High detection rate of adenomas in familial colorectal cancer.

BACKGROUND AND AIMS: Subjects with one first-degree relative (FDR) with colorectal cancer (CRC) <50 years old or two FDRs with CRC have an increased risk for CRC (RR 4-6). Current guidelines recommend colonoscopic surveillance of such families. However, information about the yield of surveillance is limited. The aim of the present study was to evaluate the outcome of surveillance and to identify risk factors for the development of adenomas. PATIENTS AND METHODS: Subjects were included if they fulfilled the following criteria: asymptomatic subjects aged between 45 and 65 years, with one FDR with CRC <50 years old (group A) or two FDRs with CRC diagnosed at any age (group B). Subjects with a personal history of inflammatory bowel disease or colorectal surgery were excluded. RESULTS: A total of 551 subjects (242 male) met the selection criteria. Ninety-five subjects with a previous colonoscopy were excluded. Two of 456 remaining subjects (0.4%) were found to have a colorectal tumour (one CRC and one carcinoid). Adenomas were detected in 85 (18.6%) and adenomas with advanced pathology in 37 subjects (8.1%). 30 subjects (6.6%) had multiple (>1) adenomas. Men were more often found to have an adenoma than women (24% vs 14.3%; p=0.01). Adenomas were more frequent in group B compared with group A (22.0% vs 15.6%; p=0.09). CONCLUSION: The yield of colonoscopic surveillance in familial CRC is substantially higher than the yield of screening reported for the general population.

Colonic work-up after incomplete colonoscopy: significant new findings during follow-up.

BACKGROUND AND STUDY AIMS: Cecal intubation is not achieved in 2 - 23 % of colonoscopies. The efforts made by physicians to visualize the remaining colon and the number of missed significant lesions are unknown. This study evaluates 1) the reasons for incomplete colonoscopy, 2) the rates of complete colonic evaluation after incomplete colonoscopy, and 3) the number of (pre-) malignant lesions missed by incomplete colonoscopy. PATIENTS AND METHODS: In this population-based cohort study index colonoscopies were performed between September and December 2005. Prospectively collected data from consecutive patients with an incomplete colonoscopy were analyzed. For up to 18 months after the index colonoscopy, any further examinations performed in these patients were identified retrospectively. These secondary examinations included: repeat colonoscopy, computed tomography (CT) colonography, barium enema, abdominal CT scan, and surgery involving the colorectum. RESULTS: Of 5278 colonoscopies, 511 were incomplete (9.7 %). The most frequent causes of incomplete colonoscopy were looping of the scope (20.4 %), patient discomfort (15.3 %), and obstructing tumor (13.9 %). Secondary examination was performed in 278 patients (54.4 %) after incomplete colonoscopy. Patients undergoing surveillance after colorectal cancer (CRC) (78.9 %) and those with anemia (73.1 %) most frequently received a secondary examination. Incomplete colonoscopies due to stenosis (78.9 %), severe inflammation (77.8 %) or an obstructing tumor (74.6 %) were most frequently followed by a secondary examination. In all of the follow-up examinations, CRC was diagnosed in 18 patients (3.5 %) and advanced adenoma in four patients (0.8 %). CONCLUSIONS: In 4.3 % of the patients, advanced neoplasia was missed by incomplete colonoscopy. Our data therefore suggest that additional imaging is obligatory to visualize the remaining colon adequately.

Practice and yield of early CT scan in acute pancreatitis: a Dutch Observational Multicenter Study.

BACKGROUND: Early computed tomography (CT) (within 4 full days after symptom onset) may be performed to distinguish acute pancreatitis (AP) from other intra-abdominal conditions or to identify early pancreatic necrosis. We analyzed practice and yield of early CT in patients with an established clinical diagnosis of AP in a Dutch cohort (EARL study). METHODS: Multicenter observational study. Etiology, disease course, CT timing, Balthazar CT score, and clinical management were evaluated. RESULTS: First documented hospital admissions of 166 patients were analyzed. Etiology was biliary (42.8%), unknown (20.5%), alcoholic (18.1%), post-endoscopic retrograde cholangiopancreatography (11.4%), and miscellaneous (7.2%). In 89.2% (148/166), the disease course was mild. Out of 18 patients with severe AP, 11 eventually developed (peri)pancreatic necrosis. At least one CT (range 1-12) was performed in 47% (78/166) of all patients and in 62.8% (49/78) it was acquired within 4 full days after symptom onset. Practice, timing, and Balthazar CT score of early CTs were not significantly different between mild and severe AP. None of the early CTs showed necrosis and no alternative diagnoses were established. In 89.8% (44/49), clinical management was not altered after early CT. In 10.2% (5/49), prophylactic antibiotics were started, but in absence of necrosis. CONCLUSIONS: A CT scan was frequently acquired early in the course of AP, but its yield was low and had no implications with regard to clinical management. It seems prudent that clinicians should be more restrictive in the use of early CT, in particular in mild AP, to prevent unnecessary radiation exposure and to save costs.

