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

Efficacy and safety of proton pump inhibitors and H2 receptor antagonists in the initial non‑eradication treatment of duodenal ulcer: A network meta‑analysis

The present network meta-analysis aimed to enhance the corresponding evidence with respect to the efficacy and safety of pharmaceuticals treatments. Frequentist network meta-analysis was used. Medical literature up to November 2022 was searched for randomized clinical trials assessing the efficacy and safety of these pharmaceuticals, either compared with each other or compared with placebo. With the exception of ranitidine (300 mg four times daily) and vonoprazan (20 mg once daily) having lower safety than placebo, the efficacy and safety of the remaining treatments were superior to placebo. Cimetidine (400 mg four times daily) and pantoprazole (40 mg once daily) were ranked first in terms of efficacy. The frequentist network meta-analysis shows that for cimetidine (except 400 mg once daily), famotidine, rabeprazole, ilaprazole, lansoprazole (except 7.5 mg once daily) and omeprazole (except 10 mg once daily or 30 mg once daily), the efficacy comparison between the different doses of each of the aforementioned pharmaceuticals did not indicate statistically significant differences. In conclusion, pantoprazole (40 mg once daily) was the best choice for the initial non-eradication treatment of patients with duodenal ulcer, and cimetidine (400 mg twice daily), omeprazole (20 mg once daily), lansoprazole (15 mg once daily), ilaprazole (5 mg once daily) and rabeprazole (10 mg once daily) could be used as the first choice. If the aforementioned pharmaceuticals cannot be prescribed, famotidine (40 mg twice daily) is recommended.

Standard-Dose Proton Pump Inhibitors in the Initial Non-eradication Treatment of Duodenal Ulcer: Systematic Review, Network Meta-Analysis, and Cost-Effectiveness Analysis

Background: Short-term use of standard-dose proton pump inhibitors (PPIs) is the first-line initial non-eradication treatment for duodenal ulcer (DU), but the choice on individual PPI drug is still controversial. The purpose of this study is to compare the efficacy, safety, and cost-effectiveness of standard-dose PPI medications in the initial non-eradication treatment of DU. Methods: We searched PubMed, Embase, Cochrane Library, Clinicaltrials.gov, China National Knowledge Infrastructure, VIP database, and the Wanfang database from their earliest records to September 2017. Randomized controlled trials (RCTs) evaluating omeprazole (20 mg/day), pantoprazole (40 mg/day), lansoprazole (30 mg/day), rabeprazole (20 mg/day), ilaprazole (10 mg/day), ranitidine (300 mg/day), famotidine (40 mg/day), or placebo for DU were included. The outcomes were 4-week ulcer healing rate (4-UHR) and the incidence of adverse events (AEs). A network meta-analysis (NMA) using a Bayesian random effects model was conducted, and a cost-effectiveness analysis using a decision tree was performed from the payer's perspective over 1 year. Results: A total of 62 RCTs involving 10,339 participants (eight interventions) were included. The NMA showed that all the PPIs significantly increased the 4-UHR compared to H2 receptor antagonists (H2RA) and placebo, while there was no significant difference for 4-UHR among PPIs. As to the incidence of AEs, no significant difference was observed among PPIs, H2RA, and placebo during 4-week follow-up. Based on the costs of both PPIs and management of AEs in China, the incremental cost-effectiveness ratio per quality-adjusted life year (in US dollars) for pantoprazole, lansoprazole, rabeprazole, and ilaprazole compared to omeprazole corresponded to $5134.67, $17801.67, $25488.31, and $44572.22, respectively. Conclusion: Although the efficacy and tolerance of different PPIs are similar in the initial non-eradication treatment of DU, pantoprazole (40 mg/day) seems to be the most cost-effective option in China.

The Success of Histamine-2 Receptor Antagonists

The lives of both patients and doctors have been revolutionized since the development of histamine-2 receptor antagonists. Their development has introduced, for the first time, a rapid, reliable, and save means of healing both duodenal and gastric ulceration. The continuous administration of these agents has additionally been shown to reduce ulcer relapse and subsequent complications. In addition, they offer some protection from the development of nonsteroidal anti-inflammatory drug-induced damage. The symptomatic relief of reflux together with healing of oesophagitis has been of further benefit. The drugs in this group have become one of the most widely used ethical pharmaceuticals in the world, with ranitidine (Zantac) as the biggest-selling drug in the world for the last few years. Their success can be attributed to their simplicity of use, safety, and above all, their efficacy. Their current role in gastroenterologic practice, in the face of new developments such as Helicobacter eradication and the development of proton pump inhibitors, will be discussed.

What is an intractable duodenal ulcer and how should it be managed?

An intractable duodenal ulcer is an ulcer that has not healed after 8 weeks of full-dose treatment with a modern anti-ulcer drug. Such ulcers are relatively rare--perhaps five in 100 patients will have intractable duodenal ulceration. The differential diagnosis includes non-compliance as a cause of continuing ulceration, hypersecretion of gastric acid or other rare causes of ulcers in the duodenum. Investigations should include biopsy of the continuing ulceration at endoscopy, measurement of fasting plasma gastrin and routine haematology and biochemistry profiles. An intractable duodenal ulcer can be treated either by using a powerful antisecretory regimen (high doses of ranitidine or famotidine or a conventional dose of omeprazole), by changing to tripotassium dicitrato bismuthate or, in exceptional circumstances, by extremely careful surgical intervention.

Future prospects for proton pump inhibitors

Future prospects for proton pump inhibitors depend on their efficacy and safety relative to H2-receptor antagonists, the therapeutic standard for acid peptic disorders. As safety concerns diminish, efficacy considerations become more important as these may pertain to cost effectiveness. Comparative, controlled trials show that omeprazole and lansoprazole are somewhat more effective than H2-blockers in healing duodenal and gastric ulcers, providing faster relief of symptoms. Relapse after cessation of therapy is similar between the two classes. The proton pump inhibitors are substantially more effective in healing lesions and relieving symptoms in patients with reflux oesophagitis, and are particularly effective in cases that have failed to heal after 12 weeks of treatment with H2-blockers. Relapse rates of oesophagitis are significantly less with prolonged treatment with omeprazole than ranitidine. A proton pump inhibitor combined with amoxicillin is less effective than triple therapy with antibiotics and bismuth in eradicating Helicobacter pylori infections, but is more convenient and associated with fewer side-effects. Efficacy might be improved by more optimal dosing regimens. Prospects for reversible proton pump inhibitors depend on the balance between their theoretical advantages and their acid inhibition profile which, at present, closely resembles that of H2-blockers.

