Randomized, double-blind, pilot study of geranylgeranylacetone versus placebo in patients taking low-dose enteric-coated aspirin. Low-dose aspirin-induced small bowel damage

Drugs Effective for Nonsteroidal Anti-inflammatory Drugs or Aspirin-induced Small Bowel Injuries: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

The frequency of small bowel (SB) injuries has increased due to the increased use of nonsteroidal anti-inflammatory drugs (NSAIDs) or aspirin. This study was a systematic review and meta-analysis to compare drugs effective for SB injuries caused by NSAIDs or aspirin use.

METHODS

We searched MEDLINE, Embase, and Cochrane registries for randomized controlled trials through February 2023. The extracted data included changes in the number of erosions or ulcers in the jejunum or ileum observed through capsule endoscopy in patients taking NSAIDs or aspirin and administration of various mucoprotectants. We investigated the therapeutic or preventive efficacy of these drugs. The methodological bias was evaluated using Risk of Bias 2.0.

RESULTS

Eighteen randomized controlled trials of drugs effective for NSAIDs or aspirin-induced SB injuries were included and analyzed. The agents used to treat or prevent SB injuries were rebamipide, misoprostol, geranylgeranylacetone, and probiotics. In the meta-analysis, the mucoprotectants that showed a significant effect in treating NSAID users, who developed SB injuries, were misoprostol (mean difference: -9.88; 95% CI: -13.26 to -6.50). Meanwhile, the mucoprotectant that can prevent SB injuries caused by NSAIDs or aspirin in the general population was rebamipide (mean difference: -1.85; 95% CI: -2.74 to -0.96).

CONCLUSIONS

Misoprostol was effective in treating SB injuries caused by NSAIDs or aspirin (CRD42023410946).

Mucoprotective drugs can prevent and treat nonsteroidal anti-inflammatory drug-induced small bowel enteropathy: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Small bowel enteropathy (SBE) is a complication of nonsteroidal anti-inflammatory drug (NSAID) therapy occurring in 71% of NSAID users. We aimed to analyse the efficacy and safety of medications to prevent and treat NSAID-induced SBE in randomized controlled trials (RCTs).

METHODS

This review was registered on PROSPERO (CRD42021223371). We systematically searched four databases until 20 October for comparing mucoprotective (MP), antibiotic and probiotic treatments to placebo, proton-pump inhibitors (PPIs) or histamine-2 (H2) receptor antagonists in NSAID-associated small intestinal injuries. The main outcomes were mucosal integrity, mucosal breaks after treatment, mucosal injury improvement and complete healing of mucosal breaks. Meta-analytical calculations for weighted mean differences (WMDs) and odds ratios (ORs) were performed with the random-effects model and interpreted with 95% confidence intervals (CIs).

RESULTS

A total of 18 RCTs were included in the quantitative synthesis. MP medications administered preventively reduced the number of mucosal erosions (WMD = -1.24, CI: -2.15 to -0.34) and lead to a significantly lower chance of developing mucosal breaks after treatment (OR = 0.38, CI: 0.16-0.93). MP therapy was associated with a higher rate of complete healing of mucosal breaks (OR = 5.39, CI: 2.79-10.42). In the qualitative synthesis, there were tendencies for a lower increase in the mean number of mucosal breaks and reddened lesions with prophylactic and a higher decrease in mucosal breaks with therapeutic MP drug administration.

CONCLUSION

MP treatment administered with NSAIDs can prevent and reduce small intestinal mucosal lesions.

Inhibition of Aspirin-Induced Gastrointestinal Injury: Systematic Review and Network Meta-Analysis

Background: Administration of aspirin has the potential for significant side effects of gastrointestinal (GI) injury mainly caused by gastric acid stimulation, especially in long-term users or users with original gastrointestinal diseases. The debate on the optimal treatment of aspirin-induced gastrointestinal injury is ongoing. We aimed to compare and rank the different treatments for aspirin-induced gastrointestinal injury based on current evidence.

Methods: We searched PubMed, EMBASE, Cochrane Library (Cochrane Central Register of Controlled Trials), and Chinese databases for published randomized controlled trials (RCTs) of different treatments for aspirin-induced gastrointestinal injury from inception to 1 May 2021. All of the direct and indirect evidence included was rated by network meta-analysis under a Bayesian framework.

Results: A total of 10 RCTs, which comprised 503 participants, were included in the analysis. The overall quality of evidence was rated as moderate to high. Eleven different treatments, including omeprazole, lansoprazole, rabeprazole, famotidine, geranylgeranylacetone, misoprostol, ranitidine bismuth citrate, chili, phosphatidylcholine complex, omeprazole plus rebamipide, and placebo, were evaluated in terms of preventing gastrointestinal injury. It was suggested that omeprazole plus rebamipide outperformed other treatments, whereas geranylgeranylacetone and placebo were among the least treatments.

Conclusion: This is the first systematic review and network meta-analysis of different treatments for aspirin-induced gastrointestinal injury. Our study suggested that omeprazole plus rebamipide might be considered the best option to treat aspirin-induced gastrointestinal injury. More multicenter, high quality, large sample size randomized controlled trials will confirm the advantages of these medicines in the treatment of aspirin-induced gastrointestinal injury in the future.

Enteric-Coated Aspirin and the Risk of Gastrointestinal Side Effects: A Systematic Review

Introduction

Aspirin appeared as a medicine to deal with aches and inflammation, but due to its antiplatelet properties, it has evolved into a drug mainly used to avert cardiovascular disease. Regardless of its therapeutic uses, the limiting aspect for aspirin use has been its affiliation with gastrointestinal (GI) toxicity, classifying from acute mucosal damage to GI problems and death.

Objective

The aim of this systematic review is to address the question regarding the ECA effect on the gastric mucosa.

Methods

A systematic search of the literature was conducted in the PubMed electronic databases from April 10th to April 23rd, 2020. Eligibility has been set, and based on those criteria, initially a total of 637 results were obtained, from these 58 of them were not written in English. Then, 168 articles which were free from duplication were screened and all the included articles were RCTs published after 2000. Based on these, final number of articles included on this review was 6.

Results

Data were obtained from 6 published articles which reported on 15,621 participants. The reports were from 3 different countries. Most of the studies revealed that enteric-coated aspirin (ECA) treatment was not an effective mechanism against GI protection. ECA administration with omeprazole can hugely reduce the incidence of endoscopic GI damage compared to the impact of ECA used alone. Even short-term administration of a low dose of ECA was significantly associated with an apparent small bowel injury.

Conclusion

ECA treatment is not an effective mechanism against GI protection, and it is highly associated with small bowel injury. So the coating does not reduce risk of GI complications.

Asymptomatic small intestinal ulcerative lesions: Obesity and Helicobacter pylori are likely to be risk factors

It is often difficult to explain why ulcerative lesions are found in the small intestine because there are no obvious aggressors such as gastric acid. In particular, the treatment of small intestinal ulcerative lesions in asymptomatic patients with no symptoms, normal physical examinations, and normal blood test findings is not well documented. According to a summary of capsule endoscopy studies in healthy subjects, approximately 10% of subjects have small intestinal mucosal breaks. The number of mucosal breaks in these instances is approximately 1-3. We examined small intestinal mucosal breaks in healthy subjects recruited from our past two studies. Mucosal breaks were observed in approximately 10% of subjects, and the average number was 0.24 ± 1.21. The number of mucosal breaks in the small intestine was correlated with body mass index and was significantly higher in Helicobacter pylori-infected subjects and higher in males. These results indicate that 1-2 small ulcerative lesions, such as erosions in the small intestine, can be considered to be in the normal range, and close examination is not required. It is assumed that a follow-up medical examination is required for such asymptomatic persons. The presence of many small ulcerative lesions or an unequivocal ulcer indicates an abnormality for which close examination is desired. However, in many cases, it is sufficient to scrutinize after detecting anemia, but it is difficult to make a judgment due to insufficient reports, and future studies are required.

