Ulcers, nonsteroidal antiinflammatory drugs, and related matters

Development andIn-VitroEvaluation of pH Responsive Polymeric Nano Hydrogel Carrier System for Gastro-Protective Delivery of Naproxen Sodium

Current research work was carried out for gastro-protective delivery of naproxen sodium. Polyethylene glycol-g-poly (methacrylic acid) nanogels was developed through free radical polymerization technique. Formulation was characterized for swelling behaviour, entrapment efficiency, Fourier transform infrared (FTIR) spectroscopy, Differential scanning calorimetry (DSC), and Thermal Gravimetric Analysis (TGA), Powder X-ray diffraction (PXRD), Zeta size distribution, and Zeta potential measurements, andin-vitrodrug release. pH dependent swelling was observed with maximum drug release at higher pH. PXRD studies confirmed the conversion of loaded drug from crystalline to amorphous form while Zeta size measurement showed size reduction. On the basis of these results it was concluded that prepared nanogels proved an effective tool for gastro-protective delivery of naproxen sodium.

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.

Smoking and hyperpepsinogenemia are associated with increased risk for duodenal ulcer in Helicobacter pylori-infected patients

BACKGROUND

Although Helicobacter pylori has been established as a major etiologic factor of chronic gastritis and makes an important contribution to peptic ulceration, the reason why H. pylori causes different gastroduodenal diseases in different people is at present not clear.

GOALS

The aim of this study is to identify risk factors associated with duodenal ulcers in H. pylori-infected patients in a multivariate context.

STUDY

Demographic data, personal habits, stressful life events, psychologic distress, severity of histology of antral mucosa, and serum pepsinogen I concentrations were studied in 54 consecutive dyspeptic patients with duodenal ulcers and 40 patients with functional dyspepsia.

RESULTS

As compared with functional dyspepsia patients, duodenal ulcer patients had more smokers (53.7% vs. 12.5%, P=0.000), higher pepsinogen I levels (median 96.0 vs. 74.5 ng/mL; P=0.002), more males (74.1% vs. 42.5%, P=0.004), more single (22.6% vs. 7.5%, P<0.05), and less in religion belief (44% vs. 70%, P<0.05). Only smoking remained significant on multivariate analysis (odds ratio=10.86, 95% CI=2.92-40.41, P<0.001). Among nonsmokers, only serum pepsinogen I level was found higher in duodenal ulcer patients as compared with functional dyspepsia patients (88 vs. 71, P<0.05).

CONCLUSIONS

Smoking and hyperpepsinogenemia are associated with increased risk for duodenal ulcer in H. pylori-infected patients.

Clinical implications of prostaglandin inhibition in the small bowel

NSAID-induced intestinal toxicity is more common than previously recognized and may have clinically significant sequelae, especially in elderly arthritic patients. Increased awareness of the potential intestinal complications associated with prostaglandin inhibition is required for early recognition and appropriate management. An increase in the level of suspicion by physicians may lead to earlier diagnosis and subsequent discontinuation of the offending NSAID; this is important in that discontinuation of the offending agent may be preferable to multiple endoscopic radiologic and surgical procedures in the patient with obscure blood loss and anemia. Appropriate diagnosis in selected patients may prevent the increased morbidity and mortality associated with small intestinal surgery. The emergence of selective COX-2 inhibitors likely will bring this issue to the forefront because it will become increasingly important to determine the effects of these agents on the small intestine and colon, in addition to their effects on the gastroduodenal mucosa. The new generation of selective COX-2 inhibitors may offer a potential therapeutic advantage over the nonselective NSAIDs with respect to their intestinal toxicity. Well-designed safety trials that have intestinal injury as a predefined end point will provide important information as to the overall gastrointestinal safety of these compounds. These agents must be evaluated with respect to their overall safety profile and not just by their gastrointestinal safety. Nevertheless, these agents are continuing to provide new directions for exciting basic and clinical scientific investigation.

Peptic ulcer disease in children

A peptic ulcer in a child looks the same as it does in an adult, and many of the aetiologies of peptic ulcer disease in children are similar to those in adults. However, there are many differences between children and adults, especially in the areas of clinical presentation, the prevalences of different types of ulcer disease, and the prevalence of complications of ulcer disease. Therefore the approach to diagnosis and management in children is often at variance with that in adults. One important example is the approach to suspected Helicobacter pylori (H. pylori) disease in children, in which consensus groups have advised a considerably different approach in children. While the chapter deals with the full range of peptic ulcer disease in children, the focus is on those aspects in which there are differences between adults and children.

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.

