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A Walan

Publications and source records attributed to A Walan.

At least 19 recordsLinked to original sources
PubMed1992

Safety experience from long-term treatment with omeprazole.

Omeprazole was administered for up to 6 years in 859 patients for 'prevention of relapse in patients with poorly responsive peptic ulcer or reflux oesophagitis'. The pattern of adverse events reported during long-term treatment was similar to the adverse-event profile in short-term treatment with omeprazole (n = 2,818), ranitidine (n = 1,572) and cimetidine (n = 891). Omeprazole had essentially the same adverse-event profile as the two H2-receptor antagonists. The adverse-event profile for omeprazole during long-term treatment did not differ from that seen during short-term treatment with either omeprazole or the H2-receptor antagonists. The rate of occurrence of any specific adverse event decreased with time, and no previously unidentified adverse event occurred with long-term omeprazole therapy. There were no serious adverse events that were considered to be causally related to omeprazole therapy. Thus, omeprazole has been shown to be well tolerated in both short- and long-term treatment.

Adolescent↗
PubMed1992

Phagocyte killing of Campylobacter jejuni in relation to oxidative activation.

When studying the interaction between Campylobacter jejuni and human neutrophils, we found that four different clinical isolates showed a great variability in this association. Also the ability to induce neutrophil production of oxidative metabolites, measured as chemiluminescence (CL), differed between the strains. Surprisingly, strain 1, which showed weak interaction with neutrophils and high resistance to killing, induced the highest CL response. All strains evoked an intracellular CL response, and three strains also gave rise to an extracellular response. This extracellular release of toxic oxygen species might contribute to the local tissue damage during infection. There was no clear correlation between association, killing and oxidative response. However, one strain that only evoked an intracellular generation of oxygen metabolites also showed the highest sensitivity to killing. Phagocytosis was increased up to ten times after opsonization with normal human serum. The intracellular CL production increased several fold, whereas the extracellular generation of oxygen species disappeared or was considerably decreased after opsonization. These results indicate that complement-opsonized C. jejuni are phagocytosed and readily attacked by the oxidative defence system within the phagosome.

Campylobacter jejuni↗
PubMed1990

Intravenous omeprazole: effect of a loading dose on 24-h intragastric pH.

To determine the effect of three times daily dosing with intravenous omeprazole on intragastric acidity, 24 h intragastric pH was measured continuously with a monocrystalline antimony electrode system in II patients with inactive duodenal ulceration during fasting conditions. After a baseline investigation, two different dosage regimens of intravenous omeprazole were compared in a double-blind crossover study, with regard to their ability to keep the pH greater than or equal to 4 for as long as possible. Success in the individual patient was defined as pH greater than or equal to 4 for at least 90% over the 24-h period. Two doses of omeprazole [40 mg t.d.s. (120 mg) and 80 mg + 40 mg + 40 mg (160 mg)] were compared. Omeprazole (120 mg) increased the median of individual median intragastric 24-h pH from 1.49 to 6.67. The pH was greater than or equal to 4 for greater than or equal to 90% of the 24 h in three of the 11 patients. With omeprazole, 160 mg (a loading dose of 80 mg), the median of individual median intragastric 24-h pH increased to 7.33. The pH was greater than or equal to 4 for greater than or equal to 90% of the 24 h in seven of the 11 patients. Median time to reach pH 4 was 39 min after 40 mg and 20 min after 80 mg omeprazole. An initial loading dose of 80 mg omeprazole seems preferable to 40 mg to achieve a fast and sustained increase in intragastric pH to above 4 in the fasting patient.

Adult↗
PubMed1990

Clinical development programme for omeprazole.

