Non-steroid anti-inflammatory drug associated ulcer: epidemiology, causation and treatment

Oleic acid as a restorative agent in alleviating adrenaline induced altered morphofunctional milieu of gastric tissue and mitochondria

The role of oleic acid as a protective antioxidant has recently been recognized. The present study is aimed to explore whether oleic acid can afford protection to rat gastric tissue when challenged with adrenaline. Sixty adult healthy male albino rats were divided into 10 groups comprising of 6 animals each. First group constituted the control. Rats of the second group were injected sub-cutaneously with adrenaline bitartrate at the dose of 0.3mg/kg body weight, every day for a period of 17 days. Rats of the third, to the sixth groups were orally fed with different doses of oleic acid (2.5, 5, 10, 20 mg/kg body weight/day) respectively. The rats of seventh to tenth groups were orally fed with doses of oleic acid as mentioned above and subsequently injected with adrenaline bitartrate at 0.3mg/kg body weight sub-cutaneously. After the treatment period, the animals were euthanized through cervical dislocation following light ether anaesthesia and gastric tissues were collected for morphological and biochemical studies. Subcutaneously administered pharmacological dose of adrenaline bitartrate caused oxidative stress inducing gastric lesion in male albino rats as evident from the altered levels of biomarkers of oxidative stress, activities of antioxidant and mitochondrial enzymes related to energy metabolism with changes in tissue morphology. Pre-treatment of rats with oleic acid dose-dependently protected against these gastric injuries induced by adrenaline indicating the potentiality of oleic acid in protecting against adrenaline induced gastric injury in male albino rats where antioxidant mechanisms appear to play a pivotal role in mediating such protection.

Gastro-protective potentials of Spirulina: role of vitamin B12

Gastric ulcer is a chronic health problem world over. Spirulina is known to contain significant amounts of vitamin B₁₂ hence Spirulina was evaluated for gastroprotective properties against gastric ulcerations. Spirulina biomass (SB) and Spirulina extract (SE) were evaluated in swim stress induced gastric ulcers in adult male albino rats. Both SB and SE inhibited 45% and 60% of ulcers formation induced by swim stress respectively. Gastroprotection has been elucidated to be due to inhibition of (a) upregulated H⁺, K⁺-ATPase activity that induced ulcer condition; (b) lipid peroxidation and (c) altered antioxidant enzyme levels. The data highlighted the importance of vitamin B₁₂ in protecting the gut against gastric ulcerations and suggested that both Spirulina biomass and Spirulina extract contain bioavailable B₁₂. Spirulina based product/food can be used as alternatives to gastroprotective agents that are known to cause acidity themselves upon long term use.

In vitro antioxidant and H(+), K(+)-ATPase inhibition activities of Acalypha wilkesiana foliage extract

Aims:

The aim of this study was to evaluate the antioxidant activty and anti-acid property of Acalypha wilkesiana foliage extract.

Materials and Methods:

Hot and cold aqueous extracts were prepared from healthy leaves of A. wilkesiana. Free radical scavenging activity and H⁺, K⁺-ATPase inhibition activities of aqueous foliage extracts was screened by in vitro models.

Statistical Analysis Used:

All experiments were performed in triplicate and results are expressed as mean ± SEM.

Results:

A. wilkesiana hot aqueous extract (AWHE) showed significant antioxidants and free radical scavenging activity. Further, AWHE has shown a potent H⁺, K⁺-ATPase inhibitory activity (IC₅₀: 51.5 ± 0.28 μg/ml) when compare to standard proton pump inhibitor omeprazole (56.2 ± 0.64 μg/ml); however, latter activity is equal to A. wilkesiana cold aqueous extract (AWCE). Quantitative analysis of AWHE has revealed more content of phenols and flavonoids; this is found to be the reason for good antioxidant activity over AWCE. Molecular docking was carried out against H⁺, K⁺-ATPase enzyme crystal structure to validate the anti-acid activity of A. wilkesiana major phytochemicals.

Conclusions:

The present study indicates that the constituents of AWHE and AWCE have good antacid and free radical scavenging activity.

Comparative gastroprotective effect of post-treatment with low doses of rutin and cimetidine in rats

The anti-ulcerogenic potentials of low doses of rutin and cimetidine in ethanol-, acetic acid-, and stress-induced ulcers in rats have been evaluated and compared in this study. In each model, male Wistar rats were randomly divided into six groups (I-VI). Groups II-VI were administered 1 mL/100 g ethanol orally, 0.05 mL of 20% acetic acid submucosally or kept in a cold chamber for 6 h to induce ulcer in the ethanol-, acetic acid-, and stress-induced ulceration model, respectively. Thereafter, group III was post-treated with 300 mg/kg cimetidine and groups IV-VI with 20, 40, and 80 mg/kg rutin, respectively, while the control (group I) received distilled water in Tween 20. One hour after post-treatment, all groups were killed and the gastric ulcer index was calculated. Malondialdehyde (MDA) level, vitamin C content, and glutathione peroxidase (GPx) activity were evaluated in the gastric mucosa of animals. Post-treatment with rutin significantly reduced ulcerogen-induced gastric damage in all models. This effect was significant at all dose levels compared with the ulcer-induced groups. Rutin significantly reduced the MDA levels but increased the vitamin C content and GPx activity. Ulcer index and MDA level were highest in the ethanol-induced ulcer model while vitamin C content and GPx activity were lowest in the stress-induced ulcer model. The study showed that all three models of ulceration appeared to be linked to oxidative stress and also ascribed significant anti-ulcerogenic potential to rutin especially at lower doses of 20-80 mg/kg.

The role of erythropoietin in the protection of gastric mucosa from indometacin-induced gastric injury and its relationship with oxidant and antioxidant parameters in rats

Objectives

Erythropoietin has anti-oxidative and anti-inflammatory activity. We wanted to evaluate its activity in preventing damage to the gastric mucosa.

Methods

We examined the protective effect of erythropoietin on indometacin-induced gastric mucosa damage in the rat stomach and compared its potency with that of famotidine. We also measured effects on oxidant and antioxidant parameters in the rat stomach.

Key findings

Famotidine and erythropoietin 2500 and 5000 IU/kg reduced the ulcer area by 98%, 31% and 58%, respectively, compared with the indometacin group. Superoxide dismutase activity and glutathione level were decreased and myeloperoxidase activity increased in the indometacin group compared with healthy rats. Famotidine and erythropoietin at all doses increased superoxide dismutase and glutathione levels significantly compared with the indometacin group. Myeloperoxidase activity was decreased by erythropoietin and famotidine.

Conclusions

These results support the view that erythropoietin counteracts the effects of indometacin in inducing gastric ulcer and could be used as a an antiulcer compound. Its antiulcer effect is less potent than that of famotidine. The antiulcerogenic effects of erythropoietin may be related to its intrinsic ability to sustain the activities of free-radical scavenging enzymes and the bioavailability of glutathione.

Molecular mechanism and functional consequences of lansoprazole-mediated heme oxygenase-1 induction

AIM: To investigate the molecular mechanism and functional consequences of heme oxygenase-1 (HO-1) activation by lansoprazole in endothelial cells and macrophages.