Effect of a proton-pump inhibitor on intestinal microbiota in patients taking low-dose aspirin

BACKGROUND AND AIM

Low-dose aspirin (LDA) administration prevents cerebral infarction and myocardial infarction, but many studies found an association with mucosal injury. Proton-pump inhibitors (PPIs) can prevent gastric and duodenal mucosal damage, but they may exacerbate small-intestinal mucosal injury by altering the microbiota. We aimed to assess the effect of PPIs on the intestinal flora of LDA users.

METHODS

Thirty-two recruited patients, who received LDA (100 mg/day) but did not take PPIs, were divided into 15 patients additionally receiving esomeprazole (20 mg/day) and 17 patients additionally receiving vonoprazan (10 mg/day). On days 0, 30, 90, and 180, the microbiota of each patient was examined by terminal restriction fragment length polymorphism analysis, and the serum gastrin, hemoglobin, and hematocrit levels were measured.

RESULTS

Additional PPI administration increased the proportion of Lactobacillales in the microbiota of LDA users. This trend was more prevalent in the vonoprazan group (p < 0.0001) than in the esomeprazole group (p = 0.0024). The Lactobacillales proportion was positively correlated with the gastrin level (r = 0.5354). No significant hemoglobin or hematocrit level reduction was observed in subjects receiving LDA with additional PPI.

CONCLUSIONS

Additional PPI administration increased the Lactobacillales proportion in the microbiota of LDA users. The positive correlation between the gastrin level and the proportion of Lactobacillales suggested that the change in the intestinal flora was associated with the degree of suppression of gastric acid secretion. Additional oral PPI did not significantly promote anemia, but the risk of causing PPI-induced small-intestinal mucosal injury in LDA users should be considered.

P2Y12 Inhibitors Exacerbate Low-dose Aspirin-induced Small Bowel Injury in Dual Antiplatelet Therapy

Objective Antithrombotic drugs are being used increasingly frequently to prevent cardiovascular diseases. Few studies have evaluated small bowel mucosal injury induced by dual antiplatelet therapy (DAPT). The aim of the present study was to evaluate small bowel mucosal injury induced by DAPT compared with other antithrombotics using video capsule endoscopy (VCE). Methods The study included chronic users of antithrombotics who underwent VCE for obscure gastrointestinal bleeding between January 2007 and July 2018. We evaluated the instances of small bowel injury classified into erosions and ulcers. Results Overall, 183 patients (114 men and 69 women; mean age, 73.6 years old) were enrolled, and the study groups comprised 49 patients taking low-dose aspirin (LDA) only, 50 taking anticoagulants only, 37 being treated with DAPT, 33 on combined LDA and anticoagulants, and 14 taking P2Y12 inhibitors. Small bowel erosions and ulcers were most frequently observed in the DAPT group, with frequencies of 78.4% and 37.8%, respectively. Exacerbating factors of small bowel ulcers were DAPT [odds ratio (OR) 3.0, 95% confidence interval (CI) 1.2-7.7] and age over 80 years old (OR 2.4, 95% CI 1.1-5.4). Conclusion P2Y12 inhibitors seem to exacerbate LDA-induced small bowel injury. Preventive strategies for small bowel injury induced by LDA, especially DAPT, are urgently required.

Small-Bowel Lesions in Patients Taking Direct Oral Anticoagulants Detected Using Capsule Endoscopy

METHODS

This study was a prospective, open-label, nonblinded, multicenter, and observational study. From September 2013 to March 2017, patients taking DOACs were enrolled. Patients underwent VCE. The type and location of small-bowel lesions were registered. Also, (1) the proportion of lesions detected between types of DOAC was evaluated and (2) the hemoglobin (Hb) and serum ferritin levels were compared between patients with and without small-bowel lesions.

RESULTS

33 patients were enrolled, but 4 patients withdrew their consent, and VCE was performed on 29 patients. Eight, 13, and 8 patients received dabigatran, rivaroxaban, and apixaban, respectively. Small-bowel transit was complete in 27 of 29 patients (93.1%). Small-bowel lesions were detected in 23 (79.3%), redness in 12 (41.4%), erosions in 14 (48.3%), and angioectasia in 3 (10.3%) patients, and 6 patients (20.7%) had no abnormalities. Redness and erosions were detected in the upper, middle, or lower portions, but erosions tended to be less frequent in the middle portion (p = 0.25, 0.06). Angioectasia was not detected in the lower portion. No patients had active bleeding. The findings did not differ according to the drug. The relationships between the endoscopic findings and the Hb and serum ferritin levels were not significant.

CONCLUSION

Many patients taking DOACs had small-bowel lesions; however, most lesions were relatively mild. Observing small-bowel lesions over longer periods may be necessary in patients taking DOACs. This trial is registered with UMIN000011527.

Non-steroidal anti-inflammatory drug-induced enteropathy as a major risk factor for small bowel bleeding: a retrospective study

Background

Small bowel (SB) bleeding accounts for 5% of all gastrointestinal (GI) bleeding cases and 80% of obscure GI bleeding cases. Although angioectasia is the common etiology of SB bleeding, nonsteroidal anti-inflammatory drug (NSAID)-induced SB lesions are also reported as a major cause in studies from Eastern countries. Herein, we assessed the frequency of occurrence of NSAID-induced SB lesions in Korean patients with obscure GI bleeding.

Methods

We retrospectively analyzed medical records of all consecutive patients aged ≥18 years who underwent capsule endoscopy from March 2018 to February 2019 at Ulsan University Hospital and Kosin University Gospel Hospital.

Results

Of the 83 subjects (all Korean; mean age ± standard deviation: 59 ± 18 years; age range: 18–84 years; men: n = 52; women: n = 31), 55 (66.2%) had stool with clear blood and 28 (33.8%) had normal stool with iron deficiency anemia. The detection rate of SB bleeding and lesions using capsule endoscopy was 72.3% (60 of 83 patients). A significantly higher frequency (40 of 51) of ulcerative/erosive lesions than other causes was observed in patients with inactive bleeding but visible SB lesions. As a result, NSAID-induced enteropathy accounted for 30.1% of 83 patients with obscure GI bleeding (25 of the all 60 SB bleeding cases).

Conclusions

Contrary to what is reported for patients in Western countries, this study in Korean patients showed an improved diagnostic yield of capsule endoscopy for obscure GI bleeding and that NSAID-induced enteropathy was the most common etiology of SB bleeding. Aggressive small intestine examination is required for patients with unexplained GI bleeding.

Misoprostol Heals Small Bowel Ulcers in Aspirin Users With Small Bowel Bleeding

BACKGROUND & AIMS

There is no effective treatment for aspirin-induced small bowel ulcer bleeding. We performed a double-blind, randomized, placebo-controlled trial to determine whether misoprostol can heal small bowel ulcers in patients with small bowel bleeding who require continuous aspirin therapy.

METHODS

We performed a prospective study of 84 aspirin users with small bowel bleeding who required continued aspirin therapy in Hong Kong and Japan. Patients with small bowel ulcers or multiple erosions, detected by capsule endoscopy, were randomly assigned to groups that received either misoprostol (200 μg, 4 times daily; n = 42) or placebo (n = 42) for 8 weeks. All patients continued taking aspirin (100 mg, once daily). The primary end point was complete ulcer healing at follow-up capsule endoscopy. Secondary end points included changes in hemoglobin level and number of ulcer/erosions from baseline.

RESULTS

Complete healing of small bowel ulcers was observed in 12 patients in the misoprostol group (28.6%; 95% CI, 14.9%-42.2%) and 4 patients in the placebo group (9.5%; 95% CI, 0.6%-18.4%), for a difference in proportion of 19.0% (95% CI, 2.8%-35.3%; P = .026). The misoprostol group had a significantly greater mean increase in hemoglobin than the placebo group (mean difference, 0.70 mg/dL; 95% CI, 0.05-1.36; P = .035). The reduction in medium number of ulcers or erosions was significantly greater in the misoprostol group (from 6.5 [range, 1-85] to 2 [range, 0-25]) than in the placebo group (from 7 [range, 1-29] to 4 [range, 0-19] (P = .005).