Prevention of gastric ulcer relapse induced by indomethacin in rats by a mutein of basic fibroblast growth factor

We found indomethacin aggravates healed gastric ulcers (ulcer relapse) in rats. In the present study, we examined the effects of human basic fibroblast growth factor (bFGF) mutein CS23 (TGP-580) and histamine H2-receptor antagonists (H2-RAs) on ulcer relapse in this model. In male SD rats, gastric ulcers were induced in the antrum by injection of acetic acid. Indomethacin (1 mg/kg/day) given s.c. for 2 weeks starting 4 weeks after the operation aggravated the healed ulcer; the areas with and without indomethacin were 4.8 +/- 1.4 and 0.4 +/- 0.3 mm2, respectively. Drugs were given orally once daily for 4 weeks starting 2 days after the operation or for the 2-week indomethacin administration period. Treatment with ranitidine (100 mg/kg), cimetidine (100 mg/kg) and TGP-580 (0.1 mg/kg) for 4 weeks accelerated the healing. The aggravation by indomethacin was significantly inhibited by pretreatment with TGP-580 and mildly inhibited by cimetidine but not ranitidine. When the drugs were co-administered with indomethacin for 2 weeks, the aggravation was significantly prevented by ranitidine and mildly inhibited by cimetidine and TGP-580. Both TGP-580 and H2-RAs can prevent the ulcer relapse induced by indomethacin but via different modes of action: TGP-580 inhibits relapse mainly by acting on the process of healing, while H2-RAs act mainly on the process of aggravation.

Indomethacin-induced lesion modifies contractile activity in rat small intestines

BACKGROUND

Indomethacin induces intestinal lesions. The change in contractility of segments with lesions was studied.

METHODS

Motility was recorded in segments with lesions isolated from the rat small intestine 24 h after a subcutaneous injection of indomethacin (20 mg/kg).

RESULTS

Concentration-contraction curves for acetylcholine shifted leftward independently of the degree of severity of lesions, but the curves for carbachol and 5-hydroxytryptamine did not. Contractions produced by intramural nerve stimulation were enhanced in segments with no visible damage but decreased with progression of lesions. Neostigmine augmented them in normal rats but not in indomethacin-treated rats. The peristaltic activity was enhanced in segments with no visible lesions.

CONCLUSIONS

The results suggest that treatment of the rat with indomethacin enhances contractility of the small intestine owing to diminution of acetylcholinesterase activity independently of the degree of lesions and reduces it owing to decreased responsiveness of enteric neurons with the progression of lesions.

The effect of misoprostol on aspirin-induced gastroduodenal lesions in dogs

Misoprostol, a synthetic prostaglandin E1 analog, is effective in treating and preventing nonsteroidal antiinflammatory drug (NSAID)--induced gastrointestinal lesions in humans. The effectiveness of misoprostol in preventing aspirin-induced gastroduodenal injury was studied in 3 groups of 6 adult mixed breed dogs. Group I received 3 micrograms/kg misoprostol PO tid. Group II received 3 micrograms/kg misoprostol PO tid and 35 mg/kg aspirin PO tid. Group III received 35 mg/kg aspirin PO tid. Endoscopy was performed on days 0, 5, 14, and 30. Five regions of the upper gastrointestinal tract were qualitatively scored from 1 to 12 based on the presence of submucosal hemorrhage, erosion, or ulceration, with ulceration receiving a higher numerical score than submucosal hemorrhage. A total score was assigned based on the sum of the scores from all regions. Comparisons among groups on each day were performed using the Kruskal-Wallis test. Differences within a group among different time periods were determined using appropriate multiple comparisons. Significant difference in mean gastroduodenal lesion score was found among all groups at 5, 14, and 30 days. Mean total score on days 5, 14, and 30 were as follows: group I, 5.0, 5.2, 9.0; group II, 12.0, 12.7, 16.2; and group III, 26.0, 23.8, 21.5, respectively. Significant differences within a group among different time periods were found from days 0 to 5 in groups I and II, and from days 14 to 30 in group I. It was concluded that misoprostol effectively decreased endoscopically detectable mucosal lesions in dogs given aspirin.

Pharmacokinetic optimisation of the treatment of peptic ulcer in patients with renal failure

The pathogenesis of peptic ulceration is not yet clear. It could be due to an imbalance between acid secretion and mucosal defensive and/or protective mechanisms, but the association between Helicobacter pylori and peptic ulceration has questioned this hypothesis. Therefore, drugs inhibiting acid secretion and/or eradicating H. pylori are of major interest. Peptic ulcer disease is often associated with renal failure. For the selection of the proper dosage of these agents their pharmacokinetic properties and alterations in pharmacokinetics in various disease states, including renal failure, should be known. As histamine H2-receptor antagonists and pirenzepine are mainly eliminated by the renal route their elimination is dependent on creatinine clearance. Consequently, their elimination will be impaired in patients with renal insufficiency, which makes dosage reduction mandatory in these patients. No dosage supplementation is necessary after any type of dialysis because the drugs are removed in insignificant amounts by the various blood purification procedures. Misoprostol and proton pump inhibitors, such as omeprazole, lansoprazole and pantoprazole, are primarily eliminated by nonrenal routes. Therefore no dosage adjustments are necessary in patients with renal insufficiency. Bismuth salts, sucralfate and antacids should be avoided in patients with renal failure because of the accumulation of their cations and the associated risk of toxic reactions. For most agents more long term experience from comparative and double-blinded studies is needed to define better their clinical efficacy and tolerability in patients with renal failure.

