Diseases and drugs that increase risk of acute large bowel ischemia

Contrast-induced ischemic colitis following coronary angiography: A case report

BACKGROUND

Ischemic colitis (IC) is common, rising in incidence and associated with high mortality. Its presentation, disease behavior and severity vary widely, and there is significant heterogeneity in therapeutic strategies and prognosis. The common causes of IC include thromboembolism, hemodynamic insufficiency, iatrogenic factors and drug-induced. However, contrast-induced IC, especially isolated right colon ischemia is rarely reported.

CASE SUMMARY

A 52-year-old man was admitted to the hospital due to intermittent chest distress accompanied by palpitation. Coronary angiography was performed using 60 mL of the iodinated contrast agent iohexol (Omnipaque 300), and revealed moderate stenosis of the left anterior descending artery and right coronary artery. At 3 h post-procedure, he complained of epigastric pain without fever, diarrhea and vomiting. Vital signs remained normal. An iodixanol-enhanced abdominal computed tomography (CT) scan revealed thickening, edema of the ascending and right transverse colonic wall and inflammatory exudate, without thrombus in mesenteric arteries and veins. Following 4 days of treatment with antibiotic and supportive management, the patient had a quick and excellent recovery with disappearance of abdominal pain, normalization of leucocyte count and a significant decrease in C reactive protein. There was no recurrence of abdominal pain during the patient's two-year follow-up.

CONCLUSION

This case emphasizes that contrast-induced IC should be considered in the differential diagnosis of unexplained abdominal pain after a cardiovascular interventional procedure with the administration of contrast media. Timely imaging evaluation by CT and early diagnosis help to improve the prognosis of IC.

The association between irritable bowel syndrome and ischemic colitis: a systematic review and meta-analysis

INTRODUCTION

Studies have suggested an association between ischemic colitis and irritable bowel syndrome (IBS) although the results were inconsistent. This systematic review and meta-analysis were performed to comprehensively examine the association between IBS and ischemic colitis by identifying all available cohort and case-control studies and combining their effect estimates together.

EVIDENCE ACQUISITION

EMBASE, MEDLINE and Google Scholar databases were systematically reviewed up to June 2020. Eligible study had to be either cohort or case-control studies that evaluated whether patients with IBS have a higher risk of ischemic colitis than individuals without IBS. Point estimates and standard errors from each eligible study were combined together using the generic inverse variance method of DerSimonian and Laird.

EVIDENCE SYNTHESIS

The systematic review identified three cohort and eight case-control studies. The pooled analysis found a significantly higher risk of ischemic colitis among patient with IBS with the pooled odds ratio of 2.50 (95% CI, 2.00-3.14; I² 57%). Funnel plot was relatively symmetric and was not suggestive of presence of publication bias.

CONCLUSIONS

A significantly increased risk of ischemic colitis among patients with IBS was observed in this systematic review and meta-analysis.

Bad blood: ischemic conditions of the large bowel

PURPOSE OF REVIEW

Colon ischemia is the most common form of intestinal ischemic injury and is seen frequently in an elderly population. This disease is usually self-limited, and many causes have been identified. The recent literature has focused on estimates of prognosis, triaging appropriate level of care, and identification of optimal treatments. In this review, we will address our current understanding of colon ischemia including epidemiology, pathophysiology, segmental distribution, presentation, diagnosis, and management.

RECENT FINDINGS

Research has recently been focused on factors associated with poor outcome. The medical comorbidities identified include chronic obstructive pulmonary disease (COPD), hepatic cirrhosis, and chronic aspirin use. Serological markers are noninvasive tools that can triage severity. Recent studies have shown procalcitonin, C-reactive protein, D-dimer, and neutrophil counts can help predict those at greatest risk for poor outcome. The timing of colonoscopy relative to symptomatic onset also can help predict severity. Early colonoscopy allows for quicker identification of ischemic stigmata, reducing the chance of misdiagnosis and potentially unnecessary and harmful treatment. The treatment of colon ischemia has classically been conservative with antimicrobials reserved for those with moderate or severe disease. Recent retrospective analysis calls into question the utility of antibiotics in the treatment of colon ischemia, although the data is not convincing enough to advise against antimicrobial treatment in patients with severe and fulminant disease.

