The influence of CYP2C19 polymorphisms on exacerbating effect of rabeprazole in celecoxib-induced small bowel injury

The influence of different proton pump inhibitors and potassium-competitive acid blockers on indomethacin-induced small intestinal injury

BACKGROUND AND AIM

The influence of gastric acid inhibitors (GAIs) on nonsteroidal anti-inflammatory drug (NSAID)-induced enteropathy is controversial. Herein, the influences of different GAIs on NSAID-induced intestinal injury and the underlying mechanisms are clarified.

METHODS

Indomethacin (IND; 10 mg/kg/day) was administered to mice to induce small intestinal injury. Disease activity was examined macroscopically and histologically. The permeability of small intestine was evaluated by measuring plasma lipopolysaccharide levels. 16S rDNA sequencing was performed to determine the composition of intestinal flora.

RESULTS

Among the four GAIs, ilaprazole (IPZ) significantly attenuated IND-induced small intestinal injury and maintained the integrity of the mucosal barrier. Omeprazole (OPZ) and vonoprazan (VPZ) ameliorated ulceration without significant differences, while rabeprazole (RPZ) failed to protect against the injury. To explore the potential mechanism, we investigated changes in the gut microbiota mediated by GAIs. After 5-day administration, GAIs significantly altered the composition of the gut microbiota. The IND group had a significant decrease in alpha diversity compared with the control group, and this decrease was reversed by OPZ and IPZ treatment, respectively. After IPZ treatment, the community membership was more assembled in the control group than the IND group. Further, we found that Lactobacillus was significantly increased in the groups of OPZ, IPZ, and VPZ, while Bacteroides was significantly increased in the RPZ group.

CONCLUSION

Our results indicated that GAIs have different influences on the mucosal barrier, possibly by altering the composition of intestinal microbiota, and the impacts mediated by various GAIs in the IND-induced intestinal damage model seem different.

Review article: drug-induced small bowel injury

BACKGROUND

Drug-induced gastrointestinal injury has been increasingly reported, but its exact incidence is not known. The small and large intestines represent the most affected sites of injury, accounting for 20%-40% of all gastrointestinal side effects.

AIM

To provide an updated literature review detailing medications linked to the development of small bowel injury.

METHODS

We conducted a literature search on PubMed from its inception to May 1, 2021. We included English-language original studies, meta-analyses, systematic reviews, review articles and case reports.

RESULTS

Drug-induced enteropathy can range from asymptomatic histological changes resulting in a subtle, self-limited disease to a chronic inflammatory condition mimicking inflammatory bowel disease, or bowel perforation. Endoscopy can demonstrate erythema, mucosal friability, oedema, erosions, ulcers or strictures in severe cases. Histology may include mucosal erosions and ulcerations, focal active enteritis, villous atrophy, epithelial apoptosis or necrotising enteritis. A well-established association has been found with the use of nonsteroidal anti-inflammatory drugs, immunosuppressants, chemotherapeutic agents, antibiotics, immunotherapies, etanercept and olmesartan. Possible associations have been reported with other biologic agents, medications used for glycemic control, antihypertensives, cholinesterase inhibitors, potassium and iron supplements, with conflicting data regarding contraceptives/hormonal therapy and isotretinoin.

CONCLUSION

Physicians should be aware of the manifestations of drug-induced enteropathy as early recognition can lead to prompt discontinuation of the offending therapy and, therefore, a reduced risk of future complications.

Enhanced Analgesic Effects and Gastrointestinal Safety of a Novel, Hydrogen Sulfide-Releasing Anti-Inflammatory Drug (ATB-352): A Role for Endogenous Cannabinoids

Aims: The covalent linking of nonsteroidal anti-inflammatory drugs to a hydrogen sulfide (H₂S)-releasing moiety has been shown to dramatically reduce gastrointestinal (GI) damage and bleeding, as well as increase anti-inflammatory and analgesic potency. We have tested the hypothesis that an H₂S-releasing derivative of ketoprofen (ATB-352) would exhibit enhanced efficacy without significant GI damage in a mouse model of allodynia/hyperalgesia. Results: ATB-352 was significantly more potent and effective as an analgesic than ketoprofen and did not elicit GI damage. Pretreatment with an antagonist of the CB1 cannabinoid receptor (AM251) significantly reduced the analgesic effects of ATB-352. The CB1 antagonist exacerbated GI damage when coadministered with ketoprofen, but GI damage was not induced by the combination of ATB-352 and the CB1 antagonist. In vitro, ATB-352 was substantially more potent than ketoprofen as an inhibitor of fatty acid amide hydrolase, consistent with a contribution of endogenous cannabinoids to the analgesic effects of this drug. Blood anandamide levels were significantly depressed by ketoprofen, but remained unchanged after treatment with ATB-352. Innovation: Ketoprofen is a potent analgesic, but its clinical use, even in the short term, is significantly limited by its propensity to cause significant ulceration and bleeding in the GI tract. Covalently linking an H₂S-releasing moiety to ketoprofen profoundly reduces the GI toxicity of the drug, while boosting analgesic effectiveness. Conclusion: This study demonstrates a marked enhancement of the potency and effectiveness of ATB-352, an H₂S-releasing derivative of ketoprofen, in part, through the involvement of the endogenous cannabinoid system. This may have significant advantages for the control and management of pain, such as in a postoperative setting.