Nutritional management of patients with acute pancreatitis: a Dutch observational multicentre study.

BACKGROUND: Following a nil per os (NPO) regimen, most patients with acute pancreatitis (AP) can resume normal oral intake within 1 week. If not tolerated, it is recommended to initiate artificial feeding, preferably by the enteral route. AIM: To evaluate the nutritional management of patients with AP in a Dutch cohort (EARL study). METHODS: Observational study in 18 hospitals. Total days of NPO, tube feeding (TF) with/without oral feeding, total parenteral nutrition (TPN) and total starvation time were analysed. RESULTS: In mild AP, a majority of cases (80.7%, 117/145) were managed with an NPO regimen only. Twenty-seven patients (18.6%) with mild AP additionally received TF; one received TPN. Of those with severe AP, more than half of the patients (56.2%, nine of 16) were treated with TF besides an NPO regimen; four received TPN. TF was delivered preferably via the jejunal route. The median period of total starvation was 2 days for both mild and severe AP. Only 5.5% (nine of 164) of patients had a prolonged starvation time of more than 5 days. CONCLUSIONS: The total time of starvation was limited in a majority of patients admitted for AP. According to international guidelines, additional nutritional interventions were quickly undertaken with enteral feeding via the jejunum as the preferred route.

The effect of a lactose-restricted diet in patients with a positive lactose tolerance test, earlier diagnosed as irritable bowel syndrome: a 5-year follow-up study.

DESIGN AND METHODS: Prospectively, the effect of a lactose-restricted diet was evaluated among irritable bowel syndrome patients with lactose malabsorption. Lactose malabsorption was defined by a positive hydrogen breath test and a positive blood-glucose test. An analysis of symptoms was completed before, during, 6 weeks after and 5 years after starting the diet. In addition, the number of visits made by the patients to the outpatient clinic was scored during 6 years. RESULTS: In 17 out of 70 irritable bowel syndrome patients (24.3%), lactose malabsorption was detected. There was no difference in the symptom score between patients with a positive lactose tolerance test and patients with a negative lactose tolerance test. After 6 weeks of the lactose-restricted diet, symptoms were markedly improved in lactose malabsorption-positive patients (P < 0.001). After 5 years, one patient was lost for follow-up, and 14 out of the remaining 16 lactose malabsorption patients (87.5%) still had no complaints during the lactose-restricted diet. Two patients chose not to follow the diet continuously and accepted the discomfort caused by lactose intake. Only two out of 16 patients (12.5%) no longer experienced any benefit from lactose restriction. In the 5 years before their diagnosis of lactose malabsorption, these 16 patients visited the outpatient clinic a total of 192 times (mean 2.4 visits per year per person; range 1-7 visits). In the 5 years after diagnosis, they visited the outpatient clinic a total of 45 times (mean 0.6 visits per year per person; range 0-6 visits; P < 0.0001). CONCLUSIONS: In a large majority of irritable bowel syndrome patients with lactose malabsorption, which was previously clinically unrecognized, a lactose-restricted diet improved symptoms markedly both in the short term and the long term. Furthermore, visits by all patients to the outpatient clinic were reduced by 75%. We conclude that diet therapy is extremely cost- and time-saving. Therefore, it is strongly recommended that lactose malabsorption, which is easily treatable, is excluded before diagnosing irritable bowel syndrome.

Predictive value of inflammatory and coagulation parameters in the course of severe ulcerative colitis.

Alterations in markers of coagulation have been found in patients with inflammatory bowel disease. Our aim was to study the predictive value of coagulation and inflammatory parameters in the course of severe ulcerative colitis. Twenty-seven patients were included. The disease course was followed for one year. Sensitivity, specificity, negative predictive value, positive predictive value, and likelihood ratio, as well as the clinical predictive value of laboratory variables were calculated. Inflammatory variables, such as ESR, CRP, and leukocyte and platelet count showed poor diagnostic accuracy. Several coagulation parameters, such as fibrinogen and fibrin(ogen) degradation products, were increased in patients with active ulcerative colitis, whereas coagulation factor XIII was decreased. No significant relationship between clinical course and coagulation parameters was demonstrated, though both inflammatory and coagulation parameters were useful in the assessment of disease activity in patients with active ulcerative colitis.