SUMMARY

It is an exciting time for research focused on colon ischemia. With an improved knowledge, awareness of associated risk factors and predictors of severity, clinicians now have enhanced clinical tools to diagnose and triage patients earlier in the disease. This should help institute prompt and appropriate therapies ultimately improving outcomes.

Severe acute ischemic colitis: What is the place of endoscopy in the management strategy?

Background and study aims  Ischemic colitis (IC) is potentially lethal. Clinical and biology information and results of computed tomography (CT) scan and/or colonoscopy are used to assess its severity. However, decision-making about therapy remains a challenge. Patients and methods  This was a retrospective, single-center study between 2006 and 2015. Patients with severe IC who underwent endoscopic evaluation were included. The aims were to determine outcomes depending on endoscopic findings and assess the role of endoscopy in the management. Results  A total of 71 patients were included (men = 48 (68%), mean age = 71 ± 13 years). There was hemodynamic instability in 29 patients (41 %) and severity signs on CT scan in 18 (38 %). Twenty-nine patients (41 %) underwent surgery and 24 (34 %) died. The endoscopic grades were: 15 grade 1 (21 %), 32 grade 2 (45 %), and 24 grade 3 (34%). Regarding patients with grade 3 IC, 55 % had hemodynamic instability, 58 % had severity signs on CT scan, 68 % underwent surgery, and 55 % died. The decision to perform surgery was based on hemodynamic status in 62 % of cases, CT scan data in 14 %, endoscopic findings in 10 %, and other in 14 %. Colectomy was more frequent in patients with grade 3 IC ( P  < 0.05). A mismatch between mucosal aspect (necrosis) and serous (normal) was observed in 13 patients (46 %). Risk factors for colectomy in univariate analysis were aortic aneurysm surgery, hemodynamic instability, no colic enhancement on CT scan, and endoscopic grade 3. Risk factors for mortality in multivariate analysis were hemodynamic instability, colectomy, and Charlson score > 5 ( P  < 0.05). Conclusions  This study suggests a low impact of endoscopy on surgical decision making. Hemodynamic instability was the first indication for colectomy. A discrepancy between endoscopic mucosal (necrosis) and surgical serous (normal) aspects was frequently noted.

Chronic obstructive pulmonary disease is associated with worse outcomes in ischemic colitis: a nationwide retrospective study

BACKGROUND

Ischemic colitis (IC) occurs when the blood supply of the large intestine becomes compromised. Several cardiovascular conditions, such as coronary artery disease, congestive heart failure, and atrial fibrillation, are well-established risk factors for the development of IC. The effects of pulmonary conditions, namely chronic obstructive pulmonary disease (COPD), on IC have not been well studied.

AIMS

Our aim was to elucidate if the presence of COPD worsened outcomes in patients with IC.

METHODS

Retrospective analysis of patients hospitalized with IC in 2016 was evaluated using the National Inpatient Sample database. Baseline demographic data, length of hospital stay (LOS), total hospital cost/charge, rates of colectomy, and in-hospital mortality were extracted from the database. Categorical variables were compared using the chi-square test and continuous variables were compared using the t-test.

RESULTS

A total of 25,035 patients with IC were identified while 4482 of these patients also had COPD. We found that IC patients with COPD had a longer LOS (5.8 days vs 4.4 days; P<0.01), higher total hospital charge ($56,682 vs $42,365; P<0.01), higher total hospital cost ($13,603 vs $10,238; P<0.01), higher mortality rate (6.5% vs 3.1%; P<0.01), and higher colectomy rate (5.1% vs 3.7%; P<0.01).

CONCLUSIONS

The presence of COPD portends poor outcomes in patients with IC. This was evidenced by increased risk of death and increased risk of undergoing colectomy. Given these findings, patients with COPD warrant closer observation. We advocate that COPD be considered as part of the risk assessment of patients with acute IC who need surgical intervention.

