Evidence for endoscopic ulcers as meaningful surrogate endpoint for clinically significant upper gastrointestinal harm

Intestinal Barrier Dysfunction in Inflammatory Bowel Disease: Underpinning Pathogenesis and Therapeutics

The intestinal barrier is composed of several essential elements including luminal enzymes, bile acids, water layer, epithelial layer, and enterocyte layer. It acts as a dynamic interface between the luminal contents of food, commensal and pathogenic bacteria, and the gastrointestinal tract. The role of barrier dysfunction is of significant research interest in the development and targeted treatment of chronic inflammatory gastrointestinal conditions, such as inflammatory bowel disease. This review aims to examine the role of intestinal barrier dysfunction in the development of inflammatory bowel disease, the pathophysiology of increased barrier permeability in inflammatory bowel disease, and to explore potential treatment targets and clinical applications.

Predictive value of gastrointestinal symptoms and patient risk factors for NSAID-associated gastrointestinal ulcers defined by endoscopy? Insights from a pooled analysis of two naproxen clinical trials

OBJECTIVE

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to treat pain and rheumatic conditions. To facilitate patient management, we determined the predictive value of gastrointestinal (GI) symptoms and risk factors for the development of NSAID-associated GI injuries.

METHODS

Post-hoc analysis of pooled data from naproxen treatment arms of two identical, randomized, double-blind, controlled phase 3 trials in arthritis patients at risk of GI adverse events. Endoscopic incidence of GI ulcers at baseline, and 1, 3, and 6 months was employed as a surrogate parameter for GI injury. For GI symptom analysis, Severity of Dyspepsia Assessment questionnaire was used. For GI risk factor analysis, the high risk factors: previous GI injury, concomitant selective serotonin reuptake inhibitors or corticosteroids, ulcer history, concomitant low-dose aspirin, and age >65 years were employed.

RESULTS

Data of 426 naproxen patients were analyzed. Distribution of GI symptoms between patients with and without ulcer was similar; about one third of patients developing an ulcer reported no GI pain symptoms. GI symptoms experienced under naproxen treatment were thus not indicative of GI injury. The proportion of patients developing an ulcer increased with the number of risk factors present, however, about a quarter of patients without any of the analyzed risk factors still developed an ulcer.

CONCLUSION

GI symptoms and the number of risk factors are not reliable predictors of NSAID-induced GI injury to decide which patients need gastroprotection and will lead to a large group of patients with GI injuries. A preventive rather than reactive approach should be taken.

Magnetically-controlled Capsule Endoscopy for Assessment of Antiplatelet Therapy-induced Gastrointestinal Injury

BACKGROUND

Gastrointestinal bleeding is the most frequent major complication of antiplatelet therapy. In patients at low bleeding risk, however, clinically overt gastrointestinal bleeding is relatively uncommon.

OBJECTIVE

We sought to assess the effects of different antiplatelet regimens on gastrointestinal mucosal injury using a novel magnetically-controlled capsule endoscopy system in patients at low bleeding risk.

METHODS

Patients (n=505) undergoing percutaneous coronary intervention in whom capsule endoscopy demonstrated no ulcerations or bleeding (although erosions were permitted) after 6 months of dual antiplatelet therapy (DAPT) were randomly assigned to aspirin plus placebo (n=168), clopidogrel plus placebo (n=169), or aspirin plus clopidogrel (n=168) for an additional 6 months. The primary endpoint was the incidence of gastrointestinal mucosal injury (erosions, ulceration, or bleeding) at 6-month or 12-month capsule endoscopy.

RESULTS

Gastrointestinal mucosal injury through 12 months was less with single antiplatelet therapy (SAPT) compared with DAPT (94.3% vs. 99.2%, P=0.02). Aspirin and clopidogrel monotherapy had similar effects. Among 68 patients without any gastrointestinal injury at randomization (including no erosions), SAPT compared with DAPT caused less gastrointestinal injury (68.1% vs. 95.2%, P=0.006), including fewer new ulcers (8.5% vs. 38.1%, P=0.009). Clinical gastrointestinal bleeding between 6 and 12 months was less with SAPT compared with DAPT (0.6% vs. 5.4%, P=0.001).

CONCLUSIONS

Despite being at low risk of bleeding, nearly all patients receiving antiplatelet therapy developed gastrointestinal injury, although overt bleeding was infrequent. DAPT for 6 months followed by SAPT with aspirin or clopidogrel between 6 and 12 months resulted in less gastrointestinal mucosal injury and clinical bleeding compared with DAPT through 12 months.

Human Intestinal Barrier: Effects of Stressors, Diet, Prebiotics, and Probiotics

The objectives of this article are to understand the effects of stressors (nonsteroidal antiinflammatory drug, exercise, and pregnancy) and components in the diet, specifically prebiotics and probiotics, on intestinal barrier function. Stressors generally reduce barrier function, and these effects can be reversed by supplements such as zinc or glutamine that are among the substances that enhance the barrier. Other dietary factors in the diet that improve the barrier are vitamins A and D, tryptophan, cysteine, and fiber; by contrast, ethanol, fructose, and dietary emulsifiers increase permeability. Effects of prebiotics on barrier function are modest; on the other hand, probiotics exert direct and indirect antagonism of pathogens, and there are documented effects of diverse probiotic species, especially combination agents, on barrier function in vitro, in vivo in animal studies, and in human randomized controlled trials conducted in response to stress or disease. Clinical observations of benefits with combination probiotics in inflammatory diseases have simultaneously not appraised effects on intestinal permeability. In summary, probiotics and synbiotics enhance intestinal barrier function in response to stressor or disease states. Future studies should address the changes in barrier function and microbiota concomitant with assessment of clinical outcomes.