Hemostatic imbalance in active and quiescent ulcerative colitis.

OBJECTIVE: In healthy conditions, factors inducing or inhibiting coagulation and factors inducing or inhibiting fibrinolysis are in balance. In ulcerative colitis, hypercoagulation is presumed, which may explain part of the clinical features of this disease. Therapy strategies affecting hemostasis may improve the course of ulcerative colitis. This study was conducted to evaluate the balance of coagulation and fibrinolysis in the course of treatment of active ulcerative colitis. METHODS: Patients with active ulcerative colitis were studied by serial determination of markers of the coagulation cascade (thrombin-antithrombin complexes and fibrin degradation products [FbDP]) and the fibrinolytic cascade (fibrinogen degradation products [FgDP]). Parameters of inflammation were also measured (C-reactive protein [CRP], erythrocyte sedimentation rate [ESR], albumin, platelet count, and fibrinogen). Disease activity was assessed by endoscopic and histopathological scores. Follow-up measurement was performed in the course of treatment at the third or fourth month after baseline. Measurements were compared with healthy controls. RESULTS: Thirty-three patients and 22 healthy controls were included. During active ulcerative colitis, inflammatory parameters (CRP, ESR, platelet count) and hemostatic parameters (thrombin-antithrombin complexes, fibrinogen, FgDP, and FbDP) were elevated in comparison with healthy controls. Albumin was decreased and antithrombin-III remained unchanged. During treatment, disease activity decreased significantly endoscopically and histopathologically (p < 0.001). CRP, ESR, platelet count, and fibrinogen also decreased significantly. The hemostatic balance, expressed as the ratio between the plasmin-dependent generation of FgDP and coagulation-dependent generation of FbDP, increased from 0.69 to 1.12 during treatment, mainly because of a decrease of FbDP. In healthy controls, this ratio was CONCLUSIONS: The coagulation and fibrinolytic cascades were activated in active ulcerative colitis, with a hemostatic imbalance in favor of coagulation. This hypercoagulability persisted in 20% (7/33) of patients with ulcerative colitis in remission. The decrease of FbDP and the increase in the FgDP/FbDP ratio during reconvalescence of ulcerative colitis showed that the coagulation cascade was more activated than the fibrinolytic cascade in active disease.

Serum eosinophil cationic protein in active and quiescent ulcerative colitis.

Inflammatory bowel disorders are characterized by an accumulation of eosinophilic granulocytes, mast cells, lymphocytes and neutrophilic granulocytes in the intestinal mucosa. The aim of this study was to examine the concentration of eosinophilic granulocytes in the blood of patients during active ulcerative colitis in comparison with patients during remission and apparently healthy control subjects. Besides counting, the activity grade of eosinophilic granulocytes has been studied by estimation of their degranulation product eosinophil cationic protein. Subjects with active ulcerative colitis could be distinguished from patients with quiescent ulcerative colitis by establishment of the eosinophil cationic protein concentration, neutrophilic granulocyte count, erythrocyte sedimentation rate, C-reactive protein and albumin concentration. After two weeks of corticosteroid treatment, serum eosinophil cationic protein concentrations and eosinophil counts in blood were significantly decreased. A decrease in blood eosinophil count was accompanied by a decrease in eosinophil cationic protein concentrations in serum in most subjects with ulcerative colitis. After twelve weeks of corticosteroid administration, serum albumin concentrations were significantly increased, whereas serum concentrations of C-reactive protein were significantly decreased. During treatment with corticosteroids, serum eosinophil cationic protein concentrations and blood eosinophil counts are appropriate laboratory markers to detect the effect of medication in the course of ulcerative colitis.

Omeprazole as a diagnostic tool in gastroesophageal reflux disease.