Omeprazole has been shown to provide more rapid symptom relief and to heal ulcers more quickly and reliably than H2-receptor antagonists in duodenal ulcer, gastric ulcer and reflux oesophagitis. In addition, omeprazole is well tolerated and has a good safety profile. Among the areas for clinical development with omeprazole are the maintenance treatment of duodenal ulcer, treatment of non-steroidal anti-inflammatory drugs (NSAID)-induced gastro-duodenal lesions, maintenance treatment of reflux oesophagitis and the treatment of bleeding ulcer. Two studies of patients with duodenal ulcer have shown that maintenance treatment with omeprazole, 10 mg once daily, was as effective as, or superior to, treatment with omeprazole, 20 mg given on Friday, Saturday and Sunday only, and markedly superior to placebo. In patients with gastric ulcer which developed during treatment with NSAIDs omeprazole, 20 mg once daily, resulted in a higher healing rate than ranitidine, 150 mg b.i.d., both at 4 and at 8 weeks. Reflux oesophagitis is often a persistent condition requiring continuous maintenance treatment. In a recent multicentre trial, a substantially higher proportion of patients remained in remission with omeprazole, 20 mg once daily, than with ranitidine, 150 mg b.i.d. Studies comparing omeprazole and ranitidine (administered intravenously) in patients with bleeding peptic ulcers have also demonstrated the superiority of omeprazole with regard to the control of bleeding and the avoidance of surgery. Further studies are currently underway in this and other related areas.

Drug Administration Schedule↗
PubMed1989

Effect of omeprazole and ranitidine on ulcer healing and relapse rates in patients with benign gastric ulcer.

Omeprazole blocks the action of H+,K+-ATPase in the gastric mucosa and thus inhibits the secretion of hydrochloric acid. We conducted a double-blind multicenter study (45 centers in 13 countries) of 602 patients with benign gastric or prepyloric ulcers to compare the effectiveness of omeprazole (20 mg once daily, 203 patients, or 40 mg once daily, 194 patients) and ranitidine, an H2-receptor antagonist (150 mg twice daily, 205 patients) in promoting ulcer healing and to evaluate the pattern of ulcer relapse during a six-month follow-up. Healing occurred at four weeks in 80 percent of the patients receiving 40 mg of omeprazole, 69 percent of those receiving 20 mg of omeprazole, 69 percent of those receiving ranitidine. At eight weeks, the corresponding figures were 96, 89, and 85 percent. A multivariate analysis of ulcer healing showed that at four weeks the ulcers of significantly more patients receiving omeprazole had healed as compared with patients receiving ranitidine (omeprazole, 40 mg, vs. ranitidine, P less than 0.0005; omeprazole, 20 mg, vs. ranitidine, P = 0.01). At eight weeks, the 40-mg dose of omeprazole was significantly more effective than ranitidine (P = 0.001) or the 20-mg dose of omeprazole (P = 0.03). Ulcer symptoms were relieved faster with omeprazole. In 68 patients receiving concurrent nonsteroidal antiinflammatory drugs, the healing rates at four weeks were 81 percent in the group receiving 40 mg of omeprazole, 61 percent in the group receiving 20 mg, and 32 percent in the group receiving ranitidine; at eight weeks, the corresponding figures were 95, 82, and 53 percent. During the six-month follow-up period (without treatment), significantly more patients in the omeprazole groups were free of symptoms and ulcers than in the ranitidine group. We conclude that in the dose used, omeprazole is superior to ranitidine in the treatment of benign gastric ulcers.

Adult↗
PubMed1989

The clinical utility and safety of omeprazole.

More than 13,000 individuals with duodenal ulcer, gastric ulcer or reflux oesophagitis have now taken part in controlled clinical studies with omeprazole. In duodenal ulcer, treatment with omeprazole, 20 mg daily or more, has resulted in healing rates of 58%-83% after 2 weeks and 84%-100% after 4 weeks. In all of these studies, healing rates with omeprazole have been higher than with either ranitidine or cimetidine. Omeprazole has also had a more pronounced effect on ulcer symptoms. Although the first comparative study on gastric ulcer showed only marginally higher healing rates with omeprazole than with an H2-receptor antagonist, later studies have all shown significantly higher healing rates with omeprazole. Healing rates of the order of 70% or more have been achieved within 4 weeks, rising to over 88% after 8 weeks. Symptom relief has also been faster with omeprazole. In both duodenal ulcer and gastric ulcer, almost every patient can be healed, including those resistant to treatment with H2-receptor antagonists. The influence of omeprazole on the healing of reflux oesophagitis has been investigated in several studies comparing omeprazole with ranitidine. Healing rates have been markedly higher with omeprazole in all studies. These unprecedentedly high healing rates (81%-96% at 8 weeks) have also been accompanied by rapid symptom relief. In clinical studies with omeprazole, no clinically significant side-effects which could be ascribed to treatment, nor indeed any serious side-effects, have been observed, neither have any clinically significant changes in laboratory variables been seen. Furthermore, no pathological changes of the gastric mucosa have been detected after long-term treatment with omeprazole.