METHODS: Expression of HO-1 mRNA was analyzed by Northern blotting. Western blotting was used to determine the HO-1 and ferritin protein levels. NADPH-dependent reactive oxygen species (ROS) formation was measured with lucigenin-enhanced chemiluminescence. HO-1 promoter activity in mouse fibroblasts, stably transfected with a 15-kb HO-1 gene that drives expression of the reporter gene luciferase, was assessed using in vivo bioluminescence imaging.

RESULTS: Lansoprazole increased HO-1 mRNA levels in endothelial cells and HO-1 protein levels in macrophages. In addition, lansoprazole-induced ferritin protein levels in both cell systems. Moreover, induction of the antioxidant proteins HO-1 and ferritin by lansoprazole was followed by a decrease in NADPH-mediated ROS formation. The radical scavenging properties of lansoprazole were diminished in the presence of the HO inhibitor, chromium mesoporphyrin IX. Induction of HO-1 gene expression by lansoprazole was not related to oxidative stress or to the activation of the mitogen-activated protein kinase pathway. However, the phosphatidylinositol 3-kinase inhibitor LY294002 showed a concentration-dependent inhibition of HO-1 mRNA and promoter activity.

CONCLUSION: Activation of HO-1 and ferritin may account for the gastric protection of lansoprazole and is dependent on a pathway blocked by LY294002.

Gastroprotective effect of Dodonaea viscosa on various experimental ulcer models

AIM OF THE STUDY

Dodonaea viscosa Linn. (Sapindaceae) is used as a medicinal herb by the tribes of Shola forest regions of Western Ghats. It is used for headaches, backaches, stomach pain, piles and simple ulcers. The present study was performed to evaluate the gastroprotective effect and acute toxicity of this plant in various experimental models.

MATERIALS AND METHODS

Studies were performed in two different models (ethanol and indomethacin induced gastric ulcer) in wistar rats. Gastric protection was evaluated by measuring the ulcer index, gastric glutathione assay, alkaline phosphate assay and histopathological studies. Gastric secretion studies were done by pyloric ligation experiment.

RESULTS AND CONCLUSIONS

Water and ethanol extract (500 mg/kg body weight) showed moderate activity compared to hexane extract. Hexane extract of Dodonaea viscosa dose dependently inhibited ethanol induced gastric lesions, causing 90% protection at 500 mg/kg, 81% protection at 250 mg/kg, and 70% protection at 125 mg/kg and it also dose dependently inhibited indomethacin induced gastric lesions, causing 92% protection at 500 mg/kg, 77% protection at 250 mg/kg, and 52% protection at 125 mg/kg. The various degrees of inhibition were statistically significant (p<or=0.05). Further in our gastric secretion studies, we found that hexane extract of Dodonaea viscosa (500 mg/kg) decreased the amount of total acid in gastric juice. Dodonaea viscosa hexane extract thus inhibits acid secretion to prevent ulcer aggravation. Acute toxicity study with a higher dose of 1250 mg/kg did not manifest any toxicological signs in rats. We also performed preliminary phytochemical screening of the crude extract which gave positive results for the presence of flavanoids, saponins, bitter principles and phenols.

Ulcer preventive and antioxidative properties of astaxanthin from Haematococcus pluvialis

The anti-ulcer properties of astaxanthin fractions such as total carotenoid and astaxanthin esters from Haematococcus pluvialis were evaluated in ethanol-induced gastric ulcers in rats. Since oxygen radical release is a pathogenic factor of ethanol-induced gastric damage, astaxanthin - a free radical scavenger, was investigated as a potential ulcer preventive agent. Astaxanthin fractions - total carotenoid and astaxanthin esters were orally administered to experimental rats at 100, 250 and 500 microg/kg b.w. prior to ulcer induction. Alcian blue binding assay indicates that, total carotenoid and astaxanthin esters at 500 microg/kg b.w could protect gastric mucin approximately 40% and 67% respectively. Pre-treatment with astaxanthin esters, also resulted in significant increase in antioxidant enzyme levels - catalase, superoxide dismutase, and glutathione peroxidase in stomach homogenate. Histopathological examination substantiated the protective effect of astaxanthin in pre-treated rats. The increased antioxidant potencies such as free radical scavenging activity with an IC(50) of approximately 8 microg/ml and reducing power abilities (59 x 10(3) U/g) in vitro, reveal that H. pluvialis astaxanthin may protect gastric mucosal injury by antioxidative mechanism. In addition, approximately 23 fold increased lipoxygenase-inhibitory property, in comparison with standard astaxanthin and significant H(+), K(+)-ATPase-inhibitory activity of astaxanthin esters, in comparison with known proton pump blocking anti-ulcer drug - omeprazole, may envisage the potential gastroprotective effect by regulating the gastric mucosal injury and gastric acid secretion by the gastric cell during ulcer disease.

Lansoprazole protects and heals gastric mucosa from non-steroidal anti-inflammatory drug (NSAID)-induced gastropathy by inhibiting mitochondrial as well as Fas-mediated death pathways with concurrent induction of mucosal cell renewal

We have investigated the mechanism of antiapoptotic and cell renewal effects of lansoprazole, a proton pump inhibitor, to protect and heal gastric mucosal injury in vivo induced by indomethacin, a non-steroidal anti-inflammatory drug (NSAID). Lansoprazole prevents indomethacin-induced gastric damage by blocking activation of mitochondrial and Fas pathways of apoptosis. Lansoprazole prevents indomethacin-induced up-regulation of proapoptotic Bax and Bak and down-regulation of antiapoptotic Bcl-2 and Bcl(xL) to maintain the normal proapoptotic/antiapoptotic ratio and thereby arrests indomethacin-induced mitochondrial translocation of Bax and collapse of mitochondrial membrane potential followed by cytochrome c release and caspase-9 activation. Lansoprazole also inhibits indomethacin-induced Fas-mediated mucosal cell death by down-regulating Fas or FasL expression and inhibiting caspase-8 activation. Lansoprazole favors mucosal cell renewal simultaneously by stimulating gene expression of prosurvival proliferating cell nuclear antigen, survivin, epidermal growth factor, and basic fibroblast growth factor. The up-regulation of Flt-1 further indicates that lansoprazole activates vascular epidermal growth factor-mediated controlled angiogenesis to repair gastric mucosa. Lansoprazole also stimulates the healing of already formed ulcers induced by indomethacin. Time course study of healing indicates that it switches off the mitochondrial death pathway completely but not the Fas pathway. However, lansoprazole heals mucosal lesions almost completely after overcoming the persisting Fas pathway, probably by favoring the prosurvival genes expression. This study thus provides the detailed mechanism of antiapoptotic and prosurvival effects of lansoprazole for offering gastroprotection against indomethacin-induced gastropathy.

