Treatment of non-steroidal anti-inflammatory drug induced enteropathy

Gut Microbiota in NSAID Enteropathy: New Insights From Inside

As a class of the commonly used drugs in clinical practice, non-steroidal anti-inflammatory drugs (NSAIDs) can cause a series of adverse events including gastrointestinal injuries. Besides upper gastrointestinal injuries, NSAID enteropathy also attracts attention with the introduction of capsule endoscopy and double balloon enteroscopy. However, the pathogenesis of NSAID enteropathy remains to be entirely clarified. Growing evidence from basic and clinical studies presents that gut microbiota is a critical factor in NSAID enteropathy progress. We have reviewed the recent data about the interplay between gut microbiota dysbiosis and NSAID enteropathy. The chronic medication of NSAIDs could change the composition of the intestinal bacteria and aggravate bile acids cytotoxicity. Meanwhile, NSAIDs impair the intestinal barrier by inhibiting cyclooxygenase and destroying mitochondria. Subsequently, intestinal bacteria translocate into the mucosa, and then lipopolysaccharide released from gut microbiota combines to Toll-like receptor 4 and induce excessive production of nitric oxide and pro-inflammatory cytokines. Intestinal injuries present in the condition of intestinal inflammation and oxidative stress. In this paper, we also have reviewed the possible strategies of regulating gut microbiota for the management of NSAID enteropathy, including antibiotics, probiotics, prebiotics, mucosal protective agents, and fecal microbiota transplant, and we emphasized the adverse effects of proton pump inhibitors on NSAID enteropathy. Therefore, this review will provide new insights into a better understanding of gut microbiota in NSAID enteropathy.

The Protective Effect of 5-Aminosalicylic Acid Against Non-Steroidal Anti-Inflammatory Drug-Induced Injury Through Free Radical Scavenging in Small Intestinal Epithelial Cells

Background and objectives: Non-steroidal anti-inflammatory drugs (NSAIDs) have been among the major causes of small intestinal injury in clinical practice. As such, the current study investigated the protective effect of 5-aminosalicylic acid (5-ASA) against an NSAID-induced small intestinal injury. Materials and Methods: IEC-6 cells were treated with various concentrations of indomethacin with or without 5-ASA in a serum-free medium, after which an 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Dromide (MTT) assay, a cell apoptosis assay, a caspase-3 activity assay, a reactive oxygen species (ROS) content and Superoxide dismutase 2 (SOD2) activity measurement, a Western blotting for occludin and zonula occludens-1 (ZO-1) and a wound healing assay were conducted. Results: 5-ASA ameliorated indomethacin-induced cell apoptosis and an increase in the intracellular ROS content while augmenting the indomethacin-induced suppression of SOD2 activity in IEC-6 cells. Moreover, 5-ASA reversed the indomethacin-induced attenuation of occludin and ZO-1 expression and promoted faster wound healing effects in IEC-6 cells following an indomethacin-induced injury. Conclusions: Our results suggested that 5-ASA protects small intestinal cells against an NSAID-induced small intestinal injury by scavenging free radicals. Therefore, 5-ASA could be a potential treatment for an NSAID-induced small intestinal injury.

Review article: a practical approach to the clinical management of NSAID enteropathy

Co-prescription of acid suppressive therapy, together with advances in small bowel imaging techniques, have shifted the burden of NSAID-related toxicity from gastro-duodenal to more distal small bowel injury. Due to predominantly subclinical disease, NSAID enteropathy remains under-recognised, with an incidence of 53-80% amongst healthy short-term users, and a prevalence of 50-71% following long-term (>3 months) use. Despite their distinct pathogenesis, those at risk of NSAID-related gastro-duodenal and small bowel complications share several risk factors. Clinical complications of NSAID enteropathy such as protein-losing enteropathy, small bowel strictures and diaphragm disease, confer significant morbidity, and are often irreversible. Small bowel prophylaxis has proven of modest efficacy after short-term, high-dose NSAID use in asymptomatic patients. While selective COX-2 inhibitors are associated with fewer gastro-duodenal complications relative to non-selective NSAIDs, their comparative benefit in protecting against small bowel enteropathy remains unclear. Prophylaxis should be considered in those at high risk of small bowel complications, as treatment options for established disease remain limited; however, the optimal agent remains unclear. We propose a clinical algorithm that may help prevent, monitor, investigate, and manage the sequelae of NSAID-induced small bowel toxicity.

Clinical Features, Diagnosis, and Treatment Strategies of Gastrointestinal Diaphragm Disease Associated with Nonsteroidal Anti-Inflammatory Drugs

Background. To demonstrate the clinical features, diagnosis, and treatment of nonsteroidal anti-inflammatory drug- (NSAID-) induced diaphragm disease (DD). Methods. A literature search between January 1973 and August 2015 was undertaken. The clinical data of patients with NSAID-induced DD were recorded and analyzed. Results. 159 patients were included. The ratio of male to female was 1 : 2.3; the mean age was 65 ± 11 years. The most common clinical manifestations were gastrointestinal bleeding and obstruction. 121 (84%) patients took traditional NSAIDs. The durations of NSAIDs use ranged from 2 to 300 months. A majority (59.7%) of DD were seen in the small bowel, were seen secondly in the colon (30.2%), and were mainly located in the ileum (57.9%) and right colon (91.7%), respectively. 80% of patients had multiple diaphragms. 41.5% of small bowel DD were diagnosed preoperatively by capsule endoscopy and/or double-balloon enteroscopy, 52.1% at laparotomy. Nearly 75% of patients underwent surgery, endoscopic balloon dilation was performed in 22 patients, and NSAIDs were withdrawn in 53 patients. Conclusions. NSAID-induced DD is relatively rare. The small bowel is most commonly involved. Preoperative diagnosis of small bowel DD is relatively difficult. Discontinuation of the NSAIDs is recommended, surgical resection is the main treatment presently, and endoscopic balloon dilation should be considered as an alternative therapy.