Drug-Induced Colitis

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

Ischaemic colitis: practical challenges and evidence-based recommendations for management

Ischaemic colitis (IC) is a common condition with rising incidence, and in severe cases a high mortality rate. Its presentation, severity and disease behaviour can vary widely, and there exists significant heterogeneity in treatment strategies and resultant outcomes. In this article we explore practical challenges in the management of IC, and where available make evidence-based recommendations for its management based on a comprehensive review of available literature. An optimal approach to initial management requires early recognition of the diagnosis followed by prompt and appropriate investigation. Ideally, this should involve the input of both gastroenterology and surgery. CT with intravenous contrast is the imaging modality of choice. It can support clinical diagnosis, define the severity and distribution of ischaemia, and has prognostic value. In all but fulminant cases, this should be followed (within 48 hours) by lower gastrointestinal endoscopy to reach the distal-most extent of the disease, providing endoscopic (and histological) confirmation. The mainstay of medical management is conservative/supportive treatment, with bowel rest, fluid resuscitation and antibiotics. Specific laboratory, radiological and endoscopic features are recognised to correlate with more severe disease, higher rates of surgical intervention and ultimately worse outcomes. These factors should be carefully considered when deciding on the need for and timing of surgical intervention.

Quantifying risk factors for ischemic colitis: A nationwide, retrospective cohort study

BACKGROUND

Despite identifying numerous factors associated with colonic ischemia, the relative risk has been variable and not thoroughly evaluated. Hence, we aimed to quantify the risk of diseases and medications associated with ischemic colitis (IC).

METHODS

A population-based retrospective analysis in International Business Machines (IBM) Explorys (1999-2018), a pooled, de-identified database of 57 million patients in the USA, was performed. Odds ratios (OR) were calculated between IC and other diseases/medications. IC patients were also stratified by age to assess trends of IC in different age groups.

RESULTS

A total of 1560 patients had IC in the database. Hyperlipidemia had the highest association with IC (OR 15.3), consistent with prior reports of atherosclerosis being a major risk factor for IC. Hypertension, congestive heart failure, constipation, prior abdominal surgery, and atrial fibrillation all conferred odds greater than 10, which is consistent with prior reports. Novel findings of our study include that beta blockers (OR 9.6) and pro-inflammatory disease states such as vasculitis, rheumatoid arthritis, and malignancy all increase the risk of IC.

CONCLUSION

Early identification of IC is critical for minimizing morbidity and mortality. Epidemiologic information could be integrated with current clinical algorithms to more rapidly identify patients at risk.

Advanced urothelial cancer: a radiology update

The recent genomic characterization of urothelial carcinoma by the Cancer Genome Atlas Project, made possible by the introduction of high throughput, reduced cost, and sequence analysis, has shed new insights on the biology of advanced disease. In addition, studies on imaging of advanced urothelial carcinoma have widened the knowledge on disease presentation and on pattern of metastatic spread and their correlation with the underlying biology of urothelial carcinoma. The wide range of treatments for advanced urothelial cancer, including combined chemotherapy regimens and immune checkpoint inhibitors, each result in treatment class-specific patterns of response and adverse events. Results of studies point to the need for a reliable biomarker, perhaps with imaging, that predicts prognosis and treatment response to systemic treatment, and can be used to select the most effective treatment while minimizing toxicity. This review of advanced urothelial cancer introduces the latest advances in genetic profiling, the current role of imaging, the radiographic appearance of treatment response and their toxicities, and details potential future areas of imaging research.

Colonic Ischemia After Vaginal Delivery

Ischemic colitis is a common form of bowel ischemia typically associated with vasculopathy in advanced age. Although some predisposing factors can increase the risk of developing ischemic colitis, the disease is relatively uncommon in young adults. Furthermore, cases of ischemic colitis associated with pregnancy are exceedingly rare. We present a young woman with severe ischemic colitis after vaginal delivery that ultimately led to sigmoid resection due to persistent stricturing.