Comorbidities in rheumatoid arthritis

Rheumatoid arthritis (RA) is often characterized by the burden of swollen joints, pain, and decreased physical function, but less understood are the many manifestations of additional health conditions that are associated with RA and its treatments. First brought to light with observations of increased mortality in RA, studies noted the increased rates of cardiovascular and infection events. The chronic, debilitating, autoimmune nature of RA affects the patient directly or indirectly in almost all organ systems, from cardiovascular problems and infections to depression and gastrointestinal ulcers. On average, the established RA patient has two or more comorbid conditions. It should be the responsibility of the rheumatologist to take these and the risk of additional conditions into account when treating the patient. This chapter reviews important comorbidities in patients with RA, their prevalence, and their relation to RA.

A novel phenol-bound pectic polysaccharide from Decalepis hamiltonii with multi-step ulcer preventive activity

AIM: To investigate H⁺, K⁺-ATPase inhibition, anti-H pylori, antioxidant, and the in vivo antiulcer potential of a pectic polysaccharide from Swallow root (Decalepis hamiltonii; SRPP).

METHODS: SRPP, with known sugar composition [rhamnose: arabinose: xylose: galactose in the ratio of 16:50:2:32 (w/w), with 141 mg/g of uronic acid] was examined for anti-ulcer potency in vivo against swim/ethanol stress-induction in animal models. Ulcer index, antioxidant/antioxidant enzymes, H⁺, K⁺-ATPase and gastric mucin levels were determined to assess the anti-ulcer potency. Anti-H pylori activity was also determined by viable colony count and electron microscopic studies.

RESULTS: SRPP, containing phenolics at 0.12 g GAE/g, prevented stress-induced gastric ulcers in animal models by 80%-85%. Down regulation of gastric mucin 2-3 fold, antioxidant/antioxidant enzymes and upregulation of 3 fold of H⁺, K⁺-ATPase in ulcerous animals were normalized upon treatment with SRPP. Histopathological analysis revealed protection to the disrupted gastric mucosal layer and epithelial glands. SRPP also inhibited H⁺, K⁺-ATPase in vitro, at an IC₅₀ of 77 μg/mL as opposed to that of 19.3 μg/mL of Lansoprazole and H pylori growth at Minimum Inhibitory Concentration (MIC) of 150 μg/mL. In addition, free radical scavenging (IC₅₀-40 μg/mL) and reducing power (3200 U/g) activities were also observed.

CONCLUSION: SRPP, with defined sugar composition and phenolics, exhibited multi-potent free radical scavenging, antioxidant, anti-H pylori, inhibition of H⁺, K⁺-ATPase and gastric mucosal protective activities. In addition, SRPP is non-toxic as opposed to other known anti-ulcer drugs, and therefore may be employed as a potential alternative for ulcer management.

Matrix metalloproteinase-9 activity and expression is reduced by melatonin during prevention of ethanol-induced gastric ulcer in mice

Matrix metalloproteinases (MMPs) play an important role in degradation of gastric extracellular matrix proteins. However, no reports are available on the relationship between the activity of MMPs and gastric ulceration induced by alcohol. Our objective was to investigate the effect of melatonin (N-acetyl-5-methoxytryptamine) on the regulation of MMP-9 and MMP-2 activities during prevention of ethanol-induced gastric ulcer. Biochemical and zymographic methods were used to analyze MMP-9 and -2 activities in gastric tissues of Balb/c mice following induction of gastric ulcer by ethanol. Our studies reveal that melatonin arrested cell injury, protein carbonyl formation, and lipid peroxidation in mice during gastroprotection. Melatonin dose-dependently reduced proMMP-9 activity that was induced ( approximately 25-fold) during ethanol-induced gastric ulceration. Severity of gastric ulcers were correlated proportionately with increased dose of ethanol and elevated activity of proMMP-9 and -2. The reduced activities of MMP-9 and -2 were associated with reduced expression of TNF-alpha and increased expression of tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2). We conclude that melatonin's ability to prevent ethanol-induced gastric ulceration in mice is related to a reduction in proMMP-9 activity and expression.

Risk of serious NSAID‐related gastrointestinal events during long‐term exposure: a systematic review

OBJECTIVE

Exposure to non-steroidal anti-inflammatory drugs (NSAIDs) is associated with increased risk of serious gastrointestinal (GI) events compared with non-exposure. We investigated whether that risk is sustained over time.

DATA SOURCES

Cochrane Controlled Trials Register (to 2002); MEDLINE, EMBASE, Derwent Drug File and Current Contents (1999-2002); manual searching of reviews (1999-2002).

STUDY SELECTION

From 479 search results reviewed and 221 articles retrieved, seven studies of patients exposed to prescription non-selective NSAIDs for more than 6 months and reporting time-dependent serious GI event rates were selected for quantitative data synthesis. These were stratified into two groups by study design.

DATA EXTRACTION

Incidence of GI events and number of patients at specific time points were extracted.

DATA SYNTHESIS

Meta-regression analyses were performed. Change in risk was evaluated by testing whether the slope of the regression line declined over time. Four randomised controlled trials (RCTs) provided evaluable data from five NSAID arms (aspirin, naproxen, two ibuprofen arms, and diclofenac). When the RCT data were combined, a small significant decline in annualised risk was seen: - 0.005% (95% CI, - 0.008% to - 0.001%) per month. Sensitivity analyses were conducted because there was disparity within the RCT data. The pooled estimate from three cohort studies showed no significant decline in annualised risk over periods up to 2 years: - 0.003% (95% CI, - 0.008% to 0.003%) per month.

CONCLUSIONS

Small decreases in risk over time were observed; these were of negligible clinical importance. For patients who need long-term (> 6 months) treatment, precautionary measures should be considered to reduce the net probability of serious GI events over the anticipated treatment duration. The effect of intermittent versus regular daily therapy on long-term risk needs further investigation.

Indomethacin inactivates gastric peroxidase to induce reactive-oxygen-mediated gastric mucosal injury and curcumin protects it by preventing peroxidase inactivation and scavenging reactive oxygen

We have investigated the mechanism of indomethacin-induced gastric ulcer caused by reactive oxygen species (ROS) and the gastroprotective effect of curcumin thereon. Curcumin dose-dependently blocks indomethacin-induced gastric lesions, showing 82% protection at 25 mg/kg. Indomethacin-induced oxidative damage by ROS as shown by increased lipid peroxidation and thiol depletion is almost completely blocked by curcumin. Indomethacin causes nearly fivefold increase in hydroxyl radical (()OH) and significant inactivation of gastric mucosal peroxidase to elevate endogenous H(2)O(2) and H(2)O(2)-derived ()OH, which is prevented by curcumin. In vitro studies indicate that indomethacin inactivates peroxidase irreversibly only in presence of H(2)O(2) by acting as a suicidal substrate. 5,5-Dimethyl-pyrroline-N-oxide (DMPO) protects the peroxidase, indicating involvement of indomethacin radical in the inactivation. Indomethacin radical was also detected in the peroxidase-indomethacin-H(2)O(2) system as DMPO adduct (a(N) = 15 G, a(beta)(H) = 16 G) by electron spin resonance spectroscopy. Curcumin protects the peroxidase in a concentration-dependent manner and consumes H(2)O(2) for its oxidation as a suitable substrate of the peroxidase, thereby blocking indomethacin oxidation. Curcumin can also scavenge ()OH in vitro. We suggest that curcumin protects gastric damage by efficient removal of H(2)O(2) and H(2)O(2) -derived ()OH by preventing peroxidase inactivation by indomethacin.