Omeprazole treatment of Korean patients: effects on gastric pH and gastrin release in relation to CYP2C19 geno- and phenotypes

This study aimed to investigate the effect of omeprazole on intragastric pH and gastrin release as well as the plasma concentration of omeprazole in relation to CYP2C19 genotypes after repeated doses in Korean patients. Twenty-six Korean patients with acid related disease were genotyped for CYP2C19 by allele specific PCR (wt/wt, CYP2C19*1/*1; wt/mut, CYP2C19*1/*2 or *1/*3; mut/mut, CYP2C19*2/*2, *2/*3 or *3/*3). Intragastric pH was monitored during 24 hr, and the plasma concentrations of omeprazole, hydroxyomeprazole, omeprazole sulfone and meal-stimulated gastrin were measured during 4 hr before and after 8 consecutive daily doses of 20 mg omeprazole. Unexpectedly the AUCs of omeprazole in the three genotypes were similarly high on Day 8. The mean 24 hr pH increased significantly in all three genotypes (paired t-test; P<0.0001), and the AUCs (4 hr) of gastrin in all patients increased markedly from 129+/-73 to 298+/-142 pMhr (P<0.0001). However, there was no statistically significant difference between the three genotypes in the mean pH and gastrin AUCs on Day 8. After 8 consecutive doses of 20 mg omeprazole, the gastric pH and the plasma gastrin were increased significantly in all three CYP2C19 genotypes, which were confirmed by high plasma concentrations of omeprazole in all three genotype groups. We suggest that the reason why the wt/wt had high concentrations of omeprazole similar to those in the other two genotype groups is that some of them were old with low CYP2C19 activity. In these patients omeprazole accumulated from the first to the eighth dose similar to that in the heterozygotes.

A rational approach to uninvestigated dyspepsia in primary care: review of the literature

In this paper the rationale and limitations of the four most important approach strategies to dyspepsia in primary care (empiric treatment, prompt endoscopy, "test-and-scope", and "test-and-treat") are analysed. It is concluded that in the absence of alarm symptoms, a "test-and-treat" approach is currently the most rational approach provided that three conditions are met: (1) a highly accurate test should be used, (2) the prevalence of Helicobacter pylori in the population should not be too low, and (3) an effective anti-H pylori regimen should be prescribed taking sufficient time to instruct and motivate the patient.

Reappraisal of non-invasive management strategies for uninvestigated dyspepsia: a cost-minimization analysis

BACKGROUND

The benefits of the Helicobacter pylori test-and-treat strategy are attributable largely to the cure of peptic ulcer disease while limiting the use of endoscopy.

AIM

To reappraise the test-and-treat strategy and empirical proton pump inhibitor therapy for the management of uninvestigated dyspepsia in the light of the decreasing prevalence of H. pylori infection, peptic ulcer disease and peptic ulcer disease attributable to H. pylori.

METHODS

Using a decision analytical model, we estimated the cost per patient with uninvestigated dyspepsia managed with the test-and-treat strategy ($25/test; H.pylori treatment, $200) or proton pump inhibitor ($90/month). Endoscopy ($550) guided therapy for persistent or recurrent symptoms.

RESULTS

In the base case (25%H. pylori prevalence, 20% likelihood of peptic ulcer disease, 75% of ulcers due to H.pylori), the cost per patient is $545 with the test-and-treat strategy and $529 with proton pump inhibitor, and both strategies yield similar clinical outcomes at 1 year. H. pylori prevalence, the likelihood of peptic ulcer disease and the proportion of ulcers due to H.pylori are important determinants of the least costly strategy. At an H. pylori prevalence below 20%, proton pump inhibitor is consistently less costly than the test-and-treat strategy.

CONCLUSIONS

As the H. pylori prevalence, the likelihood of peptic ulcer disease and the proportion of ulcers due to H. pylori decrease, empirical proton pump inhibitor becomes less costly than the test-and-treat strategy for the management of uninvestigated dyspepsia. Given the modest cost differential between the strategies, the test-and-treat strategy may be favoured if patients without peptic ulcer disease derive long-term benefit from H.pylori eradication.

Pantoprazole versus ranitidine in the treatment of duodenal ulcer: a multicenter study in Brazil

OBJECTIVE

The aim of this study was to compare the effectiveness and tolerance of pantoprazole versus ranitidine in the treatment of duodenal ulcers in the Brazilian population.

METHODS

A total of 222 patients with active duodenal ulcers (DU) were randomly allocated to a double dummy blind treatment, either with ranitidine (RAN) 300 mg (111, aged from 20-68 yr old, 56 female) or with pantoprazole (PANT) 40 mg (111 patients, 18-70 yr old, 45 female). After a 2-wk course of treatment, each patient was clinically and endoscopically assessed for ulcer healing. Failure to heal required a further 2-wk course of treatment and a new evaluation thereafter.

RESULTS

In all, 77 of the 103 patients in the PANT group (74.8%) and 42 of the 94 patients in the RAN group (44.7%) who completed the study had ulcer healing after one 2-wk treatment course, and an additional 23 in the PANT group (22.3%) and 28 in the RAN group (29.8%) after the second 2-wk treatment course, totaling 100 (97.1%) and 70 (74.5%), respectively. Therapeutic gain in favor of pantoprazole was significant both at the end of the first and the second 2-wk treatment course (p<0.001). At 2 wk, symptoms remission was significantly higher in the PANT group (97.6%) than with the RAN group (77.5%) (p<0.001). The Intention-to-treat analysis showed results statistically similar to those observed in the per-protocol analysis. Minor adverse events were reported by four patients in the PANT group and three in the RAN group. No relevant laboratory abnormalities were seen. No patient withdrew from the study due to adverse events.

CONCLUSIONS

Our results show that pantoprazole is more effective than ranitidine in the treatment of duodenal ulcer providing faster ulcer healing in most patients (97.1%), in 4 wk. Adverse events were rare and were similar in both groups, and had no influence on the therapeutic outcome.