CONCLUSIONS

In a double-blind, randomized, placebo-controlled trial, we found misoprostol to be superior to placebo in promoting healing of small bowel ulcers among aspirin users complicated by small bowel ulcer bleeding who require continuous aspirin therapy. However, use of misoprostol alone would provide only limited protection against aspirin on the small bowel. ClinicalTrials.gov ID NCT01998776.

Dual antiplatelet therapy does not affect the incidence of low-dose aspirin-induced small intestinal mucosal injury in patients after percutaneous coronary intervention for coronary stenosis: a multicenter cross-sectional study

Although low-dose aspirin (LDA) is known to induce small intestinal mucosal injury, the effect of dual antiplatelet therapy (DAPT; LDA + clopidogrel) on small intestinal mucosa in patients after percutaneous coronary intervention (PCI) for coronary stenosis is unknown. Fifty-one patients with a history of PCI and LDA use were enrolled, and 45 eligible patients were analyzed. Patients were grouped based on DAPT (DAPT: n = 10 and non-DAPT: n = 35) and proton pump inhibitor (PPI) use (PPI user: n = 22 and PPI-free patients: n = 23) to compare small intestinal endoscopic findings. The relationship between LDA-use period and small intestinal endoscopic findings was also examined. Multivariate analysis was performed to identify risk factors for LDA-induced mucosal injury using age, sex, DAPT, PPI, gastric mucoprotective drug, and LDA-use period. The rate of small intestinal mucosal injury incidence did not significantly differ between DAPT and non-DAPT patients (50% vs 51.1%, respectively; p = 0.94), or PPI users and PPI-free patients (50% vs 52.2%, respectively; p = 0.88). Additionally, LDA-use period of ≤24 months (n = 15) yielded a significantly higher rate of small intestinal mucosal injury incidence than LDA-use period >24 months (n = 30) (80% vs 36.7%, respectively; p = 0.006). Multivariate analysis revealed that a LDA-use period of ≤24 months was a significant risk factor for small intestinal mucosal injury (odds ratio: 19.5, 95% confidence interval: 2.48–154.00, p = 0.005). Following PCI for coronary stenosis, neither DAPT nor PPI affected LDA-induced small intestinal mucosal injury. Moreover, patients who used LDA within the last 24 months were at a greater risk of small intestinal mucosal injury.

NSAIDs and the small bowel

PURPOSE OF REVIEW

The review describes the effects of NSAID gastrointestinal toxicity on the small bowel, wherein injury is as prevalent as in the gastroduodenum. This is well documented by capsule endoscopy, which also provides an endoscopic endpoint for novel treatment strategies.

RECENT FINDINGS

Appreciation of the prevalence of NSAID enteropathy has grown with capsule endoscopy and the use of composite end points that include obscure haemoglobin decreases in clinical studies. Along with dual cyclo-oxygenase isoform inhibition, gram-negative antigen presentation plays a role in the pathogenesis of NSAID enteropathy. The concomitant use of proton pump inhibitor (PPI) agents with both selective and nonselective NSAIDs in gastroduodenal protection exacerbates endoscopic enteropathy, which is thought to be due to intestinal dysbiosis. Strategies for small bowel mucosal protection include prostaglandin repletion and augmenting the intestinal flora.

SUMMARY

NSAID- related enteropathy is common and often presents subclinically. The most common presentation is anaemia, which may be less common in those on cyclo-oxygenase (COX)-2 inhibitors than nonselective NSAIDs. PPI use worsens NSAID enteropathy with more occult bleeding and ulceration and has been linked to gram-negative intestinal dysbiosis. If NSAID cessation is not possible, COX-2 inhibition without PPI therapy should be considered in patients with upper gastrointestinal risk factors. Mucoprotective agents such as misoprostol and rebamipide show promise and probiotics may have a future role.

Associations between drugs and small-bowel mucosal bleeding: Multicenter capsule-endoscopy study

BACKGROUND AND AIM

Although several drugs may induce small-bowel mucosal injuries, it is unclear whether these injuries contribute to overt small-bowel bleeding. This study was designed to evaluate the associations between drug use and small-bowel mucosal injury and between these mucosal injuries and overt bleeding in a disease-relevant population.

METHODS

We retrospectively studied patients with suspected small-bowel diseases who underwent capsule endoscopy between 2010 and 2013. Drug exposure, Charlson Comorbidity Index, smoking, and alcohol consumption were assessed before capsule endoscopy. Adjusted odds ratios (AOR) and confidence intervals (CI) were estimated for small-bowel mucosal injury and small-bowel overt bleeding.

RESULTS

In total, 850 patients were analyzed during the study period. Median age was 64 years, and 544 patients (64.0%) were men. Among the patients with small-bowel mucosal injury (n = 60) and without mucosal injury (n = 705), use of non-steroidal anti-inflammatory drugs (NSAIDs) (AOR 1.8, 95% CI 1.01-3.31) was significantly associated with an increased risk of small-bowel mucosal injury compared with non-use. Patients with small-bowel mucosal injury with overt bleeding (n = 85) and without overt bleeding (n = 60) were compared, and no significant difference between the groups in the usage rates for NSAIDs, thienopyridine, other antiplatelets, anticoagulants, acetaminophen, tramadol hydrochloride, or steroids was revealed, even after adjusting for confounders.

CONCLUSION

Although the use of NSAIDs was significantly associated with an increased risk of small-bowel mucosal injury, no significant associations were observed between the use of such drugs and small-bowel overt bleeding.

Determination of the adequate dosage of rebamipide, a gastric mucoprotective drug, to prevent low-dose aspirin-induced gastrointestinal mucosal injury

Small intestinal mucosal injury caused by low-dose aspirin is a common cause of obscure gastrointestinal bleeding. We aimed to investigate the protective effects and optimal dose of rebamipide for low-dose aspirin-induced gastrointestinal mucosal injury. In this prospective randomized trial, 45 healthy volunteers (aged 20–65 years) were included and divided into three groups. The groups received enteric-coated aspirin 100 mg (low-dose aspirin) plus omeprazole 10 mg (Group A: proton pump inhibitor group), low-dose aspirin plus rebamipide 300 mg (Group B: standard-dose group), or low-dose aspirin plus rebamipide 900 mg (Group C: high-dose group). Esophagogastroduodenoscopy and video capsule endoscopy were performed, and the fecal occult blood reaction and fecal calprotectin levels were measured before and two weeks after drug administration. Although the fecal calprotectin levels increased significantly in Group A, they did not increase in Groups B and C. The esophagogastroduodenoscopic and video capsule endoscopic findings and the fecal occult blood test findings did not differ significantly among the three groups. In conclusion, standard-dose rebamipide is sufficient for preventing mucosal injury of the small intestine induced by low-dose aspirin, indicating that high-dose rebamipide is not necessary.

Clinical importance of nonsteroidal anti-inflammatory drug enteropathy: the relevance of tumor necrosis factor as a promising target

The pathogenesis of nonsteroidal anti-inflammatory drug (NSAID) enteropathy is still unclear, and consequently, there is no approved therapeutic strategy for ameliorating such damage. On the other hand, molecular treatment strategies targeting tumor necrosis factor (TNF) exerts beneficial effects on NSAID-induced intestinal lesions in rodents and rheumatoid arthritis patients. Thus, TNF appears to be a potential therapeutic target for both the prevention and treatment of NSAID enteropathy. However, the causative relationship between TNF and NSAID enteropathy is largely unknown. Currently approved anti-TNF agents are highly expensive and exhibit numerous side effects. Hence, in this review, the pivotal role of TNF in NSAID enteropathy has been summarized and plant-derived polyphenols have been suggested as useful alternative anti-TNF agents because of their ability to suppress TNF activated inflammatory pathways both in vitro and in vivo.

