New data on healing of nonsteroidal anti-inflammatory drug-associated ulcers and erosions. Omeprazole NSAID Steering Committee

The Effect of H2 Receptor Antagonist in Acid Inhibition and Its Clinical Efficacy

The first histamine H₂ receptor antagonists (H₂RAs) were developed in the early 1970s. They played a dominant role in treating peptic ulcer disease and gastroesophageal reflux disease (GERD). H₂RAs block the production of acid by H⁺, K⁺-ATPase at the parietal cells and produce gastric luminal anacidity for varying periods. H₂RAs are highly selective, and they do not affect H1 receptors. Moreover, they are not anticholinergic agents. Sequential development of H₂RAs, proton pump inhibitors (PPIs), and discovery of Helicobacter pylori infection changed the paradigm of peptic ulcer disease with marked decrease of morbidity and mortality. PPIs are known to be the most effective drugs that are currently available for suppressing gastric acid secretion. Many studies have shown its superiority over H₂RAs as a treatment for acid-related disorders, such as peptic ulcer disease, GERD, and Zollinger-Ellison syndrome. However, other studies have reported that PPIs may not be able to render stomach achlorhydric and have identified a phenomenon of increasing gastric acidity at night in individuals receiving a PPI twice daily. These nocturnal acid breakthrough episodes can be eliminated with an addition of H₂RAs at night. The effectiveness of nighttime dose of H₂RA suggests a major role of histamine in nocturnal acid secretion. H₂RAs reduce secretion of gastric acid, and each H₂RA also has specific effects. For instance, nizitidine alleviates not only symptoms of GERD, but also provokes gastric emptying, resulting in clinical symptom improvement of functional dyspepsia. The aim of this paper was to review the characteristics and role of H₂RAs and assess the future strategy and treatment of upper gastrointestinal disease, including acid related disorders.

Pharmacodynamic evaluation of intragastric pH and implications for famotidine dosing in the prophylaxis of non-steroidal anti-inflammatory drug induced gastropathy-a proof of concept analysis

Objective

Famotidine given at a dose of 80 mg/day is effective in preventing NSAID-induced gastropathy. The aim of this proof of concept study was to compare twice a day (BID) vs 3-times a day (TID) administration of this total dose of famotidine on intragastric pH in healthy volunteers.

Research design and methods

Two analyses were undertaken: (1) a 13 subject controlled cross-over 24-h intragastric pH evaluation of the BID and TID administration of 80 mg/day of famotidine, as well as measures for drug accumulation over 5 days (EudraCT, number 2006-002930-39); and (2) a pharmacokinetic (PK)/pharmacodynamic (PD) model which predicted steady-state famotidine plasma concentrations and pH of the two regimens.

Results

For the cross-over study, gastric pH was above 3.5 for a mean of 20 min longer for TID dosing compared to BID dosing on Day 1. On Day 5, the mean time above this threshold was higher with the BID regimen by ∼25 min. For pH 4, subjects’ gastric pH was above this pH value for a mean of 25 min longer for TID dosing compared to BID dosing on Day 1. For Day 5, the pH was above 4 for ∼45 min longer with the TID regimen as compared with the BID regimen. The mean 24-h gastric pH values when taken in the upright position trended higher for the TID dosing period compared to the BID regimen on Day 1. The steady-state simulation model indicated that, following TID dosing, intragastric pH will be above 3 for 24 h vs 16 h for the BID regimen. There was no evidence for plasma accumulation of famotidine with TID dosing as compared to BID dosing from either analysis.

Conclusion

The data indicate that overall more time is spent above the acidic threshold pH values when 80 mg/day of famotidine is administered TID vs BID. Key limitations included small study size with a short duration and lack of a baseline examination, but was compensated for by the cross-over and PK/PD modeling design. Although most of the comparisons in this proof of concept study were not statistically significant these results have important implications for future research on gastric acid lowering agents used for the prevention of NSAID-induced gastropathy.