Leaky gut: mechanisms, measurement and clinical implications in humans

The objectives of this review on 'leaky gut' for clinicians are to discuss the components of the intestinal barrier, the diverse measurements of intestinal permeability, their perturbation in non-inflammatory 'stressed states' and the impact of treatment with dietary factors. Information on 'healthy' or 'leaky' gut in the public domain requires confirmation before endorsing dietary exclusions, replacement with non-irritating foods (such as fermented foods) or use of supplements to repair the damage. The intestinal barrier includes surface mucus, epithelial layer and immune defences. Epithelial permeability results from increased paracellular transport, apoptosis or transcellular permeability. Barrier function can be tested in vivo using orally administered probe molecules or in vitro using mucosal biopsies from humans, exposing the colonic mucosa from rats or mice or cell layers to extracts of colonic mucosa or stool from human patients. Assessment of intestinal barrier requires measurements beyond the epithelial layer. 'Stress' disorders such as endurance exercise, non-steroidal anti-inflammatory drugs administration, pregnancy and surfactants (such as bile acids and dietary factors such as emulsifiers) increase permeability. Dietary factors can reverse intestinal leakiness and mucosal damage in the 'stress' disorders. Whereas inflammatory or ulcerating intestinal diseases result in leaky gut, no such disease can be cured by simply normalising intestinal barrier function. It is still unproven that restoring barrier function can ameliorate clinical manifestations in GI or systemic diseases. Clinicians should be aware of the potential of barrier dysfunction in GI diseases and of the barrier as a target for future therapy.

Role for diet in normal gut barrier function: developing guidance within the framework of food-labeling regulations

A reduction in intestinal barrier function is currently believed to play an important role in pathogenesis of many diseases, as it facilitates passage of injurious factors such as lipopolysaccharide, peptidoglycan, whole bacteria, and other toxins to traverse the barrier to damage the intestine or enter the portal circulation. Currently available evidence in animal models and in vitro systems has shown that certain dietary interventions can be used to reinforce the intestinal barrier to prevent the development of disease. The relevance of these studies to human health is unknown. Herein, we define the components of the intestinal barrier, review available modalities to assess its structure and function in humans, and review the available evidence in model systems or perturbations in humans that diet can be used to fortify intestinal barrier function. Acknowledging the technical challenges and the present gaps in knowledge, we provide a conceptual framework by which evidence could be developed to support the notion that diet can reinforce human intestinal barrier function to restore normal function and potentially reduce the risk for disease. Such evidence would provide information on the development of healthier diets and serve to provide a framework by which federal agencies such as the US Food and Drug Administration can evaluate evidence linking diet with normal human structure/function claims focused on reducing risk of disease in the general public.

Eighteen-Year Trends in the Prevalence of, and Health Care Use for, Noncancer Pain in the United States: Data from the Medical Expenditure Panel Survey

We used data from the nationally representative Medical Expenditure Panel Survey to determine the 18-year trends in the overall rates of noncancer pain prevalence and pain-related interference, as well as in health care use attributable directly to pain management. The proportion of adults reporting painful health condition(s) increased from 32.9% (99.7% confidence interval [CI] = 31.6-34.2%;120 million adults) in 1997/1998 to 41.0% (99.7% CI = 39.2-42.4%; 178 million adults) in 2013/2014 (P_trend < .0001). Among adults with severe pain-related interference associated with their painful health condition(s), the use of strong opioids specifically for pain management more than doubled from 11.5% (99.7% CI = 9.6-13.4%) in 2001/2002 to 24.3% (99.7% CI = 21.3-27.3%) in 2013/2014 (P_trend < .0001). A smaller increase (P_interaction < .0001) in strong opioid use was seen in those with minimal pain-related interference: 1.2% (99.7% CI = 1.0-1.4%) in 2001/2002 to 2.3% (99.7% CI = 1.9-2.7%) in 2013/2014. Small but statistically significant decreases (P_trend < .0001) were seen in 1) the percentage of adults with painful health condition(s) who had ≥1 ambulatory office visit for their pain: 56.1% (99.7% CI = 54.2-58.0%) in 1997/1998 and 53.3% (99.7% CI = 51.4-55.4%) in 2013/2014; 2) the percentage who had ≥1 emergency room visit for their pain; 9.9% (99.7% CI = 8.6-11.2%) to 8.8% (99.7% CI = 7.9-9.7%); and 3) the percentage with ≥1 overnight hospitalization for their pain: 3.2% (99.7% CI = 2.6-4.0%) to 2.3% (99.7% CI = 1.8-2.8%). PERSPECTIVE: Our data illustrate changes in the management of painful health conditions over the last 2 decades in the United States. Strong opioid use remains high, especially in those with severe pain-related interference. Additional education of health care providers and the public concerning the risk/benefit ratio of opioids appears warranted.