Effect of melatonin on secreted and induced matrix metalloproteinase-9 and -2 activity during prevention of indomethacin-induced gastric ulcer

Matrix metalloproteinases (MMPs) maintain the crucial role in physiological turnover of extracellular matrix (ECM) proteins in gastric tissues. However, a little is known about the relationship of MMPs with ECM degradation during gastric ulceration and ECM remodeling during healing. Our objective was to investigate the effect of melatonin (N-acetyl-5 methoxytryptamine) on the regulation of MMP-9 and MMP-2 activity during prevention of gastric ulcer. In the present study, biochemical and zymographic methods were used to analyze the mechanism of melatonin in indomethacin-induced gastric ulcer in a rat model. Our studies reveal that melatonin dose-dependently downregulates the expression and secretion of pro-MMP-9 which is induced (approximately 10-fold) during indomethacin-induced gastric ulceration. Furthermore, melatonin prevents gastric ulceration in a dose-dependent manner through upregulation (approximately two- to threefold) of both pro-MMP-2 and active MMP-2 at the level of induction as well as secretion. It also prevents gastric ulcers by blocking glutathione depletion and lipid peroxidation in cytosolic and microsomal fractions. The novel findings of this study are attributed to the attenuation of the pro-MMP-9 and increase of MMP-2 activity by pretreatment with melatonin. The finding defines one of the MMP-mediated pathways for melatonin's action in gastric ulcer.

The inhibition of gastric mucosal injury by Punicagranatum L. (pomegranate) methanolic extract

Administration of 70% methanolic extract of Punicagranatum fruit rind (250 mg/kg and 500 mg/kg) shows a percentage of inhibition in 22.37, 74.21 and 21.95, 63.41 in aspirin- and ethanol-induced gastric ulceration, respectively. In treated groups of animals, the in vivo antioxidant levels such as superoxide dismutase (SOD), catalase, glutathione (GSH) and glutathione peroxidase (GPx) levels were increased and found more or less equal to the normal values. The tissue lipid peroxidation level was found to be decreasing in treated groups of animals as compared to the control group. The histopathological examination of the stomach of the ulcerated animals shows severe erosion of gastric mucosa, sub-mucosal edema and neutrophil infiltration. All of these symptoms were found to be normal in treated groups. In general, the results of the present investigation revealed the gastroprotective activity of the extract through antioxidant mechanism.

Clinical studies on the effect of Neem (Azadirachta indica) bark extract on gastric secretion and gastroduodenal ulcer

We have shown earlier that Neem (Azadirachta indica) bark aqueous extract has potent antisecretory and antiulcer effects in animal models and has no significant adverse effect (Bandyopadhyay et al., Life Sciences, 71, 2845-2865, 2002). The objective of the present study was to investigate whether Neem bark extract had similar antisecretory and antiulcer effects in human subjects. For this purpose, a group of patients suffering from acid-related problems and gastroduodenal ulcers were orally treated with the aqueous extract of Neem bark. The lyophilised powder of the extract when administered for 10 days at the dose of 30 mg twice daily caused a significant (p < 0.002) decrease (77%) in gastric acid secretion. The volume of gastric secretion and its pepsin activity were also inhibited by 63% and 50%, respectively. Some important blood parameters for organ toxicity such as sugar, urea, creatinine, serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, albumin, globulin, hemoglobin levels and erythrocyte sedimentation rate remained close to the control values. The bark extract when taken at the dose of 30-60 mg twice daily for 10 weeks almost completely healed the duodenal ulcers monitored by barium meal X-ray or by endoscopy. One case of esophageal ulcer (gastroesophageal reflux disease) and one case of gastric ulcer also healed completely when treated at the dose of 30 mg twice daily for 6 weeks. The levels of various blood parameters for organ toxicity after Neem treatment at the doses mentioned above remained more or less close to the normal values suggesting no significant adverse effects. Neem bark extract thus has therapeutic potential for controlling gastric hypersecretion and gastroesophageal and gastroduodenal ulcers.

Smoking and the pathogenesis of gastroduodenal ulcer--recent mechanistic update

Peptic ulcer is a common disorder of gastrointestinal system and its pathogenesis is multifactorial, where smoking and nicotine have significant adverse effects. Smoking and chronic nicotine treatment stimulate basal acid output which is more pronounced in the smokers having duodenal ulcer. This increased gastric acid secretion is mediated through the stimulation of H2-receptor by histamine released after mast cell degranulation and due to the increase of the functional parietal cell volume or secretory capacity in smokers. Smoking and nicotine stimulate pepsinogen secretion also by increasing chief cell number or with an enhancement of their secretory capacity. Long-term nicotine treatment in rats also significantly decreases total mucus neck cell population and neck-cell mucus volume. Smoking also increases bile salt reflux rate and gastric bile salt concentration thereby increasing duodenogastric reflux that raises the risk of gastric ulcer in smokers. Smoking and nicotine not only induce ulceration, but they also potentiate ulceration caused by H. pylori, alcohol, nonsteroidal anti-inflammatory drugs or cold restrain stress. Polymorphonuclear neutrophils (PMN) play an important role in ulcerogenesis through oxidative damage of the mucosa by increasing the generation of reactive oxygen intermediates (ROI), which is potentiated by nicotine and smoking. Nicotine by a cAMP-protein kinase A signaling system elevates the endogenous vasopressin level, which plays an aggressive role in the development of gastroduodenal lesions. Smoking increases production of platelet activating factor (PAF) and endothelin, which are potent gastric ulcerogens. Cigarette smoking and nicotine reduce the level of circulating epidermal growth factor (EGF) and decrease the secretion of EGF from the salivary gland, which are necessary for gastric mucosal cell renewal. Nicotine also decreases prostaglandin generation in the gastric mucosa of smokers, thereby making the mucosa susceptible to ulceration. ROI generation and ROI-mediated gastric mucosal cell apoptosis are also considered to be important mechanism for aggravation of ulcer by cigarette smoke or nicotine. Both smoking and nicotine reduce angiogenesis in the gastric mucosa through inhibition of nitric oxide synthesis thereby arresting cell renewal process. Smoking or smoke extract impairs both spontaneous and drug-induced healing of ulcer. Smoke extract also inhibits gastric mucosal cell proliferation by reducing ornithine decarboxylase activity, which synthesises growth-promoting polyamines. It is concluded that gastric mucosal integrity is maintained by an interplay of some aggressive and defensive factors controlling apoptotic cell death and cell proliferation and smoking potentiates ulcer by disturbing this balance.

