Nonsteroidal antiinflammatory drug-induced ulcers: management by traditional therapies

Cholecystokinin-Induced Duodenogastric Bile Reflux Increases the Severity of Indomethacin-Induced Gastric Antral Ulcers in Re-fed Mice

BACKGROUND/AIMS

We examined the involvement of cholecystokinin (CCK) in the exacerbation of indomethacin (IND)-induced gastric antral ulcers by gastroparesis caused by atropine or dopamine in mice.

METHODS

Male mice were fed for 2 h (re-feeding) following a 22-h fast. Indomethacin (IND; 10 mg/kg, s.c.) was administered after re-feeding; gastric lesions were examined 24 h after IND treatment. In another experiment, mice were fed for 2 h after a 22-h fast, after which the stomachs were removed 1.5 h after the end of the feeding period. Antral lesions, the amount of gastric contents, and the gastric luminal bile acids concentration were measured with or without the administration of the pro- and antimotility drugs CCK-octapeptide (CCK-8), atropine, dopamine, SR57227 (5-HT3 receptor agonist), apomorphine, lorglumide (CCK1 receptor antagonist), ondansetron, and haloperidol alone and in combination.

RESULTS

IND produced severe lesions only in the gastric antrum in re-fed mice. CCK-8, atropine, dopamine, SR57227 and apomorphine administered just after re-feeding increased bile reflux and worsened IND-induced antral lesions. These effects were significantly prevented by pretreatment with lorglumide. Although atropine and dopamine also increased the amount of gastric content, lorglumide had no effect on the delayed gastric emptying provoked by atropine and dopamine. Both ondansetron and haloperidol significantly inhibited the increase of bile reflux and the exacerbation of antral lesions induced by atropine and dopamine, respectively, but did not affect the effects of CCK-8.

CONCLUSIONS

These results suggest that CCK-CCK1 receptor signal increases bile reflux during gastroparesis induced by atropine and dopamine, exacerbating IND-induced antral ulcers.

Gastroparesis Worsens Indomethacin-Induced Gastric Antral Ulcers by Bile Reflux via Activation of 5-HT3 and Dopamine D2 Receptors in Mice

BACKGROUND/AIMS

We examined the contributions of gastric emptying and duodenogastric bile reflux in the formation of gastric antral ulcers induced by NSAIDs in mice.

METHODS

We used the murine re-fed indomethacin (IND) experimental ulcer model. Outcome measures included the appearance of gastric lesions 24 h after IND treatment and the assessment of gastric contents and the concentration of bile acids 1.5 h after re-feeding. The effects of atropine, dopamine, SR57227 (5-HT3 receptor agonist), apomorphine, ondansetron, haloperidol, and dietary taurocholate and cholestyramine were also examined.

RESULTS

IND (10 mg/kg, s.c.) induced severe lesions only in the gastric antrum in the re-fed model. The antral lesion index and the amount of food intake during the 2-h refeeding period were positively correlated. Atropine and dopamine delayed gastric emptying, increased bile reflux, and worsened IND-induced antral lesions. SR57227 and apomorphine worsened antral lesions with increased bile reflux. These effects were prevented by the anti-emetic drugs ondansetron and haloperidol, respectively. The anti-emetic drugs markedly decreased the severity of antral lesions and the increase of bile reflux induced by atropine or dopamine without affecting delayed gastric emptying. Antral lesions induced by IND were increased by dietary taurocholate but decreased by the addition of the bile acid sequestrant cholestyramine.

CONCLUSIONS

These results suggest that gastroparesis induced by atropine or dopamine worsens NSAID-induced gastric antral ulcers by increasing duodenogastric bile reflux via activation of 5-HT3 and dopamine D2 receptors.

Pharmacogenomics of NSAID-Induced Upper Gastrointestinal Toxicity

Non-steroidal anti-inflammatory drugs (NSAIDs) are a group of drugs which are widely used globally for the treatment of pain and inflammation, and in the case of aspirin, for secondary prevention of cardiovascular disease. Chronic non-steroidal anti-inflammatory drug use is associated with potentially serious upper gastrointestinal adverse drug reactions (ADRs) including peptic ulcer disease and gastrointestinal bleeding. A few clinical and genetic predisposing factors have been identified; however, genetic data are contradictory. Further research is needed to identify clinically relevant genetic and non-genetic markers predisposing to NSAID-induced peptic ulceration.

Proton Pump Inhibitors Prevent Gastric Antral Ulcers Induced by NSAIDs via Activation of Capsaicin-Sensitive Afferent Nerves in Mice

BACKGROUND/AIMS

We examined the effects of proton pump inhibitors (PPIs) on gastric antral ulcers induced by non-steroidal anti-inflammatory drugs in re-fed mice and the role of capsaicin-sensitive afferent nerves (CSANs) in the protective effects of PPIs on the antral mucosa.

METHODS

Male mice were administered indomethacin after 2 h of re-feeding of diet after a 24-h fast, and gastric lesions were examined 24 h after indomethacin dosing. The effects of PPIs (lansoprazole and omeprazole), histamine H₂-receptor antagonists (H₂-RAs, famotidine, ranitidine), capsaicin and misoprostol on the formation of antral ulcers induced by indomethacin were examined. Functional ablation of CSANs was caused by pretreatment of mice with a high dose of capsaicin.

RESULTS

Indomethacin produced lesions selectively in the gastric antrum in re-fed conditions. Formation of antral ulcers was not affected by H₂-RAs, but inhibited by PPIs, capsaicin and misoprostol. The anti-ulcer effect of lansoprazole was 30 times stronger than that of omeprazole. Antral ulcers induced by indomethacin were markedly aggravated in mice with ablated CSANs. The effects of PPIs and capsaicin on ulcer formation were inhibited by ablation of CSANs, pretreatment with a capsaicin receptor antagonist (capsazepine/ruthenium red) and an inhibitor of nitric oxide synthesis (L-NAME). However, the inhibitory effect of misoprostol was not prevented by the ablation of CSANs or drugs.