Clinical trial: evaluation of gastric acid suppression with three doses of immediate-release esomeprazole in the fixed-dose combination of PN 400 (naproxen/esomeprazole magnesium) compared with naproxen 500 mg and enteric-coated esomeprazole 20 mg: a randomized, open-label, Phase I study in healthy volunteers

BACKGROUND

PN 400 is a fixed-dose combination formulated to provide sequential delivery of immediate-release (IR) esomeprazole and enteric-coated (EC) naproxen.

AIM

To evaluate gastric acid suppression with three doses of esomeprazole in PN 400 compared with EC esomeprazole 20 mg.

METHODS

In this Phase I, randomized, open-label study, 28 healthy adults received PN 400 b.d. (naproxen 500 mg plus esomeprazole 10, 20 and 30 mg) and non-EC naproxen 500 mg b.d. plus EC esomeprazole 20 mg o.d., each for 9 days in a crossover fashion. The primary endpoint was percentage of time on day 9 that intragastric pH was >4.0; secondary endpoints included pharmacokinetics and safety.

RESULTS

Day 9 percentage of time where intragastric pH was >4.0 was 76.5%, 71.4%, 40.9% and 56.9% [corrected] for PN 400 containing 30, 20 and 10 mg esomeprazole, and naproxen plus esomeprazole 20 mg respectively. This was significantly greater for PN 400 containing 30 and 20 mg esomeprazole vs. naproxen plus esomeprazole 20 mg (95% CI: 13.0-26.0 and 7.8-20.7 respectively). The pharmacokinetics of PN 400 were consistent with its formulation. No serious adverse events occurred.

CONCLUSION

PN 400 containing 20 mg esomeprazole was the lowest dose to achieve gastric acid suppression comparable to EC esomeprazole 20 mg and was selected for further evaluation.

Risk factors and therapeutic response in Chinese patients with peptic ulcer disease

AIM: To assess the risk factors and the efficacy of medications of patients with gastric and duodenal ulcers among Chinese patients in Taiwan.

METHODS: Patients with peptic ulcers, diagnosed by upper endoscopy, were retrospectively collected between January 2008 and December 2008. The differences were compared.

RESULTS: Among all 448 cases, 254 (56.6%) and 194 (43.4%) patients had gastric ulcers and duodenal ulcers respectively. Patients with gastric ulcers were younger than those with duodenal ulcers. Although more men existed, there was a female predominance in middle-aged cases. Patients with duodenal ulcers had a higher rate of Helicobacter pylori (H. pylori) infection (62.4% vs 43.3%, P = 0.001), and those with gastric ulcers owned a significantly higher amount of aspirin and nonsteroidal anti-inflammatory drug (NSAID) use (7.5% vs 1.5%, 6.7% vs 2.1%, P = 0.001). Tobacco smoking and alcohol drinking had no different impact between these two groups. Proton-pump inhibitors and H2-receptor antagonists (H2RA) were effective, but significantly less so in cases with duodenal ulcers receiving H2RAs, or in those with H. pylori infection and a history of NSAID use.

CONCLUSION: Patients with gastric ulcers had lower H. pylori infection but more aspirin or NSAID use. Antisecretory therapy was ineffective in gastric ulcers underwent H2RA treatment, and cases combined H. pylori infection and NSAID use.

[Guidelines of treatment for non-bleeding peptic ulcer disease]

Over the past century, since the introduction of non steroidal anti-inflammatory drugs (NSAID), antacid, histamine H2-receptor antagonists (H2RA), proton pump inhibitors (PPI), and discovery of Helicobacter pylori infection, the paradigm of peptic ulcer disease has changed with marked decrease in morbidity and mortality. However, peptic ulcer disease still occupies a position as a major health problem with increase of aged population and NSAIDs usage. In daily general practice, the management of peptic ulcer disease is directed according to the presence of bleeding or not. For non-bleeding peptic ulcer disease, proper acid suppression and the correction of underlying causes such as Helicobacter pylori infection and NSAID use is the main stay of treatment. Though a complete understanding of pathophysiology and a perfect treatment strategy are still a challenge, this guideline aims to provide practical recommendations based on evidences or consensus of experts through in-depth literature review and expert meeting.