Bleeding Risk with Long-Term Low-Dose Aspirin: A Systematic Review of Observational Studies

BACKGROUND

Low-dose aspirin has proven effectiveness in secondary and primary prevention of cardiovascular events, but is also associated with an increased risk of major bleeding events. For primary prevention, this absolute risk must be carefully weighed against the benefits of aspirin; such assessments are currently limited by a lack of data from general populations.

METHODS

Systematic searches of Medline and Embase were conducted to identify observational studies published between 1946 and 4 March 2015 that reported the risks of gastrointestinal (GI) bleeding or intracranial hemorrhage (ICH) with long-term, low-dose aspirin (75-325 mg/day). Pooled estimates of the relative risk (RR) for bleeding events with aspirin versus non-use were calculated using random-effects models, based on reported estimates of RR (including odds ratios, hazard ratios, incidence rate ratios and standardized incidence ratios) in 39 articles.

FINDINGS

The incidence of GI bleeding with low-dose aspirin was 0.48-3.64 cases per 1000 person-years, and the overall pooled estimate of the RR with low-dose aspirin was 1.4 (95% confidence interval [CI]: 1.2-1.7). For upper and lower GI bleeding, the RRs with low-dose aspirin were 2.3 (2.0-2.6) and 1.8 (1.1-3.0), respectively. Neither aspirin dose nor duration of use had consistent effects on RRs for upper GI bleeding. The estimated RR for ICH with low-dose aspirin was 1.4 (1.2-1.7) overall. Aspirin was associated with increased bleeding risks when combined with non-steroidal anti-inflammatory drugs, clopidogrel and selective serotonin reuptake inhibitors compared with monotherapy. By contrast, concomitant use of proton pump inhibitors decreased upper GI bleeding risks relative to aspirin monotherapy.

CONCLUSIONS

The risks of major bleeding with low-dose aspirin in real-world settings are of a similar magnitude to those reported in randomized trials. These data will help inform clinical judgements regarding the use of low-dose aspirin in prevention of cardiovascular events.

Usefulness of Ultrasonography for Diagnosis of Small Bowel Tumors: A Comparison Between Ultrasonography and Endoscopic Modalities

Ultrasonography is a standard, noninvasive modality used to evaluate patients with gastrointestinal diseases. This study assessed the usefulness of ultrasonography in the detection of small bowel tumors. This study enrolled 558 consecutive patients (295 males, 263 females; mean age 71.1 years) who underwent ultrasonography before capsule endoscopy and/or balloon-assisted endoscopy. Ultrasonographic detection of small bowel tumors was compared with detection by capsule endoscopy and/or balloon-assisted endoscopy. In addition, factors affecting small bowel tumor detection by ultrasonography and clinical characteristics of patients with small bowel tumors undetected by ultrasonography were evaluated. Ninety-seven tumors (52 benign, 45 malignant) detected by capsule endoscopy and/or balloon-assisted endoscopy were retrospectively analyzed. The sensitivity and specificity of ultrasonography in the detection of small bowel tumors were 50.5% (47/93) and 100% (465/465), respectively. If we restricted patients to those with a tumor >20 mm in size, its detection ratio would become higher (91.7%): the ratio of submucosal tumor >20 mm in size was 85.7% (6/7) and that of partial and circumferential ulcerative tumors >20 mm in size was 96.9% (31/32), respectively. Small bowel tumors detected by ultrasonography (mean 33.2 mm) were significantly larger than those undetected by ultrasonography (mean 8.7 mm). The percentage of small bowel tumors located in the ileum detected by ultrasonography (70.6%) was significantly higher than those undetected by ultrasonography (29.4%). Of the 46 small bowel tumors undetected by ultrasonography, 42 (91.3%) were benign tumors with good clinical prognosis. Ultrasonography is a useful modality for detecting larger small bowel tumors and ulcerative lesions. Ultrasonography should be considered a first-line modality for patients suspected of having small bowel tumors, because most small bowel tumors undetected by ultrasonography were benign tumors with good clinical prognosis.

Effect of long-term proton pump inhibitor therapy and healing effect of irsogladine on nonsteroidal anti-inflammatory drug-induced small-intestinal lesions in healthy volunteers

This study assessed time-course changes of the small intestinal lesions during long-term treatment with diclofenac sodium plus omeprazole and the effects of irsogladine on such lesions. Thirty two healthy volunteers were treated with diclofenac sodium (75 mg/day) plus omeprazole (10 mg/day) for 6 weeks, with irsogladine (4 mg/day) added from weeks 6 to 10 (Group A) or with diclofenac sodium plus irsogladine for 6 weeks (Group B). Five volunteers received diclofenac sodium plus omeprazole for 10 weeks (Group C). Subjects underwent capsule endoscopy at each time. In Group A, the number of lesions remarkably increased at week 2, but the worse was not found at week 6 compared with week 2, whereas no exacerbation of lesions was observed in Group B. Additional treatment with irsogladine from weeks 6 to 10 in Group A significantly decreased the number of lesions at weeks 10 compared with Group C. In Group C, no significant change in lesions was observed since weeks 2. In conclusions, a PPI did not prevent the occurrence of small intestinal damage. However such lesions were not aggravated since weeks 2. These suggested mucosal adaptation may occur in the small intestine. Irsogladine was effective in both preventing and healing such lesions.

Small bowel injury in low-dose aspirin users

The use of low-dose aspirin (LDA) is well known to be associated with an increased risk of serious upper gastrointestinal complications, such as peptic ulceration and bleeding. Until recently, attention was mainly focused on aspirin-induced damage of the stomach and duodenum. However, recently, there has been growing interest among gastroenterologists on the adverse effects of aspirin on the small bowel, especially as new endoscopic techniques, such as capsule endoscopy (CE) and balloon-assisted endoscopy, have become available for the evaluation of small bowel lesions. Preliminary CE studies conducted in healthy subjects have shown that short-term administration of LDA can induce mild mucosal inflammation of the small bowel. Furthermore, chronic use of LDA results in a variety of lesions in the small bowel, including multiple petechiae, loss of villi, erosions, and round, irregular, or punched-out ulcers. Some patients develop circumferential ulcers with stricture. In addition, to reduce the incidence of gastrointestinal lesions in LDA users, it is important for clinicians to confirm the differences in the gastrointestinal toxicity between different types of aspirin formulations in clinical use. Some studies suggest that enteric-coated aspirin may be more injurious to the small bowel mucosa than buffered aspirin. The ideal treatment for small bowel injury in patients taking LDA would be withdrawal of aspirin, however, LDA is used as an antiplatelet agent in the majority of patients, and its withdrawal could increase the risk of cardiovascular/cerebrovascular morbidity and mortality. Thus, novel means for the treatment of aspirin-induced enteropathy are urgently needed.

Geranylgeranylacetone protects against small-intestinal injuries induced by diclofenac in patients with rheumatic diseases: a prospective randomized study

BACKGROUND

We aimed to explore the effect of geranylgeranylacetone on small-intestinal mucosal injuries induced by diclofenac sodium in patients with rheumatic diseases.

METHODS

The patients were randomly divided into two groups in our prospective study. The patients in the geranylgeranylacetone group received diclofenac sodium plus geranylgeranylacetone, and those in the control group received only diclofenac sodium for 12 weeks. We examined small-intestinal mucosal injuries using capsule endoscopy before and after treatment.