Lower Gastrointestinal Bleeding due to Non-Steroid Anti-Inflammatory Drug-Induced Colopathy Case Report and Literature Review

The adverse effects of non-steroidal anti-inflammatory drugs (NSAIDs) on the upper gastrointestinal (GI) tract and small intestine are well established. The effect of such therapy on the large intestine, so called NSAID-induced colopathy, is less well described. NSAID-induced colopathy usually involves the right colon due to a higher concentration of the drug at this site, but the rectum may also be involved. NSAIDs possibly damage the normal large intestine, which presents as ulceration, colitis and stricture. Even though several studies found that NSAIDs can cause diverticular bleeding and perforation, flare-up of inflammatory bowel disease ,and play a role as an etiologic factor in lymphocytic colitis. Inflammatory bowel diseases , malignancy and infectious colitis must be ruled out before establishing the diagnosis of NSAID -induced colopathy. Discontinuation of the offending drug is mandatory. Here, we have reported the case of a 43-year-old female, NSAID user due to low back pain, who was admitted to the hospital with painless hematochezia.

Mucosal healing effect of mesalazine granules in naproxen-induced small bowel enteropathy

AIM: To investigate the effect of mesalazine granules on small intestinal injury induced by naproxen using capsule endoscopy (CE).

METHODS: This was a single center, non-randomized, open-label, uncontrolled pilot study, using the PillCam SB CE system with RAPID 5 software. The Lewis Index Score (LIS) for small bowel injury was investigated to evaluate the severity of mucosal injury. Arthropathy patients with at least one month history of daily naproxen use of 1000 mg and proton pump inhibitor co-therapy were screened. Patients with a minimum LIS of 135 were eligible to enter the 4-wk treatment phase of the study. During this treatment period, 3 × 1000 mg/d mesalazine granules were added to ongoing therapies of 1000 mg/d naproxen and 20 mg/d omeprazole. At the end of the 4-wk combined treatment period, a second small bowel CE was performed to re-evaluate the enteropathy according to the LIS results. The primary objective of this study was to assess the mucosal changes after 4 wk of mesalazine treatment.

RESULTS: A total of 18 patients (16 females), ranging in age from 46 to 78 years (mean age 60.3 years) were screened, all had been taking 1000 mg/d naproxen for at least one month. Eight patients were excluded from the mesalazine therapeutic phase of the study for the following reasons: the screening CE showed normal small bowel mucosa or only insignificant damages (LIS < 135) in five patients, the screening esophagogastroduodenoscopy revealed gastric ulcer in one patient, capsule technical failure and incomplete CE due to poor small bowel cleanliness in two patients. Ten patients (9 female, mean age 56.2 years) whose initial LIS reached mild and moderate-to-severe enteropathy grades (between 135 and 790 and ≥ 790) entered the 4-wk therapeutic phase and a repeat CE was performed. When comparing the change in LIS from baseline to end of treatment in all patients, a marked decrease was seen (mean LIS: 1236.4 ± 821.9 vs 925.2 ± 543.4, P = 0.271). Moreover, a significant difference between pre- and post-treatment mean total LIS was detected in 7 patients who had moderate-to-severe enteropathy gradings at the inclusion CE (mean LIS: 1615 ± 672 vs 1064 ± 424, P = 0.033).

CONCLUSION: According to the small bowel CE evaluation mesalazine granules significantly attenuated mucosal injuries in patients with moderate-to-severe enteropathies induced by naproxen.

Diagnosis and management of mid-gastrointestinal bleeding by double-balloon endoscopy

The new methods of capsule endoscopy (CE) and double-balloon endoscopy (DBE) have revolutionized the diagnostic approach to middle (mid) gastrointestinal bleeding (MGIB) in recent years. DBE also has therapeutic options and enables us to treat the MGIB endoscopically. In this review, we discuss endoscopic diagnosis and management of three major categories of sources of MGIB - vascular lesions, ulcers/erosions and tumors/polyps.