Older patients are significantly more likely to have colon ischaemia-associated conditions that are chronic and complex

BACKGROUND

Colon ischaemia is a common disease which has been associated with various medications and comorbidities.

AIM

To test the hypothesis that there are differences in the frequencies of these associations in older compared with younger patients.

METHODS

A retrospective cohort study was performed of patients hospitalized with colon ischaemia at two major medical centres from 2005-2017. Clinical, colonoscopic and pathologic criteria were used to identify patients admitted with colon ischaemia; patients with other types of colitis were excluded. Demographic and medical data were extracted. Two cohorts were created: patients aged 18-64 years and patients > 65 years. These were compared using SAS 14.3.

RESULTS

A total of 788 patients were included, of which 271 (34.4%) were of ages 18-64 years, and 517 (66.6%) were 65 years old or older. In the older cohort, constipation-inducing medications (83.8% vs 64.1%; P = <0.0001), diuretics (38.1% vs 25.1%; P = <0.001) and nonsteroidal anti-inflammatory drugs (58% vs 41.5%; P = <0.0001) were more common than in the younger cohort. Antipsychotic medication use was more common in the younger cohort (10.4% vs 5.4%; P = 0.01). There was a higher percentage of younger patients with a history of hypercoaguable state (1.9% vs 0.2%; P = 0.03) and dialysis dependence (22.9% vs 8.7%; P = <0.01), while a higher percentage of patients in the older cohort had a history of chronic obstructive pulmonary disease (12% vs 6.3%; P = 0.01) or atrial fibrillation (18.9% vs 10.3%; P = <0.01).

CONCLUSIONS

Our study shows that older patients are more likely to have colon ischaemia-associated conditions that are chronic and complex, while younger patients are more likely to have acute colon ischaemia-associated conditions.

Safety and tolerability of linaclotide for the treatment of chronic idiopathic constipation and irritable bowel syndrome with constipation: pooled Phase 3 analysis

BACKGROUND

Linaclotide is approved for treating irritable bowel syndrome with constipation (IBS-C; 290 µg QD) and chronic idiopathic constipation (CIC; 145 µg or 72 µg QD). These analyses aimed to assess linaclotide safety in a large, pooled Phase 3 population.

METHODS

In six randomized controlled trials (RCTs), patients received linaclotide (72 µg, 145 µg, 290 µg) or placebo daily for 12-26 weeks; in two long-term safety (LTS) studies, patients received open-label linaclotide for ≤78 additional weeks. Laboratory values, vital signs, and treatment-emergent adverse events (TEAEs) were assessed.

RESULTS

Overall, 3853 patients received ≥1 dose of linaclotide. The most common TEAE was diarrhea (majority [90.5% in RCTs] mild/moderate). Linaclotide patients experienced 1.1 diarrhea TEAE per patient-year in the RCTs (0.2 in placebo), and 0.3 in the LTS studies. In RCTs, 6.9% linaclotide and 3.0% placebo patients discontinued due to any adverse event (AE); 4.0% linaclotide and 0.3% placebo patients discontinued due to diarrhea. In LTS studies, 9.4% patients discontinued due to any AE, and 3.8% due to diarrhea. Serious AEs (SAEs) were rare and similar across treatment groups; there were no SAEs of diarrhea.

CONCLUSION

These pooled analyses of patients treated for ≤104 weeks confirm linaclotide's overall safety.

Association between ischaemic bowel syndromes and androgen deprivation therapy in patients with prostate cancer: a retrospective cohort study

OBJECTIVE

This study investigated the risk of ischaemic bowel syndrome (IBS) in androgen deprivation therapy (ADT) users to explore the long-term outcomes of patients with prostate cancer (PC) receiving ADT treatment.

METHODS

We performed a population-based retrospective cohort study. All the clinical information of the study participants were acquired from the Longitudinal Health Insurance Database for Catastrophic Illness Patients in Taiwan. We extracted data for all the patients newly diagnosed with prostate malignancy (ICD-9-CM 185 or C61 in ICD-10-CM) from 2000 to 2008. The patients were then divided into two groups: 7160 male ADT cohort receiving ADT and 7160 male non-ADT comparison group frequency matched by age and index year of ADT treatment of the ADT group. Cox proportional hazard regression was used to estimate the adjusted HR and 95% CIs of the IBS risk.