Mechanisms of Damage to the Gastrointestinal Tract From Nonsteroidal Anti-Inflammatory Drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs) can damage the gastrointestinal tract, causing widespread morbidity and mortality. Although mechanisms of damage involve the activities of prostaglandin-endoperoxide synthase 1 (PTGS1 or cyclooxygenase [COX] 1) and PTGS1 (COX2), other factors are involved. We review the mechanisms of gastrointestinal damage induction by NSAIDs via COX-mediated and COX-independent processes. NSAIDs interact with phospholipids and uncouple mitochondrial oxidative phosphorylation, which initiates biochemical changes that impair function of the gastrointestinal barrier. The resulting increase in intestinal permeability leads to low-grade inflammation. NSAID inhibition of COX enzymes, along with luminal aggressors, results in erosions and ulcers, with potential complications of bleeding, protein loss, stricture formation, and perforation. We propose a model for NSAID-induced damage to the gastrointestinal tract that includes these complex, interacting, and inter-dependent factors. This model highlights the obstacles for the development of safer NSAIDs.

Differing disintegration and dissolution rates, pharmacokinetic profiles and gastrointestinal tolerability of over the counter ibuprofen formulations

OBJECTIVES

Formulations of over the counter (OTC) NSAIDs differ substantially, but information is lacking on whether this alters their gastrointestinal profiles. To assess disintegration and dissolution rates and pharmacokinetics of four preparations of OTC ibuprofen and relate these with spontaneously reported gastrointestinal adverse events.

METHODS

Disintegration and dissolution rates of ibuprofen tablets as (a) acid, (b) sodium salt, (c) lysine salt, and (d) as a liquid gelatine capsule were assessed. Pharmacokinetic data gastrointestinal and spontaneously reported adverse events arising from global sales were obtained from files from Reckitt Benckiser.

KEY FINDINGS

Disintegration at low pH was progressively shorter for the preparations from a-to-d with formation of correspondingly smaller ibuprofen crystals, while dissolution was consistently poor. Dissolution at a neutral pH was least rapid for the liquid gelatine capsule. Pharmacokinetic data showed a shorter t_max and a higher C_max for preparations b-d as compared with ibuprofen acid. Spontaneously reported abdominal symptoms were rare with the liquid gelatine preparation.

CONCLUSIONS

The formulations of OTC ibuprofen differ in their disintegration and dissolution properties, pharmacokinetic profiles and apparent gastrointestinal tolerability. Spontaneously reported abdominal symptoms were five times lower with the liquid gelatine capsule as compared with ibuprofen acid despite a 30% increase in C_max .

Clinical Risk Factors for Gastroduodenal Ulcer in Romanian Low-Dose Aspirin Consumers

Background. Aspirin use for cardiovascular or cancer prevention is limited due to its gastrointestinal side effects. Objective. Our prospective, observational case-control study aims to identify the predictive factors for ulcers in low-dose aspirin consumers (75-325 mg/day). Methods. The study included patients who underwent an upper digestive endoscopy and took low-dose aspirin treatment. Results. We recruited 51 patients with ulcer (ulcer group) and 108 patients with no mucosal lesions (control group). In univariate analysis, factors significantly associated with ulcers were male gender (p = 0.001), anticoagulants (p = 0.029), nonsteroidal anti-inflammatory drugs (p = 0.013), heart failure (p = 0.007), liver (p = 0.011) or cerebrovascular disease (p = 0.004), diabetes mellitus (p = 0.043), ulcer history (p = 0.044), and alcohol consumption (p = 0.018), but not Helicobacter pylori infection (p = 0.2). According to our multivariate regression analysis results, history of peptic ulcer (OR 3.07, 95% CI 1.06-8.86), cotreatment with NSAIDs (OR 8, 95% CI 2.09-30.58) or anticoagulants (OR 4.85, 95% CI 1.33-17.68), male gender (OR 5.2, 95% CI 1.77-15.34), and stroke (OR 7.27, 95% CI 1.40-37.74) remained predictors for ulcer on endoscopy. Conclusions. Concomitant use of NSAIDs or anticoagulants, comorbidities (cerebrovascular disease), and male gender are the most important independent risk factors for ulcer on endoscopy in low-dose aspirin consumers, in a population with a high prevalence of H. pylori infection.