Gastrointestinal and hepatic manifestations of rheumatoid arthritis

Rheumatoid arthritis (RA), characterized by inflammation of the synovium and surrounding structures, has a prevalence of 0.5-1%. Rheumatoid vasculitis (RV) is an inflammatory condition of the small- and medium-sized vessels that affects up to 5% of patients with RA with intestinal involvement in 10-38% of these cases. Clinically apparent RV of the gastrointestinal (GI) tract, while rare, is often catastrophic, resulting in ischemic ulcers and bowel infarction. Vasculitis of the colon may present as pancolitis clinically similar to ulcerative colitis. Rectal biopsies that include submucosal vessels are positive for vasculitis in up to 40% of cases. Abnormal esophageal motility in RA may result in heartburn and dysphagia. Chronic atrophic gastritis may be associated with hypergastrinemia and hypo- or achlorhydria, promoting small bowel bacterial overgrowth. RA is the most common cause of secondary amyloidosis with GI symptoms in 22% of affected patients. Although amyloid is usually found in the liver, it is rarely evident clinically. Felty's syndrome occurs in less than 1% of patients with RA and is characterized by neutropenia and splenomegaly. The liver may be involved with portal fibrosis or nodular regenerative hyperplasia. Liver histology is abnormal in 92% of RA patients at autopsy, although the changes are usually mild without associated hepatomegaly. Drug-induced liver disease may occur with aspirin, sulfasalazine, and methotrexate. Significant liver damage is rare if the drug is discontinued or the patient is properly monitored. RA can affect both the GI tract and the liver; changes are usually mild except with RV.

Nonsteroidal anti-inflammatory drug-induced small-bowel lesions identified by double-balloon endoscopy: endoscopic features of the lesions and endoscopic treatments for diaphragm disease

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) occasionally induce small-bowel injury. However, the clinical features have only been partially clarified. The aim of this study was to clarify the clinical features of the disease and evaluate the effectiveness of endoscopic balloon dilation therapy for diaphragm disease, using double-balloon endoscopy (DBE).

METHODS

This is a retrospective case study using our DBE database. Our inclusion criteria required patients to meet all the following criteria: (1) history of NSAID use; (2) endoscopic findings of erosion and/or ulcer and/or typical diaphragm-like strictures; (3) improvement in clinical findings (signs and symptoms) and/or endoscopic findings by cessation of NSAIDs, except for diaphragm disease; and (4) exclusion of other causes (e.g., malignant tumor, inflammatory bowel disease, and infectious disease). The clinical records of patients were investigated.

RESULTS

Eighteen patients were included. Sixteen patients showed ulcerative lesions, and the remaining 2 patients showed diaphragm diseases. For localized lesions, 12 patients evidenced lesions in the ileum, 5 patients had lesions in the duodenum and/or jejunum, and 1 had lesions in both intestines. The ulcerative lesions were multiple with various morphologies that were located unrelated to mesenteric or antimesenteric sides. The endoscopic balloon dilations were performed safely, and all patients improved with regard to their symptoms.

CONCLUSIONS

Symptomatic NSAID-induced small-bowel injuries exhibit a variety of patterns of ulcerative lesions as observed in the ileum in many cases. The endoscopic balloon dilation appears to be a safe and effective treatment for diaphragm disease.

Nonsteroidal antiinflammatory drugs and the small intestine

PURPOSE OF REVIEW

The small intestine may be a more common site for nonsteroidal antiinflammatory drug toxicity than the gastroduodenal mucosa. Two-thirds of regular nonsteroidal antiinflammatory drug users develop subclinical small bowel enteropathy. This review highlights this emerging issue in patients requiring antiinflammatory drugs.

RECENT FINDINGS

Nonsteroidal antiinflammatory drug enteropathy is a stepwise process involving direct mucosal toxicity, mitochondrial damage, breakdown of intercellular integrity, enterohepatic recirculation and neutrophil activation by luminal contents including bacteria. Unlike upper gastrointestinal toxicity, cyclooxygenase-mediated mechanisms are probably less important. Newer imaging modalities such as capsule endoscopy studies demonstrate nonsteroidal antiinflammatory drug-induced small bowel erosions, but the clinical implications are unclear.

SUMMARY

Nonsteroidal antiinflammatory drug toxicity to the small intestine is common. Useful research tools have been developed to indirectly measure intestinal inflammation and permeability, but these are not generally available to the clinician, although enteroscopy and capsule endoscopy can be illuminating. Anaemia or hypoalbuminaemia are useful indications of nonsteroidal antiinflammatory drug enteropathy. Cessation of the drug would be the preferred option, alternatively there are experimental data to support the use of sulphasalazine and metronidazole. Animal models are unravelling new mechanisms for mucosal toxicity beyond the cyclooxygenase model, including mucosal oxidative injury and nitric oxide mediated pathways.

NSAIDs, coxibs, and the intestine

Nonsteroidal anti-inflammatory drugs (NSAIDs) are capable of damaging the whole gastrointestinal tract. Small and large intestinal injuries manifest as acute changes in permeability with endoscopic erosions, chronic erosions and ulcers, diaphragms in the small bowel, and an increase in small and large bowel complications including perforation and diverticular bleeding. It is quite likely, though not proven, that such lesions contribute to anemia in patients taking them. A growing body of data shows that selective inhibitors of the cyclooxygenase-2 enzyme have much reduced toxicity in this respect. In addition, NSAID use has also been associated with development or relapse of ulcerative colitis. Whether the same is true of Crohn's disease, particularly of the small bowel, is less clear. An important point is that there are data that suggest that paracetamol may also not be devoid of toxicity. This makes use of selective cyclooxygenase-2 inhibitors attractive. There have been a number of reports of their use in inflammatory bowel disease. However, many of these have principally involved Crohn's disease and there have not been enough to be clear whether they affect the influence of relapse of ulcerative colitis.