RESULTS

No significant difference was noted in the overall incidence rate for IBS between the ADT and non-ADT cohorts (0.86 and 0.89 per 1000 person-year, respectively, p=0.89). Even after adjusting for potential risk factors, a 1.06-fold risk of IBS (95% CI 0.62 to 1.82, p=0.82) was observed in the ADT cohort relative to the non-ADT cohorts. Moreover, we stratified the ADT cohort by time point of ADT treatment after PC diagnosis. Different IBS incidence rates were observed among the early ADT, late-ADT and non-ADT users at 0.77, 1.23 and 0.89 per 1000 person-years, respectively; nonetheless, the difference was not statistically significant. Moreover, no difference was found between the ADT treatment types and IBS risk, including sole orchiectomy, sole luteinising-hormone-releasing hormone and both.

CONCLUSIONS

Results showed that ADT treatment in patients with PC is not an independent factor for IBS incidence. Large sample sizes for patients with IBS with patients with PC who had received ADT treatment are needed for further study.

Ischemic Colitis as a Complication of Medication Use: An Analysis of the Federal Adverse Event Reporting System

BACKGROUND

More than one decade ago, rising cases of ischemic colitis (IC) prompted the Federal Drug Administration to revoke alosetron's approval as treatment of irritable bowel syndrome (IBS). The aim of this study was to identify medical therapies associated with development of IC.

METHODS

The Federal Adverse Event Reporting System was queried for the time between January 2004 and September 2015. We identified reports listing IC as treatment complication and extracted suspected causative and concomitantly administered drugs, indications for their use and outcomes.

RESULTS

After eliminating duplicates, we found 2811 cases of IC (68.4 % women; 59.4 ± 0.4 years). Patients with IBS accounted for 3.9 % of the cases, mostly attributed to tegaserod or alosetron. Chemotherapeutic and immunosuppressive drugs, sex hormones, and anticoagulants were the most commonly suspected causes. Bisphosphonates, nonsteroidal anti-inflammatory drugs, antipsychotics, triptans, interferon therapy, and laxative use prior to colonoscopy were among the more commonly listed treatments. In 8 %, the adverse event contributed to the patient's death with male sex and older age predicting fatal outcomes.

CONCLUSION

Beyond confirming known risks of IC, the results identified several potential culprits of ischemic colitis. This information may not only explain the development of this serious adverse event, but could also guide treatment decisions, cautioning healthcare providers when considering these agents in persons with known risk factors or other drugs that may increase their risk of IC.

Colon Ischemia: An Update for Clinicians

Colon ischemia (CI) is an underrecognized entity associated with high morbidity and mortality. Establishing the diagnosis and initiating appropriate and timely treatment is critical for improving outcomes. Colon ischemia is a disease spectrum that requires a full understanding for recognition and treatment. This review outlines the full spectrum of CI management from initial presentation to medical and surgical treatment.

Olanzapine-induced ischemic colitis

Ischemic colitis (IC) is an uncommon adverse event associated with antipsychotic agents, more commonly found with phenothiazine drugs and atypical neuroleptics such as clozapine. The risk of developing ischemic colitis increases when anticholinergic drugs are associated. We report the case of a 38-year-old woman with a history of schizoaffective disorder who had been on chronic quetiapine for 3 years, and presented to the ER because of diarrhea for 5 days. Four months previously, olanzapine had been added to her psychiatric drug regimen. Physical examination revealed abdominal distension with abdominal tympanic sounds and tenderness. Emergency laboratory tests were notable for increased acute phase reagents. Tomography revealed a concentric thickening of the colonic wall in the transverse, descending and sigmoid segments, with no signs of intestinal perforation. Colonoscopy demonstrated severe mucosal involvement from the sigmoid to the hepatic flexure, with ulcerations and fibrinoid exudate. Biopsies confirmed the diagnosis of ischemic colitis. The only relevant finding in her history was the newly added drug to her baseline regimen. An adverse effect was suspected because of its anticholinergic action at the intestinal level, and the drug was withdrawn. After 6 months of follow-up clinical, laboratory and endoscopic recovery was achieved. Therefore, antipsychotic medication should be considered as a potential cause of ischemic colitis, particularly atypical antipsychotics such as clozapine and olanzapine; despite being uncommon, this adverse event may result in high morbidity and mortality.