CONCLUSIONS

The results suggested that CSANs play an important role in protection of the antral mucosa and that both lansoprazole and omeprazole are capable of preventing NSAID-induced antral ulcers by activating CSANs.

Colonic mucosal lesions associated with long-term or short-term administration of nonsteroidal anti-inflammatory drugs

AIM

The effects of short- or long-term administration of nonsteroidal anti-inflammatory drugs (NSAIDs) on the colon have not been well characterized. We assessed the risk of developing colonic mucosal lesions according to the duration of exposure to NSAIDs: short-term and/or long-term use.

METHOD

A case-controlled study was performed by reviewing medical records for endoscopic findings, underlying disease, pre-endoscopic symptoms, category of NSAIDs used and duration of use. The patients underwent colonoscopy between January and October 2004, and 75 colitis cases and 1801 non-colitis controls were identified. The prevalence of NSAID use was compared between the cases and controls. The age- and sex- adjusted odds ratios (OR) were estimated using multiple logistic regression models.

RESULTS

NSAIDs had been used in colitis cases and non-colitis controls for over six months in 20.0% and 12.7%, and for one week in 4.0% and 2.1%. Overall 76.0% and 85.2% had not received NSAIDs. The adjusted OR (95% confidence interval) for colonic mucosal lesions with short- and long term NSAID administration combined vs. non-use was 2.04 (1.16-3.61). When determined separately for short- and long-term NSAID users, the adjusted ORs were 1.48 (0.42-5.25) and 2.21 (1.19-4.11), compared to non-users. These values signify a trend toward an increased frequency of colonic mucosal lesions with longer use of NSAIDs (P=0.011 for trend).

CONCLUSION

Long-term use of NSAIDs increased the risk of colonic mucosal lesions, suggesting that NSAIDs may contribute to the pathogenesis of colonic ulcer or colitis.

Synthesis of 6- and 9-alkylaminomethyl furoflavones as gastroprotective agents

The synthesis of 9- and 6-alkylaminomethyl furoflavones 5a, b, 9a-c, 13a, b, 15a-g and 18 from the naturally occurring chromones visnagin and khellin. Gastroprotective potency of these compounds in the ethanol damage model was determined. The results indicate that, through appropriate substitution, furoflavones can be obtained that are gastroprotective.

An economic model of long-term use of celecoxib in patients with osteoarthritis

Background

Previous evaluations of the cost-effectiveness of the cyclooxygenase-2 selective inhibitor celecoxib (Celebrex, Pfizer Inc, USA) have produced conflicting results. The recent controversy over the cardiovascular (CV) risks of rofecoxib and other coxibs has renewed interest in the economic profile of celecoxib, the only coxib now available in the United States. The objective of our study was to evaluate the long-term cost-effectiveness of celecoxib compared with nonselective nonsteroidal anti-inflammatory drugs (nsNSAIDs) in a population of 60-year-old osteoarthritis (OA) patients with average risks of upper gastrointestinal (UGI) complications who require chronic daily NSAID therapy.

Methods

We used decision analysis based on data from the literature to evaluate cost-effectiveness from a modified societal perspective over patients' lifetimes, with outcomes expressed as incremental costs per quality-adjusted life-year (QALY) gained. Sensitivity tests were performed to evaluate the impacts of advancing age, CV thromboembolic event risk, different analytic horizons and alternate treatment strategies after UGI adverse events.

Results

Our main findings were: 1) the base model incremental cost-effectiveness ratio (ICER) for celecoxib versus nsNSAIDs was $31,097 per QALY; 2) the ICER per QALY was $19,309 for a model in which UGI ulcer and ulcer complication event risks increased with advancing age; 3) the ICER per QALY was $17,120 in sensitivity analyses combining serious CV thromboembolic event (myocardial infarction, stroke, CV death) risks with base model assumptions.

Conclusion

Our model suggests that chronic celecoxib is cost-effective versus nsNSAIDs in a population of 60-year-old OA patients with average risks of UGI events.

Non-steroidal anti-inflammatory drug-induced gastroduodenal injury: therapeutic recommendations

Non-steroidal anti-inflammatory drug (NSAID) use is associated with gastro-duodenal erosions and ulcers. Bleeding and perforation are reported complications in NSAID users. Therapeutic recommendations for NSAID-induced gastroduodenal injury are necessary because of our rapidly growing geriatric population, a steady increase in prescriptions for NSAIDs, and the widespread use of over-the-counter NSAIDs. Studies seem to indicate that there is no relationship between acute NSAID-induced mucosal injury and potential damage from chronic NSAID ingestion. Ranitidine (150 mg) b.d. effectively reduces the incidence of duodenal ulcer in NSAID users, but the same dose does not reduce the incidence of gastric ulcer. Misoprostol is effective in reducing the incidence of gastric ulcer in NSAID users, although confirmatory data on its effectiveness in preventing NSAID-induced duodenal ulcer are lacking. In addition to anti-ulcer therapy, treatment of NSAID-induced ulcers includes discontinuing the drug, reducing the dose, or switching to a less potent NSAID. Longer courses of anti-ulcer treatment may be required to achieve expected healing rates when NSAIDs are not discontinued. Results of treatment of NSAID-related ulcers with currently available anti-ulcer medications vary. Several studies have shown that 150 mg ranitidine b.d heals both gastric and duodenal NSAID-induced ulcers. Sucralfate has also been shown to heal NSAID-induced duodenal ulcers. Misoprostol treatment of NSAID-induced ulcers is not well documented, although there are placebo-controlled data that substantiate its benefit in gastric ulcer patients not taking NSAIDs.

Pathophysiology of NSAID-induced gastroduodenal damage: epidemiology and mechanisms of action of therapeutic agents

All NSAIDs cause gastroduodenal mucosal damage. The mechanisms by which NSAIDs damage the mucosa are not fully understood. Peptic ulcers appear to be caused by an imbalance between acid output and mucosal resistance; therapeutic agents that act favourably on either variable will heal NSAID-induced ulcers, particularly if the NSAID is discontinued. Inhibition of acid secretion and/or stimulation of prostaglandin secretion are also believed to have a protective effect against NSAID-induced mucosal damage. Thus, antisecretory agents, such as the H2 blockers, and prostaglandin analogues, such as misoprostol, can provide protection against NSAID-induced gastroduodenal damage.

