Analysis of the Therapeutic Effect of Clopidogrel Bisulfate Tablets + Aspirin Enteric-Coated Tablets on Acute Myocardial Infarction

Objective:To investigate and analyze the clinical effect of clopidogrel bisulfate tablets combined with aspirin enteric-coated tablets on acute myocardial infarction(AMI)patients.Methods:The study period was from January 2020 to December 2023,the sample source was 82 AMI patients admitted to our hospital,grouped into an observation group(n=41)and a control group(n=41)by the numerical table method.The patients in the control group were treated with aspirin enteric-coated tablets,and the patients in the observation group were treated with aspirin enteric-coated tablets combined with clopidogrel bisulfate.The clinical efficacy,coagulation indexes,and the incidence of cardiovascular adverse events between the two groups were compared.Results:The clinical efficacy of the observation group was higher than that of the control group(P<0.05);the platelet aggregation rate(PAR)of the observation group was lower than that of the con-trol group after treatment(P<0.05),and there was no significant difference in the prothrombin time(PT)and activated partial thromboplastin time(APTT)between the two groups(P>0.05).The incidence of cardiovascular adverse events in the observation group was lower than that of the control group(P<0.05).Conclusion:The treatment effect of clopidogrel bisulfate tablets combined with aspirin enteric-coated tablets on AMI patients is remarkable.It reduces the PAR and the incidence of cardiovascular adverse events,so this treatment method should be popularized.

Clinical features of gastroduodenal injury associated with long-term low-dose aspirin therapy

Low-dose aspirin(LDA) is clinically used for the prevention of cardiovascular and cerebrovascular events with the advent of an aging society.On the other hand,a very low dose of aspirin(10 mg daily) decreases the gastric mucosal prostaglandin levels and causes significant gastric mucosal damage.The incidence of LDAinduced gastrointestinal mucosal injury and bleeding has increased.It has been noticed that the incidence of LDA-induced gastrointestinal hemorrhage has increased more than that of non-aspirin non-steroidal anti-inflammatory drug(NSAID)-induced lesions.The pathogenesis related to inhibition of cyclooxygenase(COX)-1 includes reduced mucosal flow,reduced mucus and bicarbonate secretion,and impaired platelet aggregation.The pathogenesis related to inhibition of COX-2 involves reduced angiogenesis and increased leukocyte adherence.The pathogenic mechanisms related to direct epithelial damage are acid back diffusion and impaired platelet aggregation.The factors associated with an increased risk of upper gastrointestinal(GI) complications in subjects taking LDA are aspirin dose,history of ulcer or upper GI bleeding,age > 70 years,concomitant use of non-aspirin NSAIDs including COX-2-selective NSAIDs,and Helicobacter pylori(H.pylori) infection.Moreover,no significant differences have been found between ulcer and non-ulcer groups in the frequency and severity of symptoms such as nausea,acid regurgitation,heartburn,and bloating.It has been shown that the ratios of ulcers located in the body,fundus and cardia are significantly higher in bleeding patients than the ratio of gastroduodenal ulcers in patients taking LDA.Proton pump inhibitors reduce the risk of developing gastric and duodenal ulcers.In contrast to NSAIDinduced gastrointestinal ulcers,a well-tolerated histamine H2-receptor antagonist is reportedly effective in prevention of LDA-induced gastrointestinal ulcers.The eradication of H.pylori is equivalent to treatment with omeprazole in preventing recurrent bleeding.Continuous aspirin therapy for patients with gastrointestinal bleeding may increase the risk of recurrent bleeding but potentially reduces the mortality rates,as stopping aspirin therapy is associated with higher mortality rates.It is very important to prevent LDA-induced gastroduodenal ulcer complications including bleeding,and every effort should be exercised to prevent the bleeding complications.