Review article: controversies in NSAID-induced gastroduodenal damage--do they matter?

BACKGROUND

This article reviews various issues surrounding NSAID-induced gastroduodenal ulceration, about which there appear to be conflicting views and data in the literature. These issues include the size, clinical relevance and main site of the problem; when complications occur (early or late?); the relevance of non-ulcer lesions and whether adaptation is a clinically relevant phenomenon.

METHOD

A comprehensive literature search was carried out to identify relevant new data published since 1987.

RESULTS

NSAIDs are causally associated with more gastric than duodenal ulcers but their use may be associated with duodenal ulcers or complications. Erosive lesions may progress to more severe damage. The theories of early or late onset of complications during a course of NSAID therapy may not be mutually exclusive.

CONCLUSIONS

Available data indicate that NSAID ulcers are at least as dangerous as classic peptic ulcers, and result in significant morbidity and mortality which in the patient population does not appear to be significantly reduced by processes such as adaptation.

Ingestion of aspirin prevents platelet-induced human fibroblast growth. Implications for peptic ulcer healing

Because aspirin (ASA) may affect peptic ulcer healing through actions on platelets (for example, by inhibiting release of growth factors), human foreskin fibroblast mitogenesis was used for two bioassays (24-h growth with 3H-thymidine incorporation and 5- to 6-day cell proliferation) for serum derived from collagen-aggregated platelet-rich plasma (PRP) or platelet-poor plasma (PPP) or from clotted whole blood (WBS). Blood was taken from five normal subjects before and 6 h after ingestion of ASA. After ASA ingestion serum (WBS or PRP) was less mitogenic (p < 0.01) by both bioassays, whereas PPP serum was not mitogenic either before or after ASA. In vitro, neither ASA nor salicylic acid alone at levels normally found in plasma with ASA use inhibited fibroblast growth. We conclude that ASA ingestion inhibits the mitogenic action of platelets on fibroblast culture by inhibiting the release of putative growth factors. Such an effect might explain the adverse effects of ASA on ulcer healing.

Antiulcer therapy

Perhaps older drugs to treat ulcers, such as antacids, are just as effective as the newer drugs, but veterinarians have all but abandoned these drugs in favor of H2-receptor antagonists, sucralfate, and omeprazole. For most patients, one of the H2-receptor antagonists or sucralfate is probably the initial drug of choice. For patients refractory to these drugs or for which once-a-day dosing is desirable, omeprazole has an advantage. The doses for these drugs are listed in Table 1. Patients presented with acute bleeding ulcers should be managed with emergency therapy. Fluid therapy and blood transfusions are the essential elements of the initial therapy. Surgical resection of the ulcers may be necessary, and most patients should be administered H2-receptor antagonists or sucralfate while they recuperate. Longer term therapy with antiulcer drugs will depend on the predisposing factors that initiated the ulcers. The practice of lavage of the stomach with iced saline or epinephrine to stop bleeding from gastric ulcers is not effective. A common cause of ulcers in small animals is the administration of NSAIDs. Ulcers caused by these agents should be managed like any other ulcers. Fortunately, if ulcers are diagnosed early, they usually heal once the NSAID is discontinued. Unfortunately, many NSAID-induced ulcers identified postmortem did not produce clinical signs, and the ulcers may not be apparent until severe bleeding occurs. In cases in which patients are at risk for developing ulcers from NSAIDs, there may be an advantage in administering the synthetic prostaglandin misoprostol. In many patients that are sensitive to the GI irritation of NSAIDs, switching from one NSAID to another may alleviate some of the signs. Buffered aspirin may be somewhat less irritating than plain uncoated aspirin but will not completely prevent ulcers. The administration of enteric-coated aspirin tablets to dogs is discouraged, because systemic absorption from these tablets is unpredictable.

Nonsteroidal anti-inflammatory drugs and peptic ulcer hospitalization rates in New South Wales

BACKGROUND

Consumption of nonaspirin nonsteroidal anti-inflammatory drugs (NANSAIDS) increased substantially during the 1980s. The effects of this trend on hospitalization rates for peptic ulcer in different age groups in New South Wales, Australia, was investigated.

METHODS

A population model based on sales of NANSAIDS and aspirin, age specific estimates of the relative risk of ulcer complications with these drugs, and hospitalization data for 1979 through 1988 was created.

RESULTS

All age groups increased consumption of NANSAIDS. The increases were greatest in elderly subjects, with women over age 65 years increasing the prevalence of their use of the drugs from 11.9% in 1979 to 22.5% in 1988 and males over age 65 increasing use from 9.7% to 20%. Aspirin use remained relatively unchanged in all age groups. Hospitalization rates for peptic ulcer decreased in both sexes under age 64 despite increasing use of NANSAIDs. Hospitalization increased in males and females over age 65, but in females the increase was substantially greater than predicted by the computer model. In women and men over age 75 the increases in hospitalization rates predicted by the model were only 18% and 33%, respectively, of the observed rises.