OBJECTIVE: To determine the diagnostic value of empirical treatment with omeprazole in the diagnosis of gastroesophageal reflux disease (GERD). METHODS: Patients with symptoms suggestive of GERD underwent upper gastrointestinal endoscopy and 24-h esophageal pH monitoring. Patients with reflux esophagitis grade 0 or 1 were included in the study and were randomized to double-blind treatment with either 40 mg omeprazole or placebo o.m. The effect of treatment was evaluated after 1 and 2 wk with a symptom questionnaire with a four-grade Likert scale, and symptomatic response outcome was compared with the results of 24-h pH-metry. RESULTS: Ninety-eight patients were included; however, 13 were excluded from the final analysis because of protocol violation. Of the remaining 85 patients, 54 had no signs of esophagitis at endoscopy, and 31 had esophagitis grade 1. The pH registration showed pathological gastroesophageal reflux in 47 patients (55%). Forty-one patients were randomized to treatment with omeprazole and 44 to placebo. There was a significant correlation between the pH registration result and response to omeprazole (p = 0.04, chi2), but not to placebo (p = 0.16). With pH-metry as the gold standard, the omeprazole test had positive and negative predictive values of 68% and 63%, respectively, for the diagnosis of GERD. When the omeprazole test was used as the gold standard, the positive and negative predictive values of pH monitoring were 68 % and 63 %, respectively. Similar sensitivity was found when the pH-metry was compared with presence of esophagitis. CONCLUSION: Determination of the symptomatic response to 40 mg of omeprazole for 14 days is a simple and inexpensive tool for the diagnosis of GERD, with a sensitivity and specificity comparable to 24-h pH monitoring.

Gastroesophageal reflux disease in intellectually disabled individuals: leads for diagnosis and the effect of omeprazole therapy.

OBJECTIVES: The therapeutic approach to gastroesophageal reflux disease (GERD) in intellectually disabled individuals has not been studied extensively. So far, only low response rates to medical and surgical therapy of GERD have been reported. However, the efficacy of proton pump inhibitors, to date the most effective medical therapy for GERD, has never been evaluated in this population. Our purpose, therefore, was to study the effect of omeprazole on healing and symptom relief in the intellectually disabled. METHODS: The treatment scheme was as follows: omeprazole 40 mg was given once daily (o.d.) as a healing dose for 3 months, and omeprazole 20 mg o.d. was given as a maintenance dose for another 3 months, to intellectually disabled subjects with endoscopically proven esophagitis, grades I-IV, according to Savary-Miller classification. After 3 and 6 months, the result of this treatment was evaluated by symptom scoring and/or endoscopy. In case of relapse, the dose was increased. RESULTS: At the first endoscopy, 40 of 107 patients (37%) had grade I, 36 (34%) grade II, 18 (17%) grade III, and 13 (12%) grade IV esophagitis. In 92 of 104 patients (88%), the treatment scheme was effective in healing the esophagitis and keeping patients in remission, independent of the severity of esophagitis. In 11 of 104 (11%) patients, a symptomatic relapse was observed after the dose was decreased to 20 mg o.d. However, all of these patients became symptom free again after the dose was increased to 40 mg o.d., and all were healed endoscopically at the end of the study. One (1%) patient needed omeprazole 60 mg o.d. for healing, but in this patient, no relapse was seen while on a maintenance dose of omeprazole 40 mg o.d. Marked improvement of persistent vomiting, hematemesis, regurgitation, food refusal, iron deficiency anemia, and depressive symptoms was seen at the end of the study. CONCLUSIONS: This study indicates that omeprazole is highly effective for all grades of esophagitis in the intellectually disabled. The dose needed to maintain them in remission can be titrated according to the reflux symptoms.

[Acute transit symptoms caused by spontaneous rupture of the esophagus]. / Acute passageklachten veroorzaakt door een spontane intramurale ruptuur van de oesofagus.

A 44-year-old woman was admitted to our hospital with acute severe chest pain and dysphagia, without an assignable cause. Radiological investigation of the oesophagus with water soluble contrast revealed an intramural rupture. Conservative management led to complete recovery within eight days. Spontaneous intramural rupture of the oesophagus is a very uncommon disease requiring adequate differentiation from other more serious diseases in order to apply correct therapy.

The clinical relevance of lactose malabsorption in irritable bowel syndrome.

