Epidemiology and differential diagnosis of NSAID-induced injury to the mucosa of the small intestine

Effects of Non-steroidal Anti-inflammatory Drugs (NSAIDs) and Gastroprotective NSAIDs on the Gastrointestinal Tract: A Narrative Review

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used for their anti-inflammatory, antipyretic, and analgesic properties. However, their use is often associated with gastrointestinal tract (GIT) side effects due to the inhibition of both cyclooxygenase (COX)-1 and COX-2 enzymes, leading to a decrease in gastroprotective prostaglandins (PG). To minimize these adverse effects, various approaches have been explored, including selective COX-2 inhibitors, NO-NSAIDs (nitric oxide-releasing NSAIDs), and dual COX/LOX (lipoxygenase) NSAIDs. However, the effects of these gastroprotective NSAIDs on the GIT and their efficacy remains uncertain. This review aims to provide an overview of the current understanding of the effects of traditional NSAIDs and gastroprotective NSAIDs on GIT. We discuss the underlying mechanisms of GIT damage caused by NSAIDs, including mucosal injury, ulceration, and bleeding, and the potential of gastroprotective NSAIDs to mitigate these effects. We also summarize recent studies on the efficacy and safety of various gastroprotective NSAIDs and highlight the limitations and challenges of these approaches. The review concludes with recommendations for future research in this field.

The relationship between the frequency and severity of restless legs syndrome and anaemia in patients with ankylosing spondylitis

Background Background The study aims to determine the frequency of restless legs syndrome (RLS) in patients with ankylosing spondylitis (AS) and the relationship between the International Restless Legs Syndrome Study Group Rating Scale (IRLSSG-RS) score and anemia. Material and Methods It was a case-control study that included 106 patients with AS and 106 age- and sex-matched healthy controls in the rheumatology clinic of a training and research hospital. The patients were divided into two groups according to their hemoglobin levels. A hemoglobin level lower than 12 g/dL in women and less than 13 g/dL in men was the criterion for anemia. Results Although the frequency of RLS was higher in AS patients than in control groups, there was no significant difference in the IRLSSG-RS score between AS patients and control groups. 23 (57.5%) of the AS patients with anemia had RLS, and the IRLSSG-RS score was 21.3±5.7. Of the AS patients without anemia, 11 (16.7%) had RLS, and the IRLSSG-RS score was 15±6. Statistically significant differences between AS patients with and without anemia regarding RLS frequency and IRLSSG-RS score were found. The IRLSSG-RS scores of AS patients were negatively correlated with serum iron and hemoglobin level. Conclusions Patients with AS had a higher RLS frequency than the control group; AS patients with anemia had a higher RLS and IRLSSG-RS score than AS patients without anemia. Also, a negative and significant correlation was found between the IRLSS-RS score and serum iron and hemoglobin levels in AS patients.

Cell-free probiotic supernatant (CFS) treatment alleviates indomethacin-induced enterocolopathy in BALB/c mice by down-modulating inflammatory response and oxidative stress: potential alternative targeted treatment

Probiotics and their metabolites appear to be a promising approach that targets both the intestinal inflammation and dysbiosis in bowel diseases. In this context, the emergence of the probiotic cell-free supernatant (CFS) has attracted more attention as a safe and targeted alternative therapy with reduced side effects. The use of nonsteroidal anti-inflammatory drugs (NSAIDs) can cause significant intestinal alterations and inflammation, leading to experimental enterocolopathy resembling Crohn disease. Therefore, we investigated the effect of CFS supplementation on the inflammation and the mucosal intestinal alterations induced by NSAIDs, indomethacin. In the current study, a murine model of intestinal inflammation was generated by the oral gavage (o.g) of indomethacin (10 mg/kg) to BALB/C mice. A group of mice treated with indomethacin was concomitantly treated orally by CFS for 5 days. The Body Health Condition index was monitored, and histological scores were evaluated. Moreover, oxidative and pro-inflammatory markers were assessed. Interestingly, we observed that CFS treatment attenuated the severity of the intestinal inflammation in our enterocolopathy model and resulted in the improvement of the clinical symptoms and the histopathological features. Notably, nitric oxide, tumor necrosis factor alpha, malondialdehyde, and myeloperoxidase levels were down-modulated by CFS supplementation. Concomitantly, an attenuation of NF-κB p65, iNOS, COX2 expression in the ileum and the colon was reported. Collectively, our data suggest that CFS treatment has a beneficial effect in experimental enterocolopathy model and could constitute a good therapeutic candidate for alleviating inflammatory responses and to maintain mucosal homeostasis during chronic and severe conditions of intestinal inflammation.

Drug-Induced Colitis

Drug-induced colitis encompasses a wide spectrum of colon disorders that can manifest microscopically or macroscopically. Patients present with new-onset colitis or exacerbations of inflammatory bowel diseases; in some cases, colitis resolves with discontinuation of medication. Mucosal injury can be focal or extensive, involving the entire colonic mucosa, and sometimes involves other parts of the gastrointestinal tract. It has been a challenge to determine the proportion of new-onset colitis caused by medication and there are few data on the overall prevalence. We review the drugs that have been linked with development of drug-induced colitis and strategies for physicians who believe their patients have this disorder-usually discontinuation of the drug believed to cause colitis and treatment with steroids or immune-modulating therapies. Physicians must be aware of medications that can cause colitis.

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.

Clinical phenotype and mortality in patients with idiopathic small bowel villous atrophy: a dual-centre international study

OBJECTIVE

Causes of small-bowel villous atrophy (VA) include coeliac disease (CD), its complications and other rare non-coeliac enteropathies. However, forms of VA of unknown aetiology may also exist. We defined them as idiopathic VA (IVA). To retrospectively classify the largest cohort of IVA patients and compare their natural history with CD.

METHODS

Notes of 76 IVA patients attending two tertiary centres between January 2000 and March 2019 were retrospectively reviewed. CD, its complications and all the known causes of VA were excluded in all of them. Persistence of VA during follow-up and lymphoproliferative features were used to retrospectively classify IVA, as follows. Group 1: IVA with spontaneous histological recovery (50 patients). Group 2: persistent IVA without lymphoproliferative features (14 patients). Group 3: persistent IVA with lymphoproliferative features (12 patients). Survival was compared between IVA groups and 1114 coeliac patients. HLA was compared between IVA patients, coeliac patients and appropriate controls.

RESULTS

Five-year survival was 96% in IVA group 1, 100% in IVA group 2, 27% in IVA group 3 and 97% in CD. On a multivariate analysis hypoalbuminemia (P = 0.002) and age at diagnosis (P = 0.04) predicted mortality in IVA. Group 2 showed association with HLA DQB1*0301 and DQB1*06.

CONCLUSION

IVA consists of three groups of enteropathies with distinct clinical phenotypes and prognoses. Mortality in IVA is higher than in CD and mainly due to lymphoproliferative conditions necessitating more aggressive therapies.