Right-Side Colon Ischemia: Clinical Features, Large Visceral Artery Occlusion, and Long-Term Follow-Up

CONTEXT

Large visceral artery occlusion (LVAO) could underlie right-side colon ischemia (RSCI) but is little known.

OBJECTIVE

To assess patients with RSCI through long-term follow-up, including features and management of LVAO.

MAIN OUTCOME MEASURES

Mesenteric ischemia and mortality.

DESIGN

Retrospective observational study in an integrated health care system.

RESULTS

Of 49 patients (30 women [61.2%]; mean [standard deviation] age, 69.4 [11.9] years), 19 (38.8%) underwent surgery—that is, 5 (83.3%) of 6 who developed RSCI in hospital following surgical procedures and 14 (32.6%) of 43 who had RSCI before hospitalization (p value = 0.03); overall, 5 (10.2%) died. Among 44 survivors with a median (range) follow-up of 5.19 (0.03-14.26) years, 5 (11.4%), including 3 (20.0%) of 15 operated cases, had symptomatic LVAO and underwent angioplasty and stent placement: 2 for abdominal angina that preceded RSCI, 1 for acute mesenteric ischemia 1 week after resection of RSCI, 1 for RSCI 6 weeks after resection of left-side ischemia, and 1 for abdominal angina that began 3 years after spontaneous recovery from RSCI. None had further mesenteric ischemia until death from nonintestinal disease or the end of follow-up (1.6 to 10.2 years later). Kaplan-Meier survival estimates for all 44 survivors at 1, 3, 5, and 10 years were 88.6%, 72.3%, 57.6%, and 25.9%, respectively. Thirty-one patients (70.4%) died during follow-up, 19 (61.3%) of a known cause; the 39 patients not treated for LVAO lacked mesenteric ischemia.

CONCLUSION

Patients with RSCI may have symptomatic LVAO; therefore, we advise they undergo careful query for symptoms of abdominal angina and routine visceral artery imaging.

Abdominal Fat Accumulation, as Measured by Computed Tomography, Increases the Risk of Ischemic Colitis: A Retrospective Case-Control Study

BACKGROUND AND AIM

Visceral fat contributes to insulin resistance and atherosclerosis. We retrospectively investigated whether abdominal fat accumulation, as measured by computed tomography, is a risk of ischemic colitis and related clinical outcomes.

MATERIALS AND METHODS

Outpatient-onset ischemic colitis patients (n = 58) and age- and sex-matched controls (n = 58) underwent colonoscopy and computed tomography. Associations between body mass index, visceral adipose tissue area, subcutaneous adipose tissue area, and ischemic colitis were estimated using odds ratios adjusted for hypertension, diabetes mellitus, and dyslipidemia.

RESULTS

In multivariate analysis, ischemic colitis was significantly associated with subcutaneous adipose tissue area (P for trend 0.030) and marginally associated with visceral adipose tissue area (P for trend 0.094), but was not associated with body mass index (P for trend 0.460). The adjusted odds ratios for the highest quartile of subcutaneous and visceral adipose tissue in ischemic colitis were 3.48 (1.06-11.4) and 2.43 (0.74-8.00), respectively, compared with the lowest quartile. When body mass index was considered simultaneously, ischemic colitis remained associated with subcutaneous adipose tissue (P for trend 0.016) and visceral adipose tissue (P for trend 0.077). No significant differences were noted between any of the obesity indices and the distribution type of colitis, blood transfusion requirement, or length of hospital stay.