[Guidelines of prevention and treatment for NSAID-related peptic ulcers]

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most commonly used medications in Korea. Gastrointestinal toxicity, including peptic ulcer, is a common adverse effect of NSAIDs. Risk factors for NSAID-related peptic ulcer include a previous history of peptic ulcer, advanced age, high dose, concomitant use of corticosteroids, anticoagulants, other NSAIDs including low-dose aspirin. Preventive measure(s), such as COX-2 inhibitor, proton pump inhibitor or misoprostrol, should be done for patients requiring NSAID therapy who have high-risk factor(s) for peptic ulcer. Low dose aspirin also increases the risk of peptic ulcer, so preventive measure(s) should be done for high-risk patients. The eradication of Helicobacter pylori is recommended for high-risk NSAID-users. Treatment strategies for peptic ulcers in NSAID users are mostly the same for peptic ulcers in NSAID non-users.

Peptic ulcer disease today

Over the past few decades, since the introduction of histamine H(2)-receptor antagonists, proton-pump inhibitors, cyclo-oxygenase-2-selective anti-inflammatory drugs (coxibs), and eradication of Helicobacter pylori infection, the incidence of peptic ulcer disease and ulcer complications has decreased. There has, however, been an increase in ulcer bleeding, especially in elderly patients. At present, there are several management issues that need to be solved: how to manage H. pylori infection when eradication failure rates are high; how best to prevent ulcers developing and recurring in nonsteroidal anti-inflammatory drug (NSAID) and aspirin users; and how to treat non-NSAID, non-H. pylori-associated peptic ulcers. Looking for H. pylori infection, the overt or surreptitious use of NSAIDs and/or aspirin, and the possibility of an acid hypersecretory state are important diagnostic considerations that determine the therapeutic approach. Combined treatment with antisecretory therapy and antibiotics for 1-2 weeks is the first-line choice for H. pylori eradication therapy. For patients at risk of developing an ulcer or ulcer complications, it is important to choose carefully which anti-inflammatory drugs, nonselective NSAIDs or coxibs to use, based on a risk assessment of the patient, especially if the high-risk patient also requires aspirin. Testing for and eradicating H. pylori infection in patients is recommended before starting NSAID therapy, and for those currently taking NSAIDs, when there is a history of ulcers or ulcer complications. Understanding the pathophysiology and best treatment strategies for non-NSAID, non-H. pylori-associated peptic ulcers presents a challenge.

Omeprazole and misoprostol for preventing gastric mucosa effects caused by indomethacin and celecoxib in rats