Geographic differences in low-dose aspirin-associated gastroduodenal mucosal injury

Aspirin, even at low doses, has been known to cause upper gastro-intestinal complications, such as gastroduodenal ulcers, despite the definite benefits from its antithrombotic effects. Helicobacter pylori (H. pylori) is major pathogen responsible for gastroduodenal ulcer formation. There have been conflicting results about the potential interaction between these two ulcerogenic factors and the geographic areas involved. In Western countries, the prevalence of gastroduodenal ulcers is consistently higher in H. pylori-positive low-dose aspirin (LDA) users than in H. pylori-negative ones, suggesting that H. pylori infection exacerbates LDA-induced gastroduodenal mucosal injury in these geographic areas. Meanwhile, previous studies from Japan have generally reported a similar prevalence of LDA-induced gastroduodenal mucosal injury regardless of the presence of H. pylori infection, indicating that the infection is not an overall exacerbating factor for drug-induced injury. H. pylori infection could have a synergistic or antagonistic interaction with LDA use in adverse gastroduodenal events depending on gastric acid secretion. It is well-recognized that the net effect of H. pylori infection on gastric acid secretion shows considerable geographic variation at the population level. While gastric acid secretion levels were not decreased and were well-preserved in most patients with H. pylori infection from Western countries, the majority of Japanese patients with H. pylori infection exhibited decreased gastric acid secretion. Such large geographic differences in the net effect of H. pylori infection on gastric acid secretion could be at least partly responsible for the geographically distinct interaction between LDA use and H. pylori infection on adverse gastroduodenal lesions.

Management of low-dose aspirin and clopidogrel in clinical practice: a gastrointestinal perspective

Low-dose aspirin, alone or combined with other antiplatelet agents, is increasingly prescribed for cardiovascular prevention. However, the cardiovascular benefits should be evaluated together with the gastrointestinal risks. Low-dose aspirin is associated with upper and lower gastrointestinal injury, although lower gastrointestinal effects are poorly characterized. This gastrointestinal risk differs among antiplatelets drugs users. The most important risk factors are history of peptic ulcer, older age, and concomitant use of non-steroidal anti-inflammatory drugs or dual antiplatelet therapy. Effective upper gastrointestinal prevention strategies are available and should be used in at-risk patients taking low-dose aspirin or clopidogrel. Proton pump inhibitors seem to be the best gastroprotective agents, whereas the benefits of Helicobacter pylori eradication are still unclear. Low-dose aspirin has additional effects in the gastrointestinal tract. A large body of evidence indicates that it can protect against different cancers, in particular colorectal cancer. This effect could modify the future indications for use of low-dose aspirin and the risk-benefit balance.

Impact of morphine, fentanyl, oxycodone or codeine on patient consciousness, appetite and thirst when used to treat cancer pain

BACKGROUND

There is increasing focus on providing high quality care for people at the end of life, irrespective of disease or cause, and in all settings. In the last ten years the use of care pathways to aid those treating patients at the end of life has become common worldwide. The use of the Liverpool Care Pathway in the UK has been criticised. In England the LCP was the subject of an independent review, commissioned by a Health Minister. The Neuberger Review acknowledged that the LCP was based on the sound ethical principles that provide the basis of good quality care for patients and families when implemented properly. It also found that the LCP often was not implemented properly, and had instead become a barrier to good care; it made over 40 recommendations, including education and training, research and development, access to specialist palliative care services, and the need to ensure care and compassion for all dying patients. In July 2013, the Department of Health released a statement that stated the use of the LCP should be "phased out over the next 6-12 months and replaced with an individual approach to end of life care for each patient".The impact of opioids was a particular concern because of their potential influence on consciousness, appetite and thirst in people near the end of life. There was concern that impaired patient consciousness may lead to an earlier death, and that effects of opioids on appetite and thirst may result in unnecessary suffering. This rapid review, commissioned by the National Institute for Health Research, used standard Cochrane methodology to examine adverse effects of morphine, fentanyl, oxycodone, and codeine in cancer pain studies as a close approximation to possible effects in the dying patient.

OBJECTIVES

To determine the impact of opioid treatment on patient consciousness, appetite and thirst in randomised controlled trials of morphine, fentanyl, oxycodone or codeine for treating cancer pain.

SEARCH METHODS

We assessed adverse event data reported in studies included in current Cochrane reviews of opioids for cancer pain: specifically morphine, fentanyl, oxycodone, and codeine.

SELECTION CRITERIA

We included randomised studies using multiple doses of four opioid drugs (morphine, fentanyl, oxycodone, and codeine) in cancer pain. These were taken from four existing or ongoing Cochrane reviews. Participants were adults aged 18 and over. We included only full journal publication articles.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted adverse event data, and examined issues of study quality. The primary outcomes sought were numbers of participants experiencing adverse events of reduced consciousness, appetite, and thirst. Secondary outcomes were possible surrogate measures of the primary outcomes: delirium, dizziness, hallucinations, mood change and somnolence relating to patient consciousness, and nausea, vomiting, constipation, diarrhoea, dyspepsia, dysphagia, anorexia, asthenia, dehydration, or dry mouth relating to appetite or thirst.Comparative measures of harm were known to be unlikely, and we therefore calculated the proportion of participants experiencing each of the adverse events of interest with each opioid, and for all four opioid drugs combined.

MAIN RESULTS

We included 77 studies with 5619 randomised participants. There was potential bias in most studies, with small size being the most common; individual treatment groups had fewer than 50 participants in 60 studies. Participants were relatively young, with mean age in the studies typically between 50 and 70 years. Multiple major problems with adverse event reporting were found, including failing to report adverse events in all participants who received medication, all adverse events experienced, how adverse events were collected, and not defining adverse event terminology or whether a reporting system was used.Direct measures of patient consciousness, patient appetite, or thirst were not apparent. For opioids used to treat cancer pain adverse event incidence rates were 25% for constipation, 23% for somnolence, 21% for nausea, 17% for dry mouth, and 13% for vomiting, anorexia, and dizziness. Asthenia, diarrhoea, insomnia, mood change, hallucinations and dehydration occurred at incidence rates of 5% and below.