Diaphragm disease of the ileum

Diaphragm disease is a condition wherein the bowel lumen is divided into a series of short compartments by circular membranes of mucosa and submucosa, leading to a pinhole lumen and subsequent obstruction. It is a very rare condition commonly attributed to non-steroidal anti-inflammatory drugs (NSAIDs) usage. We present two cases of obstruction secondary to diaphragm disease of the ileum diagnosed on histology of the resected specimen. One patient had no history of chronic NSAID intake.

Nonsteroidal antiinflammatory drugs and the small intestine

PURPOSE OF REVIEW

The small intestine is a more common site for nonsteroidal antiinflammatory drug (NSAID) toxicity than the well-recognized effects on the stomach and duodenum. Although NSAID strictures and perforation are rare, two thirds of regular NSAID users may be prone to small bowel enteropathy. This review highlights this emerging issue in patients requiring antiinflammatory drugs.

RECENT FINDINGS

NSAID enteropathy is a stepwise process involving direct mucosal toxicity, mitochondrial damage, breakdown of intercellular integrity, enterohepatic recirculation, and neutrophil activation by luminal contents, including bacteria. Unlike upper gastrointestinal toxicity, cyclooxygenase-mediated mechanisms are probably less important. Newer imaging modalities such as capsule endoscopy studies suggest that small bowel erosions may be common in nonselective NSAID users. Sulfasalazine and metronidazole may prove to be useful, therapeutic options for patients who cannot cease their NSAIDs.

SUMMARY

NSAID toxicity to the small intestine is common. Useful research tools have been developed to measure intestinal inflammation and permeability indirectly, but these are not generally available to the clinician, although enteroscopy and capsule endoscopy may be helpful. Anemia or hypoalbuminemia are useful clues to NSAID enteropathy. Cessation of the drug is ideal; otherwise, there is experimental data to support the use of sulfasalazine and metronidazole. Animal models are unraveling new mechanisms for mucosal toxicity beyond the cyclooxygenase model.

Complications intestinales liées aux AINS

Chronic use of non-salicylate NSAIDs causes in most individuals an asymptomatic enteropathy involving the small bowel, particularly its distal part. This enteropathy is characterised by an increase in intestinal permeability and a mild mucosal inflammation. Hypoalbuminemia and iron deficiency may occur. In addition, non-salicylate NSAIDs may cause focal lesions of the small intestine. Ulcerations and ulcers, that can be accidentally discovered during an ileoscopy, may cause acute or chronic bleeding. Deep ulcers may provoke sudden peritonitis. Small bowel diaphragms are rare fibrotic lesions, specifically associated with the use of non-salicylate NSAIDs or salicylates (duodenal diaphragms only). NSAID use is not associated with a constant toxicity on colonic mucosa. NSAID-induced colonic ulcers and diaphragms are rare. In patients with colonic diverticulosis, NSAID intake is a risk factor for severe attacks of diverticulitis. Acute or chronic use of non-salicylate NSAIDs increases the risk for ischemic colitis and flare-ups of inflammatory bowel disease. De novo colitis caused by non-salicylate NSAIDs are rare. The definite diagnosis of this entity relies on the absence of recurrence of colitis in the 2-3 following years. Such a recurrence would lead to the post-hoc diagnosis of first attack of inflammatory bowel disease triggered by NSAID use. Experimental data suggest that selective COX-2 inhibitors do not alter constantly mucosa of the small intestine. Pilot epidemiological works suggest that severe intestinal lesions are less frequent in association with COX-2 inhibitor use than in association with conventional NSAIDs. However, COX-2 appears as playing a beneficial role in mucosal healing, and it seems that COX-2 inhibitors, like conventional NSAIDs, may trigger flare-ups of inflammatory bowel disease.

Determining small bowel integrity following drug treatment

Intestinal integrity is maintained by a delicate balance between mucosal defence and luminal aggressors that cause damage if exposed to the mucosa. The intestinal barrier function appears to be the gatekeeper for controlling this balance. It is becoming increasingly clear that if the intestinal barrier is disrupted the consequences are low grade intestinal inflammation which carry with it the risk of significant blood and protein loss both of which may cause clinical management problems. We review the strength and weaknesses of methods for assessing small bowel function that are useful for assessing drug-induced intestinal toxicity. There are a number of imaging methods for assessing intestinal integrity but these do not provide functional information. Intestinal permeability measurements have been optimized for specificity and there are now ways of measuring intestinal permeability regionally, but marker analyses continue to be cumbersome. Recent developments of faecal inflammatory markers make it a matter of routine to assess this in any routine chemical pathology laboratory. Bleeding, protein loss and other complications of inflammation can also be measured with good specificity, but again the methods are cumbersome. Using a combination of functional and imaging techniques it is now possible to characterize and define with precision, the small bowel side-effects of drugs, the best example being the small bowel side-effects of nonsteroidal anti-inflammatory drugs (NSAIDs).