Double-blind comparison of lansoprazole 15 mg, lansoprazole 30 mg and placebo as maintenance therapy in patients with healed duodenal ulcers resistant to H2-receptor antagonists

BACKGROUND

Maintenance antisecretory therapy is often used to prevent duodenal ulcer recurrence and control symptoms. This study compared the efficacy and safety of lansoprazole 15 mg and 30 mg daily with placebo in preventing ulcer recurrence in patients with a recent history of duodenal ulcer disease.

METHODS

Fifty-six patients were treated with either lansoprazole 15 mg, 30 mg or placebo o.m.

RESULTS

Within 1 month of study initiation, 27% (four out of 15) of placebo-treated patients experienced ulcer recurrence as compared to 13% (two out of 15) and 6% (one out of 18) of lansoprazole 15 mg and 30 mg treated patients, respectively. Median time to first ulcer recurrence was > 12 months in lansoprazole patients. At Month 12, significantly (P < 0.001) more lansoprazole 15 mg patients (70%) and lansoprazole 30 mg patients (85%) remained healed. Eighty-two per cent of lansoprazole 15 mg and 76% of lansoprazole 30 mg patients remained asymptomatic during the entire study period. All placebo patients became symptomatic, experienced ulcer recurrence, or withdrew from the study by month six. The incidence of adverse events was comparable among the three treatment groups.

CONCLUSIONS

Lansoprazole safely and effectively reduces duodenal ulcer recurrence and ulcer-related symptoms.

Comparison of rabeprazole 20 mg versus omeprazole 20 mg in the treatment of active duodenal ulcer: a European multicentre study

BACKGROUND

Rabeprazole sodium is the newest member of a class of substituted benzimidazole molecules known as proton pump inhibitors. Other proton pump inhibitors have been shown to be effective in healing active duodenal ulcer.

METHOD

This randomized, double-blind, multicentre study, conducted at 25 European sites, compared the efficacy and tolerability of rabeprazole and omeprazole in patients with active duodenal ulcers. One hundred and two patients with active duodenal ulcer received rabeprazole 20 mg and 103 patients omeprazole 20 mg once daily for 2 or 4 weeks, with ulcer healing monitored by endoscopy.

RESULTS

After 2 weeks, complete ulcer healing was documented in 69% of patients given rabeprazole 20 mg and in 62% of patients given omeprazole 20 mg (N.S.). After 4 weeks, healing rates were 98% in the rabeprazole group and 93% in the omeprazole group (P = 0.083). Rabeprazole-treated patients had significantly greater improvement in daytime pain symptom relief than those treated with omeprazole at the conclusion of the study (P = 0.038). Both drugs were well tolerated over the 4-week treatment period. Mean changes from baseline to end-point in fasting serum gastrin were significantly greater in the rabeprazole group, but at end-point mean values were well within normal limits for both groups. No clinically meaningful changes or other between-group differences were observed in laboratory parameters.

CONCLUSION

In this study, rabeprazole produced healing rates equivalent to omeprazole at weeks 2 and 4, and provided significantly greater improvement in daytime pain. Both treatments were well tolerated.

Biochemical and pharmacological characteristics of 3-butyryl-8-methoxy-4-[(2-thiophenyl)amino]quinoline, a new proton-pump inhibitor, in rabbit gastric microsomes and in rats

We have investigated the properties of the newly synthesized proton-pump inhibitor, 3-butyryl-8-methoxy-4-[(2-thiophenyl)amino]quinoline (YJA20379-6), on gastric mucosal proton-pump (H+/K+-ATPase) activity, gastric acid secretion and gastroduodenal lesions in experimental rats. YJA20379-6 markedly inhibited H+/K+-ATPase activity in rabbit isolated gastric mucosal microsomes, confirming its classification as a proton-pump inhibitor. The inhibitory efficacy of YJA20379-6 on the proton pump was approximately 14-times higher than that of omeprazole at pH 7.4. YJA20379-6 given intraduodenally had a potent inhibitory effect on gastric secretion in pylorus-ligated rats (ED50 22.9 mg kg(-1)) but was less active than omeprazole. Pretreatment of rats with YJA20379-6 dose-dependently protected the gastric mucosa from damage induced by water-immersion stress, indomethacin and absolute ethanol, and the duodenal mucosa from damage induced by mepirizole. Repeated administration of YJA20379-6 also dose-dependently accelerated the spontaneous healing of acetic acid-induced gastric ulcers. These results suggest that YJA20379-6 has potent anti-secretory and anti-ulcer effects which are exerted by suppression of H+/K+-ATPase activity in gastric parietal cells. YJA20379-6 might be useful for the clinical treatment of peptic ulcer diseases.

Determination of omeprazole in pharmaceuticals by derivative spectroscopy

A new derivative UV spectroscopic method was developed for the analysis of omeprazole in borate buffer (pH 10.0; 0.1 M). Second derivative spectra were generated between 200-400 nm at N = 9, delta gamma = 31.5. The linearity range for values obtained from second derivative spectra was 0.2-40.0 micrograms ml-1. The developed method was applied to five different commercial preparations of hard gelatin capsules containing enteric coated granules. The relative standard deviations were found to be 2.24% (brand A), 1.87% (brand B), 2.80% (brand C), 4.55% (brand D) and 1.09% (brand E). The data were compared with ones obtained from the polarographic method given in the literature and no difference was found statistically.

A comparison of three doses of lansoprazole (15, 30 and 60 mg) and placebo in the treatment of duodenal ulcer. The Lansoprazole Study Group

BACKGROUND

Lansoprazole is a new proton pump inhibitor for the treatment of peptic ulcer disease.

METHODS

A double-blind, multicentre study was undertaken in 296 patients with endoscopically proven duodenal ulcer to compare the efficacy and safety of lansoprazole 15, 30 or 60 mg with placebo. Ulcer healing was documented by endoscopy at 2 and 4 weeks; patients whose ulcers healed after 4 weeks were followed for up to 6 months post-treatment.

RESULTS

Four-week healing rates of 89.4%, 91.7% and 89.9% were obtained with lansoprazole 15, 30 and 60 mg, respectively, compared with 46.1% on placebo (P < 0.001). All three doses of lansoprazole produced rapid symptom relief, although patients taking 60 mg lansoprazole required fewer antacids than did those taking 15 mg. At 6 months, the percentages of patients healed were 45.3%, 40.0% and 38.4% in the lansoprazole 15, 30 and 60 mg dosage groups, respectively, and 25.3% for the placebo group. No significant adverse events were documented during the period of this trial.