A novel antioxidant and antiapoptotic role of omeprazole to block gastric ulcer through scavenging of hydroxyl radical

The mechanism of the antiulcer effect of omeprazole was studied placing emphasis on its role to block oxidative damage and apoptosis during ulceration. Dose-response studies on gastroprotection in stress and indomethacin-induced ulcer and inhibition of pylorus ligation-induced acid secretion indicate that omeprazole significantly blocks gastric lesions at lower dose (2.5 mg/kg) without inhibiting acid secretion, suggesting an independent mechanism for its antiulcer effect. Time course studies on gastroprotection and acid reduction also indicate that omeprazole almost completely blocks lesions at 1 h when acid inhibition is partial. The severity of lesions correlates well with the increased level of endogenous hydroxyl radical (*OH), which when scavenged by dimethyl sulfoxide causes around 90% reduction of the lesions, indicating that *OH plays a major role in gastric damage. Omeprazole blocks stress-induced increased generation of *OH and associated lipid peroxidation and protein oxidation, indicating that its antioxidant role plays a major part in preventing oxidative damage. Omeprazole also prevents stress-induced DNA fragmentation, suggesting its antiapoptotic role to block cell death during ulceration. The oxidative damage of DNA by *OH generated in vitro is also protected by omeprazole or its analogue, lansoprazole. Lansoprazole when incubated in a *OH-generating system scavenges *OH to produce four oxidation products of which the major one in mass spectroscopy shows a molecular ion peak at m/z 385, which is 16 mass units higher than that of lansoprazole (m/z 369). The product shows no additional aromatic proton signal for aromatic hydroxylation in (1)H NMR. The product absorbing at 278 nm shows no alkaline shift for phenols, thereby excluding the formation of hydroxylansoprazole. The product is assigned to lansoprazole sulfone formed by the addition of one oxygen atom at the sulfur center following attack by the *OH. Thus, omeprazole plays a significant role in gastroprotection by acting as a potent antioxidant and antiapoptotic molecule.

Gastroprotective effect of Neem (Azadirachta indica) bark extract: possible involvement of H(+)-K(+)-ATPase inhibition and scavenging of hydroxyl radical

The antisecretory and antiulcer effects of aqueous extract of Neem (Azadirachta indica) bark have been studied along with its mechanism of action, standardisation and safety evaluation. The extract can dose dependently inhibit pylorus-ligation and drug (mercaptomethylimidazole)-induced acid secretion with ED(50) value of 2.7 and 2 mg Kg(-1) b.w. respectively. It is highly potent in dose-dependently blocking gastric ulcer induced by restraint-cold stress and indomethacin with ED(50) value of 1.5 and 1.25 mg Kg(-1) b.w. respectively. When compared, bark extract is equipotent to ranitidine but more potent than omeprazole in inhibiting pylorus-ligation induced acid secretion. In a stress ulcer model, it is more effective than ranitidine but almost equipotent to omeprazole. Bark extract inhibits H(+)-K(+)-ATPase activity in vitro in a concentration dependent manner similar to omeprazole. It offers gastroprotection against stress ulcer by significantly preventing adhered mucus and endogenous glutathione depletion. It prevents oxidative damage of the gastric mucosa by significantly blocking lipid peroxidation and by scavenging the endogenous hydroxyl radical ((z.rad;)OH)-the major causative factor for ulcer. The (z.rad;)OH-mediated oxidative damage of human gastric mucosal DNA is also protected by the extract in vitro. Bark extract is more effective than melatonin, vitamin E, desferrioxamine and alpha-phenyl N-tert butylnitrone, the known antioxidants having antiulcer effect. Standardisation of the bioactive extract by high pressure liquid chromatography indicates that peak 1 of the chromatogram coincides with the major bioactive compound, a phenolic glycoside, isolated from the extract. The pharmacological effects of the bark extract are attributed to a phenolic glycoside which is apparently homogeneous by HPLC and which represents 10% of the raw bark extract. A single dose of 1g of raw extract per kg b.w. (mice) given in one day and application of 0.6g raw extract per kg b.w. per day by oral route over 15 days to a cumulative dose of 9g per kg was well tolerated and was below the LD(50). It is also well tolerated by rats with no significant adverse effect. It is concluded that Neem bark extract has therapeutic potential for the control of gastric hyperacidity and ulcer.

Critical role of an endogenous gastric peroxidase in controlling oxidative damage in H. pylori-mediated and nonmediated gastric ulcer

The objective of the present study is to delineate the mechanism of oxidative damage in human gastric ulcerated mucosa despite the presence of some antioxidant enzymes. We report for the first time the critical role of an endogenous peroxidase, a major H(2)O(2) metabolizing enzyme, in controlling oxidative damage in gastric mucosa. Human gastric mucosa contains a highly active peroxidase in addition to the myeloperoxidase contributed by neutrophil. In both non-Helicobacter pylori (H. pylori)- and H. pylori-mediated gastric ulcer, when myeloperoxidase level increases due to neutrophil accumulation, gastric peroxidase (GPO) level decreases significantly. Moreover, gastric ulcer is associated with oxidative damage of the mucosa as evidenced by significant increase in lipid peroxidation, protein oxidation, and thiol depletion indicating accumulation of reactive oxygen metabolites (ROM). Mucosal total superoxide dismutase (Mn and Cu-Zn SOD) level also decreases significantly leading to increased accumulation of O(2)(*-). To investigate the plausible ROM-mediated inactivation of the GPO during ulceration, the enzyme was partially purified from the mucosa. When exposed to an in vitro ROM generating system, using Cu(2+), ascorbate, and H(2)O(2,) the enzyme gets inactivated, which is dependent on Cu(2+), ascorbate, or H(2)O(2). Insensitivity to SOD excludes inactivation by O(2)(*-). However, complete protection by catalase indicates that H(2)O(2) is essential for inactivation. Sensitivity to EDTA and hydroxyl radical *OH) scavengers indicates that GPO is inactivated most probably by *OH generated from H(2)O(2). We propose that GPO is inactivated in vivo by ROM generated by activated neutrophil. This leads to further accumulation of endogenous H(2)O(2) to cause more oxidative damage to aggravate the ulcer.

Risk factors of oesophagitis in arthritic patients

BACKGROUND

The risk factors that precipitate the occurrence of oesophageal mucosal injury in patients on continuous nonsteroidal anti-inflammatory drug (NSAID) therapy are unknown.

METHODS

Outpatients who regularly consumed NSAIDs for osteoarthritis were recruited from a rheumatology clinic into a prospective case-control study. All patients answered a structured interview and underwent upper gastrointestinal endoscopy.

RESULTS

Of 450 eligible patients, 195 (43%) consented to be interviewed and undergo upper gastrointestinal endoscopy. Oesophagitis was diagnosed in 41 of these 195 patients (21%). The occurrence of gastric or duodenal ulcer in individual patients did not predict the concomitant damage of the oesophageal mucosa. Young age (odds ratio: 1.79 per decade of life; 95% confidence interval: 1.11-2.86) and hiatus hernia (odds ratio: 3.72; 95% confidence interval: 1.63-8.49) both increased the risk of developing oesophagitis. When questioned, all oesophagitis patients revealed at least one gastrointestinal symptom, heartburn being named most frequently (odds ratio: 4.78; 95% confidence interval: 2.04-11.17). The type of anti-inflammatory medication, the use of alcohol and the use of nicotine were not associated with any significant risk for erosive oesophagitis.