Nonsteroidal anti-inflammatory drugs induce hypermotilinemia and disturbance of interdigestive migrating contractions in instrumented dogs

Nonsteroidal anti-inflammatory drugs (NSAIDs) induce gastric ulcers due to inhibition of prostaglandin production. Prostaglandins have an influence on physiological gastrointestinal motility, but the relationships between NSAID-induced gastric ulcer, gastrointestinal motility and motilin are unknown. Fifteen dogs were allocated randomly to three groups in which either gelatin, meloxicam or indomethacin was administered. Fecal occult blood and gastrointestinal motility were monitored continuously for 6 days. In addition, analyses of the plasma motilin concentration, gastrointestinal endoscopy and gastric emptying, and detection of motilin cells were performed. Gastrointestinal motility was disturbed in the indomethacin group, presenting as disappearance of interdigestive migrating contractions (IMCs) 3 days before gastric ulcers were detected. Delayed gastric emptying and hypermotilinemia were observed significantly more often in the indomethacin group compared with the other groups. Motilin cell-crypt/villi ratio in the indomethacin group significantly decreased in the duodenum and jejunum, compared with the other groups. No significant changes in any tests were observed in the meloxicam group, when compared with the gelatin group. These findings suggest that the disturbance of IMCs caused by hypermotilinemia, with changes in motilin cell distribution, and delayed gastric emptying induced by indomethacin may contribute to the development of gastric ulcers.

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.

Gastric ulcers and risk for cancer. Is follow-up necessary for all gastric ulcers?

The aim of this study was to determine the accuracy of initial endoscopy combined with histology and to define whether there is a point in following-up all gastric ulcers until complete healing. We have studied all patients with gastric ulcers documented at endoscopy during a 6-year period. Ulcers were macroscopically characterised as benign or suspicious for malignancy, and biopsies were taken. A follow-up endoscopy and histology was performed 4-6 weeks and 3 months after an anti-ulcer treatment. Resistant ulcers were treated surgically. All patients were followed-up clinically and endoscopically for a year after complete ulcer healing. 802 patients with gastric ulcers were enrolled. At initial endoscopy, 732 ulcers (91.3%) were macroscopically characterised as benign and 70 ulcers (8.7%) as suspicious for malignancy. In the group of endoscopically benign ulcers, only one (0.1%) had malignancy detected by biopsy in the first examination. None of these ulcers turned out to be malignant on subsequent examinations. From the suspicious for malignancy ulcers, 20 (28.6%) were proven to be malignant. Endoscopy may recognise with great accuracy benign ulcers, but it overestimates the malignant ones. The cost-benefit of serial follow-up endoscopies should be re-evaluated in ulcers that appear benign, and biopsies are negative at the initial examination.

Impact de l’infection à Helicobacter pylori sur le risque de complications gastro-duodénales des traitements anti-inflammatoires non stéroïdiens

The interaction of Helicobacter pylori (H. pylori) and non steroidal anti-inflammatory drugs (NSAIDs) on the development of gastro-duodenal ulcers and their complications is complex and controversial. From a clinical point of view, the question is whether or not H. pylori infection should be tested and eradicated in patients treated or about to be treated by NSAIDs or low-dose aspirin. Contradictory results have been reported in epidemiological studies. Recent data suggest that H. pylori-NSAID interaction may be different depending on the type of treatment, non aspirin NSAIDs or low-dose aspirin, the gastric or duodenal localization of ulcer and the strains of H. pylori. Controlled randomized studies suggest that eradication of H. pylori may be beneficial in NSAID-naïve patients but not in those already on long term NSAID therapy. Recommendations are proposed for different subgroups of patients. In NSAID users presenting with gastro-duodenal ulcer or complications, H. pylori screening and eradication are indicated. In patients treated or about to be treated by NSAIDs, the "test and treat" H. pylori strategy is recommended if there is a history of gastroduodenal ulcer or complications. Whether this strategy should be generalized preventively in patients without ulcer history is still controversial and deserves further studies.

Magnesium hydroxide in ibuprofen tablet reduces the gastric mucosal tolerability of ibuprofen

GOAL

The study was designed to compare the gastrointestinal tolerability of a magnesium hydroxide-containing ibuprofen tablet (buffered ibuprofen) and the conventional ibuprofen tablet in healthy volunteers.

BACKGROUND

Magnesium hydroxide has been shown to increase the rate of absorption of ibuprofen.

METHODS

A double blind, randomized, 2-period crossover study design was used. Twenty healthy men ingested 800 mg ibuprofen 3 times daily either in conventional tablets (2 doses of 400 mg) or in tablets containing magnesium hydroxide (2 doses of 400 mg ibuprofen and 200 mg magnesium hydroxide). On the 5th day only the morning dose was administered. Endoscopy was performed at baseline and on the 5th day in both treatments 2 hours after the last dose, and gastric pH was determined. In addition, plasma concentrations of ibuprofen were determined up to 90 minutes.

RESULTS

The magnesium hydroxide-containing formulation increased the number of subjects evincing erosions in gastric corpus and antrum. In the gastric corpus 2 and 7 volunteers had erosions after conventional and buffered ibuprofen, respectively (P = 0.08). In the gastric antrum 5 and 13 volunteers showed erosions after conventional and buffered ibuprofen, respectively (P = 0.02). There was a trend toward faster absorption of ibuprofen when given together with magnesium hydroxide. The difference was not however statistically significant.

CONCLUSIONS

Prolonged use of magnesium hydroxide together with high doses of ibuprofen should be avoided, because the combination may incur a higher risk of gastrointestinal irritation.