CONCLUSION

Lansoprazole is an effective and safe treatment for duodenal ulcer and the 15 mg dose is as effective as 30 or 60 mg.

Effect of omeprazole and feeding on plasma gastrin in patients with achlorhydria

BACKGROUND

The mechanism of hypergastrinaemia during omeprazole therapy is unclear, but is generally assumed to be entirely a consequence of acid suppression. However, direct stimulation of G cells by omeprazole could also be a factor. In order to further investigate the mechanism of omeprazole-induced hypergastrinaemia, we have studied the effects of the drug on plasma gastrin in patients with achlorhydria, in whom altered acid secretion cannot play a role.

METHODS

We estimated fasting and peptone meal stimulated plasma gastrin in nine patients (seven female) with pernicious anaemia and achlorhydria, before and on the final day of 4 weeks' dosing with omeprazole 40 mg daily.

RESULTS

Despite the high fasting gastrin concentrations, the peptone meal produced a further elevation in plasma gastrin concentrations, median gastrin concentrations rising from 1500 ng/L (range 225-10,875 ng/L) to 3750 ng/L (range 585-15,600 ng/L) post-prandially (P = 0.004). The median post-prandial rise in plasma gastrin at this initial visit was 44% (3-260%), and the median time interval until plasma gastrin concentrations returned to fasting levels was 120 min (range 10- > 150 min). There was a significant negative correlation between fasting plasma gastrin concentrations and the percentage increase in plasma gastrin levels in response to meal stimulation (Spearman correlation coefficient -0.79, P = 0.01). Fasting plasma gastrin concentrations were similar pre-omeprazole (median 1950 ng/L, range 240-16,500 ng/L) and post-omeprazole (median 1500 ng/L, range 315-7650 ng/L). Likewise, peak plasma gastrin concentrations were also similar pre-omeprazole (median 2700 ng/L, range 585-16,500 ng/L) and post omeprazole (median 3420 ng/L, range 720-11,250 ng/L).

CONCLUSIONS

(i) The hyperplastic G cell mass in patients with pernicious anaemia can be further stimulated by a peptone meal, which causes a prolonged rise in plasma gastrin concentrations. (ii) There is a negative correlation between fasting plasma gastrin concentrations and the percentage increase in plasma gastrin levels in response to meal stimulation. (iii) Omeprazole has no effect on plasma gastrin in achlorhydric patients, which is consistent with its hypergastrinaemic effect being entirely secondary to acid inhibition.

Comparison of pantoprazole versus omeprazole in the treatment of acute duodenal ulceration--a multicentre study

METHODS

In this randomized, double-blind, multicentre study, the proton pump inhibitors pantoprazole and omeprazole were compared in patients with active duodenal ulcers. Two hundred and seventy-six protocol-correct patients received either pantoprazole 40 mg (n = 185) or omeprazole 20 mg (n = 91), once daily for 2 or 4 weeks, depending on the progress of ulcer healing.

RESULTS

Rates of complete ulcer healing after 2 weeks were 71% in patients given pantoprazole and 74% in patients given omeprazole. After 4 weeks the figures were 96% and 91%, respectively. These differences were not significant. There was no significant difference in ulcer pain prior to treatment, and 85% of the pantoprazole group and 86% on omeprazole were pain-free after 2 weeks (not significant). The time until complete pain relief with pantoprazole or omeprazole, based on data from diary cards, was not significantly different (P > 0.05, Uleman's U-test). Both treatments were equally well tolerated. Changes in routine laboratory parameters were minimal in both groups.

CONCLUSION

Pantoprazole was shown to be a highly-effective and well-tolerated treatment for acute duodenal ulcer. Pantoprazole 40 mg and omeprazole 20 mg were equally effective with respect to ulcer healing and pain relief, and have similar adverse event profiles.

Lansoprazole versus omeprazole in active duodenal ulcer. A double-blind, randomized, comparative study

BACKGROUND

Lansoprazole is a new substituted benzimidazole that inhibits the H+,K(+)-adenosine triphosphatase in the parietal cell and, like the first developed proton pump inhibitor omeprazole, gives a strong inhibition of gastric acid output.

METHODS

In this double-blind randomized comparative study patients with active duodenal ulcers were treated with either 30 mg lansoprazole or 20 mg omeprazole in the morning. All demographic data in the two treatment groups were comparable.

RESULTS

A total of 279 patients entered the study. There was no difference in healing rates between the groups either after 2 weeks (86.2% for lansoprazole and 82.1% for omeprazole) or after 4 weeks (97.1% and 96.2%). No patient ceased treatment owing to side effects.

CONCLUSIONS

Both lansoprazole and omeprazole generate very high healing rates and good symptom relief in active duodenal ulcer. Side effects are few and mild.

Pantoprazole versus omeprazole in the treatment of acute gastric ulcers

BACKGROUND

Pantoprazole is a new substituted benzimidazole which is a potent inhibitor of gastric acid secretion by its action upon H+,K(+)-ATPase.

METHODS

The proton pump inhibitors pantoprazole and omeprazole were compared in a randomized, double-blind study in 219 patients with benign gastric ulcers. Patients received either pantoprazole 40 mg (n = 146) or omeprazole 20 mg (n = 73), once daily before breakfast for 4 weeks. Treatment was extended for a further 4 weeks if the ulcer had not healed.

RESULTS

After 4 weeks, complete ulcer healing was seen in 88% of protocol-correct patients given pantoprazole and in 77% given omeprazole (between-group difference P < 0.05). At 8 weeks, the corresponding values were 97% and 96% (not significant). In the comparative intention-to-treat analysis there were no statistical differences between the treatment groups. Among the patients who had ulcer pain prior to treatment, 79% of the pantoprazole group and 68% of the omeprazole group were pain-free after 2 weeks, and after 4 weeks 88% and 81%, respectively (not significant). Pronounced improvement in the other gastrointestinal symptoms was seen in both groups. Only 10% of patients in each group reported adverse events. There were moderate increases in fasting serum gastrin levels with both treatments at 4 and 8 weeks.

CONCLUSION

Pantoprazole, 40 mg once daily in the morning, is a highly effective, well tolerated treatment for acute, benign gastric ulcer. Pantoprazole and omeprazole were equally safe in the therapy of gastric ulcer.