CONCLUSIONS

Patients on chronic NSAID therapy for rheumatological disease suffer frequently from erosive oesophagitis. While the risk may be higher in patients with a pre-existing tendency for gastro-oesophageal reflux, any concomitant history of NSAID-induced peptic ulcer disease does not add to the risk. Erosive oesophagitis should be considered especially in patients on NSAIDs who complain of heartburn.

The effects on gastroduodenal mucosa of a new nonsteroidal anti-inflammatory drug, amtolmetin-guacyl, versus piroxicam in healthy volunteers: a short-term, double-blind, endoscopically controlled study

AIM

Amtolmetin-guacyl (AMG) (2-[2[1-methyl-5-(4-methylbenzoyl) pyrrol-2-yl] acetamido] acetic acid 2-methoxyphenyl ester) is a recent drug that, in preliminary studies, has shown effective anti-inflammatory properties with improved gastrointestinal safety. Our study was designed to investigate the effects of AMG and piroxicam on gastroduodenal mucosa in healthy volunteers.

MATERIALS AND METHODS

Forty-two healthy volunteers aged 18--45 years were randomized in a double-blind manner to AMG 1200 mg for 2 days and 600 mg for 12 days, or piroxicam 40 mg for 2 days and 20 mg for 12 days. Endoscopic evaluation and laboratory tests were performed at baseline and at the end of the treatment. The mucosa was evaluated by endoscopy using a predefined scale: the score could range from 0 to 4. Only volunteers with endoscopy grade 0-1 entered the trial.

RESULTS

The median post-treatment endoscopy gastric injury scores were 1 (range 0--4) in the AMG-treated volunteers and 3 (range 0--4) in the piroxicam-treated volunteers (P = 0.04). There were two cases with an endoscopic gastric score of 4 in the AMG group, and seven in the piroxicam group (P = 0.1). The corresponding values in the duodenum were 1/21 volunteers in the AMG group and 1/21 in the piroxicam group. Eight out of 11 subjects with an endoscopic score of 4 were Helicobacter pylori negative, and 3/11 were infected by the micro-organism. Different adverse reactions were reported by 15/21 volunteers (71%) in the AMG group and by 12/21 (57%) in the piroxicam group. None of these events resulted in interruption of the study.

CONCLUSIONS

AMG is a new anti-inflammatory drug with limited gastric toxicity. If these findings are confirmed on a wider scale in long-term trials, then the drug might become a valid alternative to current treatments, especially for patients such as those with rheumatoid arthritis who need steroids and second-line drugs simultaneously.

Approaches to healing and prophylaxis of nonsteroidal anti-inflammatory drug-associated ulcers

Treating and preventing peptic ulcers associated with nonsteroidal anti-inflammatory drugs (NSAIDs) calls for clinical judgment. Physicians must weigh their patients' need for anti-inflammatory therapy against their individual risks for ulcer development; their likelihood of coping with an ulcer complication if it should develop; and the economics, efficacy, and tolerability of various treatment and prevention options. This article considers some general strategies common to both treatment and prevention. Data from randomized trials that can guide clinicians and their patients as they attempt to heal an established NSAID ulcer or prevent one occurring in the future are also reviewed.

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

A total of 1,456 patients were available for the All Patients Treated analysis of two large, randomized, double-blind, multicenter, controlled studies (Acid Suppression Trial: Ranitidine versus Omeprazole for NSAID-Associated Ulcer Treatment [ASTRONAUT] and Omeprazole versus Misoprostol for NSAID-Induced Ulcer Management [OMNIUM]). These studies examined the efficacies of omeprazole, 20 and 40 mg once daily (both studies), ranitidine, 150 mg twice daily (ASTRONAUT), and misoprostol, 200 microg four times daily (OMNIUM), for the healing of gastric ulcer, duodenal ulcer, or erosions, and the relief of dyspeptic symptoms. At entry, patients were receiving, and continued to receive, nonsteroidal anti-inflammatory drugs (NSAIDs), and had a gastric or duodenal ulcer, and/or >10 erosions in the stomach or duodenum at initial endoscopy. Patients were randomized to blinded treatment for 4/8 weeks until treatment success, which was defined as the healing of ulcer(s), <5 erosions at any site, and not more than mild dyspeptic symptoms. The proportions of patients reaching treatment success by 8 weeks were 77% with both doses of omeprazole, 63% with ranitidine, and 71% with misoprostol. In patients who initially had a gastric ulcer, more ulcers were healed at 8 weeks with omeprazole, 20 (83%) and 40 mg once daily (82%), than with ranitidine (64%) or misoprostol (74%). In patients who initially had a duodenal ulcer, 93% were healed at 8 weeks with omeprazole, 20 mg once daily, compared with 88% for omeprazole, 40 mg once daily, 79% for ranitidine, and 79% for misoprostol. Erosions healed slightly faster at 4 weeks with misoprostol, compared with the other regimens, but by 8 weeks most patients had <5 erosions per gastroduodenal region in each treatment group. Diarrhea and abdominal pain were more common in patients taking misoprostol, as were adverse events leading to withdrawal. Patients with duodenal ulcer or erosions at entry and the presence of Helicobacter pylori were good prognostic factors for overall treatment success. Using a model that included only patients with ulcers, those with smaller ulcers also had a higher likelihood of achieving treatment success. Against the background of these new data, omeprazole is the treatment of choice for healing NSAID-associated ulcers, on the basis of its efficacy and tolerability, and the optimal dose appears to be 20 mg once daily.

A comparison of omeprazole with ranitidine for ulcers associated with nonsteroidal antiinflammatory drugs. Acid Suppression Trial: Ranitidine versus Omeprazole for NSAID-associated Ulcer Treatment (ASTRONAUT) Study Group

BACKGROUND

Suppressing acid secretion is thought o reduce the risk of ulcers associated with regular use of nonsteroidal antiinflammatory drugs (NSAIDs), but the best means of accomplishing this is uncertain.

METHODS

We studied 541 patients who required continuous treatment with NSAIDs and who had ulcers or more than 10 erosions in either the stomach or duodenum. Patients were randomly assigned to double-blind treatment with omeprazole, 20 mg or 40 mg orally per day, or ranitidine, 150 mg orally twice a day, for four or eight weeks, depending on when treatment was successful (defined as the resolution of ulcer and the presence of fewer than five erosions in the stomach, and fewer than five erosions in the duodenum, and not more than mild dyspepsia). We randomly assigned 432 patients in whom treatment was successful to maintenance treatment with either 20 mg of omeprazole per day or 150 mg of ranitidine twice a day for six months.

RESULTS

At eight weeks, treatment was successful in 80 percent (140 of 174) of the patients in the group given 20 mg of omeprazole per day, 79 percent (148 of 187) of those given 40 mg of omeprazole per day, and 63 percent (110 of 174) of those given ranitidine (P<0.001 for the comparison with 20 mg of omeprazole and P=0.001 for the comparison with 40 mg of omeprazole). The rates of healing of all types of lesions were higher with omeprazole than with ranitidine. During maintenance therapy, the estimated proportion of patients in remission at the end of six months was 72 percent in the omeprazole group and 59 percent in the ranitidine group. The rates of adverse events were similar between groups during both phases. Both medications were well tolerated.