Feasibility of gastric endoscopic submucosal dissection with continuous low-dose aspirin for patients receiving dual antiplatelet therapy

BACKGROUND Endoscopic submucosal dissection(ESD) for gastric neoplasms during continuous low-dose aspirin(LDA) administration is generally acceptable according to recent guidelines. This retrospective study aimed to investigate the effect of continuous LDA on the postoperative bleeding after gastric ESD in patients receiving dual antiplatelet therapy(DAPT).AIM To investigate the feasibility of gastric ESD with continuous LDA in patients with DAPT.METHODS A total of 597 patients with gastric neoplasms treated with ESD between January2010 and June 2017 were enrolled. The patients were categorized according to type of antiplatelet therapy(APT).RESULTS The postoperative bleeding rate was 6.9%(41/597) in all patients. Patients were divided into the following two groups: no APT(n = 443) and APT(n = 154). APT included single-LDA(n = 95) and DAPT(LDA plus clopidogrel, n = 59)subgroups. In the single-LDA and DAPT subgroups, 56 and 39 patients were received continuous LDA, respectively. The bleeding rate with continuous singleLDA(10.7%) was similar to that with discontinuous single-LDA(10.3%)(P >0.99). Although the bleeding rate with continuous LDA in patients receiving DAPT(23.1%) was higher than that with discontinuous LDA in patients receiving DAPT(5.0%), no significant difference was observed(P = 0.141).CONCLUSION The bleeding rate with continuous LDA in patients receiving DAPT was not statistically different from that with discontinuous LDA in patients receiving DAPT. Therefore, continuous LDA administration may be acceptable for ESD in patients receiving DAPT, although patients should be carefully monitored for possible bleeding.

Small-bowel mucosal injuries in low-dose aspirin users with obscure gastrointestinal bleeding

AIM: To investigate the clinical differences between small intestinal injuries in low-dose aspirin (LDA) users and in non-steroidal anti-inflammatory drug (NSAID) users who were examined by capsule endoscopy (CE) for obscure gastrointestinal bleeding (OGIB).

Gender differences of low-dose aspirin-associated gastroduodenal ulcer in Japanese patients

AIM:To clarify the gender differences about the clini-cal features and risk factors of low-dose aspirin (LDA) (81-100 mg daily)-associated peptic ulcer in Japanese patients.METHODS: There were 453 patients under treatment with LDA (298 males, 155 females) who underwent esophagogastroduodenoscopy at the Department of Gastroenterology and Hepatology of Hiratsuka City Hospital between January 2003 and December 2007. They had kept taking the LDA or started treatmentduring the study period and kept taking LDA during the whole period of observation. Of these, 119 patients (87 males, 32 females) were diagnosed as having LDA-associated peptic ulcer. We examined the clinical factors associated with LDA-associated peptic ulcer in both sexes.RESULTS: A history of peptic ulcer was found to be the risk factor for LDA-associated peptic ulcer common to both sexes. In female patients, age greater than 70 years (prevalence ORs 8.441, 95% CI: 1.797-33.649, P = 0.0069) was found to be another significant risk fac-tor, and the time to diagnosis as having LDA-associat-ed peptic ulcer by endoscopy was significantly shorter than that in the male patients (P = 0.0050). CONCLUSION: We demonstrated gender differences about the clinical features and risk factors of LDA-asso-ciated peptic ulcer. Special attention should be paid to aged female patients taking LDA.

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

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

Esophageal mucosal lesion with low-dose aspirin and prasugrel mimics malignancy: A case report

Dual antiplatelet therapy consisting of low-dose aspirin (LDA) and other antiplatelet medications is recommended in patients with coronary heart disease, but it may increase the risk of esophageal lesion and bleeding. We describe a case of esophageal mucosal lesion that was difficult to distinguish from malignancy in a patient with a history of ingesting LDA and prasugrel after implantation of a drug-eluting stent. Multiple auxiliary examinations were performed to make a definite diagnosis. The patient recovered completely after concomitant acid-suppressive therapy. Based on these findings, we strongly argue for the evaluation of the risk of gastrointestinal mucosal injury and hemorrhage if LDA therapy is required, and we stress the paramount importance of using drug combinations in individual patients.