Long term treatment with omeprazole 20 mg three days a week or 10 mg daily in the prevention of duodenal ulcer relapse

BACKGROUND

The aim of this study was to compare omeprazole 10 mg o.m. (daily) with omeprazole 20 mg o.m. on Friday to Sunday inclusive (weekend) in the prevention of duodenal ulcer relapse over a 6-month period.

METHODS

After an open healing phase (4 to 8 weeks) with omeprazole 20 mg o.m., 81 patients entered the follow-up phase. Forty-two were randomized in a double-blind double-dummy technique, to omeprazole 10 mg o.m., and 39 to omeprazole 20 mg at weekends. At 3 and 6 months or on symptomatic relapse the patients underwent endoscopy with gastric biopsies (quantitative assessment of argyrophilic and gastrin cells), symptom evaluation, and laboratory screening with fasting serum gastrin.

RESULTS

Five patients in the 10 mg group and four in the weekend group were lost to follow-up. The estimated relapse rates over six months in the two groups receiving 10 mg daily or 20 mg at weekends were 19% and 31%, respectively (95% CI of percentage difference: -33% to 8%: intention-to-treat analysis, P = N.S.). During the follow-up phase, symptoms tended to be milder in the omeprazole 10 mg daily group compared to the weekend group. Gastrin levels increased significantly during the healing phase but then stayed almost constant in the omeprazole 10 mg group, and significantly decreased with weekend treatment. The median number of argyrophilic cells showed a slight but statistically significant increase in the omeprazole 10 mg daily group, but did not change in the weekend group. Both the healing and long-term therapies were well tolerated.

CONCLUSIONS

Our data do not show a clear difference between the two treatment regimens, but there was a tendency towards a lower recurrence rate with omeprazole 10 mg daily compared with 20 mg weekend therapy.

Pharmacokinetics of intravenous omeprazole in children

This study was undertaken to define the pharmacokinetics of omeprazole in children and included 13 patients, heterogeneous in terms of age (0.3 to 19 years), underlying disease and biological constants, indication of omeprazole administration and associated therapy. The dose administered ranged from 36.9 to 139 mg.1.73 m-2. The pharmacokinetic parameters of omeprazole were: systemic clearance, 0.23 l.kg-1.h-1; volume of distribution, 0.45 l.kg-1; elimination half life 0.86 h; but were highly variable between individuals. Dosage, differences in hepatic and renal function and associated therapy may contribute to inter-individual variability. Within the range of doses administered, the pharmacokinetic parameters were similar to those reported in adults. The drug has been well tolerated in all children.

Identification of human liver cytochrome P450 isoforms mediating secondary omeprazole metabolism

1. The in vitro metabolism of omeprazole was studied in human liver microsomes in order to define the secondary metabolic pathways and identify the cytochrome P450 (CYP) isoforms responsible for the formation of the secondary metabolites of omeprazole. 2. The major secondary omeprazole metabolite was the hydroxysulphone, which was formed during incubation with both hydroxyomeprazole and omeprazole sulphone. A second metabolite, tentatively identified as pyridine-N-oxide omeprazole sulphone, was also formed during incubation with omeprazole sulphone. The formation kinetics of these two metabolites from omeprazole sulphone were biphasic suggesting the involvement of multiple CYP isoforms in each case. In contrast, the formation kinetics of hydroxysulphone from hydroxyomeprazole were linear. 3. Inhibition studies, performed with omeprazole sulphone as substrate at concentrations at which the high affinity activities predominated, with a series of isoform selective inhibitors as well as with an anti-CYP2C3 antibody suggested a dominant role of S-mephenytoin hydroxylase in the formation of hydroxysulphone from omeprazole sulphone. By contrast, CYP3A activities were predominant in the formation of hydroxysulphone from hydroxyomeprazole as well as in the formation of pyridine-N-oxide omeprazole sulphone from omeprazole sulphone.

Antacids. Indications and limitations

Antacids have served us well for over a century. In terms of peptic ulcer disease, the attitude in the late 1950s to 1970s that antacids should be taken only on demand was unjustified and erroneous. 13 recent endoscopic controlled studies have confirmed the efficacy of antacids in the healing of duodenal ulcer, achieving about 75% healing in 4 weeks. The efficacy of antacids in promoting gastric ulcer healing has been less well studied and the results are controversial. The most appropriate and economical antacid regimens for the treatment of duodenal ulcer disease should include tablets or liquid that have acid neutralising capacity of 400 mmol/day given at least an hour after meals. As a long term therapy, antacids appear to work, but need be taken in multiple daily doses, a regimen which is unlikely to meet with long term patient compliance. Patients with gastro-oesophageal reflux disorders or pregnancy-related reflux have also benefited from the usage of antacids ad libitum. Early previous studies have clearly demonstrated the efficacy of antacids in reducing gastro-oesophageal reflux and healing of reflux oesophagitis. The acidity of the gastric contents is the major determining factor in the outcome of the aspiration pneumonitis occurring during delivery. The prophylactic use of antacids during delivery has helped to reduce the severity of this complication. Similarly, the prophylactic administration of antacid aiming to maintain gastric pH between 3.5 to 7.0 has resulted in significant reduction of bleeding due to stress associated ulcers and/or erosive haemorrhagic gastritis in critically ill patients. Antacid therapy, however, is controversial in the management of nonulcer dyspepsia or nonsteroidal anti-inflammatory drug related upper gastrointestinal mucosal damage. Undoubtedly, antacids have major roles to play in the treatment of gastric acid related disorders. They have clear advantages and disadvantages when compared with the antisecretory agents. New proton pump inhibitors in particular have certainly superseded antacids and even the H2-receptor antagonists in many respects. However, the long term safety record of antacids remains unsurpassed by any of the new antisecretory agents.