AUTHORS' CONCLUSIONS

We found no direct evidence that opioids affected patient consciousness, appetite or thirst when used to treat cancer pain. However, somnolence, dry mouth, and anorexia were common adverse events in people with cancer pain treated with morphine, fentanyl, oxycodone, or codeine.We are aware that there is an important literature concerning the problems that exist with adverse event measurement, reporting, and attribution. Together with the known complications concerning concomitant medication, data collection and reporting, and nomenclature, this means that these adverse events cannot always be attributed unequivocally to the use of opioids, and so they provide only a broad picture of adverse events with opioids in cancer pain. The research agenda includes developing definitions for adverse events that have a spectrum of severity or importance, and the development of appropriate measurement tools for recording such events to aid clinical practice and clinical research.

Risk factor profiles, drug usage, and prevalence of aspirin-associated gastroduodenal injuries among high-risk cardiovascular Japanese patients: the results from the MAGIC study

BACKGROUND

Low-dose aspirin is widely used for the prevention of cardiovascular events. The prevalence of gastroduodenal injuries and the risk factor profile including gastroprotective drug therapy needs to be clarified in Japanese patients taking daily aspirin for cardioprotection.

METHODS

This Management of Aspirin-induced Gastro-Intestinal Complications (MAGIC) study was conducted with a prospective nationwide, multicenter, real-world registry of Japanese patients at high-risk of cardiovascular diseases who were taking regular aspirin (75-325 mg) for 1 month or more. All patients underwent endoscopic examination for detection of gastroduodenal ulcer and mucosal erosion. The risk factor profiles including the concurrent drug therapy were compared for those patients with gastroduodenal problems and those without.

RESULTS

Gastroduodenal ulcer and erosion were detected in 6.5, and 29.2% of the 1,454 patients receiving aspirin, respectively. H. pylori infection was associated with an increased risk for ulcer: OR 1.83 (1.18-2.88 p = 0.0082). Risk of erosion was lower with enteric-coated aspirin than with buffered aspirin: odds ratio (OR) 0.47 (0.32-0.70, p = 0.0002). Patients receiving proton pump inhibitors had lower risks for both gastroduodenal ulcer and erosion: OR 0.34 (0.15-0.68, p = 0.0050) and 0.32 (0.22-0.46, p < 0.0001), respectively. However, those receiving histamine 2-receptor antagonists had reduced risks for erosion but not for ulcer: OR 0.49 (0.36-0.68, p < 0.0001).

CONCLUSION

Gastroduodenal ulcer and erosion are common in Japanese patients taking low dose aspirin for cardioprotection. Proton pump inhibitors reduce the risk of gastroduodenal mucosal injury.

Gastrointestinal safety of NSAIDs and over-the-counter analgesics

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used. It is well recognised that they may adversely cause damage throughout the gastrointestinal tract and aggravate pre-existing disease. Their side effects on the upper gastrointestinal tract can be assessed by various means; each study type has different clinical connotations. Short-term use (less than 14 days) demonstrates dose-dependent damage of prescribed NSAIDs; the damage is proportional to the acidity of the drugs and not seen with Cyclooxygenase-2 (COX-2) selective inhibitors that have a pKa over 7.0. There have not been any serious outcomes, such as bleeding or perforation in these studies, and Helicobacter pylori (HP) plays no role in this damage. Long-term (3 months or more) endoscopy studies in patients show ulcer rates from 15%-35% with the various NSAIDs, but serious outcomes are exceedingly rare. Epidemiological studies show an association between NSAID intake and serious events. Ibuprofen is consistently at the lower end of toxicity rankings, whereas ketorolac and azapropazone are the worst. The risk of bleeding is increased with advancing age, presence of HP, previous history of bleeding, anticoagulant use, etc. The mega-trials show that COX-2 selective agents halve the bleeding episodes, but NSAID-induced gastric bleeding is very rare usually, less than 1 in 200 subjects taking them for a year. Seventy percent of patients develop NSAID-enteropathy, which is associated with intestinal blood and protein loss and rarely strictures. Over-the-counter (OTC) use of ibuprofen and diclofenac is associated with symptomatic gastrointestinal side effects comparable with placebo. Ibuprofen is shown to be remarkably well tolerated at OTC doses in a number of studies. There are recent studies to suggest that OTC NSAIDs should be taken on a fasting stomach, not with food as commonly advocated.