Clinical use of low-dose aspirin for elders and sensitive subjects

The use of low-dose aspirin(LDA)has been a common preventive measure to reduce the risk of cardiovascular events.This is attributed to aspirin’s ability to inhibit platelet activation.On the other hand,the use of LDA in human subjects has been associated with the development of gastrointestinal injuries like ulcer and bleeding,especially for those sensitive subjects such as elder human subjects.This opinion review will summarize the recent clinical reports regarding the use of LDA and the development of gastrointestinal conditions in China.Based on these reports,it seems that the use of LDA is commonly associated with gastrointestinal injuries,and stopping its use leads to recovery in elderly subjects.Therefore,we would like to suggest that gastroduodenal health and conditions should be seriously taken into consideration when LDA is recommended to the elderly,or other alternative means to reduce the risk of cardiovascular events such as nutritional interventions should be suggested.

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 endos-copy after 1 and 4 wk of taking aspirin and omepra-zole,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 adminis-tration induced damage in the small bowel.Rebamipide prevented this damage,and may be a candidate drug for treating aspirin-induced small bowel complications.

Usefulness of anti-ulcer drugs for the prevention and treatment of peptic ulcers induced by low doses of aspirin

AIM： To investigate the usefulness of anti-ulcer drugs for the prevention and treatment of low-dose aspirin-induced peptic ulcer.METHODS： Upper gastrointestinal endoscopy was performed in 68 patients receiving daily low-dose aspirin （81 or 100 rag/day）. The endoscopic findings were classified according to the Lanza score, and the scores were compared between groups categorized according to the concomitant use of anti-ulcer drugs and the types of drugs used. In another study, 31 hemorrhagic peptic ulcer patients who had been receiving low-dose aspirin were enrolled. The patients were randomly classified into the proton pump inhibitor （PPI）-treated group and the H2 receptor antagonist （H2RA）-treated group. The administration of low-dose aspirin was continued concomitantly, and endoscopic examinations were performed 8 wk later.RESULTS： The Lanza scores （mean ± SD） of the gastro-mucosal lesions were 1.0 ± 1.9 and 1.9 ± 2.3 in 8 and 16 patients receiving prevention therapy with a PPI and an H2RA, respectively. Both scores were significantly smaller than the scores in 34 patients who were not receiving prevention therapy （4.7 ± 1.0） and in 10 patients receiving cytoprotective anti-ulcer drugs （4.3± 1.6）. In the prospective study, 18 and 13 patients received a PPI and an H2RA, respectively. Endoscopic examinations revealed that the tissue in the region of the gastro-mucosal lesions had reverted to normal in all patients in the PPI-treated group and in 12 patients （92%） in the H2RA-treated group; no significant differences were observed between the groups.CONCLUSION： H2RA therapy was effective for both the prevention and treatment of low-dose aspirin-induced peptic ulcer, similar to the effects of PPIs, while cytoprotective anti-ulcer drugs were ineffective in preventing ulceration.

Gastroduodenal ulcer bleeding in elderly patients on low dose aspirin therapy

AIM To determine the clinical characteristics of elderly patients of hemorrhagic gastroduodenal ulcer on low-dose aspirin(LDA)therapy.METHODS A total of 1105 patients with hemorrhagic gastroduodenal ulcer treated in our hospital between January 2000 and March 2016 were grouped by age and drugs used,and these groups were compared in several factors.These groups were compared in terms of length of hospital stay,presence/absence of hemoglobin(Hb)decrease,presence/absence of blood transfusion,Forrest Ⅰ,percentage of Helicobacter pylori infection,presence/absence of underlying disease,and percentage of severe cases.RESULTS The percentage of blood transfusion(62.6%vs 47.7%,P<0.001),Hb decrease(53.8% vs 40.8%,P<0.001),and the length of hospital stay(23.5 d vs 16.7 d,P<0.001)were significantly greater in those on drug therapy.The percentage of blood transfusion(65.3%vs 47.8%,P<0.001),Hb decrease(54.2%vs 42.1%,P<0.001),and length of hospital stay(23.3 d vs 17.5 d,P<0.001)were significantly greater in the elderly.In comparison with the LDA monotherapy group,the percentage of severe cases was significantly higher in the LDA combination therapy group when elderly patients were concerned(16.1%vs34.0%,P=0.030).Meanwhile,among those on LDA monotherapy,there was no significant difference between elderly and non-elderly(16.1%vs 16.0%,P=0.985).CONCLUSION A combination of LDA with antithrombotic drugs or nonsteroidal anti-inflammatory drugs(NSAIDs)contributes to aggravation.And advanced age is not an aggravating factor when LDA monotherapy is used.