CONCLUSIONS

The increasing hospitalization rate for peptic ulcer among elderly subjects was only partly explained by the increasing consumption of NANSAIDS. Further research is needed.

Ulcer risk factors: interactions between Helicobacter pylori infection, nonsteroidal use, and age

PURPOSE

To evaluate the influence of Helicobacter pylori, nonsteroidal anti-inflammatory drug (NSAID) use, tobacco and alcohol use, age, gender, ethnic group, and the indication for endoscopy on the frequency of gastric and duodenal ulcers in patients referred for upper endoscopy.

PATIENTS AND METHODS

One thousand eighty-eight consecutive patients without prior antrectomy or active bleeding at endoscopy who were able to provide a history were interviewed prior to endoscopy, and antral biopsies were performed for H. pylori at endoscopy. Variables were tested for univariate association with duodenal or gastric ulcer and those variables with p < 0.25 were included in the logistic regression model building.

RESULTS

One hundred seven patients had duodenal ulcer, 97 had gastric ulcers, and 5 had both. Significant risk factors in the final model for duodenal ulcer were H. pylori, history of previous ulcer, male gender, bleeding, and pain at presentation (p < 0.001), whereas alcohol was associated with a decreased risk (p = 0.026). H. pylori presence (p = 0.011), aspirin use (p = 0.009), and bleeding (p = 0.012) were associated with gastric ulcer in the final model; esophageal symptoms were associated with decreased risk of gastric ulcer (p = 0.003). NSAID use was associated with gastric ulcers only in those over 55 (p < 0.05), especially whites, and in nonwhites without prior ulcer. There was no interaction between H. pylori and NSAIDs.

CONCLUSIONS

H. pylori was associated with an increased risk of duodenal and gastric ulcers. Aspirin increases the risk for gastric ulcer in patients of all ages, whereas nonaspirin, nonsteroidal use increases the risk for gastric ulcers to varying degrees in patients over age 55, depending on race and history of ulcer.

Uncomplicated peptic ulcer disease. An overview of formation and treatment principles

The end point in peptic ulcer disease is a crater in the mucosa. The cause of gastric ulcers seems to be the breakdown of defensive factors, which then allows damage from endogenous and/or exogenous aggressive factors. Aggressive factors are more important in duodenal ulcer formation. Treatment options discussed herein have similar clinical effectiveness, and all have better results than placebo. Selection of a specific agent should be individualized. Helicobacter pylori infection has been implicated in both gastric and duodenal ulcer formation, and use of triple-drug therapy to eradicate or suppress the organism has decreased recurrence rates when maintenance therapy is not used. However, first-line treatment in acute peptic ulcer disease remains the use of antacids, sucralfate (Carafate), or histamine2 receptor antagonists. This approach to therapy is inexpensive, safe, and effective.

Effect of difluoromethylornithine (DFMO) on NSAID-induced intestinal injury in rats

Combination therapy with difluoromethylornithine (DFMO) and a nonsteroidal antiinflammatory drug (NSAID) has been proposed for the chemoprevention of colonic neoplasia. The purpose of this study was to examine whether DFMO would affect NSAID-mediated intestinal injury. Male Sprague-Dawley rats were gavaged with 20 mg/kg of indomethacin, after seven days of exposure to drinking water with or without 2% DFMO. The rats were killed 24 or 48 hr later, and the small intestine removed for macroscopic and microscopic quantitation of intestinal injury by computerized image analysis. Seven days of DFMO alone had no effect on overall mucosal thickness, but did increase the depth of proximal intestinal crypts. Forty-eight hours after indomethacin, DFMO treatment decreased the number of indomethacin-induced ulcers and percent of the surface area ulcerated. However, DFMO also decreased the mucosal thickness, villus height, and crypt depth in indomethacin-treated rats. Thus although DFMO decreases macroscopic intestinal ulceration by indomethacin, the reduction in villus and crypt height suggests that it also impairs the mucosa's ability to recover from microscopic indomethacin-induced damage. This study shows DFMO does impact NSAID-mediated intestinal injury and therefore human trials with combinations of DFMO and NSAIDs should include monitoring for small intestinal injury.

Importance of gastric acid in gastric ulcer formation in rabbits with antibody-induced prostaglandin deficiency

The role of gastric acid in the development of gastroduodenal ulcers in prostaglandin-deficient conditions is unclear. In the current study, the effect of the proton pump inhibitor omeprazole on the formation of gastric ulcers was examined in a previously validated rabbit model of antibody-induced prostaglandin deficiency. Intragastric administration of 20 mg/kg omeprazole every 12 hours caused a profound suppression of gastric acidity (i.e., pH above 5 continuously). This same dose of omeprazole significantly reduced gastric ulcer formation induced by passive immunization with 6-keto-prostaglandin F1 alpha antibodies. It is concluded from these observations that gastric acid plays a critical role in the formation of gastric ulcers in rabbits with antibody-induced prostaglandin deficiency.