Current knowledge on non-steroidal anti-inflammatory drug-induced small-bowel damage: a comprehensive review

Recent advances in small-bowel endoscopy such as capsule endoscopy have shown that non-steroidal anti-inflammatory drugs (NSAIDs) frequently damage the small intestine, with the prevalence rate of mucosal breaks of around 50% in chronic users. A significant proportion of patients with NSAIDs-induced enteropathy are asymptomatic, but some patients develop symptomatic or complicated ulcers that need therapeutic intervention. Both inhibition of prostaglandins due to the inhibition of cyclooxygenases and mitochondrial dysfunction secondary to the topical effect of NSAIDs play a crucial role in the early process of injury. As a result, the intestinal barrier function is impaired, which allows enterobacteria to invade the mucosa. Gram-negative bacteria and endogenous molecules coordinate to trigger inflammatory cascades via Toll-like receptor 4 to induce excessive expression of cytokines such as tumor necrosis factor-α and to activate NLRP3 inflammasome, a multiprotein complex that processes pro-interleukin-1β into its mature form. Finally, neutrophils accumulate in the mucosa, resulting in intestinal ulceration. Currently, misoprostol is the only drug that has a proven beneficial effect on bleeding small intestinal ulcers induced by NSAIDs or low-dose aspirin, but its protection is insufficient. Therefore, the efficacy of the combination of misoprostol with other drugs, especially those targeting the innate immune system, should be assessed in the next step.

A fatal case of bowel obstruction caused by non-steroidal anti-inflammatory drug enteropathy

We report the case of a 34-year-old woman who died after presenting to hospital with a 2-month history of vomiting, abdominal pain and diarrhea. Subsequent inquiries revealed that she had a history of non-steroidal anti-inflammatory drug (NSAID) abuse, and the autopsy revealed stricture formation consistent with being caused by NSAID enteropathy.

Cardiac toxicity of coxibs: mechanisms of development and their prevention

Development of highly selective COX-2 inhibitors – coxibs has proved a decreased risk of gastrointestinal toxicity, which was typical for non-selective NSAIDS, according to the evidence-based medicine. But such situation caused an imbalance in the impact on the synthesis of arachidonic acid metabolites: inhibition of COX-2 vasodilatatory prostacyclins and activation of thromboxane synthesis by platelets, which is accompanied by the increase in the frequency of thrombotic complications – myocardial infarctions and strokes. Some meta-analyses have proved this association: the higher is COX-2 inhibitors selectivity – the higher are CV-risks and cardiovascular toxicity of coxibs. Discontinuation or limitation of indications of coxibs, assessment of risk / benefit ratio is recommended in the conditions of comorbidity of CVS pathology, pain syndromes in rheumatology. Drugs of choice are moderately selective COX-2 inhibitors = meloxicam and nimesulide.

Histomorphometric demonstration of the effect of chronic use of nonsteroidal anti-inflammatory drugs-ibuprofen on mucosa of small intestine

The purpose of this study was to ascertain change in structure of mucosa of small intestine, if any, in small intestine of Swiss albino mice as an effect of chronic use of nonsteroidal anti-inflammatory drugs–Ibuprofen. Longitudinal study conducted on 46 adult Swiss albino mice, 23 as experimental and 23 as control. Ibuprofen was given at a dose of 40 µg/g body weight per day for 6 weeks by intragastric route in experimental group of mice while control group of mice received same volume of distilled water. Mice of both the groups were sacrificed and desired segments of small intestines were dissected out and tissues were subjected to histological processing. Histomorphometry was performed and relevant photomicrographs were obtained. Student's unpaired t test by GraphPad Prism 6 software. Height of villi was not significantly altered but there was significant reduction of the number of goblet and non-goblet cells (enterocytes and other columnar cells) in mucosal lining of the small intestine of experimental group of mice. Percent distribution of the goblet and non-goblet cells was not altered in villi of two groups. Chronic exposure of Ibuprofen in therapeutic dosage caused reduction of the functional cell mass in lining epithelium of villi of middle segment of small intestine. However, there was no evidence of ulcerative or hemorrhagic lesion.

Non-steroidal Anti-inflammatory Drug Induced Injury to the Small Intestine

Non-steroidal anti-inflammatory drug (NSAIDs) induced enteropathy represents an important complication of one of the most commonly used drugs worldwide. Due to previous diagnostics difficulties the real prevalence of this disease was underestimated for a long time. The pathogenesis of NSAID-enteropathy is more multifactorial and complex than formerly assumed but has still not been fully uncovered. A combination of the local and systemic effect plays an important role in pathogenesis. Thanks to novel enteroscopy methods (wireless capsule endoscopy, double balloon enteroscopy), small bowel lesions are described in a substantial section of NSAID users although most are clinically asymptomatic. The other non-invasive tests (small bowel permeability, faecal calprotectin, scintigraphy using faecal excretion of 111-indium-labelled leukocytes etc.) proposed for diagnostics are not generally used in clinical practice, mainly because of their non-specificity. Despite intensive research into possible treatment, the main measure for patients with NSAID-enteropathy is still withdrawal of NSAIDs. Double balloon enteroscopy plays an important role in the treatment of complications (bleeding, strictures).

Restless legs syndrome is associated with poor sleep quality and quality of life in patients with ankylosing spondylitis: a questionnaire-based study

We aimed to investigate the frequency of restless legs syndrome (RLS) and the associations between RLS and quality of sleep and life in patients with ankylosing spondylitis (AS). One hundred and eight AS patients and 64 controls were included in this study. Demographics, clinical, and laboratory data were recorded. The presence of RLS was determined with face-to-face interview by an experienced neurologist based on the International RLS Study Group criteria. RLS severity was evaluated using International RLS Study Group rating scale. Sleep quality and insomnia severity were assessed by Pittsburgh sleep quality index (PSQI) and insomnia severity index (ISI), respectively. Disease-related quality of life was evaluated by AS quality of life questionnaire (ASQoL). The frequency of RLS was significantly higher in AS patients than in controls (36.4 vs. 14.0 %, p = 0.004). RLS severity score for AS patients was significantly higher than that for controls (p = 0.03). The AS patients had higher scores in the subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medication domains of PSQI, and also total PSQI and ISI than controls (p < 0.05, for all). ASQoL scores were higher in AS patients with RLS compared to those without RLS (p < 0.001). RLS severity was observed to be independently associated with total PSQI, ISI and ASQoL (p < 0.05, for all). As RLS may adversely affect the sleep and quality of life in AS patients, clinicians should be aware of RLS for early diagnosis and management in AS patients.

Small bowel protection against NSAID-injury in rats: Effect of rifaximin, a poorly absorbed, GI targeted, antibiotic

Nonsteroidal anti-inflammatory drugs, besides exerting detrimental effects on the upper digestive tract, can also damage the small and large intestine. Although the underlying mechanisms remain unclear, there is evidence that enteric bacteria play a pivotal role. The present study examined the enteroprotective effects of a delayed-release formulation of rifaximin-EIR (R-EIR, 50mg/kg BID, i.g.), a poorly absorbed antibiotic with a broad spectrum of antibacterial activity, in a rat model of enteropathy induced by indomethacin (IND, 1.5mg/kg BID for 14 days) administration. R-EIR was administered starting 7 days before or in concomitance with IND administration. At the end of treatments, blood samples were collected to evaluate hemoglobin (Hb) concentration (as an index of digestive bleeding). Small intestine was processed for: (1) histological assessment of intestinal damage (percentage length of lesions over the total length examined); (2) assay of tissue myeloperoxidase (MPO) and TNF levels, as markers of inflammation; (3) assay of tissue malondialdehyde (MDA) and protein carbonyl concentrations, as an index of lipid and protein peroxidation, respectively; (4) evaluation of the major bacterial phyla. IND significantly decreased Hb levels, this effect being significantly blunted by R-EIR. IND also induced the occurrence of lesions in the jejunum and ileum. In both intestinal regions, R-EIR significantly reduced the percentage of lesions, as compared with rats receiving IND alone. Either the markers of inflammation and tissue peroxidation were significantly increased in jejunum and ileum from IND-treated rats. However, in rats treated with R-EIR, these parameters were not significantly different from those observed in controls. R-EIR was also able to counterbalance the increase in Proteobacteria and Firmicutes abundance induced by INDO. To summarize, R-EIR treatment significantly prevents IND-induced intestinal damage, this enteroprotective effect being associated with a decrease in tissue inflammation, oxidative stress and digestive bleeding as well as reversal of NSAID-induced alterations in bacterial population.