PURPOSE: To evaluate and to compare macro and microscopically the intense injuries of the gastric mucosa of rats which were caused by NSAIDS celecoxib and indomethacin and the gastric cytoprotection with omeprazole and misoprostol. METHODS: The sample is formed by one hundred and fifty Wistar rats with average weight 200 g, distributed in four groups, such as: Group A, subdivided in groups A1 and A2 - pre-treatment with omeprazole (20 mg/rat) during seven days and on the 8th day - use of NSAIDS, concerning A1 (20 rats) were given celecoxib (1mg/rat) and A2 (20 rats) were given indomethacin. The Group B, subdivided in group B1 and B2 - pre-treatment with misoprostol (20mg/rat) during seven days and on the 8th day use of NSAIDS, concerning B1 (20 rats) were given celecoxib (1 mg/ rat) and B2 (20 rats) were given indomethacin (12.5 mg/rat). The Group C: were not given cytoprotection during seven days, from the 7th to the 8th day - fast of food and water ad libitum, on the 8th day of NSAIDS use, concerning C1 (20 rats) were given celecoxib, C2 (20 rats) were given indomethacin (12.5 mg/ rat), C3 (20 rats) were given celecoxib (200mg/rato), and Group D - control group, concerning 10 rats were observed during seven days ingesting food and water ad libitum. On the 9th day, the stomachs were taken out and were macro and microscopically evaluated for the identification of the gastric injuries. RESULTS: On the macroscopic studies, the groups A2, B2 and C2 presented a remarkable high number of injuries for cm² /animal, respectively 18.55 injuries for cm² /animal, 16.25 injuries for cm² /animal and 13.55 injuries for cm²/animal. On the microscopic studies, the percentage of the injured mucosa, presented expressive difference among the groups A1, B1, C1 when compared to the groups A2, B2, C2 (p<0.0001). The average of the length/injury and the average of the depth of the injuries did not present expressive statistics differences among the groups A2, B2 and C2. The average of the edema presented expressive statistics difference among the groups A2 and D; B2 and C2 and between C2 and D (p < 0.05). CONCLUSIONS: The indomethacin on the applied concentration causes a great number of macroscopic and microscopic injuries to gastric mucosa of rats when compared to celecoxib which does not cause lesions. Omeprazole and misoprostol on the applied concentrations do not present macroscopic and microscopic effectiveness on the gastric cytoprotection when applying indomethacin. Considering the microscopic analysis of the average of the edema, the group of animals, which was given misoprostol as cytoprotection, presented a lower average compared to the group which was given omeprazole.

Effects of selective cyclooxygenase-2 inhibitor and non-selective NSAIDs on Helicobacter pylori-induced gastritis in Mongolian gerbils

BACKGROUND

It is still a point of controversy whether Helicobacter pylori-infected patients are more likely to develop mucosal damage while taking NSAIDs. Selective cyclooxygenase (COX-2) inhibitors may be associated with less severe gastric mucosal damage than conventional NSAIDs, but this association is undefined in H. pylori-induced gastritis. The aim of this study was to evaluate the effects of selective COX-2 and nonselective NSAIDs on H. pylori-induced gastritis.

METHODS

After intragastric administration of indomethacin, NS-398 or vehicle alone, once daily for 5 days in H. pylori-infected and uninfected Mongolian gerbils, we evaluated gastric mucosal damage, inflammatory cell infiltration and prostaglandin E2 (PGE2) concentration. We investigated whether H. pylori infection induced the COX-2 expression.

RESULTS

In H. pylori-uninfected groups, the indomethacin-treated group showed the highest mucosal damage score and the lowest PGE2 concentration. There was no difference in mucosal damage scores and PGE2 concentration between NS-398 and vehicle-alone treated group. In H. pylori-infected groups, there was no difference in mucosal damage scores, irrespective of the type of drugs administered. The indomethacin-treated group showed the lowest PGE2 concentration, similar to that of the NS-398 and vehicle-alone treated groups, both without H. pylori infection. Gastric neutrophil and monocyte infiltration scores were higher in H. pylori-infected groups than in uninfected groups. However, there was no difference in these scores according to the type of drugs administered, within H. pylori-infected or uninfected groups. COX-2 protein expression was observed in H. pylori-infected Mongolian gerbils but not in uninfected ones.

CONCLUSIONS

Our animal study showed that H. pylori infection induced COX-2 expression and increased prostaglandin concentration. Administration of NSAIDs decreased the prostaglandin concentration, but did not increase mucosal damage in H. pylori-induced gastritis. Selective COX-2 inhibitors, instead of conventional NSAIDs, had no beneficial effect on preventing mucosal damage in H. pylori-induced gastritis.