The CINOD, AZD3582, exhibits an improved gastrointestinal safety profile compared with naproxen in healthy volunteers

COX-inhibiting nitric oxide donators (CINODs) are a new class of drugs in development for the treatment of acute and chronic pain. They comprise a COX-inhibiting moiety linked to a nitric-oxide-donating component and are designed to provide an innovative mechanism of action of balanced COX inhibition and controlled nitric oxide donation. Through these pathways, CINODs should provide analgesic and anti-inflammatory efficacy, while offering gastrointestinal safety through the tissue-protective effects of nitric oxide donation. AZD3582 [4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl)propanoate] is the first agent in the CINOD class to enter extensive clinical development. Pre-clinical studies demonstrate that AZD3582 has a superior gastrointestinal safety profile to naproxen, while demonstrating analgesic and anti-inflammatory efficacy. In healthy human volunteers, AZD3582 caused little gastrointestinal damage compared with equimolar doses of naproxen. Studies to evaluate the longer-term gastrointestinal safety of AZD3582, alongside its efficacy in alleviating chronic and acute pain, are ongoing.

Changing rates of Helicobacter pylori testing and treatment in patients with peptic ulcer disease

OBJECTIVES

The aim of this study was to identify temporal trends in the rate of Helicobacter pylori (H. pylori) testing, prevalence, and treatment among patients with peptic ulcer disease in Olmsted County, MN, from 1984 through 1997.

METHODS

All 3317 Olmsted County residents with a clinical diagnosis of peptic ulcer disease at the Mayo Clinic from 1984 through 1997 were identified. The complete medical records of an age-, sex-, and calendar year-stratified random sample were reviewed (n = 720); 298 patients (41%) had confirmed peptic ulcer disease. Changes in proportions of H. pylori testing, infection, and treatment over time were analyzed by logistic regression.

RESULTS

Of the 298 patients with confirmed peptic ulcer disease, 32% were tested for H. pylori; 36% were positive for infection, of whom 66% received antibiotic therapy. The rate of testing for H. pylori increased from 0% in 1984 to 96% in 1997, but the prevalence of infection did not change (36.4% vs 36.5%). The rate of treatment of those infected increased from 0% to 95%. By logistic regression, calendar year was associated with H. pylori testing and treatment but not infection. Recent use of nonsteroidal anti-inflammatory drugs was reported by 58% of patients, and 44% presented with GI bleeding.

CONCLUSIONS

Physicians' practice of testing and treating for H. pylori in patients with confirmed peptic ulcer disease has steadily increased over the past 14 yr. However, in our study, only 36% of these patients were infected with H. pylori, whereas the majority used nonsteroidal anti-inflammatory drugs (NSAIDs). Therefore, testing seems to be more appropriate than empiric treatment in patients with peptic ulcer disease.

Prevention and treatment of gastrointestinal symptoms and complications due to NSAIDs

The mechanisms by which aspirin(ASA) and non-steroidal anti-inflammatory drugs (NSAIDs) cause gastrointestinal symptoms are poorly understood. They probably arise from several causes, including direct and indirect mucosal injury, exacerbation of underlying peptic ulcer disease or non-ulcer dyspepsia, exacerbation of Helicobacter pylori gastritis, and possibly motility disorders. No single form of therapy has been generally successful. Because, in most cases, symptoms abate fairly rapidly with continued treatment, there is little evidence that benefit associated with any symptom-directed drug therapy is superior to placebo beyond 4 weeks. Exceptions may be the subsets of patients with pre-existing ulcer disease or heartburn, exacerbated by the NSAID therapy, who usually benefit from acid-suppressive drug treatment. Different NSAIDs vary in the frequency with which their use leads to gastrointestinal(GI) complications such as haemorrhage, perforation, obstruction, or the symptomatic ulcers from which about 40% of the complications arise. Most gastroduodenal ulcers heal over time, albeit more slowly, with conventional doses of any of the available anti-ulcer drugs. Maintenance therapy may be needed in many patients who continue NSAID therapy. Anti-ulcer drugs have not, thus far, been shown to be more effective than placebo in preventing ulcer complications or their recurrence. The use of COX-2-selective inhibitors appears, in outcome studies, to reduce gastrointestinal bleeding, including bleeding from ulcers, but it is not established that the ulcers protected were caused by NSAIDs, as distinct from ulcers exacerbating or recurring from antecedent peptic ulcer disease. To-date, perforation or obstruction have not been shown to be affected by selective COX-2 inhibitor drugs. If the major problem giving rise to severe NSAID complications is pre-existing peptic ulcer disease, it may yet emerge that the most effective approach will be the use of proton pump inhibitor drugs, for the duration of NSAID therapy, in a small subset of high-risk patients. Most other low-risk patients may not need any special care. Co-morbid conditions have a major impact on outcome of NSAID therapy. Morbidity or even death attributable solely to NSAIDs is probably small in normal patients, and requires little in the way of prophylaxis.

Epidemiology of NSAID-related gastroduodenal mucosal injury

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the agents most frequently used against musculoskeletal and rheumatic disorders throughout the world. The gastroduodenal adverse effects include dyspepsia without endoscopically proven damage, asymptomatic endoscopic lesions of submucosal haemorrhage, erosions and ulcers, and-most important-ulcer complications. Established risk factors for NSAID-associated ulcer complications include patient-specific factors such as advanced age, female gender, a history of peptic ulcer, and drug-specific factors such as the use of non-selective NSAIDs (type, dose, duration, multiple use) and concomitant anticoagulant drugs or corticosteroids. Probable risk factors comprise Helicobacter pylori infection and heavy consumption of alcohol, whereas use of selective serotonin re-uptake inhibitors, smoking and a number of other factors have also been proposed to contribute. Knowledge of absolute risk estimates is important for clinical decision making. The aim of this chapter is to summarize the epidemiological data related to the broad spectrum of iatrogenic gastroduodenal mucosal injury.

Liver penetration by a duodenal ulcer in a young woman

Liver penetration is a rare but serious complication of peptic ulcer disease. We report a case of a 33-year-old woman who took large doses of nonsteroidal antiinflammatory drugs and developed a giant duodenal ulcer that penetrated into her liver. The diagnosis was based on histologic examination of endoscopic biopsies. She was initially treated with a proton pump inhibitor, but, within 5 weeks, she developed a symptomatic postbulbar stricture that required surgical correction. We also review 11 other reported cases of endoscopically and histologically diagnosed peptic ulcer penetration into the liver.