RESULTS

There were no significant differences between geranylgeranylacetone (n = 21, male: 42.9%; age: 31.0 ± 9.0 year) and control (n = 19, male: 68.4%; age: 31.0 ± 11.0 year) groups in terms of the numbers of patients with petechiae/red spots, denuded areas and mucosal breaks at baseline capsule endoscopy. After treatment, the numbers of patients with denuded areas (χ(2) = 0.000, P = 1.000) and mucosal breaks (χ(2) = 1.750, P = 0.186) did not increase in the geranylgeranylacetone group. However, the numbers of patients with petechiae/red spots (χ(2) = 5.216, P = 0.022), denuded areas (χ(2) = 8.686, P = 0.003) and mucosal breaks (χ(2) = 7.795, P = 0.005) increased after treatment in the control groups. Geranylgeranylacetone improved both the Lewis score (Z = -2.459, P = 0.017) and degree (χ(2) = 5.414, P = 0.020) on capsule endoscopy 12 weeks later.

CONCLUSIONS

In patients with rheumatic diseases, geranylgeranylacetone is effective for protecting against small-intestinal mucosal injuries induced by diclofenac sodium.

Prophylactic use of aspirin: systematic review of harms and approaches to mitigation in the general population

A careful assessment of benefits and harms is required to assess suitability of aspirin as a prophylactic public health measure. However, comprehensive population-level data on harms are lacking. We collected and synthesized age and sex-specific data on harms relevant to aspirin use in average-risk individuals aged 50 years or older. We conducted systematic literature searches to identify baseline rates of gastrointestinal (GI) bleeding, peptic ulcer, major extra-cranial bleeding, and case-fatality rates due to GI bleeding or peptic ulcer in general population. The magnitude of aspirin-associated increase, the prevalence and attributable risk of Helicobacter pylori infection on these events in aspirin users was also assessed. Baseline rates of major extracranial bleeding events and GI complications increase with age; an almost threefold to fourfold increase is observed from age 50-54 to 70-74 years. Low or standard-dose aspirin use increases GI bleeding events by 60% leading to an annual excess of 0.45 and 0.79 GI bleeding events per 1,000 women and men aged 50-54 years respectively. 5-10% of major GI complications are fatal; a clear age dependence--higher fatality in older individuals, is seen. Eradication of H. pylori infection before aspirin use could reduce the incidence of upper GI complications by 25-30%. GI complications are increased by about 60% due to aspirin use but are fatal only in a very small proportion of individuals younger than 70 years of age. Major bleeding events that are comparable in severity to cancer or CVD, are infrequent. Screening and eradication of H. pylori infection could substantially lower aspirin-related GI harms.

Nonsteroidal anti-inflammatory drugs, proton pump inhibitors, and gastrointestinal injury: contrasting interactions in the stomach and small intestine

Nonsteroidal anti-inflammatory drugs (NSAIDs) and proton pump inhibitors (PPIs) are among the most frequently prescribed groups of drugs worldwide. The use of NSAIDs is associated with a high number of significant adverse effects. Recently, the safety of PPIs has also been challenged. Capsule endoscopy studies reveal that even low-dose NSAIDs are responsible for gut mucosal injury and numerous clinical adverse effects, for example, bleeding and anemia, that might be difficult to diagnose. The frequent use of PPIs can exacerbate NSAID-induced small intestinal injury by altering intestinal microbiota. Thus, the use of PPI is considered to be an independent risk factor associated with NSAID-associated enteropathy. In this review, we discuss this important clinical problem and review relevant aspects of epidemiology, pathophysiology, and management. We also present the hypothesis that even minor and subclinical injury to the intestinal mucosa can result in significant, though delayed, metabolic consequences, which may seriously affect the health of an individual. PubMed was searched using the following key words (each key word alone and in combination): gut microbiota, microbiome, non-steroidal anti inflammatory drugs, proton pump inhibitors, enteropathy, probiotic, antibiotic, mucosal injury, enteroscopy, and capsule endoscopy. Google engine search was also carried out to identify additional relevant articles. Both original and review articles published in English were reviewed.

[Antiplatelet therapy with acetylsalicylic acid: approaches to reducing the frequency of gastrointenstinal adverse reactions]

Acetylsalicylic acid (ASA) is highly effective in preventing cardiovascular events, but associated with increased risk for digestive adverse reactions. The paper provides an update on the epidemiology, mechanisms, and risk factors of esophagogastroduodeno- and enteropathies during long-term low-dose ACA therapy. It outlines the key principles of their prevention.

The role of food for the formation and prevention of gastrointestinal lesions induced by aspirin in cats

BACKGROUND/AIMS

The effects of feeding conditions (fasted or fed) and dietary fiber (DF) in the diet on gastrointestinal (GI) damage induced by aspirin (ASA) were examined in cats.

METHODS

Plain ASA (P-ASA, 20 mg/kg) or one enteric-coated ASA tablet (EC-ASA, containing 100 mg ASA) was administered p.o. once daily for 3 or 7 days just after morning meal, 3 h after the evening meal, or in the morning without a morning meal (fasted). Several types of diet, dry food (DRY, DF: 2.8 %), canned food (CAN, DF: 0.4 %), and diets with added cellulose or pectin were provided twice daily.

RESULTS

P-ASA or EC-ASA administered just after feeding of DRY caused marked lesions in the GI tract, although EC-ASA did not produce any lesions in the stomach. GI damage was markedly decreased when ASA was administered 3 h after the evening meal. The induction of lesions by EC-ASA was markedly decreased in cats that ate CAN, but lesions were induced in cats fed CAN with added cellulose (6 %). The addition of pectin (6 %) to the DRY markedly decreased the induction of lesions by EC-ASA.

CONCLUSIONS

The results indicate that the induction of GI lesions by ASA was highly dependent on the feeding conditions and DF. To minimize the induction of GI damage, it would be better to take ASA 3 h after the evening meal, or after consuming diets that contain low amounts of insoluble DF and high amounts of soluble DF.

Effectiveness of polaprezinc for low-dose aspirin-induced small-bowel mucosal injuries as evaluated by capsule endoscopy: a pilot randomized controlled study

Background

Treatment of low-dose aspirin (LDA)-induced small-bowel injury has not been established. Polaprezinc, a chelate of zinc and L-carnosine, may be efficacious for such injury. We conducted a pilot randomized controlled study to investigate whether polaprezinc is effective against LDA-induced small-bowel injuries.

Methods

Consecutive patients under long-term (>3 months) LDA treatment and who agreed to participate in our study underwent initial capsule endoscopy (CE). Patients with LDA-induced small-bowel injury apparent upon initial CE (n = 20) were randomized into a polaprezinc (150 mg/day for 4 weeks) group and a control (no polaprezinc treatment) group. All underwent follow-up CE after 4 weeks. Changes in the number and characteristics of small-bowel mucosal injuries were compared within and between the two groups.

Results

The median number of reddened lesions and erosions/ulcers upon follow-up CE in the polaprezinc group significantly decreased (P < 0.05). However, there was no significant difference in the median number of reddened lesions and erosions/ulcers upon follow-up CE in the control group.

Conclusions

Co-administration of polaprezinc may be effective against small-bowel mucosal injury associated with long-term LDA therapy.

Trial registration

UMIN Clinical Trials Registry UMIN000003687.

Differences in the severity of small bowel mucosal injury based on the type of aspirin as evaluated by capsule endoscopy

BACKGROUND

The differences in the small intestinal toxicity of low-dose aspirin based on the type of aspirin used remains unclear. The purpose of this study was to evaluate the differences in the small bowel mucosal injury between buffered and enteric-coated aspirin users by capsule endoscopy.

METHODS

We retrospectively reviewed the findings in chronic low-dose aspirin users (>3 months) who underwent capsule endoscopy for the investigation of obscure gastrointestinal bleeding. The patients were classified into two groups based on the type of low-dose aspirin that they had been prescribed (enteric-coated aspirin group or buffered aspirin group), and evaluated the numbers of small bowel lesions and the Lewis score.