Current concepts in the management of Helicobacter pylori infection--the Maastricht 2-2000 Consensus Report

Significant progress and new insights have been gained in the 4 years since the first Maastricht Consensus Report, necessitating an update of the original guidelines. To achieve this, the European Helicobacter Pylori Study Group organized a meeting of specialists and experts from around the world, representatives from National Gastroenterology Societies and general practitioners from Europe to establish updated guidelines on the current management of Helicobacter pylori infection. The meeting took place on 21-22 September 2000. A "test and treat" approach is recommended in adult patients under the age of 45 years (the age cut-off may vary locally) presenting in primary care with persistent dyspepsia, having excluded those with predominantly gastro-oesophageal reflux disease symptoms, non-steroidal anti-inflammatory drug users and those with alarm symptoms. Diagnosis of infection should be by urea breath test or stool antigen test. As in the previous guidelines, the eradication of H. pylori is strongly recommended in all patients with peptic ulcer, including those with complications, in those with low-grade gastric mucosa-associated lymphoid tissue lymphoma, in those with atrophic gastritis and following gastric cancer resection. It is also strongly recommended in patients who are first-degree relatives of gastric cancer patients and according to patients' wishes after full consultation. It is advised that H. pylori eradication is considered to be an appropriate option in infected patients with functional dyspepsia, as it leads to long-term symptom improvement in a subset of patients. There was consensus that the eradication of H. pylori is not associated with the development of gastro-oesophageal reflux disease in most cases, and does not exacerbate existing gastro-oesophageal reflux disease. It was agreed that the eradication of H. pylori prior to the use of non-steroidal anti-inflammatory drugs reduces the incidence of peptic ulcer, but does not enhance the healing of gastric or duodenal ulcer in patients receiving antisecretory therapy who continue to take non-steroidal anti-inflammatory drugs. Treatment should be thought of as a package which considers first- and second-line eradication therapies together. First-line therapy should be with triple therapy using a proton pump inhibitor or ranitidine bismuth citrate, combined with clarithromycin and amoxicillin or metronidazole. Second-line therapy should use quadruple therapy with a proton pump inhibitor, bismuth, metronidazole and tetracycline. Where bismuth is not available, second-line therapy should be with proton pump inhibitor-based triple therapy. If second-line quadruple therapy fails in primary care, patients should be referred to a specialist. Subsequent failures should be handled on a case-by-case basis by the specialist. In patients with uncomplicated duodenal ulcer, eradication therapy does not need to be followed by further antisecretory treatment. Successful eradication should always be confirmed by urea breath test or an endoscopy-based test if endoscopy is clinically indicated. Stool antigen test is the alternative if urea breath test is not available.

Review article: should we kill or should we save Helicobacter pylori?

Results from epidemiological studies and therapeutic clinical trials have shown that Helicobacter pylori infection causes acute and chronic active gastritis and is the initiating factor for the majority of peptic ulcer disease. Eradication of the infection with antibiotics resolves gastritis and restores normal gastric physiology, accelerates healing of peptic ulcer disease, and virtually eliminates recurrence of duodenal ulcer disease. The infection also plays an important role in the initiation and/or progression of gastric atrophy and intestinal metaplasia, which may eventually lead to the development of distal gastric cancer. Furthermore, almost all patients with gastric MALT lymphoma are infected with H. pylori and cure of the infection leads to histological regression of the tumor and maintains the regression in over 80% of patients during long-term follow-up. Preliminary uncontrolled data from Japan show that eradication of the infection significantly reduced metachronous intestinal-type gastric cancer following initial endoscopic resection of early gastric cancer and might also prevent the progression of gastric adenoma to gastric dysplasia or gastric cancer. Although this overwhelming evidence has demonstrated that H. pylori infection is bad for humans, some have questioned the wisdom of eradicating the infection in all those infected. Their arguments are largely based on hypothesis and circumstantial evidence: 1) Less than 20% of all H. pylori infected persons will develop significant clinical consequences in their lifetime. 2) H. pylori strains are highly diverse at a genetic level and are of different virulence. 3) The antiquity of H. pylori infection in humans and their co-evolution suggests that H. pylori may be a commensal to humans. Eradication of H. pylori may remove some beneficial bacterial strains and may provoke esophageal disease or gastric cancer at the cardia. However, careful review of the literature confirms that H. pylori infection is a serious pathogen albeit in a minority of those infected. It remains for carefully designed prospective studies, rather than hypothesis to make changes in the current consensus position.