Endoscopic ulcers as a surrogate marker of NSAID-induced mucosal damage

The characteristic of a biomarker that makes it a useful surrogate is the ability to identify a high risk of clinically important benefits or harms occurring in the future. A number of definitions or descriptions of surrogate definition have been put forward. Most recently the Institute of Medicine of the National Academy of Sciences in the USA has put forward an evaluation scheme for biomarkers, looking at validation (assay performance), qualification (assessment of evidence), and utilisation (the context in which the surrogate is to be used). This paper examines the example of endoscopy as a surrogate marker of NSAID-induced mucosal damage using the Institute of Medicine criteria. The article finds extensive evidence that the detection of endoscopic ulcers is a valid marker. The process of qualification documents abundant evidence showing that endoscopic ulcers and serious upper gastrointestinal damage are influenced in the same direction and much the same magnitude by a variety of risk factors and interventions. Criticisms of validation and qualification for endoscopic ulcers have been examined, and dismissed. Context is the key, and in the context of serious NSAID-induced upper gastrointestinal harm, endoscopic ulcers represent a useful surrogate. Generalisability beyond this context is not considered.

Managing the adverse effects of nonsteroidal anti-inflammatory drugs

Conventional medical treatment for rheumatoid arthritis and osteoarthritis includes the use of NSAIDs (traditional and selective inhibitors of cyclooxygenase [COX]-2), because they provide unmistakable and significant health benefits in the treatment of pain and inflammation. However, they are associated with an increased risk of serious gastrointestinal (GI) and cardiovascular (CV) adverse events. Both beneficial and adverse effects are due to the same mechanism of action, which is inhibition of COX-dependent prostanoids. Since CV and GI risk are related to drug exposure, a reduction in the administered dose is recommended. However, this strategy will not eliminate the hazard owing to a possible contribution of individual genetic background. Further studies will be necessary to develop genetic and/or biochemical markers predictive of the CV and GI risk of NSAIDs.

Non-steroidal anti-inflammatory drugs and gastroprotection with proton pump inhibitors: a focus on ketoprofen/omeprazole

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most commonly prescribed agents for rheumatic disorders such as osteoarthritis (OA), rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Despite the known association between NSAID use and gastropathy, however, only around one-third of patients at risk of NSAID-induced gastrointestinal toxicity receive adequate gastroprotection, and as many as 44% of these patients are non-adherent. We review the co-prescription of proton pump inhibitors (PPIs) for the prevention of NSAID-induced gastropathy, with a particular focus on the first fixed-dose NSAID/PPI formulation: ketoprofen/omeprazole modified-release capsules. The ketoprofen/omeprazole fixed-dose combination is available in doses of 100 mg/20 mg, 150 mg/20 mg or 200 mg/20 mg as a single capsule for once-daily administration. Ketoprofen monotherapy has been shown to be generally equivalent to other NSAIDs when used in the treatment of OA. In RA, ketoprofen has demonstrated equivalent efficacy to diclofenac, indometacin, piroxicam, aceclofenac, phenylbutazone, naproxen and flurbiprofen. Studies comparing ketoprofen with ibuprofen and sulindac in patients with RA have, in general, favoured ketoprofen. Studies in AS have generally reported similar efficacy between ketoprofen and phenylbutazone and pirprofen. Prophylaxis with omeprazole is effective for the prevention of gastroduodenal ulcers, maintenance of remission and alleviation of dyspeptic symptoms in NSAID recipients. Omeprazole is well tolerated, and adverse events are generally gastrointestinal in nature. The fixed-dose combination of ketoprofen and omeprazole has demonstrated bioequivalence to the respective monotherapies. The incidence of digestive symptoms and the need for dose reduction was reported to be lower with the combination than with its components. Ketoprofen/omeprazole modified-release capsules are the first fixed-dose NSAID/PPI formulation to be approved. This formulation ensures compliance with the gastroprotective prophylaxis, as whenever the NSAID is taken, the PPI is co-administered. Additionally, the once-daily formulation has the potential to improve adherence to anti-inflammatory therapy.

Balancing the risk and benefits of low-dose aspirin in clinical practice

Antiplatelet agents are widely used in primary and secondary prevention of cardiovascular events. The scientific evidence has provided strong support for the benefits of aspirin in decreasing the risk of cardiovascular events in a wide range of pathologies. The relatively rare occurrence of major bleeding complications should not be underestimated, mainly due to its high morbi-mortality. The assessment of both gastrointestinal risk and cardiovascular benefits of low-dose aspirin for any individual patient may be difficult in clinical practice. In this review, we summarize the evidence supporting the efficacy of aspirin and the risks of side effects due to hemorrhagic complications. This article proposes a unifying framework for application to help the clinician in the decision making process of individuals who have different risk of cardiovascular and bleeding events with different examples. Finally, new developments in the field directed towards individualized risk assessment strategies are described.

NSAIDs: take with food or after fasting?

OBJECTIVE

Published and regulatory advice is to take NSAIDs with fluids and/or food irrespective whether NSAIDs are taken over the counter or long-term. The basis for this recommendation is not clear and we sought to establish the reasons for it through a search of published literature and personal files.

RESULTS

Results from experimental animals show that fasting increases the gastric side effects of NSAIDs while food increases small bowel damage, but this has not been tested in humans. The possible effects of food in modifying the gastric damage caused by NSAIDs are complex, as food quantity and composition modify the responses substantially. Food usually delays peak levels of NSAIDs (and hence onset of action) without affecting total bioavailability. This may not be important when a steady state is achieved, but rapid onset of action is highly relevant for over-the-counter use of NSAIDs. The safety of over-the-counter use of ibuprofen and naproxen appears to be excellent and comparable with paracetamol.