Nonsteroidal anti-inflammatory drugs

NSAID-associated dyspeptic symptoms are common and can be managed empirically with an H2-receptor antagonist or a proton-pump inhibitor. Treatment of established gastroduodenal ulcers is accomplished best by withholding the offending drugs. Proton-pump inhibitors appear to heal ulcers at the same rate whether or not NSAID therapy is continued. After the ulcer is healed and if NSAID therapy must be continued, prophylaxis is accomplished best by the concomitant use of proton-pump inhibitors, misoprostol (at least 200 micrograms 3 times a day), or a NSAID that preferentially inhibits COX-2. The future development of newer, safer NSAID preparations, including highly selective COX-2 inhibitors and nitric oxide-releasing NSAIDs, should provide better treatment options for the increasing number of individuals requiring anti-inflammatory agents.

The gastroduodenal toxicity of nonsteroidal anti-inflammatory drugs: a review of the literature

Nonsteroidal anti-inflammatory drugs (NSAIDs) are popular and important for the treatment of inflammation and pain. However, conventional NSAIDs are intrinsically toxic to the gastroduodenal (GD) mucosa. The literature can, and should, guide us towards safer prescribing of NSAIDs. Factors known to increase the risk of GD toxicity include: history of peptic ulcer disease; advanced age; high doses; and coadministration of aspirin, anticoagulants or corticosteroids. Patients with any one of these risk factors, with the possible exception of age alone, should receive gastroprotective prophylaxis with proton pump inhibitors or misoprostol. Standard dose H2 antagonists do not protect against NSAID-induced gastric ulcers and are unsuitable for prophylaxis. Awareness of risk factors and appropriate prophylactic agents will minimize the risk to patients. Whether the new generation of highly selective COX-2 inhibitors and nitric oxide-donating NSAIDs are safer drugs in long-term use be remains to be proven, though initial clinical trial data are positive.

The effects of omeprazole on healing and appearance of small gastric and duodenal lesions during dosing with diclofenac in healthy subjects

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are associated with gastrointestinal mucosal damage. Omeprazole prevents the formation, and accelerates the healing, of NSAID-induced ulcers.

AIM

To test whether omeprazole accelerates healing of standardized gastroduodenal lesions in the presence of diclofenac.

METHODS

In a double-blind, double-dummy, placebo-controlled, crossover study, 12 healthy volunteers received consecutive, 2-week courses of omeprazole (40 mg o.d.) and placebo, in random order, with an intervening, 4-week washout period; diclofenac (50 mg t.d.s.), was given for the second week of each course. Five endoscopies were performed, one at the outset and the others before and after each course of diclofenac. Biopsies were taken from the endoscopically normal mucosa of the corpus, antrum and duodenum and also from any new mucosal lesion that developed after diclofenac. The sites of biopsies taken before each course of diclofenac were evaluated endoscopically after each course to assess the extent of healing according to a predetermined healing score scale.

RESULTS

The healing scores observed after administration of placebo/diclofenac (median=0; range 0-6) and after omeprazole/diclofenac (median=0; range 0-6; P=0.17) did not differ. Small gastroduodenal lesions developed de novo in six subjects during placebo/diclofenac and in seven during omeprazole/diclofenac. Focal chemical gastropathy was observed only in close proximity to macroscopic lesions.

CONCLUSIONS

In healthy subjects, omeprazole does not accelerate the healing of pre-existing mucosal lesions or prevent the development of small diclofenac-induced mucosal lesions.

Non-steroidal anti-inflammatory drugs, Helicobacter pylori and bleeding gastric ulcer

BACKGROUND

Helicobacter pylori infection and NSAID usage are considered to be independent risk factors for gastric ulcer (GU). Whether they interact to influence the risk of bleeding in GU is unclear.

AIM

To determine the prevalence of H. pylori infection and NSAID ingestion in a group of patients with GU and determine their roles in bleeding and non-bleeding GU.

METHODS AND RESULTS

From January 1993 to June 1996, a total of 217 GU patients (150 male, 67 female, median age 61 years, range 26-94) were eligible for the study. Eighty-five per cent were H. pylori-positive and 15% were H. pylori-negative. NSAID usage within 4 weeks prior to endoscopy was present in 30%, more in the H. pylori-negative than H. pylori-positive patients (59% vs. 25% P = 0.0002). Aspirin was most commonly used (43%). One hundred patients bled from GU (69 male, 31 female, mean age 67 years, range 26-94) and 117 did not (81 male, 36 female, mean age 57 years, range 28-86). Univariate logistic regression showed that advanced age (>/= 65 years) and NSAID usage carried an increased risk of bleeding GU (odds ratio 3.4 and 6.8, respectively) while H. pylori infection alone was not associated with additional risk (OR = 0.8). However, when three variables were considered jointly in a multiple logistic regression, the OR associated with H. pylori infection increased to 2.4, suggesting that in the presence of NSAIDs and advanced age, H. pylori also increases the risk of bleeding GU, indicating an interaction between the variables.

CONCLUSION

NSAID usage and advanced age are risk factors for bleeding GU, whereas H. pylori infection by itself is not. In the presence of NSAIDs and advanced age, an increased risk of bleeding GU with H. pylori is observed, indicating the possibility of an interaction between these factors.