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.

Comparative study of therapeutic effects of PPI and H2RA on ulcers during continuous aspirin therapy

AIM:To compare the therapeutic effects of proton pump inhibitors(PPI) and histamine 2 receptor antagonists(H2RA) on gastroduodenal ulcers under continuous use of low-dose aspirin.METHODS:Sixty patients who had a gastroduodenal ulcer on screening endoscopy but required continuous use of low-dose aspirin were randomly assigned to receive PPI(lansoprazole 30 mg,n = 30) or H2RA(famotidine 40 mg or if famotidine had been administered before assignment,ranitidine 300 mg,n = 30).The therapeutic effects were evaluated by endoscopy after 8-wk treatment.The presence or absence of Helicobacter pylori(H.pylori) was determined by urea breath test before treatment.Abdominal symptoms were compared with the gastrointestinal symptom rating scale(GSRS) questionnaire before and after treatment.RESULTS:Twenty-six patients in the PPI group and 26 patients in the H2RA group,excluding dropouts,were analyzed.There were no significant differences in median age,sex,underlying disease,smoking status,H.pylori infection,prevalence of ulcers before treatment,and lesion site between the two groups.The therapeutic effects were endoscopically evaluated as healed in 23 patients(88.5%) and not healed in 3 patients in the PPI group and as healed in 22 patients(84.6%) and not healed in 4 patients in the H2RA group.Abdominal symptoms before treatment were uncommon in both groups;the GSRS scores were not significantly reduced after treatment as compared with before treatment.CONCLUSION:The healing rate of gastroduodenal ulcers during continuous use of low-dose aspirin was greater than 80% in both the PPI group and the H2RA group,with no significant difference between the two groups.

Helicobacter pylori infection in bleeding peptic ulcer patients after non-steroidal antiinflammatory drug consumption

AIM： TO establish the prevalence of He/icobacterpy/on （H. pylori） infection in patients with a bleeding peptic ulcer after consumption of non-steroidal antiinflammatory drugs （NSAIDs）.METHODS： A very early upper endoscopy was performed to find the source of upper gastrointestinal bleeding and to take biopsy specimens for analysis of H. pylori infection by the rapid urease （CLO） test, his- tological examination, and bacterial culture. TgG anti- CagA were also sought. The gold standard for identifying H. pylori infection was positive culture of biopsy specimens or contemporary positivity of the CLO test and the presence of H. pylori on tissue sections.RESULTS： Eighty patients, 61 males （76.3%）, mean age 61.2 ~ 15.9 years, were consecutively enrolled. Forty-seven （58.8%） patients occasionally consumed NSAIDs, while 33 （41.3%） were on chronic treatment with low-dose aspirin （LD ASA）. Forty-four （55.0%） patients were considered infected by H. pylori. The infection rate was not different between patients who occasionally or chronically consumed NSAIDs. The culture of biopsy specimens had a sensitivity of 86.4% and a specificity of 100%; corresponding figures for histological analysis were 65.9% and 77.8%, for the CLO test were 68.2% and 75%, for the combined use of histology and the CLO test were 56.8% and 100%, and for IgG anti-CagA were 90% and 98%. The high- est accuracy （92.5%） was obtained with the culture of biopsy specimens.CONCLUSION： Patients with a bleeding peptic ulcer after NSAID/LD ASA consumption frequently have H. pylori infection. Biopsy specimen culture after an early upper gastrointestinal tract endoscopy seems the most efficient test to detect this infection.

A study of the changes in the cause of peptic ulcer bleeding

AIM: To clarify the frequency of and changes in the cause of peptic ulcer bleeding. METHODS: This study retrospectively evaluated the out- and inpatients who underwent endoscopy between 2002 to 2008. The subjects were patients presenting with peptic ulcer bleeding. The details of these patients were obtained from their endoscopic reports and medical records. RESULTS: The rates of Helicobacter pylori (H. pylori ) infection were significantly low (P = 0.039), while the proportion of nonsteroidal antiinflammatory drugs (NSAIDs) users and vascular disease significantly increased over the period studied (P = 0.034 and P = 0.04, respectively). However, there was no significant difference in the proportion of low-dose aspirin users (P = 0.832).CONCLUSION: It's found that the primary cause of peptic ulcer bleeding changed from H. pylori infection to use of NSAIDs over the 7-year period of study. It seems that the number of low-dose aspirin users has increased with the increase in the proportion of vascular disease. It is necessary to take measures to prevent peptic ulcer bleeding among NSAIDs and low dose aspirin users.

