkrankungen - Konsensus der Arbeitsgruppe für chronisch entzündliche Darmerkrankungen der ÖGGH.

Patients with ulcerative colitis and Crohn's colitis are at increased risk of colorectal cancer (CRC). This risk is dependent on the duration and extent of disease, inflammatory activity and possible additional risk factors. Thus, the aim is to reduce this risk and to detect dysplastic and malignant lesions at an early stage. The working group for Inflammatory Bowel Diseases (IBD) of the Austrian Society of Gastroenterology and Hepatology (ÖGGH) has developed consensus statements on the following topics: risk of colorectal cancer, screening and surveillance, procedure of surveillance colonoscopy, dysplasia and its management, and chemoprevention. This consensus is intended to increase awareness of the increased risk of CRC in IBD and to support a standardised approach in cancer prevention.

[Infliximab therapy for Crohn's disease - a practical guideline: actualised consensus of the working group for chronic inflammatory bowel diseases of the Austrian Society for Gastroenterology and Hepatology]. / Infliximab in der Therapie des Morbus Crohn - ein praktischer Leitfaden: aktualisierter ÖGGH-Konsensus der Arbeitsgruppe Chronisch-entzündliche Darmerkrankungen der ÖGGH.

Infliximab is a monoclonal antibody against tumor necrosis factor alpha (TNF-α), which is approved for the treatment of chronic inflammatory bowel disease (IBD) such as Crohn's disease (CD), fistulating Crohn's disease (FCD), ulcerative colitis (UC), and paediatric ulcerative colitis (PUC) from 6 years onwards. Besides its therapeutic efficacy, this antibody therapy is characterised by its side effects profile, which has been addressed in a seperate consensus statement by the Working Group for chronic inflammatory bowel diseases within the Austrian Society for Gastroenterology and Hepatology. Infliximab is an effective treatment option for the above-mentioned indications; however, use of this agent requires special knowledge to assess the benefit-risk profile for each patient individually.

Simultaneous modeling of bopindolol kinetics and dynamics.

Bopindolol has beta-blocking effects for 96 hr despite a 4-hr t1/2. To investigate the concentration-effect relationship after single and repeated doses. 2-mg oral doses were given once and then daily for 13 days to six healthy subjects. In plasma, no unchanged drug, only the hydrolysis product of bopindolol (referred to as bopindolol concentration) was detectable or could be measured up to 24 hr. Chemical assay by HPLC and determination of total active beta-adrenoceptor blocking material by radioreceptor assay gave identical results. The t1/2 was 4 to 5 hr. Effects, measured as reduction in exercise-induced tachycardia (REIT) and as the isoproterenol dose ratio (DR - 1), were followed for 96 hr. The concentration of bopindolol in plasma (predicted with a one-compartment body model) could be related to the measured effects by classic effect models for 20 t1/2s. Parameter estimates for kinetic end effect models did not differ after single and repeated doses. With the parameters from the single-dose experiment, the time course of the plasma concentration and the effects after the multiple-dose experiment could be adequately predicted for 24 and 96 hr. A deep compartment, an active metabolite, or irreversible destruction of the receptor (accounting for the persistence of the effect) could be excluded. The "dissociation constant" of 100 pmol/l (from DR -1/concentration) and the minimal effective plasma concentration (from REIT/log concentration) of 1 pmol/l suggest that enough receptors are occupied at chemically unmeasurable levels in plasma to induce an effect. The "dissociation constant" determined in vivo is of the same order as that from in vitro radioligand studies.

Plasma isosorbide dinitrate concentrations and effect after chewable and high-dose, sustained-release formulations.

Isosorbide dinitrate (ISDN) was given to eight healthy volunteers either as 5 mg chewable ISDN hourly or as 40-mg, slow-release formulation every 8 h. Plasma concentration of ISDN and its two metabolites were measured during one dosing interval at steady state. Mean steady-state plasma concentration (Cpss) during the interval was taken as a measure for bioavailability. Cpss after bucal absorption was similar to that after the sustained-release preparation. Relative bioavailability of the latter reached 111%. The effect of ISDN was measured by digital plethysmography (DPG) during the first dosing interval and after 10 and 48 h, when a steady state had been reached with each formulation. DPG changes were of similar magnitude during the first 10 h, but showed a 30% decrease after 48 h. This tolerance is probably due to physiologic counterregulation. Changes in DPG reflect effects of ISDN which can be used during short-term application of the drug to assess systemic bioavailability. Development of tolerance, however, precludes the use of DPG to assess bioavailability in long-lasting steady-state experiments.