Bidirectional interactions between indomethacin and the murine intestinal microbiota

The vertebrate gut microbiota have been implicated in the metabolism of xenobiotic compounds, motivating studies of microbe-driven metabolism of clinically important drugs. Here, we studied interactions between the microbiota and indomethacin, a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenases (COX) -1 and -2. Indomethacin was tested in both acute and chronic exposure models in mice at clinically relevant doses, which suppressed production of COX-1- and COX-2-derived prostaglandins and caused small intestinal (SI) damage. Deep sequencing analysis showed that indomethacin exposure was associated with alterations in the structure of the intestinal microbiota in both dosing models. Perturbation of the intestinal microbiome by antibiotic treatment altered indomethacin pharmacokinetics and pharmacodynamics, which is probably the result of reduced bacterial β-glucuronidase activity. Humans show considerable inter-individual differences in their microbiota and their responses to indomethacin - thus, the drug-microbe interactions described here provide candidate mediators of individualized drug responses.

Small-bowel capsule endoscopy in patients with unexplained chronic abdominal pain: a systematic review

BACKGROUND

Patients frequently consult primary care physicians and gastroenterologists when experiencing chronic abdominal pain. Although its diagnostic efficacy in these settings is uncertain, small-bowel capsule endoscopy (SBCE) has been used to evaluate the unexplained reasons for abdominal pain.

OBJECTIVE

To evaluate the diagnostic yield of SBCE in patients with unexplained chronic abdominal pain.

DESIGN

We performed a retrospective review of publications reporting the diagnostic yield of SBCE in patients with unexplained chronic abdominal pain and calculated the overall diagnostic yield.

SETTING

Two investigators independently searched studies from databases and analyzed the results.

PATIENTS

A total of 1520 patients from 21 studies were included.

INTERVENTIONS

Small-bowel capsule endoscopy.

MAIN OUTCOME MEASUREMENTS

Per-patient diagnostic yield, with 95% confidence intervals (CI), was evaluated by a random-effect model. Clear categorical analysis also was performed.

RESULTS

The pooled diagnostic yield of SBCE in patients with unexplained chronic abdominal pain was 20.9% (95% CI, 15.9%-25.9%), with high heterogeneity (I(2) = 80.0%; P ＜ .001). Inflammatory lesions were the most common (78.3%) positive findings, followed by tumors (9.0%).

LIMITATIONS

Heterogeneity among studies, retrospective design, variable chronicity of abdominal pain, and different previous examinations before SBCE.

CONCLUSION

SBCE provides a noninvasive diagnostic tool for patients with unexplained chronic abdominal pain, but the diagnostic yield is limited (20.9%). Among patients with positive findings, inflammatory lesions are the most common.

Muscovite is protective against non-steroidal anti-inflammatory drug-induced small bowel injury

AIM: To evaluate the effect of muscovite in preventing small bowel injury induced by nonsteroidal anti-inflammatory drugs (NSAIDs).

METHODS: We recruited and screened thirty-two healthy volunteers who were randomly allocated equally into two groups: an NSAID control group, who received 75 mg slow-release diclofenac, twice daily for 14 d; and an NSAID-muscovite group, who received 3 g of muscovite in addition to the 75 mg of slow-release diclofenac, twice daily for 14 d. For gastroprotection, both groups were administered 20 mg/d of the proton pump inhibitor omeprazole. All eligible subjects underwent video capsule endoscopy (CE) prior to and 14 d after treatment.

RESULTS: Thirty subjects (NSAID-muscovite group, n =16; NSAID control group, n =14) finally completed the whole trail. At the baseline CE examination, no statistically significant differences between the two groups have been observed. However, after 14 d of drug treatment, a significant difference was observed in the percentage of subjects with mucosal breaks when comparing the NSAID-muscovite group with the NSAID control group. While 71.4% (10/14) of subjects in the NSAID control group had at least one mucosal break, co-administration of muscovite in the NSAID-muscovite group reduced the rate to 31.3% (5/16) (P = 0.028). Moreover, higher number of mucosal breaks was found in the NSAID control group vs that in the NSAID-muscovite group (P < 0.05).

CONCLUSION: Muscovite co-therapy reduced the incidence of small intestinal injury after 14 d of diclofenac administration.

The impact of non-steroidal anti-inflammatory drugs on the small intestinal epithelium

The small intestine has been called as a dark continent of digestive tract and it had been very difficult to diagnose or treat the disease of small intestine. However recent technological development including video capsule endoscopy or balloon-assisted endoscopy has made us to aware the various diseases of small intestine. By using capsule endoscopy, many researchers reported that more than 70% of patients treated continuously with non-steroidal anti-inflammatory drugs (NSAID) exhibit the mucosal damage of small intestine. In some cases, NSAID not only causes mucosal damage but also results in life threatening bleeding from small intestine, which had not been prevented or cured by gastro-protective drug or anti-gastric acid secretion drug administration. Therefore to investigate and identify the effective drug that protects small intestine from mucosal damage is urgently expected. In spite of extensive investigation in clinical field, only a few drugs such as misoprostol, a synthetic prostaglandin E₁ analogue, has been reported as an effective one but is not satisfactory enough to fulfill the requirement of patients who suffer from NSAID-induced mucosal damage of small intestine. And now, extensive study is being performed using several gastro-mucoprotective drugs by many researchers. In this review, we introduce the current clinical situation in small intestinal injury of patients under NSAID treatment, and to summarize the molecular mechanism by which NSAID, including acetyl salicylic acid, cause small intestinal damage. In addition, we present results of clinical trials performed so far, and refer the possible preventive method or treatment in the near future.

NSAID-Induced Enteropathy in Rheumatoid Arthritis Patients with Chronic Occult Gastrointestinal Bleeding: A Prospective Capsule Endoscopy Study

Background. The purpose of study was to evaluate the diagnostic yield of capsule endoscopy for NSAID-induced enteropathy and clinical, laboratory, and endoscopic characteristics of disease in patients with rheumatoid arthritis. Methods. 37 rheumatoid arthritis patients (30 women; mean age 55) treated with NSAIDs (>1 month), presented with anaemia and/or positive faecal occult blood testing, entered the study and underwent capsule endoscopy (EndoCapsule; Olympus), laboratory tests, and filled in questionnaires. Results. The prevalence of NSAID-induced enteropathy diagnosed by capsule endoscopy was 68% (25/37), classified as mild (red spots or erosions) in 18 (49%), moderate (10–20 erosions) in 4 (11%), and severe enteropathy (>20 erosions or ulcers) in 3 (8%) patients. We did not find statistically significant relationship between the enteropathy and gender, age, haemoglobin, leukocytes, albumin and CRP, or dyspepsia. The difference between subgroups of NSAIDs according to the COX specificity was not statistically significant. Conclusions. Capsule endoscopy is a highly accurate noninvasive method for evaluation of NSAID-induced enteropathy. It was revealed in a substantial section of the patients with rheumatoid arthritis and occult gastrointestinal bleeding, mostly classified as mild damage. No simple clinical or laboratory markers of the presence or severity of NSAID-induced enteropathy were recognised. This trial is registered with DRKS00004940.