Effect of Weikang Capsule(胃康胶囊)on Aspirin-Related Gastric and Small Intestinal Mucosal Injury

Objective To investigate the effects of Weikang Capsule(胃康胶囊,WKC)on aspirin-related gastric and small intestinal mucosal injury by magnetically controlled capsule endoscopy(MCCE).Methods Patients taking enteric-coated aspirin aged 40-75 years were enrolled in Beijing Anzhen Hospital,Capital Medical University from January 2019 to December 2019.The patients continued taking aspirin Tablet(100 mg per day)and underwent MCCE before and after 1-month combined treatment with WKC(0.9 g per time orally,3 times per day).The gastrointestinal symptom score,gastric Lanza score,the duodenal,jejunal and ileal mucosal injury scores were used to evaluate the gastrointestinal injury before and after treatment.Adverse events including nausea,vomiting,abdominal pain,abdominal distension,abdominal discomfort,dizziness,or headache during MCCE and combined treatment were observed and recorded.Results Twenty-two patients(male/female,13/9)taking enteric-coated aspirin aged 59.5±11.3 years with a duration of aspirin use of 28.0(1.0,48.0)months were recruited.Compared with pre-treatment,the gastrointestinal symptom rating scale scores,gastric Lanza scores,and duodenal mucosal injury scores were significantly reduced after 1-month WKC treatment(P<0.05),and jejunal and ileal mucosal injury scores showed no obvious change.No adverse events occurred during the trial.Conclusions WKC can alleviate gastrointestinal symptoms,as well as gastric and duodenal mucosal injuries,in patients taking enteric-coated aspirin;it does not aggravate jejunal or ileal mucosal injury,which may be an effective alternative for these patients(Clinical trial registry No.ChiCTR1900025451).

Chemoprevention of colorectal cancer in general population and high-risk population: a systematic review and network meta-analysis

Background:Many nutritional supplements and pharmacological agents have been reported to show preventive effects on colorectal adenoma and colorectal cancer(CRC).We performed a network meta-analysis to summarize such evidence and assess the efficacy and safety of these agents.Methods:We searched PubMed,Embase,and the Cochrane Library for studies published in English until October 31,2021 that fit our inclusion criteria.We performed a systematic review and network meta-analysis to assess the comparative efficacy and safety of candidate agents(low-dose aspirin[Asp],high-dose Asp,cyclooxygenase-2 inhibitors[coxibs],calcium,vitamin D,folic acid,ursodeoxycholic acid[UDCA],estrogen,and progesterone,alone or in combination)for preventing colorectal adenoma and CRC.Cochrane risk-of-bias assessment tool was employed to evaluate the quality of each included study.Results:Thirty-two randomized controlled trials(278,694 participants)comparing 13 different interventions were included.Coxibs significantly reduced the risk of colorectal adenoma(risk ratio[RR]:0.59,95%confidence interval[CI]:0.44–0.79,six trials involving 5486 participants),advanced adenoma(RR:0.63,95%CI:0.43–0.92,four trials involving 4723 participants),and metachronous adenoma(RR:0.58,95%CI:0.43–0.79,five trials involving 5258 participants)compared with placebo.Coxibs also significantly increased the risk of severe adverse events(RR:1.29,95%CI:1.13–1.47,six trials involving 7109 participants).Other interventions,including Asp,folic acid,UDCA,vitamin D,and calcium,did not reduce the risk of colorectal adenoma in the general and high-risk populations compared with placebo.Conclusions:Considering the balance between benefits and harms,regular use of coxibs for prevention of colorectal adenoma was not supported by the current evidence.Benefit of low-dose Asp for chemoprevention of colorectal adenoma still requires further evidence.