Long-term consequences with regard to clinical outcome and cost-effectiveness of episodic treatment with omeprazole or ranitidine for healing of duodenal ulcer

The clinical outcome and cost-effectiveness of episodic treatment of duodenal ulcer with omeprazole and ranitidine were evaluated over a 5-year period. The analysis was based on data from published clinical trials comparing healing rates obtained with omeprazole and with ranitidine, as well as on data from the literature on ulcer recurrence and other clinical events. Patients with an active duodenal ulcer were treated until healed or for a maximum of 24 weeks. Maintenance therapy was instituted in patients with ulcers that were very slow to heal and in patients with frequent relapses after cessation of treatment. Patients who experienced frequent relapses while receiving maintenance therapy, and those whose ulcer had not healed after 24 weeks of continuous treatment, were defined as candidates for surgery. A statistical model was set up and a random number generator used to generate a sequence of clinical events, month by month, over a 5-year period for each patient in a large cohort. Episodic treatment with omeprazole was shown to be more effective in avoiding maintenance treatment and surgery when compared with episodic treatment with ranitidine. Patients who received episodic treatment with omeprazole also spent more time in remission from disease. Using current Swedish cost data, it was found that episodic treatment with omeprazole was more cost-effective than episodic treatment with ranitidine.

Appropriate acid suppression in the treatment of acid-related conditions

Gastric acid is involved in the pathogenesis of duodenal ulcer, gastric ulcer and gastro-oesophageal reflux disease. Although levels of acid secretion may not be abnormally high in patients with these conditions, pharmacological suppression of acid secretion is associated with healing of mucosal defects and maintenance of healing in the long term. In the case of duodenal ulcer, this was demonstrated before the understanding of the importance of Helicobacter pylori infection. There is a considerable body of published work examining the pharmacological effectiveness of antisecretory drugs in suppressing gastric acid secretion, as well as their therapeutic efficacy in terms of healing ulcers or oesophageal erosions. These two parameters have been significantly correlated in each of the three conditions listed above. The purpose of this article is to review the mathematical relationships established between suppression of gastric acid secretion and healing rates of duodenal ulcer, gastric ulcer and gastro-oesophageal reflux disease.

Identification of human liver cytochrome P450 isoforms mediating omeprazole metabolism

1 The in vitro metabolism of omeprazole was studied in human liver microsomes in order to define the metabolic pathways and identify the cytochrome P450 (CYP) isoforms responsible for the formation of the major omeprazole metabolites. 2 The four major metabolites identified in vitro, in tentative order of importance, were hydroxyomeprazole, omeprazole sulphone, 5-O-desmethylomeprazole, and an unidentified compound termed metabolite X. Omeprazole pyridone was also detected but could not be quantitated. Incubation of hydroxyomeprazole and omeprazole sulphone with human microsomes resulted in both cases in formation of the hydroxysulphone. The kinetics of formation of the four primary metabolites studied were biphasic suggesting the involvement of multiple CYP isoforms in each case. Further studies used substrate concentrations at which the high affinity activities predominated. 3 Formation of the major metabolite, hydroxyomeprazole, was significantly correlated with S-mephenytoin hydroxylase and with benzo[a]pyrene metabolism and CYP3A content. Inhibition studies with isoform selective inhibitors also indicated a dominant role of S-mephenytoin hydroxylase with some CYP3A contribution in the formation of hydroxyomeprazole. Correlation and inhibition data for the sulphone and metabolite X were consistent with a predominant role of the CYP3A subfamily in formation of these metabolites. Formation of 5-O-desmethylomeprazole was inhibited by both R, S-mephenytoin and quinidine, indicating that both S-mephenytoin hydroxylase and CYP2D6 may mediate this reaction in human liver microsomes and in vivo. 4 The Vmax/Km (indicator of intrinsic clearance in vivo) for hydroxyomeprazole was four times greater than that for omeprazole sulphone. Consistent with findings in vivo, the results predict that omeprazole clearance in vivo would be reduced in poor metabolisers of mephenytoin due to reduction in the dominant partial metabolic clearance to hydroxyomeprazole.

High-performance liquid chromatographic assay for human liver microsomal omeprazole metabolism

Assays for the measurement of omeprazole metabolites in plasma and urine have been reported, but when applied to the determination of omeprazole metabolites formed by human liver microsomal incubations there were obvious limitations in sensitivity. The present high-performance liquid chromatographic (HPLC) assay, which comprises extraction, evaporation and reconstitution, is several-fold more sensitive with a limit of detection of approximately 2 pmol (2 nM in incubate) for omeprazole sulphone and 25 pmol (25 nM in incubate) for hydroxyomeprazole. Extraction efficiency is essentially quantitative and is highly reproducible (coefficient of variation = 2.1% for both metabolites). The assay is linear over a wide range of concentrations and the formation of the metabolites is linear with respect to both time (to 15 min) and protein concentration (to 1.5 mg/ml). Two minor metabolites, one of which was identified tentatively as 5-O-desmethylomeprazole, were also formed by human liver microsomes and could be determined by this method. Preliminary studies of the formation of omeprazole sulphone and hydroxyomeprazole showed that the formation kinetics in human liver microsomes were biphasic for both metabolites, suggesting that at least two different cytochrome P450 isoforms are involved in their formation.

[Treatment of acute gastrointestinal pain.]

Abdominal pain is an important and the most frequent symptom of acute gastrointestinal diseases; crucial hints on the diagnosis can be gleaned from its location and from associated symptoms and signs. As symptomatic therapy the treatment of pain plays a major role in acute gastrointestinal diseases, e.g. the acute abdomen, acute pancreatitis, biliary colic, peptic ulcer disease and diverticulitis. Acute pain arising from peptic ulcer disease is effectively treated with the H(+)-, K(+)-ATPase inhibitor omeprazole or one of the H(2)-receptor antagonists. While moderate to severe pain caused by these conditions can be effectively treated by intravenous administration of nonopioid analgesic drugs, supplemented by butylscopolamine in a biliary colic, more severe pain or inadequate responsiveness to nonopioid analgesic drugs requires the intravenous administration of a highly potent opioid. Acute severe pain arising from biliary colic and acute pancreatitis should be treated with an opioid that does not influence the sphincter of Oddi or the pressure in the common bile duct, e.g. buprenorphine, nalbuphine or tramadol. An effective but not widely known therapy for colic pain is parenteral administration of a nonsteroidal anti-inflammatory drug, e.g. indomethacin or diclofenac.