Expression of PGE2 and COX in intestinal injury induced with non-steroidal anti-inflammatory drugs in rats: Implications for protective effects of drugs

AIM: To investigate the expression of prostaglandin E₂ (PGE₂), cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2) in diclofenac sodium-induced intestinal injury in rats and to analyze their implications for protective effects of drugs.

METHODS: Thirty-two male Wistar rats were randomly and equally divided into four groups: a normal control group (given normal saline), a model control group (given diclofenac sodium), and two treatment groups (given Jinghua Weikang Jiaowan and esomeprazole, respectively). Except for the normal control group, intestinal injury was induced with diclofenac sodium in the other groups. Jinghua Weikang Jiaowan and esomeprazole were administered in the two treatment groups from the day before diclofenac sodium was given. Intestinal injury was observed by microscopy. The content of PGE₂ in the small intestine tissues was tested by ELISA. The expression of COX-1 and COX-2 proteins was detected by Western blot.

RESULTS: Compared to the normal control group, the morphological score increased significantly in the model control group (4.63 ± 0.52 vs 0.00 ± 0.00, P < 0.05); however, the morphological score was significantly lower in the two treatment groups than in the model control group (1.88 ± 0.99, 2.75 ± 1.28, both P < 0.05). Compared to the normal control group, the content of PGE₂ was significantly lower in the model control group (19.32 ng/L ± 8.22 ng/L vs 36.64 ng/L ± 3.27 ng/L, P < 0.05); however, the content of PGE₂ increased significantly in the two treatment group increased significantly compared to the model control group (29.51 ng/L ± 7.61 ng/L, 29.20 ng/L ± 7.51 ng/L, both P < 0.05). The expression level of COX-1 was significantly lower in the model control group than in the normal control group (0.47 ± 0.32 vs 0.78 ± 0.39, P < 0.05); however, the expression of COX-1 increased significantly in the treatment group compared to the model control group (1.29 ± 0.63, 1.53 ± 1.00, both P < 0.05). Compared to the normal control group, the expression of COX-2 increased significantly in the model control group (1.00 ± 0.72 vs 0.00 ± 0.00, P < 0.05); however, the expression of COX-2 increased significantly in the Jinghua Weikang Jiaowen treatment group (6.86 ± 9.81, P < 0.05). Compared to the model control group, the expression of COX-2 increased in the esomeprazole treatment group, but the difference was not significant (2.59 ± 2.87, P > 0.05).

CONCLUSION: Decreased content of PGE₂ in the small intestine tissue may be associated with diclofenac sodium-induced small intestinal injury. Jinghua Weikang Jiaowan and esomeprazole exert preventive effects against diclofenac sodium-induced intestinal injury possibly by raising the level of PGE₂. The therapeutic effect of Jinghua Weikang Jiaowan may be related to high expression of COX-1 and COX-2, and that of esomeprazole may be related to the high expression of COX-1.

Recent Advances in NSAIDs-Induced Enteropathy Therapeutics: New Options, New Challenges

The injurious effects of NSAIDs on the small intestine were not fully appreciated until the widespread use of capsule endoscopy. It is estimated that over two-thirds of regular NSAID users develop injury in the small intestinal injuries and that these injuries are more common than gastroduodenal mucosal injuries. Recently, chronic low-dose aspirin consumption was found to be associated with injury to the lower gut and to be a significant contributing factor in small bowel ulceration, hemorrhage, and strictures. The ability of aspirin and NSAIDs to inhibit the activities of cyclooxygenase (COX) contributes to the cytotoxicity of these drugs in the gastrointestinal tract. However, many studies found that, in the small intestine, COX-independent mechanisms are the main contributors to NSAID cytotoxicity. Bile and Gram-negative bacteria are important factors in the pathogenesis of NSAID enteropathy. Here, we focus on a promising strategy to prevent NSAID-induced small intestine injury. Selective COX-2 inhibitors, prostaglandin derivatives, mucoprotective drugs, phosphatidylcholine-NSAIDs, and probiotics have potential protective effects on NSAID enteropathy.

Isolated active ileitis: is it a mild subtype of Crohn's disease?

BACKGROUND

Ileal intubation is being increasingly performed at colonoscopy and has in turn lead to an increasingly recognized subgroup of patients-those with mild terminal ileal inflammation, an entity that we have coined isolated active ileitis (IAI). The aims of this study were to define the natural history of IAI and determine if IAI shares a similar genetic and serologic profile with Crohn's disease (CD).

METHODS

Patients with IAI were identified from our institution's histopathology and endoscopy databases. Cases attended for repeat colonoscopy and blood were analyzed for the expression of antineutrophil cytoplasmic antibody, anti-OmpC, anti-Saccharomyces cerevisiae antigen (ASCA) IgA, ASCA IgG, and anti-CBir antibodies and NOD2 genotyping. Age and sex-matched healthy controls, CD, and UC cases were also recruited.

RESULTS

Sixty-three patients with IAI were recruited. There was no significant difference in the prevalence of antibodies between IAI cases and healthy controls for antineutrophil cytoplasmic antibody, OmpC, ASCA IgA, or ASCA IgG. The presence of all 5 antibodies was significantly higher in the CD group than the IAI group, P < 0.05. There were 28.6% of CD cases that carried one or more NOD2 variants, compared to 26.2% of the IAI cohort and 6.1% of healthy controls. Forty-three cases underwent follow-up ileocolonoscopy. Six of 43 cases (14%) had definite CD.

CONCLUSIONS

A majority of IAI cases developed persistent symptoms and terminal ileal abnormalities; however, only 14% developed classical, histological, or radiological features of CD. Although patients with IAI have a low level of seropositivity, similar to healthy controls, they do share an excess of NOD2 mutations with CD cases.

Comparison of gastrointestinal adverse effects between cyclooxygenase-2 inhibitors and non-selective, non-steroidal anti-inflammatory drugs plus proton pump inhibitors: a systematic review and meta-analysis

BACKGROUND

There are conflicting and inconsistent data regarding the gastrointestinal (GI) protective effect of cyclooxygenase-2 (COX-2) inhibitors and of non-steroidal anti-inflammatory drugs (NSAIDs) plus proton-pump inhibitors (PPI).

AIM

To compare the adverse GI effects between COX-2 inhibitors and NSAIDs plus PPI.

METHODS

We performed a systematic review of randomized trials comparing GI adverse effects between COX-2 inhibitors and NSAID plus PPI. Trials were identified in MEDLINE, EMBASE, and the Cochrane Library. Primary outcomes were major GI complications including hemorrhage, perforation, and obstruction.

RESULTS

A total of nine trials involving 7,616 participants from 2002 to 2011 were included. All trials were randomized, double blinded, and placebo-controlled with moderate to high quality. COX-2 inhibitors were found to have significantly reduced the risk of major GI events, including perforation, obstruction, and bleeding (relative risk or RR 0.38, 95 % confidence interval or CI 0.25-0.56, p < 0.001); however, the benefit was significant only for patients who were at high risk for NSAID-related GI complications and long-term users. Additionally, the risk of diarrhea (RR 0.56, 95 % CI 0.35-0.9, p 0.02) and withdrawal (RR 0.77, 95 % CI 0.62-0.94, p 0.01) was significantly lower in use of COX-2 inhibitors, while the rate of dyspepsia was higher (RR 1.58, 95 % CI 1.26-1.98, p < 0.001).

CONCLUSIONS

COX-2 inhibitors significantly reduced the risk of perforation, obstruction, bleeding, diarrhea, and withdrawal due to GI adverse events, while the risk of dyspepsia was lower with NSAIDs plus PPI.