Comparative toxicity of nonsteroidal anti-inflammatory drugs

To compare the gastrointestinal (GI) toxicities of various nonsteroidal anti-inflammatory drugs (NSAIDs), it is first necessary to dismantle the imprecise entity "NSAID gastropathy" into its component conditions, and understand their pathogenesis. In this article, toxicities are reviewed only in so far as they affect the upper GI tract, the site of approximately 80% of GI injuries caused by NSAIDs. The phenomena discussed are platelet dysfunction, causing hemorrhage from various lesions, including but not confined to ulcers; various mucosal injuries, ranging from small erosions to large ulcers; and "complications," such as bleeding or perforations, causing admission to hospital, that may arise from ulcers but may also arise from other lesions. Ulcers, when complicated, may either be those caused by an NSAID or "peptic" ulcers that preceded NSAID therapy (having a high prevalence in the population) and gave rise to complications resulting from NSAID effects on platelets, tissues, or biologic processes, for example, healing, necrosis/apoptosis, leukocyte adherence, vasoconstriction, or generation of free radicals. NSAIDs have been compared in various ways, including fecal blood loss, endoscopic lesion development, prospective preclinical cohort studies measuring perforations, ulcers, and bleeds, post-marketing surveillance studies, and studies of the incidence of serious adverse events in populations followed in large databases linked to each individual patient record with regard to drug consumption and outcome. All methods show considerable differences between NSAIDs. Modern studies on the relative toxicities of NSAIDs are summarized and reviewed, and a number of marketed and emerging drugs that appear less toxic than classic NSAIDs are identified.

Effect of naproxen on the hamster gastric antrum: ulceration, adaptation and efficacy of anti-ulcer drugs

BACKGROUND

Various animal models of non-steroidal anti-inflammatory drug (NSAID)-induced gastric ulceration exist. These models have limitations, which make them less relevant to the human situation.

AIM

: To develop a more simple and more relevant model of NSAID-induced gastric ulceration and adaptation.

METHODS

Gastric ulceration was evaluated following the orogastric administration of naproxen (80 mg/kg b.d.) to hamsters. The effects of misoprostol and famotidine on gastric acid secretion and ulceration were also determined. Gastric adaptation was evaluated by proliferating cell nuclear antigen (PCNA) immunohistochemistry, in hamsters given naproxen for 3 weeks. Antral resistance to acute injury by NSAIDs and ethanol was also determined in these animals.

RESULTS

Naproxen caused primarily gastric antral ulceration, which decreased from day 3 to day 21. This gastric adaptation was accompanied by an increase in PCNA positive cells, particularly on days 7 and 14. The adapted gastric antral mucosa was resistant to acute damage by various agents. Misoprostol (1 or 100 microg/kg) prevented antral ulceration, without affecting gastric acid secretion. Despite decreasing acid output by> 90%, famotidine (30 mg/kg) failed to prevent ulceration.

CONCLUSION

The administration of naproxen (80 mg/kg b.d.) to hamsters is a simple, reliable and relevant method for evaluating NSAID-induced gastric antral ulceration and adaptation.

Dyspepsia and heartburn

Dyspepsia and heartburn are the two cardinal symptoms of foregut dysfunction. When confronting such a problem, that physician must first learn to discern between the two, because treatment can be quite different for the conditions presenting with these symptoms. This article details the approach to work-up and treatment of patients presenting with dyspepsia or heartburn.

Gastric ulcer formation after the Hanshin-Awaji earthquake: a case study of Helicobacter pylori infection and stress-induced gastric ulcers

BACKGROUND

Both Helicobacter pylori (H. pylori) infection and various stresses are known to induce peptic ulcer disease of the upper gastrointestinal tract. However, the pathogenetic relationship between the two factors has not yet been clarified. We conducted a case-control study to examine whether H. pylori infection played a role in the development of gastric ulcer (GU) induced by life-event stresses that were experienced after the Hanshin-Awaji earthquake.

MATERIALS AND METHODS

Serum samples from patients in the devastated area who developed GUs during the 2 months following the Hanshin-Awaji earthquake and those from GU patients in the same area during the corresponding period of the previous year, and from gender-, age- and institute-matched ulcer-free controls were tested for the presence of the H. pylori IgG antibody.

RESULTS

A significant association between H. pylori infection and the development of GU in uninjured patients was observed in all sets [matched odds ratio (OR) = 3.23, 95% confidence interval: 1.95-5.35]. Moreover, the prevalence of H. pylori infection in patients who developed GUs after the earthquake was not different from that for GU patients in the previous year. In contrast, there was no association between H. pylori infection and the development of GU in the physically injured patients after the earthquake.

CONCLUSIONS

H. pylori infection may play an important role in the development of GUs that are induced by emotional life-event stresses.

Comparison of the upper gastrointestinal safety of Arthrotec 75 and nabumetone in osteoarthritis patients at high risk for developing nonsteroidal anti-inflammatory drug-induced gastrointestinal ulcers

A 6-week, multicenter, double-masked, placebo-controlled, parallel-group study compared the upper gastrointestinal (UGI) safety of Arthrotec 75 (diclofenac sodium 75 mg-misoprostol 200 microg; G.D. Searle & Co., Skokie, Illinois) administered twice daily with that of nabumetone 1500 mg administered once daily in 1203 patients with symptomatic osteoarthritis (OA) of the hip or knee. All patients had a documented clinical history of endoscopically confirmed gastric, pyloric-channel, or duodenal ulcer or > or = 10 erosions in the stomach or duodenum. UGI endoscopy was performed at baseline and again at week 6 or early withdrawal. Treatment with Arthrotec 75 resulted in a significantly lower combined incidence of endoscopically confirmed gastric and duodenal ulcers compared with nabumetone (4% vs 11%), and its rate of endoscopically confirmed ulceration was equivalent to that of placebo. The incidence of gastric ulcers alone was also significantly lower with Arthrotec 75 than with nabumetone (1% vs 9%). The incidence of duodenal ulcer with Arthrotec 75 was not significantly different from that with nabumetone (4% vs 3%). Types of adverse events were similar for all treatment groups, with GI adverse events predominating. Arthrotec 75 was well tolerated by the majority of patients. The results of this study demonstrate that Arthrotec 75 has a superior UGI safety profile, causing significantly fewer UGI ulcers, in comparison with nabumetone in patients with symptomatic OA and a documented history of ulcers or > or = 10 erosions.