RESULTS

Capsule-endoscopic findings of a total of 70 patients taking low-dose aspirin were reviewed. Significant differences in the number of erosions and ulcers were observed between the buffered and enteric-coated aspirin groups (P=0.017 and P=0.037, respectively). The median Lewis score for the small bowel mucosal inflammatory change was significantly higher in the enteric-coated aspirin group than in the buffered aspirin group (P=0.035).

CONCLUSIONS

The results of this study suggested that enteric-coated aspirin might be more injurious to the small bowel mucosa than buffered aspirin.

Poor awareness of preventing aspirin-induced gastrointestinal injury with combined protective medications

AIM: To investigate prescribing pattern in low-dose aspirin users and physician awareness of preventing aspirin-induced gastrointestinal (GI) injury with combined protective medications.

METHODS: A retrospective drug utilization study was conducted in the 2nd Affiliated Hospital, School of Medicine, Zhejiang University. The hospital has 2300 beds and 2.5 million outpatient visits annually. Data mining was performed on all aspirin prescriptions for outpatients and emergency patients admitted in 2011. Concomitant use of proton-pump inhibitors (PPIs), histamine 2-receptor antagonists (H2RA) and mucoprotective drugs (MPs) were analyzed. A defined daily dose (DDD) methodology was applied to each MP. A further investigation was performed in aspirin users on combination use of GI injurious medicines [non-steoid anti-inflammatory drugs (NSAIDs), corticosteroids and clopidogrel and warfarin] or intestinal protective drugs (misoprostol, rebamipide, teprenone and gefarnate). Data of major bleeding episodes were derived from medical records and adverse drug reaction monitoring records. The annual incidence of major GI bleeding due to low-dose aspirin was estimated for outpatients.

RESULTS: Prescriptions for aspirin users receiving PPIs, H2RA and MPs (n = 1039) accounted for only 3.46% of total aspirin prescriptions (n = 30 015). The ratios of coadministration of aspirin/PPI, aspirin/H2RA, aspirin/MP and aspirin/PPI/MP to the total aspirin prescriptions were 2.82%, 0.12%, 0.40% and 0.12%, respectively. No statistically significant difference was observed in age between patients not receiving any GI protective medications and patients receiving PPIs, H2RA or MPs. The combined medication of aspirin and PPI was used more frequently than that of aspirin and MPs (2.82% vs 0.40%, P < 0.05) and aspirin/H2RA (2.82% vs 0.12%, P < 0.05). The values of DDDs of MPs in descending order were as follows: gefarnate, hydrotalcite > teprenone > sucralfate oral suspension > L-glutamine and sodium gualenate granules > rebamipide > sucralfate chewable tablets. The ratio of MP plus aspirin prescriptions to the total MP prescriptions was as follows: rebamipide (0.47%), teprenone (0.91%), L-glutamine and sodium gualenate granules (0.92%), gefarnate (0.31%), hydrotalcite (1.00%) and sucralfate oral suspension (0.13%). Percentages of prescriptions containing aspirin and intestinal protective drugs among the total aspirin prescriptions were: rebamipide (0.010%), PPI/rebamipide (0.027%), teprenone (0.11%), PPI/teprenone (0.037%), gefarnate (0.017%), and PPI/gefarnate (0.013%). No prescriptions were found containing coadministration of aspirin and other NSAIDs. Among the 3196 prescriptions containing aspirin/clopidogrel, 3088 (96.6%) prescriptions did not contain any GI protective medicines. Of the 389 prescriptions containing aspirin/corticosteroids, 236 (60.7%) contained no GI protective medicines. None of the prescriptions using aspirin/warfarin (n = 22) contained GI protective medicines. Thirty-five patients were admitted to this hospital in 2011 because of acute hemorrhage of upper digestive tract induced by low-dose aspirin. The annual incidence rates of major GI bleeding were estimated at 0.25% for outpatients taking aspirin and 0.5% for outpatients taking aspirin/warfarin, respectively.

CONCLUSION: The prescribing pattern of low-dose aspirin revealed a poor awareness of preventing GI injury with combined protective medications. Actions should be taken to address this issue.

Preventive effects of geranylgeranylacetone on rat ethanol-induced gastritis

AIM: To establish a rat ethanol gastritis model, we evaluated the effects of ethanol on gastric mucosa and studied the preventive effects of geranylgeranylacetone on ethanol-induced chronic gastritis.

METHODS: One hundred male Sprague-Dawley rats were randomly divided into 4 equal groups: normal control group, undergoing gastric perfusion of normal saline (NS) by gastrogavage; model control group and 2 model therapy groups that underwent gastric perfusion with ethanol (distillate spirits with 56% ethanol content) by gastrogavage for 4 wk. Low or high doses of geranylgeranylacetone were added 1 h before ethanol perfusion in the 2 model therapy groups, while the same amount of NS, instead of geranylgeranylacetone was used in that model control group. The rats were then sacrificed and stomachs were removed. The injury level of the gastric mucosa was observed by light and electron microscopy, and the levels of prostaglandin 2 (PGE₂), endothelin-1 (ET-1) and nitric oxide (NO) were measured by radioimmunoassay and the Griess method.

RESULTS: The gastric mucosal epidermal damage score (EDS; 4.5) and ulcer index (UI; 12.0) of the model control group were significantly higher than that of the normal control group (0 and 0 respectively, all P = 0.000). The gastric mucosal EDS and UI of the 2 model therapy groups (EDS: 2.5 and 2.0; UI: 3.5 and 3.0) were significantly lower than that of the model control group (all P < 0.01). There was no statistically significant difference between the low-dose and high-dose model therapy groups. The expression value of plasma ET-1 of the model control group was higher than that of the normal control group (P < 0.01) and the 2 model therapy groups (all P < 0.01). The expression values of gastric mucosal PGE₂ and serum NO of the model control group were lower than those of the normal control group (all P < 0.05) and the 2 model therapy groups (all P < 0.05). The thickness of the gastric mucous layerand the hexosamine content in the model control group were significantly lower than that in the normal control group (all P < 0.01) and the 2 model therapy groups (all P < 0.05). Scanning and transmission electron microscopy observation showed that in the model control group, the epithelial junctions were vague, the intercellular joints disappeared and damage of the intracellular organelles were significantly worse than those in the normal control group. However, in the 2 model therapy groups, damage to the intercellular joints and organelles was ameliorate relative to the model control group.

CONCLUSION: Administration of geranylgeranylacetone was correlated with a more favorable pattern of gastric mucosa damage after ethanol perfusion. The mechanism could be related to regulation of ET-1, NO and PGE₂.

Rofecoxib and clinically significant upper and lower gastrointestinal events revisited based on documents from recent litigation

INTRODUCTION

On the basis of published data, it is widely believed and cited that rofecoxib use is associated with approximately a 50% reduction in significant gastrointestinal (GI) complications such as bleeding.

METHODS

Data made available as part of litigation, including the Vioxx Gastrointestinal Outcomes Research trial and an Alzheimer's study, allow a reassessment of the reported benefits of rofecoxib in terms of a significant reduction in complicated GI events and in lower GI bleeding.

RESULTS

During the review process of the Vioxx Gastrointestinal Outcomes Research study, it was suggested that rofecoxib might have little benefit, with regard to GI toxicity, for patients with rheumatoid arthritis not treated with corticosteroids. Reanalysis of the original Merck data set showed 9 complicated confirmed events in the rofecoxib group compared with 10 in the naproxen group among corticosteroid nonusers and 7 versus 27 among corticosteroid users so that the difference between rofecoxib and naproxen in the occurrence of confirmed complicated perforations, ulcers or bleeds seemed to be entirely because of the effects within corticosteroid users. The claim that serious lower GI events were 54% lower with the use of the selective cyclooxygenase-2 inhibitor rofecoxib was stated to be based on an assessment blinded to treatment allocation. In fact, the choice did not represent the original blinded analysis that showed a nonsignificant difference, but rather was based on an assessment after treatment allocation was disclosed.