Risk factors for severe nonsteroidal anti-inflammatory drug-induced small intestinal damage

BACKGROUND

Few studies have assessed the risk factors associated with nonsteroidal anti-inflammatory drugs (NSAIDs)-induced small intestinal damage.

AIMS

To evaluate the risk factors for NSAID-induced enteropathy in patients with rheumatoid arthritis.

METHODS

A cross-sectional study using capsule endoscopy was conducted. A total of 113 patients who took NSAIDs for over 3 months underwent capsule endoscopies. Endoscopic findings were scored as (0) normal, (1) red spots, (2) 1-4 erosions, (3) >4 erosions, or (4) large erosions/ulcers. Initial scores were grouped into 3 categories: No damage (0-1), mild damage (2), and severe damage (3-4), and the potential risk factors for damage development were assessed.

RESULTS

Five patients were excluded because of incomplete visualization of the entire small intestine. Fifty-two (47.2%) and 27 (25%) patients had no damage and mild damage, respectively, while the remaining 30 patients (27.8%) had severe damage and significantly decreased hemoglobin levels. In a multivariate logistic regression analysis, ages of 65 years or more (odds ratio [OR], 4.16; 95% confidence interval [CI], 1.51-11.47), proton pump inhibitor usage (OR, 5.22; 95% CI, 1.36-20.11), and histamine H2 receptor antagonist usage (OR, 3.95; 95% CI, 1.28-12.25) were independent risk factors for severe damage.

CONCLUSIONS

Elderly patients and acid suppressant users are more likely to develop severe NSAID-induced enteropathy.

Multiple ileal perforations due to regular diclofenac sodium injections: a case report

Background

Although the adverse effects of non-steroidal anti-inflammatory drugs (NSAIDs) on the upper gastrointestinal tract have been well characterized, those specific to the lower gastrointestinal tract are less clear, as only a limited number of articles and case reports exist in the literature.

Case presentation

We describe a case of a 69-year-old woman who presented to the emergency department due to sudden onset abdominal distension and pain. Notably, she reported using intramuscular diclofenac sodium twice daily for 14 days after knee joint replacement surgery. The patient denied any other coexisting diseases. As a subsequent X-ray and computed tomography (CT) scan showed free air in the abdomen, an exploratory laparotomy was performed, revealing four free perforations in the terminal ileum. Findings on microscopic analysis were non-specific.

Conclusion

We report a unique case of multiple ileal perforations due to regular diclofenac sodium injections and contend that ileal perforation can be considered as a source for pneumoperitoneum with concomitant peritonitis in patients with a history of NSAID use if other possibilities are excluded.

Reactive gastropathy is associated with inflammatory conditions throughout the gastrointestinal tract

BACKGROUND

The epidemiology of reactive gastropathy and its relationship with other conditions of the gastrointestinal tract associated with NSAID use have not been evaluated.

AIMS

To test the hypothesis that if reactive gastropathy shares common aetiological factors with these conditions, the analysis of a large cohort would unveil associations.

METHODS

We queried a national pathology database for subjects with a diagnosis of reactive gastropathy; controls were patients with normal gastric biopsies. We also extracted diagnoses of H. pylori infection, intestinal metaplasia, duodenal lymphocytosis, duodenitis, ileitis, microscopic colitis and focal colitis.

RESULTS

Of 504 011 patients with gastric biopsies, 69 101 had oesophageal, 166 134 duodenal, 13 010 ileal and 83 334 colonic biopsies. Reactive gastropathy was diagnosed in 15.6% of patients, H. pylori infection in 10.3% and normal gastric mucosa in 16.3%. Reactive gastropathy was evenly distributed across the US and increased from 2.0% in the first decade of life to >20% in octogenarians. Compared with controls, reactive gastropathy was significantly associated with Barrett's mucosa (OR 1.21 95% CI 1.16-129); duodenitis (OR 1.36; 95% CI 1.28-1.44); duodenal intraepithelial lymphocytosis (OR 1.25; 95% CI 1.13-1.39); active ileitis (OR 1.88; 95% CI 1.47-2.40); focal active colitis (OR 1.57; 95% CI 1.33-1.86); and collagenous colitis (OR 1.50; 95% CI 1.12-2.03).

CONCLUSIONS

Reactive gastropathy, a common histopathological feature of the stomach, shows an age-dependent rise and is associated with changes of the digestive tract believed to be caused by NSAID use or duodenogastric reflux. However, a large fraction of reactive gastropathy remains unexplained; its frequent occurrence merits further efforts at elucidating its aetiology.

Non-steroidal anti-inflammatory drug-induced enteropathy

Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most commonly prescribed drugs in the world. NSAID-induced lower gastrointestinal (GI) complications are increasing while upper GI complications are decreasing. Lower GI events accounted for 40% of all serious GI events in patients on NSAIDs. Capsule endoscopy and device assisted enteroscopy are available for detection of small intestinal lesions. Capsule endoscopy studies have demonstrated that NSAIDs use in healthy volunteers raised the incidence (55% to 75%) of intestinal damage. It appears that selective cyclooxygenase-2 inhibitors (coxibs) improved upper and lower GI safety based on results of clinical trials. Selective coxibs are still capable of triggering GI adverse events and cardiovascular toxicity issues were the main focus of concerns. Unfortunately, definite strategies are not available to prevent or heal NSAID-induced intestinal injuries. Thus, there is still a strong clinical need for effective drugs with improved safety profiles than the existing NSAIDs.

Noncoeliac enteropathy: the differential diagnosis of villous atrophy in contemporary clinical practice

BACKGROUND

Duodenal villous atrophy (DVA) is a key diagnostic finding in coeliac disease (CD). However, the differential diagnosis for this finding is broad.

AIM

To identify conditions causing noncoeliac enteropathy (NCE) with villous atrophy and methods to differentiate between CD and NCE in clinical practice.

METHODS

Through record review we identified patients with DVA due to conditions other than CD. Patient demographics, clinical features and relevant investigations were compared with CD patients. Rates of CD misdiagnosis, and response to treatments were recorded.

RESULTS

Thirty cases of NCE were identified with ten different aetiologies. Unspecified immune-mediated enteropathy was the most common aetiology; affecting 10 patients. Gastrointestinal symptoms were more common in NCE than those in CD patients (P < 0.01). Twenty of the 24 NCE patients tested were HLA-DQ2/DQ8 negative. Twenty-six NCE patients were negative for IgA tissue transglutaminase (tTG) (P = 0.0001). Intraepithelial lymphocytosis was absent in 10 (33.3%) patients. Twenty-one NCE patients initially misdiagnosed with CD and one with gluten intolerance were prescribed a gluten free diet (GFD). Fifteen of 22 had repeat biopsy and none showed histological improvement.

CONCLUSIONS

Although coeliac disease is the most common cause of DVA, noncoeliac enteropathy is not rare and may easily be mistaken for coeliac disease. Noncoeliac enteropathy is suggested by a normal initial tTG (87%), lack of intraepithelial lymphocytosis on biopsy, and lack of histological response to a gluten free diet. Subjective response to gluten free diet has poor predictive value for coeliac disease. Noncoeliac enteropathy can often be confirmed by negative HLA-DQ2/DQ8 testing and targeted investigations can ascertain a definitive aetiology in most cases.

Capsule endoscopy in nonresponsive celiac disease

BACKGROUND

Nonresponsive celiac disease (CD) is defined by persistent or recurrent symptoms, common after treatment with a gluten-free diet (GFD).

OBJECTIVE

To evaluate the utility of capsule endoscopy (CE) in nonresponsive CD.

DESIGN

Case-control study.

SETTING

Tertiary-care center.