OBJECTIVE: The prevalence of lactose malabsorption (LM) in the Caucasian population of northern Europe is estimated to be low. Irritable bowel syndrome (IBS) is a very common diagnosis, and its symptoms are nearly identical to those of LM. Therefore we investigated the prevalence of LM among IBS patients in comparison with healthy volunteers. DESIGN: A double-blind clinical trial compared with healthy controls. SETTING: One out-patient gastroenterology clinic in the Netherlands. PATIENTS: 70 Caucasian IBS patients and 35 healthy volunteers (staff members). METHODS: All 105 underwent hydrogen (H2) breath and blood glucose tests, after an oral intake of 50 grams of lactose. The IBS patients were treated with a lactose-restricted diet for 6 weeks. They completed a lactose intake score before, and a symptom score scored by six separate criteria, before, during and after treatment. RESULTS: In 17 out of 70 (24.3%) IBS patients LM was detected, in comparison with 2 out of 35 (5.7%) controls (P < 0.009). There was no difference in the pre-entry mean lactose intake and symptom score between the LM positive and negative IBS patients. The mean symptom score of the LM positive group showed a marked decrease after 6 weeks of dietary therapy (P < 0.001). CONCLUSION: A substantial number of IBS patients showed a clinically unrecognized lactose malabsorption, which could not be discriminated by symptoms and dietary history, and which can be treated with a lactose-restricted diet. Therefore LM has to be excluded before the diagnosis IBS is made.

Distribution of mesalazine enemas in active and quiescent ulcerative colitis.

BACKGROUND: The efficacy of mesalazine enemas depends on intraluminal concentration of the drug and is therefore limited by the enema distribution in the colon. Active ulcerative colitis changes colon motility and this leads to uncertainty about enema spread. AIM: To assess the influence of disease activity on enema distribution, we conducted a physician-blinded, longitudinal study of the retrograde spread of three mesalazine enemas. METHODS: Thirty-one patients with mild to moderate ulcerative colitis were subdivided into three groups, and treated with 2 g mesalazine in 30 mL (group I, n = 10), 4 g mesalazine in 60 mL (group II, n = 12) or 1 g mesalazine in 100 mL (group III, n = 9). All patients received oral mesalazine 500 mg t.d.s. Enemas were labelled by adding 10 MBq (99mTc)technetium-sulphur colloid. Anterior scintigraphic images were taken at the start of the study and after 12 weeks of therapy; retrograde spread was assessed by calculating the percentage of the enema in each colonic segment. RESULTS: The activity score of ulcerative colitis diminished significantly after 12 weeks of treatment, but five patients dropped out of the study. At the start of treatment enema activity in group I was mainly concentrated in the sigmoid (99%); in group II activity was found in the rectum (9%), the sigmoid (61%) and the descending colon (15%); in group III activity was distributed between the sigmoid (66%) and descending colon (25%). The colonic distribution of mesalazine enemas was not influenced by disease activity. CONCLUSION: Volume, but not disease activity, is the important determinant of retrograde colonic spread of mesalazine enemas in ulcerative colitis.

Comparison of the efficacy and safety of 1.5 compared with 3.0 g oral slow-release mesalazine (Pentasa) in the maintenance treatment of ulcerative colitis. Dutch Pentasa Study Group.

OBJECTIVE: To investigate a possible dose-effect relationship with two dosages of oral slow-release mesalazine in patients with quiescent ulcerative colitis. METHOD: One hundred and sixty-nine patients with ulcerative colitis in remission were treated with either 1.5 or 3.0 g/day mesalazine for 1 year or until relapse into active colitis. RESULTS: Fewer of the 3.0 g dose group relapsed than of the 1.5 g dose group (33 compared with 46%). This difference failed to reach statistical significance (P = 0.057). A significant relationship between age and relapse rate was established. No dose-related adverse events were found. Three serious drug-related adverse events were, however, reported. All of the serious adverse reactions resolved after the medication was discontinued. CONCLUSION: There is a trend for high doses of oral mesalazine to be more effective in prevention of relapse of ulcerative colitis. These higher doses are not associated with a higher incidence of adverse reactions.

Fibrinolytic split products, fibrinolysis, and factor XIII activity in inflammatory bowel disease.

BACKGROUND: Factor XIII (F XIII), the last coagulation factor in the clotting cascade, plays a role in mucosal repair. Beneficial effects of F XIII supplementation in severe ulcerative colitis (UC) have been observed. The aim of this study was to relate plasma F XIII activity to the severity of inflammatory bowel disease (IBD). METHODS: A transversional and, in part, longitudinal study of F XIII activity and related clotting products was performed in 39 patients with UC, 31 patients with Crohn's disease (CD), and 20 controls. Disease activity was assessed with a combined activity score in UC and with the Dutch Activity Index in CD. RESULTS: F XIII activity was decreased in active UC (p < 0.05) and active CD (p < 0.05) and was inversely correlated with severity in both UC (r = -0.30) and CD (r = -0.46). In six patients with UC (15%) and six patients with CD (19%) F XIII activity was below the lower range of normal. In these patients apparent rectal bleeding was only found in severe UC. Hyperfibrinolysis was indicated by elevated levels of D-dimer (p < 0.001) notwithstanding increased concentrations of alpha-2 antiplasmin (p < 0.05). CONCLUSIONS: In active IBD we found decreased plasma F XIII activity and hyperfibrinolysis. Decreased F XIII activity was not associated with apparent rectal bleeding in IBD.