CONCLUSION

The rapid onset of action of NSAIDs is most important during over-the-counter use, in which case it may be more appropriate to take the drugs on a fasting stomach.

Gastrointestinal lesions and complications of low-dose aspirin in the gastrointestinal tract

Low dose aspirin (ASA) use has been associated with a wide range of adverse side effects in the upper gastrointestinal (GI) tract, which range from troublesome symptoms without mucosal lesions to more serious toxicity, including ulcers, GI bleeding, perforation and even death. Upper GI symptoms in low dose ASA users are common but often careless or misinterpreted and they are not always related to the presence of mucosal injury. Usually, low dose ASA related ulcers are reasonably small and asymptomatic, and probably heal over a period of weeks to a few months. But, the real clinical problem occurs when the ulcer results in a GI complication (mostly bleeding). The estimated average excess risk of symptomatic or complicated ulcer related to low dose ASA is five cases per 1000 ASA users per year. Death is the worst outcome of GI complications in low dose ASA users, but data about this aspect are scarce. Current evidence indicates that low dose ASA can damage the lower GI tract also, but the real size of the problem is still unknown.

Prevention of peptic ulcers with esomeprazole in patients at risk of ulcer development treated with low-dose acetylsalicylic acid: a randomised, controlled trial (OBERON)

Objective

To determine whether once-daily esomeprazole 40 mg or 20 mg compared with placebo reduces the incidence of peptic ulcers over 26 weeks of treatment in patients taking low-dose acetylsalicylic acid (ASA) and who are at risk for ulcer development.

Design

Multinational, randomised, blinded, parallel-group, placebo-controlled trial.

Setting

Cardiology, primary care and gastroenterology centres (n=240).

Patients

Helicobacter pylori-negative patients taking daily low-dose ASA (75–325 mg), who fulfilled one or more of the following criteria: age ≥18 years with history of uncomplicated peptic ulcer; age ≥60 years with either stable coronary artery disease, upper gastrointestinal symptoms and five or more gastric/duodenal erosions, or low-dose ASA treatment initiated within 1 month of randomisation; or age ≥65 years. All patients were ulcer-free at study entry.

Interventions

Once-daily, blinded treatment with esomeprazole 40 mg, 20 mg or placebo for 26 weeks.

Main outcome measures

The primary end point was the occurrence of endoscopy-confirmed peptic ulcer over 26 weeks.

Results

A total of 2426 patients (52% men; mean age 68 years) were randomised. After 26 weeks, esomeprazole 40 mg and 20 mg significantly reduced the cumulative proportion of patients developing peptic ulcers; 1.5% of esomeprazole 40 mg and 1.1% of esomeprazole 20 mg recipients, compared with 7.4% of placebo recipients, developed peptic ulcers (both p<0.0001 vs placebo). Esomeprazole was generally well tolerated.

Conclusions

Acid-suppressive treatment with once-daily esomeprazole 40 mg or 20 mg reduces the occurrence of peptic ulcers in patients at risk for ulcer development who are taking low-dose ASA.

Clinical trial registration number

ClinicalTrials.gov identifier: NCT00441727.

Clinical trial: endoscopic evaluation of naproxen etemesil, a naproxen prodrug, vs. naproxen - a proof-of-concept, randomized, double-blind, active-comparator study

BACKGROUND

Nonsteroidal anti-inflammatory drugs are associated with upper gastrointestinal mucosal injury. Naproxen etemesil is a lipophilic, non-acidic, inactive prodrug of naproxen that is hydrolysed to pharmacologically active naproxen once absorbed. We hypothesized that with lesser topical exposure to naproxen from the prodrug, there would be reduced gastroduodenal mucosal injury compared with naproxen.

AIM

To compare the degree of endoscopic mucosal damage of naproxen etemesil vs. naproxen.

METHODS

This multicentre, randomized, double-blind, double-dummy trial compared oral naproxen etemesil 1200 mg twice daily (n = 61) with naproxen 500 mg twice daily (n = 59) for 7.5 days in 120 healthy subjects (45-70 years; mean 51 years; 58% female) with baseline total modified gastroduodenal Lanza score ≤ 2 (no erosions/ulcers) on endoscopy. The primary endpoint was mean total modified gastroduodenal Lanza score on day 7. A secondary endpoint was incidence of gastric ulcers.

RESULTS

The day 7 mean total modified gastroduodenal Lanza score was 2.8 ± 1.7 for naproxen etemesil vs. 3.5 ± 2.0 for naproxen (P = 0.03), and significantly fewer naproxen etemesil-treated subjects (3.3%) developed gastric ulcers compared with naproxen-treated subjects (15.8%) (P = 0.02).

CONCLUSION

In this first proof-of-concept study, naproxen etemesil was associated with significantly lower gastroduodenal mucosal injury compared with naproxen after 7 days of exposure (

CLINICAL TRIAL NUMBER

NCT00750243).

Clinical trial: the incidence of NSAID-associated endoscopic gastric ulcers in patients treated with PN 400 (naproxen plus esomeprazole magnesium) vs. enteric-coated naproxen alone

BACKGROUND

Gastroprotective co-therapy may reduce the risk of nonsteroidal anti-inflammatory drug (NSAID)-associated gastric ulcers, but adherence is suboptimal.