Haemodynamic changes and oxygen uptake during crossclamping of the thoracic aorta in dexmedetomidine pretreated dogs

This study was designed to test the hypothesis that the alpha 2 adrenergic agonist, dexmedetomidine (DEX), decreases tissue oxygen demand thereby increasing tolerance to hypoxic insult. In 17 anaesthetized dogs, cardiac output was measured with thermodilution, blood flow through the inferior caval vein was determined using an electromagnetic flowmeter, and oxygen consumption was calculated by the Fick principle. The animals were divided into three groups: control group (n = 5), D3 and D30 groups (n = 6 for each group) treated with two doses of DEX (3 micrograms.kg-1 and 30 micrograms.kg-1, respectively) prior to aortic crossclamping. Upon crossclamping of the thoracic aorta, the cardiac index decreased in all three groups with the largest decrease in the D30 group, and the smallest decrease in the control group. Blood flow through the inferior vena cava decreased in all three groups of animals while blood flow through the superior caval vein increased in the control group, did not change in the D3 group, and decreased in the D30 group. Oxygen saturation in mixed venous blood increased in the control group, did not change in the D3 group and decreased in D30 group. Blood flow and oxygen uptake in the lower part of the body decreased in all groups. Oxygen consumption in the upper part of the body decreased equally in all three groups. Arterial lactate concentrations increased almost two-fold in the control group while it increased by only 30% in animals treated with DEX. A lesser increase in lactate concentrations and oxygen extraction in tissues below aortic crossclamping is consistent with the hypothesis that DEX decreases tissue oxygen requirement which might prove particularly useful in clinical situations where tissue hypoxia is expected.

Medical Therapy of Peptic Ulcer Disease

The gastric duodenal mucosa normally is protected from the damaging effects of gastric acid and pepsin by ill-defined mechanisms. Ulcers may arise when there is an imbalance between the aggressive and defensive factors that renders the mucosa susceptible to damage. A variety of factors have been identified that may favor the development of peptic ulcers, but no single pathophysiologic defect applies in all ulcer patients. In duodenal ulcers, gastric acid hypersecretion is observed in as many as one third of patients; however, most patients with duodenal ulcers secrete normal amounts of gastric acid. Decreased mucosal bicarbonate secretion may be important in at least some duodenal ulcer patients. Use of NSAIDs may cause either gastric or duodenal ulcers, probably through the inhibition of mucosal prostaglandin synthesis and disruption of mucosal defenses. Finally, a recently identified bacterium, H. pylori, causes a chronic gastritis that is found in the overwhelming majority of patients with duodenal ulcers and non-NSAID-associated gastric ulcers. This bacterium may play a pivotal role in ulcer pathogenesis and, especially, in ulcer recurrences. A number of drugs of proved efficacy are available for the treatment of acute duodenal and gastric ulcers. The H2 receptor antagonists administered once daily remain the mainstay of ulcer therapy because of their efficacy, ease of use, and excellent safety profile. More thorough and long-lasting acid inhibition is afforded by the H+/K(+)-ATPase inhibitor omeprazole. This agent also promotes more rapid ulcer healing, but in most patients, this minor advantage may not justify the higher cost. It is not known whether more rapid healing will translate into lower ulcer complication rates. Until further data are available, this drug may be preferable in patients with large or complicated ulcers. In patients with refractory ulcers, omeprazole is clearly superior to other available agents. Agents that promote mucosal defense mechanisms are becoming increasingly popular in the treatment of duodenal ulcers but have undergone less testing than in gastric ulcers. Sucralfate 1 g four times daily is equivalent to H2 antagonists in the treatment of duodenal ulcers and, probably, gastric ulcers. Its requirement for multiple daily doses makes it somewhat less attractive at present to most patients. Low- to medium-dose Al-containing antacids are inexpensive and efficacious in duodenal ulcer therapy. They should remain as therapeutic options for the compliant patient in whom cost considerations are important. Colloidal bismuth subcitrate 120 mg four times a day is comparable to other agents in the acute treatment of duodenal ulcers and likely gastric 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.