Nonsteroidal anti-inflammatory drug-induced diaphragms and ulceration in the colon

The toxic effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on the small bowel have been reported extensively. A growing number of reports of toxic effects of NSAIDs on the colon have appeared recently. The clinical presentation, endoscopic appearances and histological findings of so-called NSAID colopathy are quite varied, as illustrated by a series of four patients described in this report. Presenting symptoms and signs in this series include iron-deficiency anaemia and crampy abdominal pain, but alteration of bowel habit, weight loss, and even nausea and vomiting have also been described. One patient in this series has large-bowel diaphragms, considered by some to be pathognomonic of NSAID effects. Each of the four patients had right-sided colonic lesions only, possibly supporting a direct toxic effect of NSAIDs. Management usually involves simply stopping the offending NSAID. A review of the literature on this under-recognized entity is presented.

Small Bowel Ulcers

Treatment of small intestinal ulcers depends on the cause of the ulcers. Ulcerations of the small intestine (apart from duodenal ulcers) are uncommon. Two diverse syndromes of idiopathic small bowel ulcerations include the isolated nonspecific ulcer and idiopathic chronic ulcerative enteritis (ICUE). Treatment of isolated nonspecific ulcers include discontinuation of medications known to cause nonspecific ulcerations, balloon dilation of strictures, and segmental resection of involved segments. Treatment of ICUE includes a diet trial of gluten restriction and consideration of early surgery because of the potential for associated malignancies. Steroid therapy has not been shown to be effective in the treatment of ICUE.

Clinical, endoscopic, and histologic spectrum of nonsteroidal anti-inflammatory drug-induced lesions in the colon

PURPOSE

It has become increasingly clear that nonsteroidal anti-inflammatory drugs may cause damage not only to the upper gastrointestinal tract but also to the small and large intestine. Although the colon may be readily investigated by endoscopy, drug-induced lesions are not well known, probably because they are considered to occur only rarely. In the present study we describe endoscopic, histologic, and gross characteristics of nonsteroidal anti-inflammatory drug-induced colonic damage. Furthermore, pathogenetic mechanisms and therapeutic options are discussed.

METHODS

The histories of all patients diagnosed as having nonsteroidal anti-inflammatory drug colitis during the last two years at the department of gastroenterology or the department of pathology at our hospital were reviewed. Endoscopic, histologic, and gross pathologic findings were systematically recorded. In addition, data on duration and type of nonsteroidal anti-inflammatory drug intake and time from onset of symptoms to diagnosis were collected. Therapy and outcome of our patients, if available, are reported.

RESULTS

During the study period 11 patients were diagnosed as having nonsteroidal anti-inflammatory drug colitis. Most patients presented with diarrhea with or without blood loss and complained about diffuse abdominal pain. Endoscopy revealed flat ulcers in the entire colon being more severe in the right colon in the three cases with acute onset of diarrhea. In four cases concentric "diaphragm-like" strictures were seen, all located in the right colon. In the remainder endoscopy showed nonspecific erosions and was normal in one patient. Histology revealed findings similar to ischemic colitis. Additionally, in two cases collagenous colitis was found. Diclofenac slow release was the most commonly involved drug. The median time from onset of symptoms to diagnosis was 1.8 (range, 0-11.5) years.

CONCLUSIONS

Nonsteroidal anti-inflammatory drug colitis is a clinically significant disease, which may present with diarrhea, anemia, and nonspecific abdominal complaints. Careful history taking, together with awareness of endoscopic and histologic findings, allows a timely diagnosis of this disease.

Selected drug complications and treatment conflicts in the presence of coexistent diseases

The presence of different coexistent systemic diseases often times complicates the selection of the appropriate treatment of an underlying rheumatologic condition. In this article, some controversial treatment conflicts that are frequently encountered in the daily practice of rheumatology are clarified and guidelines for the best available therapeutic options are provided.

An evidence-based approach to prescribing NSAIDs in musculoskeletal disease: a Canadian consensus. Canadian NSAID Consensus Participants

OBJECTIVE

To make recommendations for the long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) in primary care practice, particularly for patients at high risk for NSAID-induced complications.

OPTIONS

The use of misoprostol to prevent gastrointestinal ulceration and other unwanted NSAIDs effects was considered. The role of cyclooxygenase-2 (COX-2) versus COX-1 inhibiting agents was also examined.

OUTCOMES

Reduction of complications associated with long-term use of NSAIDs.

EVIDENCE

Evidence was gathered in late 1995 from published research studies and reviews. Position papers were prepared by faculty and advisory board members and discussed at the Canadian NSAID Consensus Symposium in Cambridge, Ont., Jan. 26 and 27, 1996.

VALUES

Recommendations were based on randomized, placebo-controlled clinical trials (level I evidence) and case-control studies (level II evidence) involving NSAID use when such evidence was available. When the scientific literature was incomplete or inconsistent in a particular area, recommendations reflect the consensus of the participants at the symposium (level III evidence). Physicians were recruited from across Canada for their expertise in rheumatology, gastroenterology, epidemiology, gerontology, family practice, and clinical and basic scientific research.

BENEFITS, HARMS AND COSTS

Although a reduction in complications due to inappropriate NSAID use should reduce costs of additional investigations, admissions to hospital and time lost from work, definitive cost analysis studies are not yet available.