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.

The frequency and clinical and endoscopic features of mixed NSAIDs-induced gastrointestinal injuries

Non-steroidal anti-inflammatory drugs (NSAIDs) can cause undesirable reactions in all parts of the gastrointestinal tract (GIT). However, the frequency of mixed injuries of various GIT parts due to the use of these drugs has not been investigated.Objective: to estimate the frequency of mixed NSAID-induced injuries of the upper GIT, small and large intestine.Patients and methods. A total of 112 patients (62.5% were women) (mean age, 56.2±14.6 years) with rheumatic diseases who had regularly taken NSAIDs were examined. All the patients underwent esophagogastroduodenoscopy and video colonoscopy. Video capsule endoscopy was performed in 35 patients with signs of NSAID-induced gastropathy.Results and discussion. The signs of NSAID-induced gastropathy (gastric and duodenal erosions and/or ulcers) were found in 43.8% of patients; those of NSAID-induced enteropathy (small bowel hemorrhages, erosions, and ulcers) were present in 68.6%; and those of NSAIDinduced colopathy (colonic hemorrhages, erosions, and ulcers) were in 14.3%. The concurrence of NSAID-induced gastro- and colonopathy was present in 28.6% of the patients (odds ratio 12.2; 95% confidence interval, 2.619–56.84); that of NSAID-induced gastro-, entero-, and colopathy was in 10 (20.4% of all the patients with NSAID-induced gastropathy). There was a significant association of the risk of mixed pathology in all GIT parts with the diagnosis of spondylarthritis, the presence of abdominal pain, the signs of dysbiosis and bacterial overgrowth syndrome, as well as with the carriage of CYP2C19 gene polymorphism (the CYP2C19*17*1/*17 allele).Conclusion. Mixed injury of various GIT parts due to the use of NSAIDs is a frequent and serious pathology that requires comprehensive diagnostic tests and combined use of preventive therapies with different mechanisms of action.

Non-variceal upper gastrointestinal bleeding

Non-variceal upper gastrointestinal bleeding (NVUGIB) is bleeding that develops in the oesophagus, stomach or proximal duodenum. Peptic ulcers, caused by Helicobacter pylori infection or use of NSAIDs and low-dose aspirin (LDA), are the most common cause. Although the incidence and mortality associated with NVUGIB have been decreasing owing to considerable advances in the prevention and management of NVUGIB over the past 20 years, it remains a common clinical problem with an annual incidence of ∼67 per 100,000 individuals in the United States in 2012. NVUGIB is a medical emergency, and mortality is in the range ∼1-5%. After resuscitation and initial assessment, early (within 24 hours) diagnostic and therapeutic endoscopy together with intragastric pH control with proton pump inhibitors (PPIs) form the basis of treatment. With a growing ageing population treated with antiplatelet and/or anticoagulant medications, the clinical management of NVUGIB is complex as the risk between gastrointestinal bleeding events and adverse cardiovascular events needs to be balanced. The best clinical approach includes identification of risk factors and prevention of bleeding; available strategies include continuous treatment with PPIs or H. pylori eradication in those at increased risk of developing NVUGIB. Treatment with PPIs and/or use of cyclooxygenase-2-selective NSAIDs should be implemented in those patients at risk of NVUGIB who need NSAIDs and/or LDA.

Gaseous Mediators in Gastrointestinal Mucosal Defense and Injury

Of the numerous gaseous substances that can act as signaling molecules, the best characterized are nitric oxide, carbon monoxide and hydrogen sulfide. Contributions of each of these low molecular weight substances, alone or in combination, to maintenance of gastrointestinal mucosal integrity have been established. There is considerable overlap in the actions of these gases in modulating mucosal defense and responses to injury, and in some instances they act in a cooperative manner. Each also play important roles in regulating inflammatory and repair processes throughout the gastrointestinal tract. In recent years, significant progress has been made in the development of novel anti-inflammatory and cytoprotective drugs that exploit the beneficial activities of one or more of these gaseous mediators.