PATIENTS

Forty-two consecutive patients with nonresponsive CD and 84 age- and sex-matched CD-free controls who underwent CE were included. In addition, capsules taken after treatment with a GFD were retrospectively evaluated in 30 patients with uncomplicated CD.

INTERVENTION

CE.

MAIN OUTCOME MEASUREMENTS

Diagnostic accuracy of CE for the detection of mucosal abnormalities in nonresponsive CD.

RESULTS

Macroscopic features of villous atrophy were detected in 13 of 42 patients (31%) with nonresponsive CD compared with none among 84 CD-free controls and 14 of 30 patients (47%) with uncomplicated CD. Among nonresponsive CD cases, the overall sensitivity and specificity of CE for the detection of any degree of villous atrophy as graded by histology were 56% and 85%, respectively. Single or multiple erosions/ulcerations of the gut were observed in 19% of nonresponsive CD patients, 18% of CD-free controls, and 31% of patients with uncomplicated CD (P = .35). The presence of erosions/ulcerations was associated with increased aspirin/nonsteroidal anti-inflammatory drug use in nonresponsive CD (P =.05). Two severe complications (ulcerative jejunitis and adenocarcinoma) were detected by CE in nonresponsive CD.

LIMITATIONS

Single-center, retrospective study.

CONCLUSIONS

Mucosal abnormalities were observed by CE in patients with both nonresponsive CD and uncomplicated CD. CE can detect severe complications in patients with nonresponsive CD.

Prevention and management of non-steroidal anti-inflammatory drugs-induced small intestinal injury

Non-steroidal anti-inflammatory drug (NSAID)-induced small bowel injury is a topic that deserves attention since the advent of capsule endoscopy and balloon enteroscopy. NSAID enteropathy is common and is mostly asymptomatic. However, massive bleeding, stricture, or perforation may occur. The pathogenesis of small intestine injury by NSAIDs is complex and different from that of the upper gastrointestinal tract. No drug has yet been developed that can completely prevent or treat NSAID enteropathy. Therefore, a long-term randomized study in chronic NSAID users is needed.

Restless Legs Syndrome in Behçet's Disease

The prevalence of restless legs syndrome (RLS) and its association with the clinical features of Behçet's disease (BD) has not previously been elucidated. The inflammatory character, central nervous system involvement and neuropathies of BD led to this investigation of RLS risk in BD patients. A total of 116 BD patients and 104 healthy control subjects were included; seven BD patients were excluded because of concurrent diseases, pregnancy or alcohol misuse that might cause RLS symptoms, and the remaining 109 BD patients were included in the analysis. The prevalence of RLS was significantly higher in patients with BD (32/109; 29.4%) than in controls (5/104; 4.8%). No significant differences were found between BD patients with and without RLS with regard to the clinical features of BD. RLS severity positively correlated with age in BD patients. In conclusion, BD-related RLS should be considered in symptomatic RLS secondary to rheumatological disorders and BD patients should be examined for RLS. Further studies are needed to clarify the pathogenetic mechanisms underlying BD-related RLS.

Nonsteroidal antiinflammatory drug-related injury to the gastrointestinal tract: clinical picture, pathogenesis, and prevention

Increasing life expectancy in developed countries has led to a growing prevalence of arthritic disorders, which has been accompanied by increasing prescriptions for nonsteroidal antiinflammatory drugs (NSAIDs). These are the most widely used agents for musculoskeletal and arthritic conditions. Although NSAIDs are effective, their use is associated with a broad spectrum of adverse reactions in the liver, kidney, cardiovascular system, skin, and gut. Gastrointestinal (GI) side effects are the most common. The dilemma for the physician prescribing NSAIDs is, therefore, to maintain the antiinflammatory and analgesic benefits, while reducing or preventing GI side effects. The challenge is to develop safer NSAIDs by shifting from a focus on GI toxicity to the increasingly more appreciated cardiovascular toxicity.

Exacerbation of inflammatory bowel diseases associated with the use of nonsteroidal anti-inflammatory drugs: myth or reality?

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs), conventional and selective cyclooxygenase-2 (COX-2) inhibitors, are among the most widely used medications for the treatment of various inflammatory conditions. There is strong evidence of a possible association between the use of these drugs and the relapse of inflammatory bowel diseases (IBD).

OBJECTIVE

Our objective was to examine the literature regarding the exacerbation of IBD associated with the use of conventional NSAIDs and selective COX-2 inhibitors and the underlying pathogenetic mechanisms.

STUDY DESIGN

We reviewed articles, including original papers, controlled trials, case reports, reviews, and editorials published in English at the PubMed, Scopus Database, and Science Direct database, searching with the following keywords: nonsteroidal anti-inflammatory drugs (NSAIDs), COX-2 inhibitors, Coxibs, inflammatory bowel diseases (IBD), ulcerative colitis (UC), Crohn's disease (CD).

RESULTS

There is substantial evidence that exacerbation of IBD happens after treatment with NSAIDs, but the available data remain conflicting, and it is not clear whether selective COX-2 inhibitors are safer than traditional NSAIDs. However, there is some evidence that selective COX-2 inhibition and COX-1 inhibition (with low-dose aspirin) appear to be well-tolerated in the short term. Regarding the mechanisms of relapse, the reduction of prostaglandins appears to be the hallmark of the NSAIDs adverse effects.

CONCLUSIONS

Further randomized, double-blind, controlled trials should be performed to address this issue, and more in vitro studies to identify the pathways involved are required.

NSAIDs and the gastrointestinal tract

NSAIDs incur significant gastrointestinal (GI) side effects. The complication risk increases with history of peptic ulcer or older age. Helicobacter pylori infection and cardioprotective aspirin have independent and additive risks in the presence of NSAID use. NSAID enteropathy is increasingly recognized. Cardiovascular and GI risk stratification and H. pylori infection testing should be done before initiating NSAIDs. An NSAID combined with a proton pump inhibitor (PPI) is comparable to cyclooxygenase (COX)-2 inhibitors for gastroprotection, but for high-risk patients, COX-2 plus PPI should be considered. Aspirin and COX-2 inhibitors are associated with reduced colon adenoma risk, but higher dose and longer duration of treatment with aspirin appears effective. Hence, patients at high risk of colorectal cancer (with significant family or personal history of premalignant adenoma) must be identified, and cardiovascular and GI risk must be assessed before using these agents as chemopreventive drugs.

Isolated asymptomatic ileitis does not progress to overt Crohn disease on long-term follow-up despite features of chronicity in ileal biopsies

Isolated ileal abnormalities may be detected during routine colonoscopy performed for polyp screening or surveillance. The significance of these abnormalities in asymptomatic patients without a prior diagnosis of inflammatory bowel disease is unknown. A critical clinical issue is whether isolated ileitis in asymptomatic patients is a manifestation of early Crohn disease (CD). We examined clinical, endoscopic, and pathologic data from 29 patients with isolated ileitis and no prior history of inflammatory bowel disease, and no colonic or upper gastrointestinal involvement. Only patients with at least 2 years of follow-up (range: 2.2 to 12.6 y) were included. Fifteen of 29 patients had colonoscopy for gastrointestinal symptoms whereas the remaining 14 were asymptomatic (screening colonoscopy). Seven of 15 (47%) of patients categorized as chronic active ileitis and 3 of 14 (21%) of those classified as focal active ileitis, on blinded histopathologic review, had a clinical diagnosis of CD at last follow-up. One or more features of chronicity were present in 11 of 14 (79%) of asymptomatic ileitis patients but none developed any manifestations of CD on long-term follow-up. In contrast, 8 of 10 (80%) of symptomatic patients with features of chronicity in ileal biopsies progressed to a diagnosis of CD, as did 2 of 5 (40%) symptomatic patients with focal active ileitis. Thus, the presence of symptoms seems to be the best predictor of likelihood of progression to CD in patients with isolated ileitis (P<0.001). Isolated ileitis detected in asymptomatic patients undergoing polyp screening or surveillance does not evolve into CD on follow-up, despite endoscopic and histologic overlap with findings typically seen in CD.