Nonsalicylate nonsteroidal antiinflammatory drugs augment prestimulated acid secretion in rabbit parietal cells. Investigation of the mechanisms of action

The effects of nonsalicylate nonsteroidal antiinflammatory drugs on acid secretion were studied in isolated rabbit parietal cells. Indomethacin, naproxen, and carprofen (10(-6)-10(-4) mol/L) potentiated histamine-, forskolin-, 3-isobutyl-1-methylxanthine-, and dibutyryl cyclic adenosine monophosphate-stimulated acid secretion without affecting basal acid secretion. This augmentation of secretagogue-stimulated acid secretion was dependent on extracellular calcium because potentiation was abolished by calcium depletion of the medium or in the presence of the calcium antagonist lanthanum chloride. Potentiation was independent of the H2 and muscarinic receptors and did not appear to involve guanine nucleotide regulatory proteins. Proton pump activity was unaffected by indomethacin. Furthermore, nonsteroidal antiinflammatory drugs increased calcium efflux through the plasma membrane, as measured by calcium 45, and decreased endogenous prostaglandin E2 content. Exogenous dimethyl prostaglandin E2 inhibited the potentiating effect of these drugs on histamine-stimulated but apparently not on dibutyryl cyclic adenosine monophosphate-stimulated acid secretion. The data indicate that nonsalicylate nonsteroidal antiinflammatory drugs interacted at a postreceptor site between adenylate cyclase and the proton pump. The potentiating effects of these drugs were regulated by calcium and possibly modulated by prostanoids.

Clinical efficacy of sucralfate in the treatment of gastric ulcer

We performed a randomized, single-blind study in Japan to investigate the efficacy and safety of two dosage regimens of sucralfate granules, 2 g, twice daily (b.i.d. group, n = 30) and 1 g, 4 times daily (q.i.d. group, n = 27), on ulcer healing in 57 patients with endoscopically proven gastric ulcer. Endoscopy was performed after 4 weeks and, if complete healing was not achieved, again after an additional 4 weeks. Of 57 patients, 11 were excluded from the statistical analysis because of protocol violation (six in b.i.d. group, five in q.i.d. group). Of 46 patients eligible for the analysis of healing rates, four patients in the b.i.d. group (all at 8 weeks) and five patients in the q.i.d. group (two at 4 weeks and three at 8 weeks) were withdrawn due to patients' inconvenience. As the possibility that the withdrawals were due to the treatment failures could not be denied, we used the Kaplan-Meier method and generalized Wilcoxon test/logrank test for the calculation and evaluation of healing rates in this study, respectively. Healing rates at 4 and 8 weeks were 50% and 94% in the b.i.d. group and 35% and 68% in the q.i.d. group. There was no significant difference in healing rates between the groups. No serious adverse effect was observed in either group. These results suggest that the 2 g b.i.d. dose of sucralfate in granule form is at least as effective as the conventional dose of 1 g q.i.d. in the treatment of active gastric ulcers and could lead to better patient compliance.

Medical treatment of peptic ulcer disease

Our understanding of PUD and its treatment has improved dramatically during the past 15 years. During this time, many new effective drugs have been approved by the FDA, and possibly even more potent and effective therapies are now being evaluated. The H2-blockers, sucralfate, and antacids heal over 90% of duodenal ulcers in 6 to 8 weeks, and H2-blockers heal about 80% of gastric ulcers by 8 weeks and over 90% by 12 weeks. The new, more potent pump blockers (omeprazole) promise to be even more effective drugs, even for the healing of patients who are taking NSAIDS. However, the potential hazards of marked, long-term acid suppression must still be evaluated. Maintenance therapy with H2-blockers or sucralfate, ideally used for patients who would otherwise have frequent symptomatic recurrences of duodenal ulcer disease or who have had complications, reduces the relapses, especially symptomatic relapses. Maintenance therapy with H2-blockers also seems to reduce the recurrences of GUD, but this use has not yet received FDA approval. Elimination of H. pylori infection with antibiotics may prove to reduce recurrent ulcer disease and negate the need for maintenance therapy. Colloidal bismuth subcitrate alone, which suppresses but does not eradicate H. pylori infection, seems to be an effective ulcer drug and may even reduce the rate of early recurrences. Effective ulcer therapy, especially if it prevents recurrent disease, may reduce the complications of PUD, but this expectation has yet to be established. The use of prophylactic cytoprotective prostaglandins (misoprostol) reduces the incidence of NSAID-induced GUD.