Omeprazole versus famotidine in the healing and relapse of duodenal ulcer

Sixty patients with symptomatic duodenal ulcer were randomized to receive either omeprazole (20 mg each morning) or famotidine (40 mg at night time) for 2-4 weeks in a double-blind parallel group clinical trial. Healing rates were higher with omeprazole in comparison with famotidine after 2 weeks (77% vs. 40%, P < 0.001) and 4 weeks (93% vs. 80%, P = 0.2) of treatment. Assessment of daily diary cards completed by all patients revealed that omeprazole rapidly relieved ulcer-related day pain and nocturnal pain in comparison to famotidine. Treatment with omeprazole for 2 weeks was also associated with lower cumulative antacid intake (P < 0.05) and reduced absenteeism from work. Helicobacter pylori infection was present in all patients and remained unaffected by treatment with either of the drugs. None of the drugs produced any significant adverse effects. During 6 months follow-up of all the patients after ulcer healing (without maintenance therapy), ulcer relapse was seen in 40% of omeprazole- and 37% of famotidine-treated patients (P > 0.1). The duration of ulcer-free period following initial healing of ulcer was also similar in both the groups (median time: 22 weeks for omeprazole, 21 weeks for famotidine). We conclude that omeprazole is superior to famotidine in rapidly healing duodenal ulcers and achieving more rapid pain relief, but does not influence subsequent ulcer relapse.

Short report: treatment of Helicobacter pylori-associated duodenal ulcer with omeprazole plus antibiotics

Omeprazole heals most duodenal ulcers after 4 weeks of treatment but relapse is common. Eradication of Helicobacter pylori is associated with reduced rate of ulcer relapse. This study investigates the effect of omeprazole with antibiotics in H. pylori-associated duodenal ulceration. Forty-three patients with endoscopically proven duodenal ulcer and H. pylori entered this study. Treatment consisted of 20 mg omeprazole daily (four weeks) and seven days (first week) treatment with 400 mg metronidazole t.d.s. and 500 mg tetracycline t.d.s. Four weeks after completing the treatment, 81% (35/43) had a healed duodenal ulcer, and 58% (25/43) had H. pylori eradication. In those who healed, at one year 21 remained H. pylori-negative, 12 had persistent H. pylori infection and 2 had re-infection. The ulcer relapse rate at one year was 26%: of the 9 who relapsed, 6 had persistent infection, 2 were re-infected, and only 1 was H. pylori-negative. This combination therapy of antibiotics with omeprazole successfully eradicates Helicobacter pylori and has a lower ulcer relapse than omeprazole alone.

Long-term omeprazole therapy in peptic ulcer disease: gastrin, endocrine cell growth, and gastritis

BACKGROUND

The effects of chronic drug-induced hypergastrinemia on the exocrine and endocrine stomach are still incompletely understood. Chronic hypergastrinemia in rats and humans is associated with gastric argyrophil cell hyperplasia.

METHODS

Seventy-four patients with chronic ranitidine-resistant ulcerations were treated chronically with omeprazole (median observation period 48 [6-84] months).

RESULTS

Median fasting serum gastrin levels increased from a pretreatment value of 74-145 pg/mL after 3 months. No further increase was observed thereafter. The finding of atrophic gastritis increased from 1.8% to 20.8% after 5 years. A doubling of the mean argyrophil cell volume density (0.36% vs. 0.74% after 5 years; P < 0.01%) was paralleled by a decrease in the normal endocrine cell growth pattern from 64.3% to 33.3% and an increase in micronodular hyperplasia (8.9% vs. 16.7%). These changes correlated with the severity of corpus gastritis and seemed to be more disease- than drug-related. No statistically significant changes were observed in the antral G- and D-cell volume densities under therapy.

CONCLUSIONS

Long-term omeprazole therapy in humans results in moderate hypergastrinemia and a significant argyrophil cell hyperplasia, which are correlated to the grade of corpus gastritis. Because hypergastrinemia and gastritis are closely related, it is difficult to quantitatively assess their respective role in this process.

Long-term follow-up after eradication of Helicobacter pylori with a combination of omeprazole and amoxycillin

Early studies have suggested that omeprazole may facilitate the eradication of Helicobacter pylori. Sixty patients with duodenal ulcer and H. pylori colonization were randomly assigned to receive either omeprazole monotherapy (n = 30) or combination therapy with omeprazole and amoxycillin (n = 30) for a total duration of 6 weeks. Four patients receiving monotherapy and three receiving combination therapy had to be withdrawn from the study. All (100%) duodenal ulcers healed in patients receiving combination therapy, and 25 out of 26 (96%) healed in the group receiving monotherapy. H. pylori was eradicated in 22 out of 27 (82%) patients receiving combination therapy; only two ulcer relapses (9%) occurred within 18 months in these 22 patients. Of the five patients who remained H. pylori-positive after combination therapy, two relapsed during the 18-month follow-up. In the monotherapy group, all patients remained H. pylori-positive after treatment, and duodenal ulcer relapsed in 16 out of 25 (64%) patients within the median follow-up of 18 months. Adverse events were not reported in the group treated with combination therapy; one patient receiving monotherapy reported severe headache. These results lend further support to existing data that H. pylori eradication prevents duodenal ulcer relapse and show that combination therapy with omeprazole and amoxycillin is effective and well tolerated.

Pharmacokinetics of [14C]omeprazole in patients with liver cirrhosis

The pharmacokinetics of omeprazole and its metabolites following single doses were studied in 8 patients with liver cirrhosis. Each patient participated in 2 experiments in which [14C]omeprazole was administered either intravenously (20mg) or in an oral solution (40mg) in a randomised crossover design. Plasma concentrations of omeprazole and 2 of its identified metabolites, as well as total radioactivity were followed for 24h; urinary excretion was followed for 96h. The mean elimination half-life of omeprazole in the patients with cirrhosis was 2.8h and the mean total plasma clearance was 67 ml/min (4.02 L/h); corresponding values from separate studies in young healthy volunteers were 0.7h and 594 ml/min (35.64 L/h). The mean systemic availability was nearly 100% in the patients with cirrhosis whereas the previously reported value in young volunteers was only 56%. Almost 80% of a given dose was excreted as urinary metabolites in both patients and young volunteers. It is concluded that, as the hepatic clearance of omeprazole was substantially reduced in these patients, the dose of omeprazole needed for a certain degree of acid suppression is lower in patients with liver cirrhosis.