Duodenal Ulcer↗
PubMed1989

Clinical experience with omeprazole: assessment of efficacy and safety.

After pharmacological studies showed that omeprazole had a marked and longlasting inhibitory effect on acid secretion, many clinical studies commenced. In duodenal ulcer, omeprazole in doses of 20-40 mg/day has been shown to give significantly higher healing rates than ranitidine or cimetidine. Omeprazole has given healing rates of 58-83% after treatment for 2 weeks and 84-100% after 4 weeks. A more pronounced effect on the relief of ulcer symptoms has also been observed. Similarly, in gastric ulcer several studies have been performed, all of which have shown higher healing rates with omeprazole both at 4 and 8 weeks. Symptom relief has also been faster and more pronounced with omeprazole. In patients with reflux oesophagitis, omeprazole has been shown to decrease the time with an acid milieu in the oesophagus. In several studies omeprazole in doses of 20-60 mg/day has consistently given healing rates approximately twice those of ranitidine in doses of 150 mg twice daily at 4 and 8 weeks. In addition, there has been a rapid improvement in the symptoms of oesophagitis. Omeprazole has been found to be very effective in the Zollinger-Ellison syndrome, with a prompt effect on acid secretion and symptoms. The accumulated experience exceeds 300 patients. More than 13,000 patients have taken part in the clinical investigations with omeprazole. Neither serious side-effects nor other side-effects which could be ascribed to treatment have been observed. There have not been any clinically significant changes in laboratory variables apart from those which are caused by the decrease in acid secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Duodenal Ulcer↗
PubMed1989

Clinical utility and safety of omeprazole.

Omeprazole inhibits H+,K+-ATPase, the enzyme responsible for the exchange of H+ and K+ in the final step in the acid secretory process within the parietal cell. It has been shown to produce a marked and long-lasting inhibition of acid secretion with a decrease in 24-hour intragastric acidity after repeated daily dosing. Omeprazole has been shown to give significantly higher healing rates than ranitidine or cimetidine in patients with duodenal ulcer and gastric ulcer. Similarly, a more pronounced effect on ulcer symptoms has been observed. In patients with reflux esophagitis, omeprazole has been shown to decrease the time with an acid milieu in the esophagus. Omeprazole has consistently given about twice as high healing rates and faster decrease in symptoms than with ranitidine. In patients with Zollinger-Ellison syndrome, omeprazole has been found to have a rapid and long-lasting effect on acid secretion and acid-induced symptoms.

Animals↗
PubMed1988

Omeprazole.

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Clinical Trials as Topic↗
PubMed1988

Surface charge and hydrophobicity of Campylobacter jejuni strains in relation to adhesion to epithelial HT-29 cells.

Hydrophobicity and surface charge of clinical isolates of Campylobacter jejuni strains were investigated by aqueous two-phase partitioning (one-step and counter-current distribution), ion exchange chromatography and hydrophobic interaction chromatography. There was a good correlation between the different physico-chemical methods reflecting the same bacterial property. All strains were negatively charged and exposed a hydrophobic surface, but to a varying extent. Bacteria with a high negative surface charge and a weak hydrophobic surface adhered better to human intestinal HT-29 cells than strains with less charge and a more hydrophobic surface. Highest adhesion was shown by a strain differing from all the others in charge properties. It was also found that the tendency to aggregate was higher among the strains showing the greatest degree of adherence.

Bacterial Adhesion↗
PubMed1988

Are endoscopic and/or histologic findings in gastroduodenal mucosa a predictor of clinical outcome in peptic ulcer disease? A 1-year follow-up study after initial healing with either cimetidine or medium-dose antacid.