Nonsteroidal anti-inflammatory drug-related gastrointestinal toxicity: definitions and epidemiology

Nonsteroidal anti-inflammatory drug (NSAID)-associated gastrointestinal (GI) toxicity is a broad topic encompassing symptoms as well as severe GI complications. GI bleeding and perforation are the 2 overlapping components that account for the majority of deaths and disability associated with these drugs. Abnormal gastric endoscopic profiles as well as symptoms such as heartburn, pain, and dyspepsia are common in NSAID users, but no correlation has been found between these factors and the occurrence of the more severe complications; therefore, neither symptoms nor endoscopic observations can necessarily be considered reliable predictors of future outcomes. Confounding factors can increase the risk of complications, and specific NSAIDs vary in the magnitude and type of risk attending their use. Recent studies have focused on the contribution of nonprescription NSAIDs to total complications, and combined with evidence suggesting that the risk is greatest during the first month of NSAID use, it is apparent that NSAID toxicity is an acute as well as a chronic problem.

Recent considerations in nonsteroidal anti-inflammatory drug gastropathy

Conservative calculations estimate that approximately 107,000 patients are hospitalized annually for nonsteroidal anti-inflammatory drug (NSAID)-related gastrointestinal (GI) complications and at least 16,500 NSAID-related deaths occur each year among arthritis patients alone. The figures for all NSAID users would be overwhelming, yet the scope of this problem is generally under-appreciated. The Arthritis, Rheumatism, and Aging Medical Information System (ARAMIS) Post-Marketing Surveillance Program (PMS) has prospectively followed patient status and outcomes, drug side effects, and the economic impact of illness for >11,000 arthritis patients at 8 participating institutions in the United States and Canada. Analysis of these data indicates that: (1) osteoarthritis (OA) and rheumatoid arthritis (RA) patients are 2.5-5.5 times more likely than the general population to be hospitalized for NSAID-related GI events; (2) the absolute risk for serious NSAID-related GI toxicity remains constant and the cumulative risk increases over time; (3) there are no reliable warning signals- >80% of patients with serious GI complications had no prior GI symptoms; (4) independent risk factors for serious GI events were age, prednisone use, NSAID dose, disability level, and previous NSAID-induced GI symptoms; and (5) antacids and H2 antagonists do not prevent NSAID-induced gastric ulcers, and high-risk NSAID users who take gastro-protective drugs are more likely to have serious GI complications than patients not taking such medications. Currently, limiting NSAID use is the only way to decrease the risk of NSAID-related GI events. Ongoing ARAMIS research is aimed at developing a simple point-score system for estimating individual risks of developing serious NSAID-related GI complications.

Aspirin-induced gastritis, like Helicobacter pylori-induced gastritis disinhibits acid secretion in humans: relation to cytokine expression

BACKGROUND

Helicobacter pylori infection contributes to hypergastrinemia and hypersecretion of acid by blocking inhibitory reflex pathways to gastrin and parietal cells normally activated by antral distention. Our aim was to investigate whether a similar blockade of inhibitory responses could be provoked by inducing gastritis with aspirin, thus implicating a common inflammatory component, possibly a proinflammatory cytokine(s).

METHODS

We studied the effects of antral distention on stimulated acid secretion and gastrin release in H. pylori-negative volunteers, before and after 3 days of aspirin therapy (2 g daily). Immediately before the examinations, the severity of gastric mucosal injury was evaluated macroscopically and histologically, and the production of interleukin (IL)-1beta, IL-6, IL-8, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma was determined by immunohistochemistry.

RESULTS

Most subjects had severe gastric injury after aspirin therapy, resulting in a substantially increased production of IL-1beta, IL-6, and IL-8 but not of TNF-alpha and IFN-gamma in the antral mucosa. In these subjects the acid-inhibitory response was abolished or markedly reduced. Conversely, aspirin therapy failed to affect the gastrin release in all subjects studied.

CONCLUSIONS

The disinhibition of acid secretion in response to antral distention is a joint feature of the gastritis induced by aspirin and H. pylori infection, possibly related to the increased production of IL-1beta, IL-6, and IL-8. The H. pylori-related hypergastrinemia apparently has a different background.

Review article: non-steroidal anti-inflammatory drug-induced gastrointestinal permeability

Non-steroidal anti-inflammatory drugs induce damage throughout the entire gastrointestinal tract. Administration of site-specific permeability probes is a non-invasive technique for assessing the functional integrity of the gastrointestinal mucosa. A systematic search tor NSAID-induced permeability studies using MEDLINE and EMBASE, and an analysis of the literature on NSAID-induced gastrointestinal permeability, were carried out. The advantages and disadvantages of the various probes and study protocols are discussed. Identification of the underlying mechanisms of regulatory control of the epithelial tight junction is still needed. A greater appreciation of the pharmacokinetics and distribution of NSAIDs, coupled with gastrointestinal permeability studies, may help delineate the pathogenesis of NSAID-induced gastrointestinal toxicity. Non-invasive tests of gastric, intestinal and colonic permeability have shown promise in both basic research and in clinical practice. While such tests could not replace endoscopy, they may represent clinically useful techniques for identifying patients who would benefit from endoscopy, to assess the response to treatment, and perhaps to predict the clinical course of disease.

Use and benefits of nonsteroidal anti-inflammatory drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs) continue to be used very widely in the community. Their use reflects the significant burden of rheumatic disease on the general population, and they form a basis for the treatment of inflammation in and around the joint. Furthermore, NSAIDs are also being used increasingly for nonrheumatic conditions, including acute and chronic pain, biliary and ureteric colic, and dysmenorrhea. Recent studies in osteoarthritis have suggested that a significant number of patients previously maintained on NSAIDs can be equally well treated using analgesic agents, such as paracetamol. In noninflammatory rheumatic diseases, analgesics and physical therapies should be the initial treatment of choice and, even in inflammatory rheumatic diseases, NSAID use may be reduced by the addition of pure analgesics to the treatment regimen. A large number of NSAIDs now exist, and there is variability in clinical response to NSAIDs among individual patients. Concern over the widespread use of NSAIDs is largely related to their side-effects. These include adverse reactions in the gastrointestinal tract, kidney, liver, dermis, and central nervous system, as well as hematologic problems. The potential for drug interactions with NSAIDs is also large, as they are often administered to a population with significant co-morbidities. NSAIDs play a major role in the management of acute and chronic rheumatic diseases, but their use needs to be tempered with the realization that they can cause potentially serious adverse reactions. These side-effects can be reduced by careful attention to the dose and duration of therapy, concomitant risk factors, and the combined use of more specific drugs to reduce disease activity. Furthermore, the gastrointestinal side-effects of NSAIDs may be treated and prevented by using appropriate therapy in combination with NSAIDs.