Pharmacokinetic study of omeprazole in elderly healthy volunteers

The pharmacokinetics of omeprazole and its metabolites were studied in 8 healthy elderly volunteers using [14C]omeprazole. In another 6 healthy elderly volunteers, the pharmacokinetics of omeprazole were studied using unlabelled drug. Each volunteer received single doses of omeprazole intravenously (20mg) and orally (40mg) as solutions in a randomized crossover design. The plasma concentrations and urinary excretion of omeprazole and metabolites were followed for 24 and 96h, respectively. The results indicate that the average metabolic capacity of omeprazole is decreased in the elderly compared with that found in earlier studies of healthy young individuals. This was reflected in an increase in bioavailability from 56 to 76%, a reduction in mean systemic clearance by approximately 50% (0.25 L/min) and a prolongation of the mean elimination half-life from 0.7 to 1.0h compared with the young. Despite these findings, the considerable overlap in these parameters between young and old volunteers, together with data from previous pharmacodynamic studies and the wide therapeutic range of omeprazole, indicate that dosage reductions are not needed in the elderly.

Double-blind comparison of omeprazole 20 mg OM and ranitidine 300 mg NOCTE in duodenal ulcer: a Taiwan multi-centre study

Two hundred and twenty-six patients with endoscopically confirmed duodenal ulcers > or = 5 mm in diameter entered a double-blind randomized trial comparing 20 mg omeprazole administered once daily in the morning with 300 mg ranitidine administered once daily at night. The patients were assessed endoscopically and symptomatically after 2 weeks, and those whose ulcers had healed terminated the study. Patients with unhealed ulcers continued treatment for a total of 4 weeks. Omeprazole produced significantly higher healing rates than ranitidine at both 2 weeks (57 vs 28%, P < 0.0001) and 4 weeks (93 vs 80%, P = 0.006). Similarly, significantly higher 'effective healing rates' (defined on the criteria established by the Japanese Society of Digestive Endoscopy) were observed with omeprazole compared with ranitidine at 2 and 4 weeks. After 2 weeks, there were significantly fewer reports of both day-time and night-time epigastric pain by omeprazole-treated patients compared with ranitidine-treated patients (22 vs 44%, P < 0.0001 for day-time pain; 24 vs 35%, P = 0.025 for night-time pain). Both drugs were well-tolerated and no major adverse effects were recorded during either treatment. In conclusion, 20 mg omeprazole administered once daily was superior to 300 mg ranitidine administered once daily for duodenal ulcer healing and symptom relief.

Omeprazole versus famotidine in the short-term treatment of duodenal ulcer disease

The efficacy and safety of omeprazole, in 241 patients with active recurrent duodenal ulcer from 21 Italian centres, was studied in a multicentre double-blind randomized trial comparing 20 mg omeprazole o.m. or 40 mg famotidine nocte with endoscopic examination, symptom recording, laboratory screening and gastrin assay. In a per protocol analysis, the duodenal ulcer healing rates for omeprazole and famotidine, documented by endoscopy, were 62% (68/109) and 33% (39/117) after 2 weeks of treatment (P less than 0.001), 92% (96/104) and 80% (86/108) cumulative after 4 weeks (P less than 0.05), and 99% (102/103) and 92% (96/104) after 6 weeks (P less than 0.05), respectively. The results of this trial demonstrate that 20 mg omeprazole o.m. is superior to 40 mg famotidine nocte in duodenal ulcer healing.

Do perforated duodenal ulcers need an acid-decreasing surgical procedure now that omeprazole is available?

If a chronic duodenal ulcer perforates, the choice of operation will depend on the patient's condition. Preoperative shock, concurrent medical diseases, severe generalized peritonitis, or the presence of an intra-abdominal abscess are contraindications to a definitive ulcer operation; hence, simple closure or omental patch closure is performed. Omeprazole can then be used to heal the ulcer in the early postoperative period, with long-term H2-blocker therapy to follow. The patient without a contraindication to a definitive operation should have a proximal gastric vagotomy in addition to an omental patch closure of the perforation. The addition of this procedure does not change the operative mortality rate in properly selected patients, does not cause the gastrointestinal sequelae associated with truncal vagotomy and pyloroplasty or resection, and has a low rate of recurrent ulcer in experienced hands. The presence of a synchronous posterior "kissing" duodenal ulcer would prompt some to choose a vagotomy and pyloroplasty in preference to a proximal gastric vagotomy. The appropriate operation to perform after perforation of an acute duodenal ulcer in a patient with any of the contraindications listed above is simple closure or omental patch closure. In the stable nonseptic patient, the choice is not as clear. Boey and associates noted cumulative recurrent ulcer rates of 37% and 31% at 3 years in separate studies in which omental patch closure was used for perforated acute duodenal ulcers. This may reflect the asymptomatic nature of chronic duodenal ulcers in some patients prior to perforation, the failure of the surgeon to recognize the extent of periduodenal scarring at operation, or differences in the length of postperforation follow-up in series reporting perforations of acute or chronic ulcers. Jordan has suggested that all stable patients with perforated duodenal ulcers should undergo a proximal gastric vagotomy in addition to omental patch closure. In his hands, the addition of proximal gastric vagotomy has an operative mortality rate of 0 to 1%, a recurrent ulcer rate of 3% to 5%, and no adverse postoperative sequelae. He has noted that "this operation gives protection from further ulcer disease to those who need it and will produce no harm to the unidentifiable patients that might not have benefited from definitive surgery." Boey and Wong suggested that omental patch closure is indicated for "acute ulcers associated with drug ingestion or acute stress" in addition to those that occur in patients who are considered to be poor risk, while proximal gastric vagotomy should be added in the remaining patients with perforations of acute ulcers.(ABSTRACT TRUNCATED AT 400 WORDS)

Management of gastroduodenopathy associated with use of nonsteroidal anti-inflammatory drugs

Adverse events associated with the use of nonsteroidal anti-inflammatory drugs (NSAIDs) are reported more frequently to the Food and Drug Administration than are those associated with any other group of drugs. The absolute risk for serious gastrointestinal events--in particular, ulcer bleeding, perforation, and death--is controversial; some investigators believe that an epidemic of NSAID-related complications is being experienced, whereas others suggest that the risks are being overemphasized. The management of patients who take NSAIDs regularly also remains controversial. Key unresolved issues include how best to identify those patients at particularly high risk for the development of ulcer complications and whether such patients should receive prophylactic therapy in an attempt to prevent such problems. In this review, we critically evaluate the currently available literature and present a management algorithm for the treatment and prevention of NSAID-associated gastroduodenopathy.