CONCLUSION

Examination and reanalysis of unpublished data regarding rofecoxib has failed to confirm a safety advantage of rofecoxib over traditional nonsteroidal anti-inflammatory drugs in terms of complicated upper or lower GI events.

Aspirin-induced small bowel injuries and the preventive effect of rebamipide

AIM: To evaluate the influence of taking low-dose aspirin for 4 wk on small intestinal complications and to examine the preventive effect of rebamipide.

METHODS: This study was conducted as a single-center, randomized, double-blind, cross-over, placebo-controlled study. Eleven healthy male subjects were enrolled. Each subject underwent video capsule endoscopy after 1 and 4 wk of taking aspirin and omeprazole, along with either rebamipide or placebo therapy. The primary endpoint was to evaluate small bowel damage in healthy subjects before and after taking low-dose aspirin for 4 wk.

RESULTS: The number of subjects with mucosal breaks (defined as multiple erosions and/or ulcers) were 1 at 1 wk and 1 at 4 wk on the jejunum, and 6 at 1 wk (P = 0.0061) and 7 at 4 wk on the ileum (P = 0.0019). Rebamipide significantly prevented mucosal breaks on the ileum compared with the placebo group (P = 0.0173 at 1 wk and P = 0.0266 at 4 wk).

CONCLUSION: Longer-term, low-dose aspirin administration induced damage in the small bowel. Rebamipide prevented this damage, and may be a candidate drug for treating aspirin-induced small bowel complications.

Incidence of gastrointestinal bleeding in patients with cardiovascular disease: buffered aspirin versus enteric-coated aspirin

OBJECTIVE

Aspirin-induced enteropathy is increasing, but whether the type of aspirin affects the gastrointestinal (GI) bleeding, especially small intestine, is unclear. The incidence of GI bleeding for buffered aspirin and enteric-coated aspirin was evaluated in patients receiving long-term low-dose aspirin (LDA) for cardiovascular (CV) diseases.

METHODS

This retrospective cohort study assessed overt GI bleeding, decreased hemoglobin levels suspecting small bowel blood loss, and CV death in patients taking LDA for more than 1 year (LDA group) and in patients not taking LDA (control group). The LDA group was divided into two subgroups, patients taking either buffered aspirin (buffered subgroup) or enteric-coated aspirin (enteric subgroup), and their outcomes were compared.

RESULTS

A total of 1402 patients (LDA group 701, control group 701; median follow-up duration 1778 ± 747 days) were assessed. The incidences of overt GI bleeding and decreased hemoglobin were 3.9% and 1.4% in LDA group, respectively, significantly higher than the control group (p < 0.01; p < 0.01). In the LDA group, 3% died during the follow-up period. Ten (3.7%) in the buffered subgroup (n = 267) and 17 (3.9%) in the enteric subgroup (n = 434) developed GI bleeding (p = 0.92). One (0.3%) in the buffered subgroup and nine (2%) in the enteric subgroup developed decreased hemoglobin (p = 0.06, log-rank test).

CONCLUSIONS

The type of aspirin does not affect the incidence of overt GI bleeding and decreased hemoglobin, but enteric-coated aspirin may be associated with an increased incidence of decreased hemoglobin.

[Antiplatelet agents and proton pump inhibitors. How can the risk-benefit balance be optimized in patients at risk for cardiovascular disease and gastrointestinal bleeding?]

Antiplatelet agents are routinely used in both primary and secondary prevention of cardiovascular events. The development of new antiplatelet agents and the strong growth of interventional cardiology have led to this therapy being more widely prescribed and for longer periods. The most important secondary effect is the rise in the incidence of hemorrhagic complications, the most prevalent being gastrointestinal bleeding. In this context, the balance between the cardiovascular benefits and bleeding risk of these agents must be optimized. This review provides specific management recommendations and highlights important practical aspects related to antiplatelet therapy, including the interaction between clopidogrel and proton pump inhibitors. The benefits and hazards in distinct clinical settings are outlined within the context of optimizing the balance between the cardiovascular benefits and bleeding risk of antiplatelet therapy.

Heat shock protein 70-dependent protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells

Protection of the small intestine from mucosal injury induced by nonsteroidal anti-inflammatory drugs including acetylsalicylic acid is a critical issue in the field of gastroenterology. Polaprezinc an anti-ulcer drug, consisting of zinc and L-carnosine, provides gastric mucosal protection against various irritants. In this study, we investigated the protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of the RIE1 rat intestinal epithelial cell line. Confluent rat intestinal epithelial cells were incubated with 70 µM polaprezinc for 24 h, and then stimulated with or without 15 mM acetylsalicylic acid for a further 15 h. Subsequent cellular viability was quantified by fluorometric assay based on cell lysis and staining. Acetylsalicylic acid-induced cell death was also qualified by fluorescent microscopy of Hoechst33342 and propidium iodide. Heat shock proteins 70 protein expression after adding polaprezinc or acetylsalicylic acid was assessed by western blotting. To investigate the role of Heat shock protein 70, Heat shock protein 70-specific small interfering RNA was applied. Cell viability was quantified by fluorometric assay based on cell lysis and staining and apoptosis was analyzed by fluorescence-activated cell sorting. We found that acetylsalicylic acid significantly induced apoptosis of rat intestinal epithelial cells in a dose- and time-dependent manner. Polaprezinc significantly suppressed acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells at its late phase. At the same time, polaprezinc increased Heat shock protein 70 expressions of rat intestinal epithelial cells in a time-dependent manner. However, in Heat shock protein 70-silenced rat intestinal epithelial cells, polaprezinc could not suppress acetylsalicylic acid -induced apoptosis at its late phase. We conclude that polaprezinc-increased Heat shock protein 70 expression might be an important mechanism by which polaprezinc suppresses acetylsalicylic acid-induced small intestinal apoptosis, a hallmark of acetylsalicylic acid-induced enteropathy.

Aspirin: old drug, new uses and challenges

Salicylates have been used since antiquity to relieve pain and inflammation. However, it has been only in the last half century that evidence has emerged that aspirin causes reproducible acute and superficial injury to the gastric and duodenal mucosa, and is an important cause of complicated and uncomplicated peptic ulcer. Superficial damage to the mucosa occurs rapidly and reproducibly and acid and pepsin then produce a second wave of deeper injury. Most of the time this heals rapidly, but some focal deeper mucosal lesions (erosions) occur frequently and the point prevalence of frank ulcers in low dose aspirin users is around 10%. It is even more recently that aspirin's unique antiplatelet action has been recognized, with long-lasting inhibition of platelet aggregation due to irreversible inactivation of the cyclooxygenase-1 mediated production of thromboxane. It has now become the mainstay of pharmacological reduction of thrombotic risk in patients with cardiovascular diseases. In addition, evidence is accumulating about the cancer-reducing effects of blocking cyclooxygenase in a number of tissues. For example, recent data indicate that even at a 75-mg/day dose, it may reduce colorectal cancer risk after a lag of a year or so. Because of its widespread use for cardiovascular protection, aspirin is now one of the most frequently prescribed drugs-and gastroenterologists regularly need to deal with its ulcerative complications along the whole length of the gastrointestinal tract. Strategies that can be used to reduce these risks include using the lowest effective aspirin dose and co-prescribing acid suppressants.

Combination of low-dose aspirin and thienopyridine exacerbates small bowel injury

OBJECTIVE

Antithrombotics is increasingly being used for cardiovascular prevention. In more recent studies, small bowel injury and enteropathy associated with low-dose aspirin are increasingly being recognized. Aim of this study was to evaluate small bowel injury using video capsule endoscopy (VCE) in obscure gastrointestinal bleeding (OGIB) patients taking low-dose aspirin including other antithrombotics.