RECOMMENDATIONS

Currently, no NSAID is available that lacks potential for serious toxicity; therefore, long-term use of NSAIDs should be avoided whenever possible, particularly in high-risk patients (e.g., those who are elderly, suffer from hypertension, congestive heart failure, renal or hepatic impairment or volume depletion, take certain concomitant medications or have a history of peptic ulcer disease) (level I evidence). If NSAIDs are to be used in patients with gastric or nephrotoxic risk factors, the lowest effective dose of NSAID should be used (level III evidence); NSAIDs that are weak COX-1 inhibitors may be preferred (level II evidence). In addition, concomitant administration of misoprostol is recommended in patients at increased risk for upper gastrointestinal complications (level I evidence). However, the clinical judgement of the practising clinician must always be part of any therapeutic decision.

VALIDATION

These recommendations are based on the consensus of Canadian experts in rheumatology, gastroenterology and epidemiology, and have been subjected to external peer review.

Colonic ulceration associated with nonsteroidal anti-inflammatory drugs. Report of three cases

Nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with a variety of gastrointestinal side effects. Effects on the large intestine have been reported with increasing frequency. Recognition of NSAID-induced colonic lesions has been confounded by variable clinical presentations, variable pathologic findings, and unfamiliarity of this entity among clinicians. We have recently seen three cases of NSAID-induced cecal ulcerations in patients undergoing right colectomy. A correct preoperative diagnosis was not made in our patients, one of whom presented with an acute abdomen and two in whom there was an inability to rule out carcinoma. The gross, radiographic, and histologic findings in each case consisted of a characteristic transverse ulceration with thin diaphragm-like scarring. NSAID-induced cecal ulcers can have a variety of presentations to the general surgeon, are likely to be misdiagnosed preoperatively, but may be recognized based on characteristic gross features evident by radiography and colonoscopy, along with a careful history. Review of recent literature suggests that laparotomy can be avoided when diagnosis is considered, but operation is indicated for complications, such as hemorrhage, obstruction, or perforation, and when carcinoma cannot be adequately excluded.

Induction of nitric oxide synthase and microvascular injury in the rat jejunum provoked by indomethacin

1. The role of nitric oxide (NO) formed by the inducible isoform of NO synthase (NOS) in the generation of indomethacin-induced intestinal microvascular leakage was investigated in the rat. 2. Indomethacin (10 mg kg-1, s.c.) provoked an elevation of vascular leakage of radiolabelled human serum albumin in the jejunum over 48 h, commencing 18 h after its administration. This was associated with the induction of a calcium-independent NOS, as assessed by the conversion of radiolabelled L-arginine to citrulline. 3. Pretreatment with the glucocorticoid, dexamethasone (1 mg kg-1 day-1, s.c.) inhibited the induction of NOS and reduced jejunal microvascular leakage, determined 24 and 48 h after indomethacin. 4. Administration of the broad-spectrum antibiotic, ampicillin (800 mg kg-1 day-1, p.o.) likewise inhibited both the induction of NOS and the plasma leakage observed 24 and 48 h after indomethacin. 5. Ampicillin pretreatment did not, however, inhibit the induction of NOS, determined 5 h following endotoxin (3 mg kg-1 i.v.) challenge. Furthermore, incubation with ampicillin (1 mM, 10 min) did not inhibit the activity of the calcium-independent isoform in vitro. 6. Administration of the NOS inhibitor, NG-nitro-L-arginine methyl ester (L-NAME, 2-10 mg kg-1, s.c.), at the time of the detectable expression of the inducible NOS (18 h after indomethacin), dose-dependently attenuated the plasma leakage, determined 6 later. This effect was reversed by pretreatment with L-arginine (300 mg kg-1, s.c.) 15 min before L-NAME. 7. These findings suggest that induction of a calcium-independent NOS following indomethacin administration involves gut bacteria and leads to microvascular injury in the rat jejunum.

Evidence for differential effects of sulphasalazine on systemic and mucosal immunity in rheumatoid arthritis

OBJECTIVE

To study the effects of sulphasalazine (SASP) on the systemic and mucosal humoral immune systems in patients with rheumatoid arthritis (RA).

METHODS

Serum concentrations of interleukin 6 (IL-6), class and subclass specific IgG, IgA and IgM, IgA and IgG antigliadin antibodies and rheumatoid factors (RF) of IgG, IgA (including IgA1 and IgA2 subclasses) and IgM isotypes were measured before and 16 weeks after sulphasalazine (SASP) therapy in 15 female and three male patients with RA. Amounts of immunoglobulins in saliva and jejunal fluid were measured as estimates of mucosal humoral immunity.

RESULTS

Serum concentrations of IgA and IgG decreased significantly during SASP therapy and correlated with reduced concentrations of IL-6. In addition, levels of circulating IgA RF, IgA anti-gliadin antibodies and IgM RF decreased significantly after the treatment. In contrast, immunoglobulin levels in saliva and jejunal fluid were unaltered.

CONCLUSION

SASP exerts powerful but selective inhibitory effects on systemic immunoglobulin production, whereas no effects on mucosal immunoglobulin production were observed. The decreased systemic B cell activity may be mediated by downregulation of the production of IL-6, a cytokine with Ig switching properties.