Patients with duodenal ulcer (DU; n = 79) or prepyloric ulcer (PPU; n = 39) received cimetidine, 400 mg twice daily, or Novaluzid, 10 ml four times daily (acid-neutralizing capacity, 340 mmol/day), in a multicentre, randomized, double-blind trial. Ulcer healing was almost identical with the two treatments at 4, 6, and 12 weeks in the DU group. Cimetidine was significantly more effective than antacids in alleviating symptoms in PPU disease, with no significant difference in ulcer healing. In the PPU group the symptomatic improvement was inferior irrespective of treatment, and there was a significantly lower healing rate at 4 weeks (p less than 0.05) than in the DU group. The relapse rate over a 1-year follow-up period with no therapy did not differ between the two treatment groups or between the two ulcer groups. No factors in history of disease or endoscopic or histologic variables were of predictive value with regard to delayed healing. The macroscopic appearance of the duodenal and antral mucosae improved significantly when ulcers had healed. In the subgroup of about 50% DU patients who experienced a relapse during the 1-year follow-up period, the histologic scoring of duodenitis remained basically unchanged, contrary to the significant improvement seen in the non-relapsing subgroup. The microscopic changes of the antral mucosa from the time of inclusion to healing seen in the PPU patients were of no predictive value with regard to relapse rate.

Adult↗
PubMed1987

Maintenance treatment with cimetidine in peptic ulcer disease for up to 4 years.

A multinational maintenance trial was conducted in 1842 peptic ulcer patients to investigate the efficacy and safety of continuous cimetidine maintenance therapy for up to 4 years. Patients with healed ulcers entered maintenance treatment with a 400-mg bedtime dose of cimetidine. Symptomatic ulcer relapse occurred in 17.2% of patients during the 1st year of treatment, in 9.6% during the 2nd year, and in 8.8% during the 3rd year. In addition to life-table analysis, the monthly prevalence of active ulceration over the 3-year period was examined. The average monthly prevalence rates were 2.1%, 1.8%, and 1.5% for the three successive yearly periods of continued cimetidine treatment. The adverse reactions observed in this study were not different from those previously reported with cimetidine. Moreover, there was a progressive decrease in the incidence of adverse events over the 4 years, thus establishing the long-term safety of continuous cimetidine treatment. It is concluded from this study that cimetidine maintenance treatment not only continues to be effective and safe beyond 1 year but also may reduce the risk of relapse over time.

Adult↗
PubMed1987

The effect of 20 Mg omeprazole daily on serum gastrin, 24-h intragastric acidity, and bile acid concentration in duodenal ulcer patients.

Serum gastrin, 24-h intragastric acidity, and bile acid concentrations were measured during physiologic conditions in 10 patients with duodenal ulcer disease. Omeprazole, 20 mg daily, for 8 days reduced acidity by greater than or equal to 99% in six patients and by 47-54% in four patients. The degree of acid reduction was related to the area under the plasma omeprazole concentration time curve (AUC). Serum gastrin levels were not significantly increased by omeprazole. Intragastric bile acid concentrations were increased by omeprazole, but this seems to be of little importance for the healing of duodenal ulcers.

Adult↗
PubMed1987

Modified sham feeding test after parietal cell vagotomy for juxtapyloric ulcer disease in patients with and without recurrent ulcers.

The mean of individual coefficients of variation of acid output after modified sham feeding was 39% in 22 patients operated on with parietal cell vagotomy. The reproducibility of the interpretation of the sham feeding test as 'positive' or 'negative' was good. An intragastric infusion of a marker to correct for pyloric loss did not increase the accuracy of the test. The prognostic value of the qualitative estimation of the sham feeding test 2 months after operation to predict recurrent ulcer after parietal cell vagotomy was poor in 39 patients studied prospectively over 3 years. With the criterion sham feeding minus basal acid output over 1.0 mmol/30 min as a positive test, 63% of patients with a positive and 24% with a negative test later had recurrent ulcers. The consistency of the interpretation as either positive or negative was low in annual tests during the 3 years of follow-up study. After parietal cell vagotomy the sham-feeding-stimulated acid output was higher in patients with duodenal than in those with prepyloric recurrent ulcers and also in those without recurrences. This indicates that the amount of vagal innervation left after parietal cell vagotomy is of special importance in the occurrence of duodenal ulcer relapse.