Cyclooxygenase-2--specific inhibitors: are they safe?

The basic tenet of the cyclooxygenase-2 (COX-2) hypothesis rests on the fact that sparing of inhibition of COX-1 should result in greater safety than if both COX isoforms are inhibited. This increase in safety should be most evident in those organs and tissues in which COX-1 alone has important, necessary physiologic functions (e.g., the stomach and platelets). Data from large clinical trials are now available to support the superior gastrointestinal safety of COX-2 inhibitors, not only for endoscopic endpoints but also for clinically significant outcomes. Additionally, lack of effect on platelets has been demonstrated at doses many times higher than being used clinically. Unfortunately, the COX-2 inhibitors still retain some of the side effects seen with traditional dual COX inhibitors (nonsteroidal anti-inflammatory drugs), namely, effects on the kidney that may manifest as an increased incidence of hypertension, edema, and associated clinical states. Similarly, effects on reproductive functions, endothelial function, and wound healing are theoretically possible but need to be evaluated in well-controlled clinical trials.

Cure of Helicobacter pylori-associated ulcer disease through eradication

The eradication of Helicobacter pylori (H. pylori) infection has led to a dramatic benefit for patients with gastroduodenal ulcer disease, as the majority of these patients receive a lifelong cure. Relapses after successful H. pylori cure may be caused by either recrudescence or reinfection, both rare events nowadays, or be attributed to non-steroidal anti-inflammatory drugs or aspirin intake. In certain geographical areas, H. pylori-negative relapses are proposed as a new, pathophysiological and not yet elucidated entity. The cure of H. pylori infection in uncomplicated duodenal ulcer diseases consists of 7 days of proton pump inhibitor (PPI) based triple therapy, containing two antibiotics from clarithromycin, amoxicillin and metronidazole. In gastric ulcer, it is recommended that the PPI is continued for a further 3 weeks as these ulcers have a prolonged healing time. Rescue therapies after failure need to take into consideration the resistance pattern of the micro-organism and are offered in the form of quadruple therapy or a high-dose PPI with amoxicillin.

Prophylaxis and treatment of NSAID-induced gastroduodenal disorders

A significant percentage of patients taking nonsteroidal anti-inflammatory drugs (NSAIDs) experience some type of adverse gastrointestinal symptoms, lesions of the gastroduodenal tract being clinically the most relevant. NSAIDs cause gastrointestinal damage by 2 independent mechanisms: a topical effect, which is pH and pKa related, and a systemic effect mediated by cyclooxygenase (COX) inhibition with a reduction in prostaglandin synthesis. Using endoscopy, gastroduodenal lesions identified include subepithelial haemorrhages, erosions and ulcers. The prevalence of ulceration in NSAID users has been reported as being between 14 and 31% with a 2-fold higher frequency of gastric ulcers compared with duodenal ulcers. Among the strategies used to decrease the risk of ulcer development are: (i) the use of analgesics other than NSAIDs; (ii) use of the lowest possible dosage of NSAID; (iii) the use of a COX-2 selective NSAID; (iv) the use of low doses of corticosteroids instead of NSAIDs; (v) avoidance of concomitant use of NSAIDs and corticosteroids; and (vi) use of preventive therapy. In an attempt to reduce the incidence of NSAID-induced gastrointestinal lesions, the following approaches have been proposed: (i) use of the prostaglandin analogue misoprostol, which is an antiulcer drug which has been proven to be as effective in the prevention of NSAID-induced gastric and duodenal ulcers as in the reduction of serious upper gastrointestinal complications; (ii) histamine H2 receptor antagonists (H2 antagonists), e.g. ranitidine, cimetidine and famotidine, which are useful in the prevention of NSAID-induced duodenal ulcers during long term treatment, but not in the prevention of NSAID-induced gastric ulcers; (iii) proton pump inhibitors, e.g omeprazole, and pantoprazole, whose efficacy in preventing NSAID-associated ulcers has been recently demonstrated; and (iv) barrier agents, e.g. sucralfate, which cannot be recommended as prophylactic agents to prevent NSAID-induced gastropathy. The first step in the treatment of NSAID-associated ulcers lies in a reduction in the dosage of the NSAID or discontinuation of the drug. If NSAID treatment cannot be withdrawn, a proton pump inhibitor appears to be the most effective treatment in healing ulcers, accelerating the slow healing observed with H2 antagonists.