AIM

To compare the incidence of gastric ulcers with PN 400 [enteric-coated (EC) naproxen 500 mg and immediate-release esomeprazole 20 mg], or EC naproxen.

METHODS

Two randomized, double-blind, multicentre studies (PN400-301, PN400-302). Patients [stratified by low-dose aspirin (< or =325 mg) use] aged > or =50 years or 18-49 years with a history of ulcer, received PN 400 BID (301, n = 218; 302, n = 210) or EC naproxen 500 mg BID (301, n = 216; 302, n = 210) for 6 months. The primary endpoint was the cumulative incidence of endoscopic gastric ulcers.

RESULTS

The cumulative incidence of gastric ulcers was significantly lower with PN 400 vs. EC naproxen (301: 4.1% vs. 23.1%, P < 0.001; 302: 7.1% vs. 24.3%, P < 0.001). PN 400 was associated with a lower combined incidence of gastric ulcers vs. EC naproxen in low-dose aspirin users (n = 201) (3.0% vs. 28.4%, P < 0.001) and non-users (n = 653) (6.4% vs. 22.2%, P < 0.001). The incidence of, and discontinuations due to, upper gastrointestinal (UGI) AEs was significantly lower with PN 400 relative to EC naproxen (P < 0.01, both studies).

CONCLUSIONS

PN 400 significantly reduces the incidence of gastric ulcers, regardless of low-dose aspirin use, in at-risk patients, and is associated with improved UGI tolerability relative to EC naproxen (ClinicalTrials.gov, NCT00527782).

Drug-related damage of the ageing gastrointestinal tract

Drug use increases with age and the elderly is at increased risk of adverse drug reactions. Gastrointestinal adverse effects are one of the most often reported. Serious event are mostly caused by NSAIDs and/or aspirin which are the most widely prescribed medications in the world. NSAIDs and/or aspirin use are associated with complications from both the upper and the lower gastrointestinal tract. The risk of these complications depends on presence of risk factors, and age is the most frequent and relevant one. At-risk patients should be on prevention strategies including the use of the lowest effective dose, co-therapy with a gastroprotective agents or use of a COX-2 selective agent. Treatment of Helicobacter pylori infection is beneficial in patients starting therapy with these agents, especially in the presence of ulcer history. The best strategy to prevent lower GI complications has yet to be defined.

Prevention of chronic NSAID induced upper gastrointestinal toxicity

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are important agents in the management of arthritic and inflammatory conditions, and are among the most frequently prescribed medications in North America and Europe. However, there is overwhelming evidence linking these agents to a variety of gastrointestinal (GI) toxicities.

OBJECTIVES

To review the effectiveness of common interventions for the prevention of NSAID induced upper GI toxicity.

SEARCH STRATEGY

A literature search was conducted, according to the Cochrane methodology for identification of randomized controlled trials in electronic databases, including MEDLINE from 1966 to January 2000, Current Contents for 6 months prior to January 2000, Embase to Febuary 1999, and a search of the Cochrane Controlled Trials Register from 1973 to 1999. Recent conference proceedings were reviewed and content experts and companies were contacted.

SELECTION CRITERIA

Randomized controlled clinical trials (RCTs) of prostaglandin analogues (PA), H2-receptor antagonists (H2RA) or proton pump inhibitors (PPI) for the prevention of chronic NSAID induced upper GI toxicity were included.

DATA COLLECTION AND ANALYSIS

Two independent reviewers extracted data regarding population characteristics, study design, methodological quality and number of patients with endoscopic ulcers, ulcer complications, symptoms, overall drop-outs, drop outs due to symptoms. Dichotomous data was pooled using Revman V3.1. Heterogeneity was evaluated using a chi square test.

MAIN RESULTS

Thirty-three RCTs met the inclusion criteria. All doses of misoprostol significantly reduced the risk of endoscopic ulcers. Misoprostol 800 ug/day was superior to 400 ug/day for the prevention of endoscopic gastric ulcers (RR=0.18, and RR=0. 38 respectively, p=0.0055). A dose response relationship was not seen with duodenal ulcers. Misoprostol caused diarrhea at all doses, although significantly more at 800ug/day than 400ug/day (p=0.0012). Misoprostol was the only prophylactic agent documented to reduce ulcer complications. Standard doses of H2RAs were effective at reducing the risk of endoscopic duodenal (RR=0.24; 95% CI: 0.10-0. 57) but not gastric ulcers(RR=0.73; 95% CI:0.50-1.09). Both double dose H2RAs and PPIs were effective at reducing the risk of endoscopic duodenal and gastric ulcers (RR=0.44; 95% CI:0.26-0.74 and RR=0.37;95% CI;0.27-0.51 respectively for gastric ulcer), and were better tolerated than misoprostol.

REVIEWER'S CONCLUSIONS

Misoprostol, PPIs, and double dose H2RAs are effective at preventing chronic NSAID related endoscopic gastric and duodenal ulcers. Lower doses of misoprostol are less effective and are still associated with diarrhea. Only Misoprostol 800ug/day has been directly shown to reduce the risk of ulcer complications.