CONCLUSION

Abdominal fat accumulation measured by computed tomography, but not body mass index, was associated with outpatient-onset ischemic colitis. Ischemic colitis remained associated with abdominal fat, even when body mass index was simultaneously considered. However, clinical outcomes of ischemic colitis were not associated with abdominal fat accumulation.

Incidence of ischemic colitis in treated, commercially insured hypertensive adults: a cohort study of US health claims data

BACKGROUND

Ischemic colitis (IC) incidence rates (IRs) among treated hypertensive patients are poorly understood, and existing literature on the subject is sparse. Antihypertensive drugs may raise the risk of developing IC. Novel antihypertensive agents—such as the direct renin inhibitor aliskiren—have not been assessed for IC risk.

OBJECTIVES

The aims of this study were to evaluate (1) the IRs of probable IC (pIC) in treated hypertensive adults, with a focus on aliskiren-treated patients; (2) the antihypertensive therapies used; and (3) the IRs of pIC in non-hypertensive adults.

METHODS

This study selected hypertensive and non-hypertensive patients (N = 2,356,226 each) from a US health plan claims database. pIC was defined as diagnosis of IC within 3 months after colonoscopy, recto-sigmoidoscopy, or colectomy. IRs were calculated per 100,000 person-years (PYs) with 95% confidence intervals (CIs) and stratified by antihypertensive regimen.

RESULTS

IRs of pIC in hypertensive and non-hypertensive subjects were 18.6 (95% CI 17.6-19.8) and 4.0 (95% CI 3.4-4.7), respectively. The non-hypertensive cohort consisted of younger patients who may have been less prone to developing IC. The overall (i.e., all antihypertensive regimens combined) monotherapy IR per 100,000 PYs was 17.5 (95% CI 16.2-18.8), the overall dual-combination regimen IR per 100,000 PYs was 19.5 (95% CI 17.37-21.83), and the overall triple-plus combination regimen IR per 100,000 PYs was 27.7 (95% CI 22.72-33.38).

CONCLUSION

Study results indicate that the treated hypertensive patients may have a higher risk of pIC compared with non-hypertensive populations. The quantity of antihypertensive agents prescribed may contribute to IC more than treatment duration.

Recurrence and mortality among patients hospitalized for acute lower gastrointestinal bleeding

BACKGROUND & AIMS

The long-term recurrence of lower gastrointestinal bleeding (LGIB) and associated mortality have not been studied extensively. We investigated rates of recurrence of LGIB, mortality, and associated risk factors.

METHODS

In a retrospective study, we analyzed data from 342 patients hospitalized for overt LGIB at the National Center for Global Health and Medicine in Japan from December 2004 through June 2013. All patients underwent colonoscopy. We assessed Charlson comorbidity index scores and the use of nonsteroidal anti-inflammatory drugs, low-dose aspirin, other antiplatelet drugs, or warfarin. Rebleeding, the total number of rebleeding episodes, and mortality were measured. The Cox proportional hazards model was used to estimate hazard ratios (HRs).

RESULTS

Rebleeding occurred in 84 patients, at a mean follow-up time of 19 months. The cumulative percentages of patients with rebleeding at 1 and 5 years were 19% and 46%, respectively. During the follow-up period, 29 patients (39%) had secondary rebleeding and 18 patients (62%) had subsequent rebleeding. Multivariate analysis showed age 65 years and older (HR, 1.7; P = .04) and the use of nonsteroidal anti-inflammatory drugs (HR, 2.0; P < .01) and nonaspirin antiplatelet drugs (HR, 1.8; P < .05) as independent risk factors for rebleeding. Dual therapy had a higher risk than single therapy (adjusted HR, 1.8; P < .05). During the mean follow-up period of 28 months, 21 patients died (2 from bleeding). Cumulative mortality rates at 1 and 5 years were 4.2% and 13%, respectively. Mortality was associated significantly with age ≥65 years (P < .05), Charlson comorbidity index score, and warfarin use.