Does Helicobacter pylori status affect nonsteroidal anti-inflammatory drug-associated gastroduodenal pathology?

There are two lines of thought regarding the interrelationship between the damaging effects of Helicobacter pylori and those of nonsteroidal anti-inflammatory drugs (NSAIDs) on the gastroduodenal mucosa. First, both pathogenic factors exert a damaging effect on the mucosa, and therefore an additive, or even synergistic, effect occurs, leading to aggravation of mucosal damage. Second, mutual antagonism exists, leading to one of the pathogenic factors actually deriving some protection from the damaging potential of the other. Microscopically, H. pylori- and NSAID-associated gastritis are recognized as two separate entities. Furthermore, pathologically, the mechanisms of mucosal damage of the two factors have important differences; for example, H. pylori increases the synthesis of prostaglandins, whereas NSAIDs inhibit prostaglandin synthesis. The role of H. pylori infection in patients with NSAID-associated peptic ulcers has been addressed recently in two large, randomized, multicenter trials. From these studies, it appears that antisecretory drugs are more effective in H. pylori-positive peptic ulcer patients taking NSAIDs than in H. pylori-negative patients taking these drugs. The studies, however, do not provide any evidence that H. pylori infection reduces the pathogenic effects of NSAIDs. Other studies, however, have shown protection against NSAID-associated gastroduodenal damage in H. pylori-negative patients. Thus, there are no firm conclusions on the role of H. pylori infection in patients with NSAID-associated peptic ulcers. Based on the available data, however, practical considerations and guidelines are listed.

Progress in prophylaxis against nonsteroidal anti-inflammatory drug-associated ulcers and erosions. Omeprazole NSAID Steering Committee

Four large clinical studies have shown that omeprazole, 20 mg once daily, is effective in preventing the significant gastroduodenal consequences of nonsteroidal anti-inflammatory drugs (NSAIDs). In the Scandinavian Collaborative Ulcer Recurrence (SCUR) study, patients were randomized (without initial endoscopy) to receive omeprazole or placebo for up to 3 months. Of the patients treated with omeprazole, 24.7% experienced treatment failure, compared with 50.0% of those on placebo. Fewer patients in the omeprazole group than in the placebo group developed a peptic ulcer (4.7% versus 16.7%, respectively) or dyspeptic symptoms (8.2% versus 20.0%, respectively). In the Omeprazole versus Placebo as Prophylaxis of Ulcers and Erosions from NSAID Treatment (OPPULENT) study, patients were also randomized to receive omeprazole or placebo. The estimated probability of remaining in remission for 6 months while receiving omeprazole was 0.78, compared with 0.53 for placebo. Fourteen (16.5%) patients on placebo developed peptic ulcer(s), compared with three (3.6%) patients on omeprazole. The Omeprazole versus Misoprostol for NSAID-Induced Ulcer Management (OMNIUM) study consisted of a healing and a prophylactic phase. Patients who successfully completed the healing phase were re-randomized to receive omeprazole, misoprostol, or placebo for up to 6 months. In patients receiving omeprazole, 36.5% experienced treatment failure, compared with 48.6% of those on misoprostol, and 67.7% of those on placebo. Omeprazole and misoprostol appeared to be equally effective in preventing gastric ulcer; by contrast, omeprazole was highly effective in preventing duodenal ulcer, when compared with misoprostol and placebo. The Acid Suppression Trial: Ranitidine versus Omeprazole for NSAID-Associated Ulcer Treatment (ASTRONAUT) study also consisted of a healing and a prophylactic phase. Patients who successfully completed the healing phase were re-randomized to receive omeprazole or ranitidine for up to 6 months. In patients receiving omeprazole, 26.2% experienced treatment failure, compared with 37.7% of those on ranitidine. The percentages of patients with a peptic ulcer relapse were 5.7% for omeprazole and 19.5% for ranitidine. The data show that omeprazole is an effective and well-tolerated agent for both primary and secondary (maintenance) prophylaxis in patients receiving NSAIDs.