Nonsteroidal anti-inflammatory drug-induced enteropathy: case discussion and review of the literature

The adverse effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on the upper gastrointestinal tract are well described. Evidence also shows that NSAIDs can be harmful to the small intestine. The use of NSAIDs has been associated with small intestinal strictures, ulcerations, perforations, diarrhea, and villous atrophy. Herein we present a case of NSAID-induced enteropathy with multiple diaphragm-like strictures that involved the distal 35 cm of ileum and review the literature of other cases of NSAID-induced enteropathy in which biopsy specimens were obtained for histologic analysis to rule out other causes. The prevalence of NSAID-induced enteropathy is unknown. Diagnosis can be made by endoscopy or at abdominal exploration. The role of radionuclide scans for diagnosis remains unclear. The pathogenesis is likely multifactorial. Mucosal diaphragms may be specific for NSAID-related disease. Treatment options for NSAID-induced enteropathy are discussed.

Nonsteroidal anti-inflammatory drug-induced enteropathy: case discussion and review of the literature

The adverse effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on the upper gastrointestinal tract are well described. Evidence also shows that NSAIDs can be harmful to the small intestine. The use of NSAIDs has been associated with small intestinal strictures, ulcerations, perforations, diarrhea, and villous atrophy. Herein we present a case of NSAID-induced enteropathy with multiple diaphragm-like strictures that involved the distal 35 cm of ileum and review the literature of other cases of NSAID-induced enteropathy in which biopsy specimens were obtained for histologic analysis to rule out other causes. The prevalence of NSAID-induced enteropathy is unknown. Diagnosis can be made by endoscopy or at abdominal exploration. The role of radionuclide scans for diagnosis remains unclear. The pathogenesis is likely multifactorial. Mucosal diaphragms may be specific for NSAID-related disease. Treatment options for NSAID-induced enteropathy are discussed.

Short report: the effect of misoprostol on the anaemia of NSAID enteropathy

BACKGROUND

Small bowel ulceration is an increasingly recognised complication of therapy with non-steroidal anti-inflammatory drugs (NSAID). The ulceration is a potent site of blood loss contributing to unexplained iron deficiency anaemia in patients with arthritis. No drug is currently available to treat NSAID small bowel ulcers.

METHODS

We have retrospectively examined the effect of therapy with the prostaglandin E1 analogue misoprostol on the anaemia of patients with enteroscopically proven NSAID small bowel enteropathy.

RESULTS

All of the patients had proven iron deficiency anaemia. Eleven patients received misoprostol and ten received no treatment. Haemoglobin in the misoprostol-treated group rose significantly from median (range) 9.1 (6.2-10.6) g/dL (95% confidence intervals 8.76, 10.13) to 10.6 (6.5-16.8) g/dL (95% confidence intervals 10.06, 11.82); P = 0.004). Those patients who did not receive misoprostol had no significant change in their haemoglobin: 9.1 (7.5-10.6) g/dL to 8.1 (5.6-14.7) g/dL (P = N.S.).

CONCLUSION

Misoprostol therapy was associated with an improvement in the anaemia in patients with proven NSAID enteropathy.

Intestinal permeability

Damage to the mucosal barrier may be assessed, non-invasively by use of sugar probes, which permeate through the transcellular or paracellular (tight junction) routes. A standardised test, with analysis of a five hour urine collection has proved useful in studying the sequelae of non-steroid anti-inflammatory drug (NSAID) administration, untreated coeliac disease, and enteric infections. Choice of probe molecule is crucial and lactulose/l-rhamnose seem to be satisfactory, in contrast with polyethylene glycol. Significant correlations have been seen between permeability and plasma IgA concentrates in nephropathy, and between permeability and the passage of neutrophil chemotactic agents. The increased permeability associated with NSAID treatment may relate to the adverse effects of NSAIDs on enterocyte mitochondrial morphology and metabolism. These two factors may predispose the mucosa to permeation of bacterial chemoattractant molecules that elaborate a local inflammatory response. A similar mechanism may operate in patients with untreated Crohn's disease, who show abnormally high permeability. Remission induced by treatment with elemental diets coincides with a reduction in permeability. The period to relapse correlated with the inability of patients to maintain low permeability to sugar probes. These results suggest a mechanism for the benefits of elemental enteral nutrients in the treatment of Crohn's disease.

Mechanisms of acute and chronic intestinal inflammation induced by indomethacin

The objective of this study was to characterize the mechanisms of acute and chronic intestinal mucosal injury and inflammation induced by subcutaneously injected indomethacin (Indo). One injection of Indo (7.5 mg/kg) produced acute injury and inflammation in the distal jejunum and proximal ileum that were maximal at three days and completely resolved within one week. Two daily subcutaneous injections of Indo produced a more extensive and chronic inflammation that lasted in an active form in more than 75% of the rats for at least two weeks. Epithelial injury, as measured by enhanced mucosal permeability, was significantly elevated only at one day in the acute model (one injection) but was persistently elevated in the chronic model (two injections). Bile duct ligation completely attenuated increased mucosal permeability in the acute model, however, depletion of circulating neutrophils had no effect. Neither Indo (0-0.1 mg/ml) nor normal bile was cytotoxic to cultured rat intestinal epithelial cells; however, they synergistically promoted significant cytotoxicity. Bile collected from rats treated with Indo was cytotoxic towards the epithelial cells in a dose-dependent manner. Sulfasalazine and metronidazole (100 mg/kg/day, both) attenuated enhanced mucosal permeability in the chronic model. Massive bacterial translocation into the mesenteric lymph nodes, liver, and spleen following two injections of Indo was significantly attenuated by metronidazole. We conclude that: (1) a single injection of Indo produces acute intestinal mucosal injury and inflammation that resolve completely within three to seven days, whereas two daily injections of Indo produce both acute and chronic injury and inflammation, (2) enterohepatic circulation of Indo is important in promoting the acute phases of injury and inflammation, (3) circulating neutrophils do not play a role in the pathogenesis of this model, and (4) endogenous bacteria play an important role in exacerbating and/or perpetuating the chronic phases of injury and inflammation.