Duodenal Ulcer↗
PubMed1986

Pharmacokinetics of [14C]omeprazole in patients with impaired renal function.

Pharmacokinetics of [14C]omeprazole and its metabolites were studied after single intravenous and oral doses of 20 and 40 mg, respectively, to 12 patients with chronic renal insufficiency. Blood samples for determination of total radioactivity, omeprazole, OH-omeprazole, sulfone, and sulfide were taken for 24 hours. Urine was collected over 96 hours for determination of total radioactivity and during the first 24 hours for additional assay of omeprazole and metabolites. The mean systemic availability was 70%. The mean plasma t1/2 of omeprazole was 0.6 hours. Unchanged omeprazole was not measurable in urine. Derived pharmacokinetic constants of intact omeprazole were within the range of those reported in healthy individuals. The accumulated 24-hour excretion of radioactive metabolites was related significantly to creatinine clearance. The cumulative excretion of total radioactivity in urine over 96 hours in percent of given dose varied between 25% and 83%.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1986

A comparison of two different doses of omeprazole versus ranitidine in treatment of duodenal ulcers.

In a study involving three centers, 105 patients with duodenal ulcer proven by endoscopy were randomly assigned to treatment with either the H+, K+, ATPase inhibitor omeprazole (20 mg or 40 mg taken as a single morning dose), or ranitidine (150 mg morning and night). It was a double-blind study using a double-dummy technique. Clinical assessment and laboratory investigations were carried out at 2, 4, and 8 weeks; endoscopy was done at 2 weeks, and if not healed, at 4 and 8 weeks. The patients in the three treatment groups were well matched. Significantly more patients treated with omeprazole healed compared with ranitidine at 2 weeks (p = 0.007) and at 4 weeks (p = 0.007), but there was no statistically significant difference between the two omeprazole groups. Pain was of similar severity at the start in all groups, but patients treated with omeprazole had fewer days with pain (median values being omeprazole 20 mg: 2 days; omeprazole 40 mg: 1 day; ranitidine: 7 days). The difference between the combined omeprazole groups and ranitidine was significant (p less than 0.02). There was also a tendency towards less severe daytime pain on omeprazole during the first week. The difference was statistically significant between omeprazole (40 mg) and ranitidine for days 2-7 (p less than 0.01). No change in laboratory screen attributable to drug treatment occurred. After healing, 79 patients entered a 6-month follow-up study with endoscopy at 3 and 6 months or whenever symptoms occurred. After 6 months relapses occurred in 14/24, 19/23, and 15/25 after 20 mg omeprazole, 40 mg omeprazole, and ranitidine, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Duodenal, prepyloric, and combined duodenal/prepyloric ulcer disease: three distinct entities of juxtapyloric ulcer disease?

One hundred and seven patients with long-standing and severe chronic juxtapyloric ulcer disease were classified in accordance with the location of the present ulcer and previous ulcers into 1) pure duodenal (DU), 2) pure prepyloric (PU), and 3) combined duodenal/prepyloric (DU/PU) or prepyloric/duodenal (PU/DU) ulcer disease. In a prospective follow-up study over a 3-year period after parietal cell vagotomy (n = 39) or during continuous treatment with cimetidine (n = 62) patients with DU had recurrent ulcers located exclusively to the duodenal bulb and patients with PU, exclusively to the prepyloric region. In patients with DU/PU and PU/DU recurrent ulcers occurred on either side of the pylorus. Basal acid and basal pepsin outputs were higher and bile acid in gastric juice was lower in patients with DU than in those with PU. There are a considerable number of patients who possess features of both duodenal and prepyloric ulcer disease. The clinical outcome of both continuous cimetidine treatment and vagotomy in these patients (DU/PU and PU/DU) was less satisfactory than in pure DU. All patients presenting with active DU should therefore be investigated for evidence of previous prepyloric ulceration.

Bile Acids and Salts↗