Abr Thomson

The prevalence of clinically significant endoscopic findings in primary care patients with uninvestigated dyspepsia: the Canadian Adult Dyspepsia Empiric Treatment – Prompt Endoscopy (CADET–PE) study

Background: Uninvestigated dyspepsia is common in family practice. The prevalence of clinically significant upper gastrointestinal findings (CSFs) in adult uninvestigated dyspepsia patients, and their predictability based on history, is unknown.

Canadian Helicobacter Study Group Consensus Conference on the Approach to Helicobacter Pylori Infection in Children and Adolescents

Gastric infection with Helicobacter pylori is common in both children and adults, but children are considerably less susceptible to peptic ulcers and other pathological sequelae. As a result, the risk to benefit ratio of diagnostic studies and therapeutic regimens for H pylori in adults are likely different from those in pediatric populations. These guidelines for the management of pediatric H pylori infection, developed by the Canadian Helicobacter Study Group, are designed to identify when the diagnosis and treatment of H pylori may improve patient care. Given the low prevalence of this infection in Canada, it is important to recognize that indiscriminate testing and treatment programs in children are not recommended, and indeed may threaten the optimal care of children. Diagnostic tests should be employed judiciously and be reserved for children who are most likely to derive measurable benefit, such as those likely to have peptic ulcer disease. At this time a test and treat strategy in children cannot be considered prudent, evidence based or cost effective. It is appropriate to limit diagnosis and treatment to children and adolescents in whom H pylori has been identified during endoscopic investigation.

Canadian Helicobacter pylori Consensus Conference Update: Infections in adults

The first Canadian Helicobacter pylori Consensus Conference took place in April 1997. The initial recommendations of the conference were published in early 1998. An update meeting was held in June 1998, and the present paper updates and complements the earlier recommendations. Key changes included the following: the recommendation for testing and treating H pylori infection in patients with known peptic ulcer disease was extended to testing and treating patients with ulcer-like dyspepsia; it was decided that the urea breath test (not serology) should be used for routine diagnosis of H pylori infection unless endoscopy is indicated for another reason; and recommended therapies were a twice daily, seven-day regimen of a proton pump inhibitor (omeprazole 20 mg, lansoprazole 30 mg, pantoprazole 40 mg) or ranitidine bismuth citrate 400 mg, plus clarithromycin 500 mg and amoxicillin 1000 mg, or plus clarithromycin 500 or 250 mg and metronidazole 500 mg. The need was reiterated to have funding for readily accessible, accurate testing for H pylori infection with the urea breath test. It was strongly recommended that regional centres be established to monitor the prevalence of antibiotic-resistant H pylori infections. The initial consensus document referred to pediatric issues that were not addressed in this update but were the subject of a subsequent Canadian Helicobacter Study Group meeting, and will be published later in 1999.

Antisecretory and serum gastrin lowering effect of enprostil in patients with duodenal ulcer disease

This study was designed to compare the effects of enprostil, a synthetic dehydro-prostaglandin E2, on 24-h intragastric pH and serum gastrin profile in patients with duodenal ulcer disease. The dosing regimen included 3 enprostil groups: 35 microgram h.s. (at bedtime), 70 micrograms h.s., and 35 micrograms b.i.d., compared with cimetidine 600 mg b.i.d., and with placebo. Ten patients with inactive duodenal ulcer disease were randomly assigned to all five treatment regimens for 1 wk each according to a Latin Square design. There was a 1-wk washout period between each treatment. Intragastric pH and serum gastrin measurements were carried out on the last day of each treatment week. In placebo-treated patients, intragastric pH rose after each meal and fluctuated between 1.5 and 3.5. Enprostil 35 micrograms b.i.d. and cimetidine elevated pH after breakfast and during the night (p less than 0.05). The single nighttime dose of enprostil had a marked effect on pH only when given in the dose of 70 micrograms and this effect lasted over 13.5 h. The pH values during the night were similar in the groups treated with enprostil 35 micrograms b.i.d. and 70 micrograms h.s. During the daytime, the readings at or above pH 4 were placebo, 5%; cimetidine, 21%; enprostil 35 micrograms b.i.d., 34%. During the nighttime, the readings greater than or equal to 4 were placebo, 12%; cimetidine, 29%; enprostil 35 micrograms b.i.d., 39%; 35 micrograms h.s., 19%, and 70 micrograms h.s., 38%. The postprandial rise in serum gastrin was greatly enhanced by cimetidine, but the change after breakfast was dramatically blunted by enprostil 35 micrograms b.i.d. Gastrin concentration was increased with cimetidine during the night but there was no difference in gastrin concentration overnight between all regimens of enprostil and placebo. This study suggests that (a) enprostil 35 micrograms b.i.d. is as effective as cimetidine 600 mg b.i.d. in suppressing postprandial and nocturnal intragastric acidity; (b) enprostil 35 micrograms b.i.d. and 70 micrograms at night are similarly potent in suppressing nocturnal acidity; and (c) in addition to its cytoprotective effect, enprostil has potent antisecretory and antigastrin properties.