MATERIAL AND METHODS

This is a retrospective review of chronic users of antithrombotics who underwent VCE for suspected small bowel bleeding. Small bowel mucosal injury was evaluated using VCE findings.

RESULTS

Fifty-four OGIB patients (36 men and 18 women, mean age 72.4 years) underwent VCE from January 2007 to May 2009. Twenty-two patients were taking 100 mg of enteric-coated aspirin (aspirin group), 8 taking thienopyridine, (ticlopidine or clopidogrel, thienopyridine group), 13 taking aspirin combined with thienopyridine (combined group), and 11 taking warfarin (warfarin group). The mucosal injury, especially ulcers were most frequently detected in the combined group (46.2%, p = 0.01) among the four groups. The median number of redness lesions in the combined group was the highest among the four groups and was significantly higher than that in the warfarin group. The lesions of redness or small erosions in the aspirin and the combined groups tended to exist in the proximal part of small bowel.

CONCLUSIONS

Combination of low-dose aspirin therapy and thienopyridine may exacerbate small bowel injury, and the preventive strategies should be established.

Evaluation of RAPID(®) 5 Access software for examination of capsule endoscopies and reading of the capsule by an endoscopy nurse

BACKGROUND

Since capsule endoscopy (CE) is time consuming, one possible cost-effective strategy could be the use of an expert endoscopic assistant and available software to select images. Aims were to examine the clinical utility of RAPID(®) 5 Access software and find the optimum setting mode for reading. We also evaluated whether a nurse could preview the CE video and detect significant lesions accurately.

METHODS

The capsule images in 14 volunteers with known mucosal injury induced by low dose aspirin and in 30 patients who were known to have a variety of significant lesions were selected. Using three setting modes of RAPID(®) 5 Access software, the detection rate and reading time for CE images by two well-trained physicians and one expert nurse were compared.

RESULTS

There was no significant difference in detection rate among the three readers. The detection rate using Quickview RAPID(®) 5 Access was significantly higher than that using RAPID(®) Reader version 4.1. Comparison among the three modes of RAPID(®) 5 Access showed that auto mode as well as displaying a single image at 12 fps was superior in the detection rate of denuded redness, while its reading time was longer compared to the other modes. Some significant lesions were not detected by using Quickview and Quadview modes.

CONCLUSIONS

RAPID(®) 5 Access improves diagnostic yield, reducing reading time; however, it is still unacceptable because of the diagnostic miss rate and may be useful as an ancillary reading tool. Developing further improved software and training expert assistants for reading capsule images are necessary.

Evaluation of small bowel blood flow in healthy subjects receiving low-dose aspirin

AIM: To investigate the relationship between low-dose aspirin-induced small bowel mucosal damage and blood flow, and the effect of rebamipide.

METHODS: Ten healthy volunteers were enrolled in this study. The subjects were divided into two groups: a placebo group given low-dose aspirin plus placebo and a rebamipide group given low-dose aspirin plus rebamipide for a period of 14 d. Capsule endoscopy and contrast-enhanced ultrasonography were performed before and after administration of drugs. Areas under the curves and peak value of time-intensity curve were calculated.

RESULTS: Absolute differences in areas under the curves were -1102.5 (95% CI: -1980.3 to -224.7, P = 0.0194) in the placebo group and -152.7 (95% CI: -1604.2 to 641.6, P = 0.8172) in the rebamipide group. Peak values of time intensity curves were -148.0 (95% CI: -269.4 to -26.2, P = 0.0225) in the placebo group and 28.3 (95% CI: -269.0 to 325.6, P = 0.8343) in the rebamipide group. Capsule endoscopy showed mucosal breaks only in the placebo group.

CONCLUSION: Short-term administration of low-dose aspirin is associated with small bowel injuries and blood flow.

NSAID-induced gastrointestinal and cardiovascular injury

PURPOSE OF REVIEW

To review recent publications related to NSAID-induced adverse effects on the gastrointestinal and cardiovascular systems.

RECENT FINDINGS

This paper explores novel mechanisms of NSAID-induced gastrointestinal injury, highlights new composite endpoints evaluating adverse events of NSAIDs in the entire gastrointestinal tract, and combines published data to establish evidence-based guidance on the best use of NSAIDs to achieve optimal clinical outcomes whilst minimizing cardiovascular and gastrointestinal injuries.

SUMMARY

NSAIDs can induce peptic ulcers via epithelial cell membrane disruption and the renin angiotensin system, independent of the cyclooxygenase (COX) pathways, whereas mast cells and bile acid sensors may have a protective effect on NSAID-induced gastrointestinal damage. Patients with arthritis treated with a COX-2 inhibitor are less likely to develop upper and lower gastrointestinal complications than those who are treated with diclofenac plus a proton pump inhibitor (PPI). PPI therapy is recommended in patients receiving dual antiplatelet treatment but observational studies show that clopidogrel users taking PPIs have an increased risk of cardiovascular events. Until further reliable controlled data are available, this potential, but currently unproven, clinical interaction can be minimized by widely separating the dosing of clopidogrel and PPI. Histamine-2 antagonists may be an alternative to PPI for the prevention of peptic ulcers in patients taking low-dose aspirin.

A Review of Anti-Inflammatory Drug-Induced Gastrointestinal Injury: Focus on Prevention of Small Intestinal Injury

Capsule endoscopy and balloon endoscopy, advanced modalities that allow full investigation of the entire small intestine, have revealed that nonsteroidal anti-inflammatory drugs (NSAIDs) can cause a variety of abnormalities in the small intestine. Recently, several reports show that traditional NSAIDs (tNSAIDs) and acetylsalicylic acid (ASA) can induce small intestinal injuries. These reports have shown that the preventive effect of proton pump inhibitors (PPIs) does not extend to the small intestine, suggesting that concomitant therapy may be required to prevent small intestinal side effects associated with tNSAID/ASA use. Recently, several randomized controlled trials used capsule endoscopy to evaluate the preventive effect of mucoprotective drugs against tNSAID/ASA-induced small intestinal injury. These studies show that misoprostol and rebamipide reduce the number and types of tNSAID-induced small intestinal mucosal injuries. However, those studies were limited to a small number of subjects and tested short-term tNSAID/ ASA treatment. Therefore, further extensive studies are clearly required to ascertain the beneficial effect of these drugs.

Roles of COX inhibition in pathogenesis of NSAID-induced small intestinal damage

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin decrease mucosal PGE(2) content by inhibiting cyclooxygenase (COX) activity and produce damage in the small intestine. The development of intestinal lesions induced by indomethacin was accompanied by increases in intestinal motility, enterobacterial invasion, and myeloperoxidase (MPO) as well as inducible nitric oxide synthase (iNOS) activity, together with the up-regulation of COX-2 and iNOS mRNA expression. Neither SC-560, a selective COX-1 inhibitor, nor rofecoxib, a selective COX-2 inhibitor, alone caused intestinal damage, but their combined administration provoked lesions in the small intestine. SC-560, but not rofecoxib, caused intestinal hypermotility, bacterial invasion and the expression of COX-2 as well as iNOS mRNA, yet the iNOS and MPO activity was increased only when rofecoxib was administered together with SC-560. Although SC-560 inhibited PG production, the level of PGE(2) recovered in a rofecoxib-dependent manner. The intestinal hypermotility in response to indomethacin was prevented by both 16,16-dimethyl PGE(2) and atropine but not by ampicillin, yet all these agents inhibited not only the bacterial invasion but also the expression of COX-2 as well as the iNOS activity in the intestinal mucosa following indomethacin treatment, thereby preventing the intestinal damage. These results suggest that inhibition of COX-1, despite causing intestinal hypermotility, bacterial invasion and iNOS expression, up-regulates the expression of COX-2, and the PGE(2) derived from COX-2 counteracts the deleterious events caused by COX-1 inhibition and maintains mucosal integrity. These sequences of events explain why intestinal damage occurs when both COX-1 and COX-2 are inhibited.