Peptic ulcer pathophysiology

Despite extensive research, the etiology of peptic ulcer disease remains unclear. Given the multiple processes that control acid and pepsin secretion and defense and repair of the gastroduodenal mucosa, it is likely that the cause of ulceration differs between individuals. Acid and pepsin appear to be necessary but not sufficient ingredients in the ulcerative process. It is clear that the majority of gastric ulcers and a substantial number of duodenal ulcers do not have increased gastric acid secretion. Recent research has focused more on protection and repair of the stomach and duodenum. NSAIDs cause a significant number of gastric and duodenal ulcers; this is probably due to inhibition of prostaglandin production with loss of its protective effects. In the absence of NSAIDs and gastrinoma, it appears that most gastric ulcers and all duodenal ulcers occur in the setting of H. pylori infection. Evidence is mounting in support of H. pylori as a necessary ingredient in the ulcerative process, similar to acid and pepsin. It is not known whether the bacteria or the accompanying inflammation is the more important factor in the pathophysiology. Although the pathophysiology of gastric ulcer and duodenal ulcer is similar, there are clearly differences between the two groups. Duodenal ulcer is typified by H. pylori infection and duodenitis and in many cases impaired duodenal bicarbonate secretion in the face of moderate increases in acid and peptic activity. These facts suggest the following process: increased peptic activity coupled with decreased duodenal buffering capacity may lead to increased mucosal injury and result in gastric metaplasia. In the presence of antral H. pylori, the gastric metaplasia can become colonized and inflamed. The inflammation or the infection itself then disrupts the process of mucosal defense or regeneration resulting in ulceration. A cycle of further injury and increased inflammation with loss of the framework for regeneration may then cause a chronic ulcer. Gastric ulcer often occurs with decreased acid-peptic activity, suggesting that mucosal defensive impairments are more important. The combination of inflammation, protective deficiencies, and moderate amounts of acid and pepsin may be enough to induce ulceration. Many questions remain in understanding the pathophysiology of peptic ulcer disease. The physiology and pathophysiology of mucosal regeneration and the mechanisms by which H. pylori and inflammation disrupt normal gastroduodenal function will be fruitful areas of future investigation.

Age does not influence acute aspirin-induced gastric mucosal damage

Gastroduodenal ulceration and complications occur more commonly in elderly patients consuming aspirin and other nonsteroidal antiinflammatory drugs than in younger cohorts. To test the hypothesis that the gastroduodenal mucosa of the elderly is more sensitive to nonsteroidal antiinflammatory drug damage, acetylsalicylic acid in low (325 mg) and high (1300 mg) doses was administered on separate days to 10 elderly (median age, 67.5; range, 60-74 years) and 10 young (median age, 24.5; range, 19-30 years) healthy, male volunteer subjects. Gastroduodenal mucosal damage was assessed 2 hours after aspirin dosage by video-endoscopic techniques. At the conclusion of the study, the videotapes of all procedures were randomly evaluated by two endoscopists blinded to subject identification or study sequence. Endoscopically observed lesions were counted in the duodenum, gastric antrum, and gastric body. Aspirin damage was dose-related and more severe in the stomach than in the duodenum. There were no significant differences in total gastroduodenal lesion counts between age groups. In addition, no differences in median gastric pH or tissue 6-ketoprostaglandin F1 alpha content were observed between age groups. These data suggest that age is not a significant factor in determining the extent of acutely administered aspirin-induced damage.

Acute upper gastrointestinal bleeding in elderly persons

We have seen that UGI bleeding is a serious and apparently growing problem for seniors. Of special concern in the older patient are the frequency with which serious peptic disease presents silently, the limitation frequently imposed on adequate pain relief from NSAIDs, and the higher complication rates from most of the causes of UGI bleeding. Care of the elderly would be enhanced by research focused on defining those older patients most at risk of experiencing NSAID-induced peptic complications, improved methods for preventing or treating NSAID-induced ulceration that are well tolerated and cost-effective, and better regimens for preventing the recurrence of ulcers and UGI bleeding in these patients. In regard to the last, future investigation of the role of H. pylori, methods for successfully eliminating the organism, and the effect of eradication on patients' subsequent course may be particularly helpful.

Nonsteroidal anti-inflammatory gastropathy: from theory to practice

The success of nonsteroidal anti-inflammatory drugs in managing joint inflammation and pain has come at the cost of impressive side effects, particularly in the gastrointestinal tract. This manuscript reviews the magnitude of the problem, the risk factors, and presentation of nonsteroidal gastropathy. It also presents some points in the prevention and management of the disorder.

Delirium in an elderly woman possibly associated with administration of misoprostol

Misoprostol has been associated with adverse reactions, including gastrointestinal symptoms, gynecologic problems, and headache. Changes in mental status, however, have not been reported. We present a case in which an 89-year-old woman in a long-term care facility became confused after the initiation of misoprostol therapy. The patient's change in mental status was first reported nine days after the initiation of therapy. Her delirium significantly improved after misoprostol was discontinued and her mental status returned to normal within a week. Because no other factors related to this patient changed significantly, the delirium experienced by this patient possibly resulted from misoprostol therapy.

Preventing upper gastrointestinal bleeding in patients receiving nonsteroidal antiinflammatory drugs

Severe upper gastrointestinal (GI) bleeding is a serious adverse effect of nonsteroidal antiinflammatory drugs (NSAIDs) and the elderly are at increased risk of developing this complication. Bleeding episodes can be prevented. Replacing NSAIDs with acetaminophen may be appropriate when a simple analgesic is needed that eliminates the risk of GI bleeding. Using the lowest effective NSAID dose may decrease the incidence and severity of NSAID gastropathy. Histamine H2-receptor antagonists, sucralfate, and misoprostol have been studied for the prevention of NSAID gastropathy, but only misoprostol prevents mucosal injury in both the stomach and duodenum. Patients who have a history of peptic ulcer disease or gastric bleeding from NSAIDs are candidates for prophylactic measures. Although other patients are at risk, no one knows who should receive prophylactic therapy for NSAID gastropathy. Future studies should attempt to define patient populations that warrant prophylactic therapy.