CONCLUSIONS

In patients with regular use of NSAIDs, omeprazole healed and prevented ulcers more effectively than did ranitidine.

The effect of ranitidine on NSAID related dyspeptic symptoms with and without peptic ulcer disease of patients with rheumatoid arthritis and osteoarthritis

The efficacy of ranitidine in the treatment of NSAID-related dyspeptic symptoms with and without peptic ulcer disease (PUD) was investigated in 124 patients with rheumatoid arthritis (RA) and osteoarthritis (OA). The patients, who continued the use of NSAIDs were investigated by gastroduodenoscopy. Patients with PUD received open label ranitidine 150 mg b.i.d. and the patients without PUD were randomly allocated to receive ranitidine 150 mg b.i.d. or placebo for 4 weeks. PUD was found in 36 (26%) consecutive patients who presented with dyspeptic symptoms. Of these patients dyspeptic symptoms had disappeared in 8 (26%) of 31 evaluable patients and PUD was healed in 18 (56%) patients after 4 weeks of treatment. After 8 weeks of treatment PUD was healed in 27 (87%) patients. Of the remaining patients without PUD dyspeptic symptoms had disappeared in 24 (26%) of the ranitidine-treated patients which was significantly better (p < 0.02) than the 5 (6%) placebo-treated patients. The minor mucosal lesions found in this patient group improved to a similar extent in the ranitidine and placebo-treated patients although 1 placebo-treated patient deteriorated and 2 placebo-treated patients developed PUD during the 4 weeks of study. The results of this study show that oral ranitidine 150 mg b.i.d. is effective in the treatment of both dyspeptic symptoms and mucosal lesions in RA and OA patient who continue the use of NSAIDs.

Gastric microbleeding following single and repeated dosing with naproxen

BACKGROUND

Adaptation to gastric damage from nonsteroidal anti-inflammatory drugs (NSAID) has been observed during ongoing dosage in rats and humans. However, this does not always occur, and our previous data suggest that NSAID half-life may be a determining factor.

AIM

To investigate whether adaptation occurs during 1 week of naproxen administration in humans.

SUBJECTS

Thirteen healthy volunteers were studied at baseline, and after one or seven daily doses of naproxen 750 mg. Gastric microbleeding was measured 4 h after naproxen in gastric washings collected during a 30-min period. Serum thromboxane B concentrations were also assayed, as a marker of cyclo-oxygenase inhibition.

RESULTS

Mean blood loss after placebo was 0.60 microL/10 min (95% CI: 0.21-0.98). This rose to 2.15 (0.73-3.57) and 1.75 (0.74-2.76) microL/10 min after one and seven daily doses of naproxen, respectively (P < 0.05 vs. baseline; day 1 vs. 7 not significant). Thromboxane B concentrations were < 10% of control at both day 1 and 7 of dosing.

CONCLUSION

In accord with our findings in rats, adaptation to this moderately long acting NSAID in humans was not apparent. We conclude that any adaptation to naproxen is unlikely to be clinically important.

Adverse interactions between warfarin and nonsteroidal antiinflammatory drugs: mechanisms, clinical significance, and avoidance

OBJECTIVE

To review the mechanisms and clinical significance of adverse interactions between warfarin and nonsteroidal anti-inflammatory drugs (NSAIDs) and discuss how these interactions can be avoided.

DATA SOURCES

Previous studies of interactions between warfarin and NSAIDs or reports of adverse interactions were identified from a MEDLINE search (1976 to present) and from the reference lists of pertinent articles.

STUDY SELECTION AND DATA EXTRACTION

All articles were considered for inclusion in the review. Pertinent information was selected for discussion.

DATA SYNTHESIS

All NSAIDs can prolong bleeding time by inhibiting platelet function. High-dose aspirin has a direct hypoprothrombinemic effect. Phenylbutazone and its analogs enhance the hypoprothrombinemic effect of warfarin through a pharmacokinetic interaction by inhibiting the hepatic metabolism of warfarin. Mefenamic acid also enhances the anticoagulant effect of warfarin, but the mechanism is not known. The clinical relevance of protein binding displacement in the interaction between warfarin and NSAIDs has been overstated, although a significant one may be more likely in the presence of high concentrations of NSAIDs in patients with slow elimination of warfarin (e.g., those with severe heart failure or impaired liver function). NSAIDs can induce gastrointestinal bleeding, which is likely to be more severe if warfarin is also given.

CONCLUSIONS

The combined use of warfarin and NSAIDs is generally discouraged because of the increased risk of bleeding in these patients. In patients receiving warfarin who also require NSAIDs, phenylbutazone and its analogs, high-dose aspirin, mefenamic acid, excessive use of topical methyl salicylate, and NSAIDs that are associated with a higher risk of bleeding peptic ulcers should be avoided. Patients should be closely monitored for anticoagulant control and bleeding complications during the combined use of warfarin and NSAIDs.

Associations of peptic ulcer and gastric cancer with other diseases in US veterans

OBJECTIVES

The purpose of this study was to examine, through the database of the Department of Veterans Affairs, the joint occurrence of different diseases in individual patients.

METHODS

Patients with a diagnosis of gastric cancer, gastric ulcer, or duodenal ulcer were extracted from the 1987 through 1990 computer files. A random sample of patients from each annual file served as a control population. All previous discharges of each case or control patient between 1970 and 1990 were searched for the occurrence of hypertensive diseases or chronic diseases of the joints, lungs, pancreas, and liver. The relative frequencies of such diagnoses in case and control patients were compared by multivariate logistic regression.

RESULTS

Gastric ulcer and duodenal ulcer, but not gastric cancer, were significantly associated with chronic diseases of the joints, lungs, pancreas, and liver. None of the three diagnoses showed any significant association with hypertensive diseases.

CONCLUSIONS

These relationships may reflect the influence of nonsteroidal anti-inflammatory drugs, smoking, and alcohol. They stress the importance of environmental risk factors other than Helicobacter pylori in terms of damage to the upper gastrointestinal mucosa.

Nonsteroidal antiinflammatory drugs and dyspepsia in the elderly

Upper gastrointestinal tract symptoms are common in the elderly and, despite a paucity of data, nonsteroidal antiinflammatory drugs (NSAIDs) are believed to be important risk factors. We aimed to evaluate the association of NSAIDs with dyspepsia and heartburn in a population-based study. An age- and gender-stratified random sample of Olmsted County, Minnesota, Caucasian residents aged 65 years and older was mailed a valid self-report questionnaire; 74% responded (N = 1375). Age- and gender-adjusted (to 1980 US Caucasian population) prevalence rates for NSAID use, dyspepsia (defined as pain located in the upper abdomen or nausea), and heartburn (defined as retrosternal burning pain) were calculated. Logistic regression analysis was used to estimate the association of dyspepsia and heartburn with potential risk factors adjusting for age and gender. The age- and gender-adjusted annual prevalences (per 100) of aspirin and nonaspirin NSAID use were 60.0 (95% CI 57.2, 62.7) and 26.1 (95% CI 23.6, 28.7), respectively. The annual prevalences of dyspepsia and heartburn were 15.0 (95% CI 12.9, 17.0) and 12.9 (95% CI 10.9, 14.8), respectively. Aspirin was associated with dyspepsia and/or heartburn (OR = 1.6, 95% CI 1.2, 2.2) as were nonaspirin NSAIDs (OR = 1.8, 95% CI 1.3, 2.6), but smoking and alcohol were not significant risk factors. Aspirin and nonaspirin NSAIDs are associated with almost a twofold risk of upper gastrointestinal tract symptoms in elderly community subjects.