Why proton pump inhibition should heal and protect against nonsteroidal anti-inflammatory drug ulcers

Several lines of evidence provide support for the potential of gastric acid-inhibitory therapy in the management of nonsteroidal anti-inflammatory drug (NSAID)-associated gastroduodenal injury. Studies on the rat stomach have shown that the acute mucosal injury produced by both aspirin and indomethacin can be prevented by elevation of the pH of the gastric contents of >4.0. The pH-dependent pattern of mucosal injury is best explained by the very low activity of gastric pepsin above pH 4.0. This view is supported by studies of experimental esophagitis, which indicate that the pH-activity curve of gastric pepsin approximates the aggressiveness of acid-pepsin mixtures to the esophageal mucosa. Healthy human volunteer studies have shown that elevation of intragastric pH with omeprazole greatly reduces, or abolishes, aspirin-associated gastric microbleeding. A small amount of clinical data also support the view that elevation of gastric pH with acid-inhibitory therapy is a promising option for both the treatment of established NSAID-associated chronic peptic ulcer, even during continued NSAID use, and for prophylaxis against the develop of chronic gastric and duodenal ulcers during NSAID therapy. These data indicate consistently that the benefits from gastric acid-inhibitory therapy are proportional to the degree of elevation of gastric pH by therapy. This dose-response relationship suggests that proton pump inhibition has the potential to achieve superior results in patients who have, or who are at risk of, NSAID-associated peptic ulcer, when compared with agents that inhibit gastric acid secretion to lower levels than seen with proton pump inhibition.

Management of nonsteroidal anti-inflammatory drug-associated lesions: a cost-effectiveness perspective

Results are presented from a cost-effectiveness analysis of the acute healing phases of two new clinical studies. Acute treatment with omeprazole, 20 mg once daily, is compared with misoprostol, 200 microg four times daily, or ranitidine, 150 mg twice daily, in patients with nonsteroidal anti-inflammatory drug (NSAID)-associated gastroduodenal lesions (gastric ulcer, duodenal ulcer, and/or >10 erosions in either the stomach or duodenum). The cost-effectiveness comparisons indicate that omeprazole is cost-effective when compared with ranitidine in the treatment of gastric ulcers, duodenal ulcers, and erosions only, and that omeprazole is cost-effective when compared with misoprostol in the treatment of gastric ulcers and duodenal ulcers. In patients with erosions only, misoprostol is cost-effective when compared with omeprazole. When assessing the uncertainty of these estimates, a definite conclusion can be made in only two comparisons: omeprazole is cost-effective when compared with ranitidine in the treatment of gastric ulcers, and misoprostol is cost-effective when compared with omeprazole in the treatment of erosions only. However, the clinical studies were not powered for assessing the cost-effectiveness of the treatment alternatives, which impedes the uncertainty assessment. The determinants of the cost-effectiveness of prophylactic strategies are also discussed, as well as the need for further studies that include relevant outcome measures and a design that reflects actual clinical practice.