Aspirin potentiates prestimulated acid secretion and mobilizes intracellular calcium in rabbit parietal cells

The effects of aspirin on gastric acid secretion were studied in isolated rabbit parietal cells (PC). Aspirin (10(-5) M) potentiated histamine-, dibutyryl cyclic AMP (dbcAMP)-, forskolin- and 3-isobutyl-1-methylxanthine-stimulated acid secretion without affecting basal acid secretion. Augmentation of secretagogue-stimulated acid secretion by aspirin was dependent on calcium (Ca2+) since potentiation was blocked by removal of extracellular Ca2+ ([Ca2+]o) or addition of the calcium antagonist lanthanum chloride. Using the Ca2+ probe fura-2, aspirin (10(-6) - 2 X 10(-5) M) rapidly increased intracellular free Ca2+ concentration ([Ca2+]i) in a dose-dependent manner. The source of released Ca2+ was intracellular as demonstrated by depletion of intracellular Ca2+ and [Ca2+]o with EGTA washing. Aspirin did not affect several other signal transduction sites involved in stimulus-secretion coupling, including the H2 receptor, intracellular cyclic AMP (cAMP), inositol 1,4,5, triphosphate (IP3) and H+,K(+)-ATPase. Aspirin decreased PC prostaglandin E2 (PGE2) content by 98%. Exogenous dimethyl PGE2 (dmPGE2) inhibited both histamine-stimulated acid secretion and its enhancement by aspirin. In contrast, dmPGE2 abolished aspirin-induced potentiation of dbcAMP-stimulated acid secretion by augmenting the dbcAMP-stimulated response. These results indicate that aspirin acts at a site beyond the adenylate cyclase/cAMP system and before the proton pump, presumably by releasing Ca2+ from an IP3-independent intracellular storage pool and by inhibiting PGE2 generation.

Cyclooxygenase inhibition with indomethacin increases human duodenal mucosal response to prostaglandin E1

In humans, prostaglandins of the E1 class stimulate duodenal mucosal bicarbonate secretion, whereas the cyclooxygenase inhibitor, indomethacin, decreases both mucosal PGE2 and bicarbonate production. The purpose of this study was to determine whether a synthetic prostaglandin E1, enisoprost, diminished the inhibitory effects of indomethacin on mucosal bicarbonate secretion. In seven healthy subjects the proximal 4 cm of duodenum was isolated by occluding balloons. The isolated test segment was perfused with 154 mM NaCl (2 ml/min, 37 degrees C). Each subject participated in four separate tests in random order. Indomethacin, 50 mg, or placebo was given 13 and 1 hr before testing. After measuring basal bicarbonate secretion, either 100 micrograms of prostaglandin E1 or placebo (in 154 mM NaCl) was perfused into the test segment over 30 min. As anticipated, PGE1 significantly increased duodenal mucosal bicarbonate secretion, and indomethacin decreased resting bicarbonate secretion. Indomethacin pretreatment significantly enhanced (P less than 0.03) the mucosa's response to PGE1 compared to PGE1 alone. These results further support the observations that endogenous prostaglandins, in part, regulate human proximal duodenal bicarbonate secretion. Furthermore, suppression of endogenous prostaglandin generation results in an increased sensitivity of the duodenal mucosa to PGE1.

Prostaglandin E2 production by dispersed canine fundic mucosal cells. Contribution of macrophages and endothelial cells as major sources

Endogenous prostaglandins (PGs) influence resistance of the gastric mucosa to injury, but the source of PGs is unknown. Using radioimmunoassay, we studied PG production by dispersed canine fundic mucosal cells. PGE2 production, stimulated by bradykinin, epidermal growth factor, zymosan, and calcium ionophore, was greater in the small-cell elutriator fraction (SCEF) than in the medium and large cell fractions, which contained mucous, chief, and parietal cells. Linear density gradients of SCEF cells revealed maximal PGE2 production in cells of light density. Mast, endocrine, and endothelial cells did not account for this PGE2 production. Macrophages, identified by uptake of acetylated-LDL, immunoreactivity with antibodies to the human Ia antigen, and phagocytosis of fluorescent latex particles, were enriched in the SCEF and correlated with PGE2 production in the density gradient. Magnetic separation of cells in the SCEF-ingesting iron particles enriched PGE2 production. Fractions enriched in endothelial cells present in intact capillary fragments, but depleted of macrophages, also produced PGE2. Regulation of PGE2 production differed among cell types. Fibroblasts were easily cultured from submucosa, but were not detected in the SCEF. We conclude that macrophages and capillary endothelial cells are major producers of PGE2 in the canine fundic mucosa.