Interobserver variation in assessment of gastroduodenal lesions associated with non-steroidal anti-inflammatory drugs

Video endoscopic images were used to investigate whether gastroenterologists could agree on the definition of lesions within the stomach seen at endoscopy, with particular reference to those seen in patients taking non-steroidal anti-inflammatory drugs. Seven experienced endoscopists, unaware of the patients' clinical history or drug consumption, recorded their classification for 93 randomised video images of gastric lesions. There was complete agreement in the diagnosis of ulceration for nine images from patients who were not taking non-steroidal anti-inflammatory drugs; eight of nine were classified as deep ulcers, with 86% agreement for this subclassification. By contrast, the overall agreement for lesions in patients taking non-steroidal anti-inflammatory drugs was only 55%. Only nine of 44 ulcers were subclassified as deep, and there was considerable cross classification of non-haemorrhagic erosions and ulcers. In conclusion, ulcers that occur in patients taking non-steroidal anti-inflammatory drugs differ from those in patients who are not taking these drugs in that they are often more superficial and difficult to distinguish from erosions. The prognostic importance of these lesions is, therefore, uncertain.

Smoking, alcohol, and analgesics in dyspepsia and among dyspepsia subgroups: lack of an association in a community

Dyspepsia is common in the general population, and despite a paucity of data, smoking, alcohol, and analgesics are believed to be important risk factors. The role of these environmental factors in subjects with uninvestigated dyspepsia was evaluated in a representative population sample. An age and gender stratified random sample of residents of Olmsted County, Minnesota, aged 20 to 64 years was mailed a valid self report questionnaire; 77% responded (n = 1644). Age and gender adjusted (1990 US white population) prevalence rates for dyspepsia (defined as frequent pain located in the upper abdomen, or nausea in the absence of a history of peptic ulcer disease) were calculated. Logistic regression analysis was used to estimate the association between dyspepsia and potential risk factors. The age and gender adjusted prevalence (per 100) of dyspepsia in the community was 21.8 (95% confidence interval 19.6, 23.9). Dyspepsia was significantly more common in younger subjects and females. Adjusting for age and gender, paracetamol (odds ratio (OR) = 2.2), aspirin (OR = 1.8), and smoking (OR = 1.5), but not alcohol (OR = 0.9), were associated with dyspepsia (all p < 0.05). When non-gastrointestinal somatic complaints were included in the logistic models, however, these environmental factors were no longer significant (OR = 1.3, 1.1, 1.2 and 0.9, respectively). Similar results were obtained when ulcer-like, dysmotility-like, and reflux-like dyspepsia were considered separately. The results were not significantly changed when subjects with a history of ulcer disease were included in the analyses. Smoking, alcohol, and analgesics may not therefore be important risk factors for dyspepsia in the community.

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.

Gastric mucosal defensive factors: the therapeutic strategy

There are several interesting approaches to augmenting defence or repair mechanisms that can be used already or may find a place in therapy for ulcer disease. Factors such as epidermal growth factor and basic fibroblast growth factor show potential. Alternative strategies might be to stimulate mucosal blood flow with agents that release nitric oxide (NO), or to scavenge free radicals in the inflamed or ischaemic mucosa. If such approaches are to find a role in therapy, it is likely that it will be restricted: perhaps for the treatment of refractory ulcers, or for prophylaxis of stress ulceration. This is because most ulcers in future are likely to be healed with tolerable and high efficacy acid-inhibiting drugs then have their recurrence prevented by regimens that eradicate Helicobacter pylori. The most important current indication for concentrating on enhancing mucosal defences is for managing non-steroidal anti-inflammatory drug (NSAID)-induced ulcers. There is no clear advantage in using a defence-enhancing agent (rather than an acid suppressant) to heal an NSAID ulcer if the NSAID can be stopped. The main value of prostaglandins is for prophylaxis of NSAID ulcers in those patients who need ongoing treatment with NSAID. For cost-benefit reasons, prostaglandins should probably be used mainly for those at high risk of NSAID complications, and there has been progress in identifying these. Another interesting approach is aimed at clarifying mechanisms of gastric adaptation to NSAID, so that we might be able to design drugs and dosing regimens to maximize this phenomenon.

Efficacy of 12 months' misoprostol as prophylaxis against NSAID-induced gastric ulcers. A placebo-controlled trial

We performed a 12-month, double-blind, randomised, placebo-controlled study to determine the long term effect of misoprostol (600-800 micrograms/d) in the prevention of gastric ulcers and gastroduodenal erosions in 83 arthritis patients on chronic NSAID therapy. Patients underwent endoscopy at 0, 3, 6 and 12 months. At the initial endoscopy, 12 patients had an ulcer (11 gastric), which was healed prior to randomization. Seventy eligible patients reached the 3 month endoscopy. Four (12.5%) of the 32 patients given misoprostol developed a gastric ulcer compared with 11 (28.9%) of the 38 on placebo (p < 0.05, life-table analysis). Six of the 11 patients with an initial gastric ulcer developed a further gastric ulcer, compared to 9 of 58 patients without an initial ulcer (p < 0.05). We conclude that misoprostol decreases the cumulative development of NSAID-induced gastric ulcers. Patients with a previous NSAID-ulcer have a higher risk of further ulceration.

High prevalence of duodenal ulcer in Indochinese immigrants attending an Australian university hospital

Indochinese migrants to Australia appear to have a high prevalence of duodenal ulcer (DU). To examine this hypothesis a 2 year audit of the prevalence of symptomatic DU among patients attending a general hospital was conducted. The last 6 months of this period included a prospective assessment of ulcer risk factors. In Australian-born patients DU prevalence was 8.4 per 1000 admissions. By comparison, prevalence in Indochinese was 24.6 per 1000 admissions (P < 0.001) with an age standardized prevalence of 30.3 per 1000 (P < 0.001). This represented a relative risk in Indochinese of 2.9 using crude data and 3.6 after age standardization. The increased risk was demonstrated only in males: very few DU were diagnosed in female Indochinese. Ulcer prevalence increased in Indochinese for each age decile between 10 and 80 years, with statistical significance (P < 0.01) reached in the age brackets 0-19, 20-39 and 60-79 years. Ulcer prevalence was also increased in some other ethnic groups. However, when referral bias was taken into account (by calculating the ratio of endoscopies to total admissions for each group), a significant increase in DU prevalence could only be confidently demonstrated in Indochinese. Analysis of risk factors showed that among DU patients, Indochinese were significantly less likely to smoke (P < 0.05) and also had a tendency to ingest less non-steroidal anti-inflammatory drugs (NSAID) and to consume less alcohol.

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.