Side effects of nonsteroidal anti-inflammatory drugs on the small and large intestine in humans

BACKGROUND

It is not widely appreciated that nonsteroidal anti-inflammatory drugs (NSAIDs) may cause damage distal to the duodenum. We reviewed the adverse effects of NSAIDs on the large and small intestine, the clinical implications and pathogenesis.

METHODS

A systematic search was made through Medline and Embase to identify possible adverse effects of NSAIDs on the large and small intestine.

RESULTS

Ingested NSAIDs may cause a nonspecific colitis (in particular, fenemates), and many patients with collagenous colitis are taking NSAIDs. Large intestinal ulcers, bleeding, and perforation are occasionally due to NSAIDs. NSAIDs may cause relapse of classic inflammatory bowel disease and contribute to serious complications of diverticular disease (fistula and perforation). NSAIDs may occasionally cause small intestinal perforation, ulcers, and strictures requiring surgery. NSAIDs, however, frequently cause small intestinal inflammation, and the associated complications of blood loss and protein loss may lead to difficult management problems. The pathogenesis of NSAID enteropathy is a multistage process involving specific biochemical and subcellular organelle damage followed by a relatively nonspecific tissue reaction. The various possible treatments of NSAID-induced enteropathy (sulphasalazine, misoprostol, metronidazole) have yet to undergo rigorous trials.

CONCLUSIONS

The adverse effects of NSAIDs distal to the duodenum represent a range of pathologies that may be asymptomatic, but some are life threatening.

Effects of metronidazole and misoprostol on indomethacin-induced changes in intestinal permeability

In previous open studies, misoprostol and metronidazole reduced nonsteroidal anti-inflammatory drug-induced intestinal permeability changes and inflammation respectively. We assessed the effects of indomethacin treatment (50 mg three times a day) for one week with either coadministered metronidazole (400 mg twice a day, group 1, N = 9) or misoprostol (200 micrograms four times a day, group 2, N = 7) on intestinal permeability to [51Cr]EDTA and mannitol in healthy volunteers, using double-blind, placebo-controlled, randomized techniques. Given alone, neither metronidazole nor misoprostol affected [51Cr]EDTA permeation, whereas indomethacin alone increased it from 1.20 (0.40) [mean percent urinary recovery (SD) groups 1 and 2] to 2.43 (0.72), P < 0.002. Coadministered metronidazole (group 1) prevented this increase [1.10 (0.39) before, 1.55 (0.54) after, P > 0.05], whereas misoprostol (group 2) did not [1.31 (0.51) before, 3.26 (1.10) after, P = 0.005]. No drug regimen altered mannitol permeation. Indomethacin and misoprostol did not affect urinary recovery of intravenously administered probes. The results with metronidazole, if related to its antibacterial effects, support evidence from animal models that bacteria contribute to NSAID-induced intestinal damage. The previously reported reduction of indomethacin-induced increased permeability by misoprostol during a one-day study is not seen when the drugs are used in standard clinical doses for one week.

Review article: non-steroidal, anti-inflammatory drugs--the extending scope of gastrointestinal side effects

The gastrointestinal side effects of non-steroidal, anti-inflammatory drugs extend beyond the duodenal bulb, and comprise a variety of lesions in all parts of the gut. Gastroduodenal ulceration is quantitatively dominant, although a major part of these lesions probably go unnoticed and heal spontaneously. Adaptation has been demonstrated for acetylsalicylic acid, and may be of importance for other substances as well. Non-steroidal anti-inflammatory drugs (NSAIDs) may induce relapse of inflammatory bowel disease. Permeability changes and mucosal inflammation are found in the small and large bowel in the majority of subjects taking NSAIDs, although the clinical significance is still not clear. Ulceration and perforation do, however, occur in this part of the gut as well. Treatment of NSAID-associated ulceration is similar to traditional ulcer treatment, possibly with extended treatment duration if the NSAID is continued. Prophylaxis is of some value, but is not required for every patient receiving an NSAID.

Misoprostol--a logical therapeutic approach to gastroduodenal mucosal injury induced by non-steroidal anti-inflammatory drugs?

Misoprostol is a synthetic analogue of naturally occurring prostaglandin E1. The basis of the damaging actions of non-steroidal anti-inflammatory drugs (NSAIDs) on the gastrointestinal (GI) tract is believed to be a consequence of two events: a direct damaging action on mucosal integrity and depletion of endogenous mucosal prostaglandins (PGs). Due to the latter effect, and because current evidence indicates that PGs play an important role in maintaining the integrity of the GI tract, misoprostol has been developed as a logical therapy to prevent and heal gastric and duodenal damage caused by NSAIDs. The purpose of this review is to consider the need for such a therapy, to describe its pharmaceutical development, to review its pharmacology and to review its efficacy compared with other available agents.