Cholestatic hepatocellular injury with azathioprine: A case report and review of the mechanisms of hepatotoxicity

Azathioprine is a drug commonly used for the treatment of inflammatory bowel disease, organ transplantation and various autoimmune diseases. Hepatotoxicity is a rare, but important complication of this drug. The cases reported to date can be grouped into three syndromes: hypersensitivity; idiosyncratic cholestatic reaction; and presumed endothelial cell injury with resultant raised portal pressures, venoocclusive disease or peliosis hepatis. The components of azathioprine, 6-mercaptopurine and the imidazole group, may play different roles in the pathogenesis of hepatotoxicity. The strong association with male sex, and perhaps with human leukocyte antigen type, suggests a genetic predisposition of unknown type. Many of the symptoms of hepatotoxicity, such as nausea, abdominal pain and diarrhea, can be nonspecific and can be confused with a flare-up of inflammatory bowel disease. As well, the subtype resulting in portal hypertension can occur without biochemical abnormalities. A 63-year-old man with Crohns disease who is presented developed the rare idiosyncratic form of azathioprine hepatotoxicity, but also had a severe disabling steroid myopathy, peripheral neuropathy, resultant deep venous thrombosis and pulmonary embolism related to immobility, and a nosocomial pneumonia. His jaundice and liver enzyme levels improved markedly on withdrawal of the drug, returning to almost normal in five weeks. Treating inflammatory bowel disease effectively while trying to limit iatrogenic disease is a continuous struggle. Understanding the risks of treatment is the first important step. There must be a low threshold for obtaining liver function tests, especially in men, and alertness to the need to discontinue the drug or perform a liver biopsy should patients on azathioprine develop liver biochemical abnormalities, unexplained hepatomegaly or signs of portal hypertension.

The Clinical Importance of Proton Pump Inhibitor Pharmacokinetics

Achieving the optimal clinical response for patients with upper gastrointestinal peptic disease is important. This response depends on the pathology treated as well as on the choice of proton pump inhibitor. Here, we identify factors in specific disease therapy and proton pump inhibitor (PPI) pharmacokinetic and pharmacodynamic characteristics that help us achieve this goal. These include differences in PPI bioavailability and acid-suppressive effects. Available data indicate that PPIs appear to have similar potency on a milligram basis, and that omeprazole and lansoprazole are more frequently double dosed than pantoprazole. The lower propensity for double dosing with pantoprazole may also result in lower medication acquisition costs and a reduction in physician visits due to ineffective therapy with the standard dosing of these other agents.

Validation of a 7-point Global Overall Symptom scale to measure the severity of dyspepsia symptoms in clinical trials.

Background  Currently there is no consensus on the optimal method to measure the severity of dyspepsia symptoms in clinical trials.

Mesalazine (Mesasal/Claversal) 1.5 g b.d. vs. placebo in the maintenance of remission of patients with Crohn's disease

Investigators: This multicentre study was conducted by 29 principal investigators in 11 countries.

Fatty acid desaturation in the intestinal mucosa

Information as to the ability of the enterocyte to desaturate fatty acids is lacking. This is important in understanding whether the source of intestinal arachidonic (20:4(n-6) acid is biliary or from de novo synthesis. Delta 9- and delta 6-desaturase enzymes were assayed in homogenates of rat jejunum, ileum and liver. Rat small intestine possesses desaturase activity to convert palmitic (16:0) to palmitoleic (16:1) and linoleic (18:2(n-6) to linolenic (18:3(n-6) acid. Enzyme activities were highest in liver relative to activity in jejunal and ileal homogenates. It is concluded that delta 9- and delta 6-desaturase activities may have an important role in determining physico-chemical properties and thus transport properties of enterocyte membranes.

Heartburn‐dominant, uninvestigated dyspepsia: a comparison of ‘PPI‐start’ and ‘H2‐RA‐start’ management strategies in primary care – the CADET‐HR Study

Background : There are few data on empiric, stepped therapy for heartburn relief or subsequent relapse in primary care.