[Adverse effects of non-steroidal anti-inflammatory drugs in the lower gastrointestinal tract]

Non-steroidal antiinflammatory drugs (NSAID) are among the most commonly used drugs worldwide. Together with the beneficial effects, several adverse effects have become evident in the past decades. NSAIDs may damage any part of the gastrointestinal (GI) tract. The adverse effect in the lower GI tract was thought to be less important, but more and more data confirm that NSAIDs can cause equally severe lesions in the lower GI tract as well, only the diagnostic procedures are limited. NSAIDs may damage the intact mucosa, and they also may cause flare-up of a preexisting disease. Adverse events in the lower GI tract are caused mainly by the dual (COX-1 and COX-2) inhibitors. Besides the inhibiting of the cyclooxygenase enzymes, an important step is the local effect of the drug that initiates the chain reaction with the damage of the epithelial cells (increase of mucosal permeability, influx of luminal factors, produce of inflammatory mediators etc.). The spectrum of adverse effects of NSAIDs on the lower GI are reviewed according to the latest literature and the available prevention and therapeutic strategies.

The protective effect of eupatilin on indomethacin-induced cell damage in cultured feline ileal smooth muscle cells: involvement of HO-1 and ERK

Chronic users of non-steroidal anti-inflammatory drugs frequently develop ulcerative lesions in their intestines. The purpose of the present study was to investigate whether eupatilin, an active ingredient derived from Artemisia plants, prevents this side effect in vitro. Extracts of the whole herb of Artemisia asiatica Nakai have been used in oriental medicine for the treatment of inflammation. As measured by the MTT assay, the treatment of cultured feline ileal smooth muscle cells (ISMCs) with 2.5mM indomethacin for 2h decreased the cell viability to 43%. Pretreatment with eupatilin resulted in dose-dependent inhibition on indomethacin-induced cell damage. This cytoprotective effect of eupatilin required concentrations of more than 150 microM and incubation periods of longer than 16 h. Pretreatment of ISMC with cycloheximide, an inhibitor of protein synthesis, attenuated the cytoprotective effect of eupatilin, suggesting that eupatilin induces proteins that are responsible for the cytoprotection. Heme oxygenase-1 (HO-1), which is known as a cytoprotective enzyme due to its anti-inflammatory actions, is a candidate protein since ZnPP, an HO-1 inhibitor, repressed the protective effect of eupatilin on indomethacin-induced cell damage in a concentration-dependent manner. Western blot analysis revealed that eupatilin-mediated HO-1 induction occurred in a concentration- and time-dependent manner. We also found that PD98059, a MEK (MAPK/ERK kinase) inhibitor, attenuated the eupatilin-induced HO-1 expression and nuclear translocation of transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2). Taken together, the data imply that eupatilin protects ISMC from cell damage caused by indomethacin, and that its cytoprotective action could be attributed to eupatilin-mediated HO-1 induction via ERK and Nrf2 signaling in ISMC.

Less small-bowel injury with lumiracoxib compared with naproxen plus omeprazole

BACKGROUND & AIMS

The selective cyclooxygenase-2 inhibitor lumiracoxib has been shown to reduce endoscopically detected ulcers and ulcer complications in the upper gastrointestinal tract compared with nonselective nonsteroidal anti-inflammatory drugs. We investigated whether lumiracoxib would reduce small-bowel injury compared with naproxen plus omeprazole.

METHODS

Healthy volunteers were randomized to receive lumiracoxib 100 mg once daily, naproxen 500 mg twice daily plus omeprazole 20 mg once daily, or placebo in a 16-day double-blind, parallel-group study. Small-bowel mucosal injury and inflammation were assessed by video capsule endoscopy, the lactulose:L-rhamnose permeability assessment, and the fecal calprotectin test.

RESULTS

Of 152 randomized subjects, 139 completed the study with valid video capsule endoscopies (lumiracoxib, n = 47; naproxen plus omeprazole, n = 45; placebo, n = 47). Compared with placebo, an increased number of subjects on naproxen plus omeprazole had small-bowel mucosal breaks (77.8% vs 40.4%, P < .001), with increased permeability (P = .023) and increased fecal calprotectin (increase, 96.8 vs 14.5 mg/kg for placebo; P < .001). With lumiracoxib, 27.7% of subjects had small-bowel mucosal breaks (P = .196 vs placebo; P < .001 vs naproxen), there was no increase in permeability (P = .157 vs placebo; P = .364 vs naproxen), and no increase in fecal calprotectin (-5.7 mg/kg; P = .377 vs placebo; P < .001 vs naproxen).

CONCLUSIONS

As assessed by 3 different measures, acute small-bowel injury on lumiracoxib treatment is less frequent than with naproxen plus omeprazole and similar to placebo.

Epithelial barrier disruption allows nondisease-causing bacteria to initiate and sustain IBD in the IL-10 gene-deficient mouse

BACKGROUND

In the IL-10 gene-deficient mouse model, development of intestinal inflammation is associated with a defect in epithelial barrier integrity that is thought to allow sufficient passage of bacteria or bacterial antigens to initiate a mucosal immune response. Microbial monoassociation experiments into axenic animals have shown that some, but not all, endogenous bacteria will initiate an intestinal inflammatory response. For instance, Bacteroides vulgatus does not initiate intestinal inflammation in axenic IL-10 gene-deficient mice. We investigated whether B. vulgatus requires concomitant disruption of the intestinal epithelial barrier integrity in order to initiate an inflammatory response.

METHODS

We first identified a dose of the indomethacin that would cause a primary disruption of the epithelial barrier without causing intestinal inflammation. IL-10 axenic mice were then administered this dose of indomethacin in their drinking water for 7 days and concomitantly monoassociated, by oral gavage, with B. vulgatus.

RESULTS

Indomethacin treatment (2 microg/g/d) for 7 days resulted in disruption of epithelial barrier integrity, but it caused neither a systemic inflammatory response nor a mucosal inflammatory response in the colon or cecum. Monoassociation with B. vulgatus alone did not lead to a mucosal inflammatory response, despite a measurable systemic response. In contrast, administration of indomethacin plus B. vulgatus-monoassociation resulted in a marked intestinal inflammatory response in colon and cecum.

CONCLUSIONS

Our data show that, in a genetically predisposed animal model, the nondisease-causing endogenous bacteria, B. vulgatus, is able to cause an intestinal inflammatory response provided that disruption of the intestinal epithelial barrier has occurred.

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.