Pharmacology of pepsinogen secretion: influence of pentagastrin on pepsinogen secretion in man.

To investigate the effect of pentagastrin on serum and urinary pepsinogens and gastric pepsin, eight healthy male volunteers were studied twice during continuous intragastric perfusion with either NaCl 0.9% or 0.1 M HCl in random order. To the perfusate 3 mg/ml phenol red was added as inert recovery marker. Gastric content was aspirated in 15-minute samples, 4 basally and subsequently 6 during continuous i.v. infusion of pentagastrin 1.5 micrograms/kg/h. Furthermore, serum and urine samples were collected immediately before and after each test. Gastric pepsin output increased after pentagastrin. There were no differences in basal or stimulated pepsin output during saline or HCl perfusion despite marked differences in intra-gastric acidity and acid delivery to the duodenum. In addition, no significant changes in serum pepsinogen levels or urinary pepsinogen excretion were observed after pentagastrin infusion. It is concluded that pentagastrin stimulates gastric pepsin secretion directly, but does not stimulate the release of pepsinogens into the systemic circulation.

Repeated high oral doses of omeprazole do not affect intrinsic factor secretion: proof of a selective mode of action.

The effect of 60 mg oral omeprazole daily for 9 days on intrinsic factor and gastric acid secretion was studied in eight healthy volunteers. Gastric secretion studies were performed during saline and 0.1 M HCl perfusion before and after omeprazole administration. During dosing with omeprazole, basal gastric acid output diminished by 94%, and pentagastrin-stimulated acid output by 97%. Basal, peak and steady-state stimulated intrinsic factor output were unaffected by omeprazole. It is concluded that high oral doses of omeprazole suppress gastric acid secretion to very low levels but they do not affect intrinsic factor secretion. Intrinsic factor secretion was also unaffected by profound hypochlorhydria.

Effect of high dose omeprazole on gastric pepsin secretion and serum pepsinogen levels in man.

To investigate the effect of omeprazole on serum and urinary pepsinogens and on gastric pepsin, 8 healthy male volunteers were studied before and after 9 days of treatment with omeprazole 60 mg/day p.o. Fasting serum samples and 24 h urine specimens were obtained, and gastric contents were aspirated at 15-min intervals, 4 prior to and 6 during pentagastrin 1.5 micrograms.kg-1.h-1 i.v. during intra-gastric perfusion with NaCl 0.9% and phenol red 3 mg.ml-1 as an inert recovery marker. Basal and pentagastrin-stimulated volume and acid secretion were significantly decreased. The basal and pentagastrin stimulated pepsin output remained unchanged but pepsin concentration in gastric secretion was increased. Administration of omeprazole resulted in a significant increase in the serum PGA and PGC levels. The 24-h urinary excretion of PGA increased, but that of PGC remained unchanged, and so did the renal clearances of creatinine and pepsinogen A. The renal clearance of pepsinogen C decreased. It was concluded that omeprazole did not affect gastric pepsin output, but, due to the decreased volume output, the concentration of pepsin in the gastric secretion was increased. Omeprazole increased the serum levels of pepsinogen A and C because more pepsinogen was released into the systemic circulation. This might be due to greater back-diffusion of pepsinogen from the gastric mucosa into the systemic circulation as a result of the higher pepsinogen concentration in gastric secretion.

Lack of effect of antacids on plasma concentrations of omeprazole given as enteric-coated granules.

Twelve male volunteers were studied after a single oral dose of 20 mg omeprazole given as enteric-coated granules with and without concomitant administration of 10 ml of a potent liquid antacid (buffering capacity 56.6 mmol 10 ml-1) under fasting conditions. No statistically significant differences were detected in median Cmax (0.41 approximately equal to 0.53 mumol l-1), the geometric mean AUC (0.80 approximately equal to 0.81 mumol l-1 h) or median tmax (1.25 h), with and without antacid.