Pharmacokinetics of intravenous isosorbide-dinitrate.

The kinetics of isosorbide dinitrate (ISDN) after i.v. administration and the absolute availability of an oral slow release preparation (SR) were studied in young healthy volunteers. ISDN and the 2- and 5-mononitrates of isosorbide (2-MN, 5-MN) were determined by GLC. After i.v. administration plasma levels of ISDN declined biexponentially and could be adequately described by an open two compartment body model. Distribution half-life was extremely rapid (2-5 min). Terminal disappearance had a half-life of 67 (62-75) min (mean, range). Total plasma clearance was 1.6 (1.2-2.2) litres X min-1, thus approaching liver blood flow. Nevertheless, absolute systemic availability (F) or oral ISDN amounted to 22% (16-29%). Assuming that oral ISDN is completely absorbed and blood levels do not exceed serum levels, an upper limit of hepatic clearance (liver blood flow 1.5 litres X min-1 X (1-F/100)) can be estimated, which is significantly smaller (p less than 0.05) than the measured clearance. This finding is best interpreted by assuming that ISDN is partly eliminated by extrahepatic routes, which is further substantiated by a different pattern of metabolites after i.v. and oral dosing. Whereas after i.v. administration more 2-MN is produced, 5-MN is the main metabolite after oral ISDN. Since the glutathione-S-transferases are found in the cytosol of most cells, it seems likely that other organs than the liver contribute to the metabolism of ISDN.

Use of a single TSH-measurement after oral thyrotrophin releasing hormone: an economical and highly sensitive thyroid screening test.

The increment of serum TSH after thyrotrophin-releasing hormone (TRH) is usually considered an extremely sensitive thyroid test, particularly useful in borderline disturbances. We evaluated 195 patients by measuring serum TSH before and 3 h after 40 mg TRH po, and by various other thyroid tests. We found a very tight correlation between the TSH- increment and the 3 h TSH. Thus the TSH-increment can reliably be estimated from the 3 h TSH. The mann-Whitney test confirmed that the 3 h TSH identified thyroid dysfunction as well as the TSH-increment. The basal TSH can therefore be omitted and we propose the measurement of the 3 h TSH as an initial screening test. This single measurement economically excludes the many euthyroid patients sent for thyroid evaluation from further costly tests.

Rate of drug metabolism in man measured by 14CO2-breath analysis.

Exhalation of 14CO2 in breath has been used to assess the rate of hepatic demethylation of (14C-dimethyl)aminopyrine, but due to the complexity of aminopyrine metabolism the pharmacokinetics of the procedure are insufficiently understood. Therefore, studies were performed in five individuals after oral administration of (14C-methoxy)glycodiazine, a model substance with relatively simple kinetic properties. Plasma concentrations of the drug and urinary output of its metabolites measured by high pressure liquid chromatography were analysed by a two-compartment open model. The terminal disappearance of 14CO2 from breath was practically identical with the terminal disappearance of glycodiazine from plasma, which could be correlated with the plasma clearance of free glycodiazine. The mean transit time of 14C-atoms from plasma to breath was 3 h. These results contribute to the pharmacokinetic basis for use of 14C-demethylation breath tests. In particular, they are consistent with the hypothesis that 14CO2-breath analysis may be used to assess certain pharmacokinetic parameters of appropriately labelled test compounds. These parameters may not necessarily be a direct reflection of the rate of demethylation.

Polymorphic acetylation and aminopyrine demethylation in Gilbert's syndrome.

Polymorphic acetylation was investigated in twenty-seven patients with Gilbert's syndrome using the sulphadimidine test. Whereas the finding of 51% slow acetylators in seventy-eight control persons agreed well with the expected frequency in a continental European population, the prevalence of slow acetylators in Gilbert's syndrome was increased to 78% (P less than 0.03, Woolf's G-test). After oral administration of 14C-aminopyrine there was no significant difference between seventeen patients with Gilbert's syndrome and twenty-seven normal controls in total plasma clearance of aminopyrine (280 +/- SD 100 and 270 +/- 60 ml/min) and in the disappearance curve of 14CO2 in breath (0.23 +/- 0.04 and 0.22 +/- 0.03 h-1, respectively). Thus, whereas aminopyrine metabolism appears unaffected in the examined patients, the data documents a new association between slow acetylator status and Gilbert's syndrome.