Intestinal tract injury by drugs: Importance of metabolite delivery by yellow bile road

Drug secretion into bile is typically considered a safe route of clearance. However, biliary delivery of some drugs or their reactive metabolites to the intestinal tract evokes adverse consequences due to direct toxic actions or indirect disruption of intestinal homeostasis. Biliary concentration of the chemotherapy agent 5-fluorodeoxyuridine (FUDR) and other compounds is associated with bile duct damage while enterohepatic cycling of antibiotics contributes to the disruptions of gut flora that produce diarrhea. The goal of this review is to describe key evidence that biliary delivery is an important factor in the intestinal injury caused by representative drugs. Emphasis will be given to 3 widely used drugs whose reactive metabolites are plausible causes of small intestinal injury, namely the nonsteroidal anti-inflammatory drug (NSAID) diclofenac, the immunosuppressant mycophenolic acid (MPA), and the chemotherapy agent irinotecan. Capsule endoscopy and other sensitive diagnostic techniques have documented a previously unappreciated, high prevalence of small intestinal injury among NSAID users. Clinical use of MPA and irinotecan is frequently associated such severe intestinal injury that dosage must be reduced. Observations from clinical and experimental studies have defined key events in the pathogenesis of these drugs, including roles for multidrug resistance-associated protein 2 (MRP2) and other transporters in biliary secretion and adduction of enterocyte proteins by reactive acyl glucuronide metabolites as a likely mechanism for intestinal injury. New strategies for minimizing the adverse intestinal consequences of irinotecan chemotherapy illustrate how basic information about key events in the biliary secretion of drugs and the nature of their proximate toxicants can lead to safer protocols for drugs.

Is non-steroidal anti-inflammaory drug (NSAID) enteropathy clinically more important than NSAID gastropathy?

The side effects of conventional non-steroidal anti-inflammatory drugs (NSAIDs) on the stomach is undoubtedly a serious public health problem contributing significantly to the morbidity and mortality of patients receiving these drugs. However, the damage of NSAIDs is not confined to the stomach. Indeed the short term and long term damage of NSAIDs on the small bowel (NSAID enteropathy) is more frequent than NSAID gastropathy. Furthermore, NSAID enteropathy is associated with complications (bleeding and protein loss). While many of these are mild, the serious events (significant bleeding, perforation, obstruction, and sudden death) are frequent as that reported for NSAID gastropathy. The diagnosis of NSAID enteropathy has been greatly aided by the introduction of wireless capsule enteroscopy.

Exacerbation of inflammatory bowel disease by nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 inhibitors: fact or fiction?

The existence of a possible link between inflammatory bowel disease (IBD) and nonsteroidal anti-inflammatory drugs (NSAIDs) has been repeatedly suggested. Recently, a few studies have addressed the issue of a possible, similar effect by selective cyclooxygenase-2 inhibitors (COXIBs). The present article reviews the available scientific evidence for this controversial subject.

Appropriate choice of proton pump inhibitor therapy in the prevention and management of NSAID-related gastrointestinal damage

Non-steroidal anti-inflammatory drugs (NSAIDs) are associated with gastrointestinal adverse effects, ranging from dyspepsia and peptic ulcer disease to more serious complications such as haemorrhage or perforation. NSAID-induced gastrointestinal toxicity is a significant medical problem worldwide. Misoprostol is effective in reducing NSAID-induced mucosal damage, but patient compliance is limited by poor tolerance. Histamine receptor antagonists are relatively effective against duodenal ulcers but offer no significant protection against gastric ulcers. Proton pump inhibitors (PPIs), such as pantoprazole, omeprazole and lansoprazole, have been shown to be effective in preventing the development of gastric and duodenal ulcers in high-risk patients taking NSAIDs. PPI therapy is also beneficial in healing NSAID-induced ulcers and preventing their recurrence in patients requiring ongoing NSAID therapy. PPIs have an excellent safety profile, and pantoprazole--with its low potential for drug-drug interactions--is particularly suitable for administration to elderly patients who often require concomitant treatment with other medications.

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.

Video capsule endoscopy to prospectively assess small bowel injury with celecoxib, naproxen plus omeprazole, and placebo

BACKGROUND & AIMS

Data indicate that cyclooxygenase-2-specific inhibitors cause less gastroduodenal mucosal damage than nonspecific NSAIDS, but their effects on the small bowel mucosa are less well recognized. In a multicenter, double-blind, placebo-controlled trial with video capsule endoscopy (VCE) we prospectively evaluated the incidence of small bowel injury in healthy subjects treated with celecoxib compared to naproxen plus omeprazole.

METHODS

We randomly assigned subjects with normal baseline VCEs to celecoxib 200 mg twice daily (n = 120), naproxen 500 mg twice daily plus omeprazole 20 mg once daily (n = 118), or placebo (n = 118) for 2 weeks. The primary end point was the mean number of small bowel mucosal breaks per subject.

RESULTS

Baseline VCE found small bowel lesions in 13.8% (57/413) of screened subjects, who became ineligible for randomization. The mean number of small bowel mucosal breaks per subject and the percentage of subjects with these mucosal breaks were 2.99 +/- 0.51, 55% for naproxen/omeprazole compared to 0.32 +/- 0.10, 16% for celecoxib and 0.11 +/- 0.04, 7% for placebo (P < .001, both comparisons). The magnitude of the difference between celecoxib and placebo was small but statistically significant (P = .04).

CONCLUSIONS

Among healthy subjects with lesion-free baseline VCEs, celecoxib was associated with significantly fewer small bowel mucosal breaks than naproxen plus omeprazole. This study also showed that the background incidence of small bowel lesions in healthy adults is not insignificant and should be considered in future trials with VCE.

Nabumetone: therapeutic use and safety profile in the management of osteoarthritis and rheumatoid arthritis

Nabumetone is a nonsteroidal anti-inflammatory prodrug, which exerts its pharmacological effects via the metabolite 6-methoxy-2-naphthylacetic acid (6-MNA). Nabumetone itself is non-acidic and, following absorption, it undergoes extensive first-pass metabolism to form the main circulating active metabolite (6-MNA) which is a much more potent inhibitor of preferentially cyclo-oxygenase (COX)-2. The three major metabolic pathways of nabumetone are O-demethylation, reduction of the ketone to an alcohol, and an oxidative cleavage of the side-chain occurs to yield acetic acid derivatives. Essentially no unchanged nabumetone and < 1% of the major 6-MNA metabolite are excreted unchanged in the urine from which 80% of the dose can be recovered and another 10% in faeces. Nabumetone is clinically used mainly for the management of patients with osteoarthritis (OA) or rheumatoid arthritis (RA) to reduce pain and inflammation. The clinical efficacy of nabumetone has also been evaluated in patients with ankylosing spondylitis, soft tissue injuries and juvenile RA. The optimum oral dosage of nabumetone for OA patients is 1 g once daily, which is well tolerated. The therapeutic response is superior to placebo and similar to nonselective COX inhibitors. In RA patients, nabumetone 1 g at bedtime is optimal, but an additional 0.5-1 g can be administered in the morning for patients with persistent symptoms. In RA, nabumetone has shown a comparable clinical efficacy to aspirin (acetylsalicylic acid), diclofenac, piroxicam, ibuprofen and naproxen. Clinical trials and a decade of worldwide safety data and long-term postmarketing surveillance studies show that nabumetone is generally well tolerated. The most frequent adverse effects are those commonly seen with COX inhibitors, which include diarrhoea, dyspepsia, headache, abdominal pain and nausea. In common with other COX inhibitors, nabumetone may increase the risk of GI perforations, ulcerations and bleedings (PUBs). However, several studies show a low incidence of PUBs, and on a par with the numbers reported from studies with COX-2 selective inhibitors and considerably lower than for nonselective COX inhibitors. This has been attributed mainly to the non-acidic chemical properties of nabumetone but also to its COX-1/COX-2 inhibitor profile. Through its metabolite 6-MNA, nabumetone has a dose-related effect on platelet aggregation, but no effect on bleeding time in clinical studies. Furthermore, several short-term studies have shown little to no effect on renal function. Compared with COX-2 selective inhibitors, nabumetone exhibits similar anti-inflammatory and analgesic properties in patients with arthritis and there is no evidence of excess GI or other forms of complications to date.