Omeprazole compared with misoprostol for ulcers associated with nonsteroidal antiinflammatory drugs. Omeprazole versus Misoprostol for NSAID-induced Ulcer Management (OMNIUM) Study Group

BACKGROUND

Misoprostol is effective for ulcers associated with the use of nonsteroidal antiinflammatory drugs (NSAIDs) but is often poorly tolerated because of diarrhea and abdominal pain. We compared the efficacy of omeprazole and misoprostol in healing and preventing ulcers associated with NSAIDs.

METHODS

In a double-blind study, we randomly assigned 935 patients who required continuous NSAID therapy and who had ulcers or more than 10 erosions in the stomach or duodenum (or both) to receive 20 mg or 40 mg of omeprazole orally in the morning or 200 microg of misoprostol orally four times daily. Patients were treated for four weeks or, in the absence of healing, eight weeks. Treatment success was defined as the absence of ulcers and the presence of fewer than five erosions at each site and not more than mild dyspepsia. We then randomly reassigned 732 patients in whom treatment was successful to maintenance therapy with 20 mg of omeprazole daily, 200 microg of misoprostol twice daily, or placebo for six months.

RESULTS

At eight weeks, treatment was successful in 76 percent of the patients given 20 mg of omeprazole (233 of 308), 75 percent of those given 40 mg of omeprazole (237 of 315), and 71 percent of those given misoprostol (212 of 298). The rates of gastric-ulcer healing were significantly higher with 20 mg of omeprazole (but not 40 mg of omeprazole) than with misoprostol. Healing rates among patients with duodenal ulcers were higher with either dose of omeprazole than with misoprostol, whereas healing rates among patients with erosions alone were higher with misoprostol. More patients remained in remission during maintenance treatment with omeprazole (61 percent) than with misoprostol (48 percent, P=0.001) and with either drug than with placebo (27 percent, P<0.001). There were more adverse events during the healing phase in the misoprostol group than in the groups given 20 mg and 40 mg of omeprazole (59 percent, 48 percent, and 46 percent, respectively).

CONCLUSIONS

The overall rates of successful treatment of ulcers, erosions, and symptoms associated with NSAIDs were similar for the two doses of omeprazole and misoprostol. Maintenance therapy with omeprazole was associated with a lower rate of relapse than misoprostol. Omeprazole was better tolerated than misoprostol.

Peptic ulcers after the Hanshin-Awaji earthquake: increased incidence of bleeding gastric ulcers

OBJECTIVE

Although physical stresses are known to induce peptic ulcers in the upper gastrointestinal tract, it remains controversial whether emotional stress can cause peptic ulcers. Therefore, we examined retrospectively the influence of the Hanshin-Awaji earthquake that occurred in Japan in January 1995 on the occurrence of peptic ulcer disease among noninjured residents.

METHODS

Sixty-one hospitals, covering 70% of all endoscopy examinations performed in this area, joined the study and were divided into three areas according to the severity of the damage. A comparison was made between a group of 10,831 patients who underwent upper gastrointestinal endoscopy within 2 months after the earthquake and 16,100 who did so in the same hospitals during the corresponding period in 1994.

RESULTS

In the most devastated area, in spite of a dramatic decrease in the total number of endoscopies (50.0%), patients with gastric ulcer (GU) were increased in 1995, whereas those with duodenal ulcer were decreased, resulting in a higher ratio of gastric to duodenal ulcers than in 1994 (3.07 vs 1.88). In particular, there was a marked increase in bleeding GU. The mean age of patients with GU was significantly higher in 1995 than in 1994.

CONCLUSION

The Hanshin-Awaji earthquake-induced life event stress not only triggered but also exacerbated GU, particularly in the elderly.

Gastrointestinal diseases in women

Gastrointestinal disorders are among the most common disorders for which women seek medical attention. Most gastrointestinal diseases in women are not inherently different from those that occur in men. There are several disorders, however, that occur more frequently or manifest themselves differently in women. This article reviews common gastrointestinal disorders affecting women. The pathophysiology, clinical manifestations, management, and gender-specific issues of gastroesophageal reflux disease, peptic ulcer disease, irritable bowel syndrome (IBS), and inflammatory bowel disease (IBD) are discussed.

Prevention of peptic ulcer and dyspeptic symptoms with omeprazole in patients receiving continuous non-steroidal anti-inflammatory drug therapy. A Nordic multicentre study

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are known to cause gastroduodenal lesions and dyspeptic symptoms.

METHODS

Patients with a history of dyspepsia or uncomplicated peptic ulcer disease and with a need for continuous NSAID treatment were randomized to receive either 20 mg omeprazole once daily or placebo. Gastroduodenal ulcers, erosions, and dyspeptic symptoms were evaluated after 1 and 3 months.

RESULTS

During a 3-month study period 4.7% (4 of 85) of omeprazole-treated patients developed peptic ulcer, compared with 16.7% (15 of 90) of patients treated with placebo. This prophylactic effect of omeprazole was sustained independently of previous peptic ulcer history or Helicobacter pylori status. Development of dyspeptic symptoms requiring active treatment, either alone or in combination with ulcer(s) or erosions, occurred in 15.3% (15 of 85) of patients treated with omeprazole and 35.6% of those who received placebo.

CONCLUSIONS

Omeprazole, 20 mg once daily, provides effective prophylactic therapy in patients at risk of developing NSAID-associated peptic ulcers or dyspeptic symptoms.