CONCLUSIONS

Based on a retrospective analysis of patients with LGIB, 46% of all patients have rebleeding, and the overall mortality rate is 13% within 5 years after hospitalization. Besides age ≥65 years, use of antithrombotic drugs increases the risk of bleeding recurrence and mortality among patients with LGIB.

Adverse cardiovascular events associated with triptans and ergotamines for treatment of migraine: systematic review of observational studies

BACKGROUND

Apart from the underlying cardiovascular (CV) risk associated with migraine, both triptans and ergotamines can induce vasoconstriction and potentially increase the risk of serious ischemic events. Because of the low frequency of such events in eligible patients, randomized controlled trials are not exhaustive to assess the drug-related CV risk. Observational studies are, therefore, an essential source of information to clarify this matter of concern.

AIM

The aim of this study was to systematically review the available published observational studies investigating the risk of serious CV events in triptan or ergotamine users, as compared to unexposed migraineur controls.

METHODS

We systematically searched MEDLINE and EMBASE electronic databases for cohort or case-control studies up to December 1, 2013. Studies retrieved from CDSR, DARE and HTA databases of the Cochrane Library were used for snowballing. Studies investigating the risk of any CV outcome in patients with a migraine diagnosis and exposed to triptans or ergotamines were considered for inclusion. Selection of studies, data extraction, and risk of bias assessment were conducted independently by two reviewers. Pooled odds ratios (ORs) with 95% confidence interval (95% CI) were computed using a random-effects model for studies and outcomes judged eligible for quantitative data synthesis.

RESULTS

From a total of 3370 citations retrieved, after duplicate removal and screening, only four studies met the inclusion criteria (three nested case-control analyses and one retrospective cohort study). These studies investigated the risk of different CV outcomes associated with either the recency or the intensity of exposure to the studied drugs. As for the intensity of use, the pooled OR of serious ischemic events was 2.28 (95% CI 1.18-4.41; I (2 )= 0%) for ergotamine use (two studies), whereas for triptans (three studies) it was 0.86 (95% CI 0.52-1.43; I (2 )= 24.5%). Recent use of ergotamines was not significantly associated with any CV outcome (only one available study). Two studies investigated the risk of stroke related to recent triptan use: the first study reported an OR of 0.90 (0.64-1.26), and the second one suggested an increased risk of 2.51 (1.10-5.71). In this case, because of the high degree of heterogeneity, results were not pooled.

CONCLUSIONS

To date, few comparative observational studies have investigated the CV safety of migraine-specific drugs in clinical practice. Evidence gathered here suggests that intense consumption of ergotamines may be associated with an increased risk of serious ischemic complications. As for triptans, available studies do not suggest strong CV safety issues, although no firm conclusions can be drawn. In particular, evidence on stroke risk is conflicting. However, if an increase of the absolute stroke risk in recently exposed patients does actually exist, it must be small. Overall, residual uncontrolled confounding factors reduce the confidence in the risk estimates collected from the included studies. Further investigations are needed to better define the risk for rare but serious CV events related to triptan and ergotamine use for treatment of migraine.

Natural history of outpatient-onset ischemic colitis compared with other lower gastrointestinal bleeding: a long-term cohort study

PURPOSES

The long-term clinical course of outpatient-onset ischemic colitis remains unknown. Our aims are to elucidate the in- and out-of-hospital clinical outcomes of ischemic colitis and compare them with those of lower gastrointestinal bleeding (LGIB).

METHOD

A cohort of 370 outpatients was hospitalized for ischemic colitis (n = 57) or other LGIB (n = 313). All patients had undergone colonoscopy. During hospitalization, the need for transfusion or interventions, further bleeding, mortality, and length of hospital stay were measured. After discharge, long-term recurrence and mortality were analyzed by the Kaplan-Meier method.

RESULTS

Colonoscopy revealed that 88% of ischemic colitis cases were left sided. Compared with other LGIB, ischemic colitis cases had significantly lower transfusion requirements (p < 0.01), further bleeding (p = 0.02), endoscopic intervention (p < 0.01), and shorter hospital stay (p = 0.03). No significant differences between the groups were noted in the need for surgery, angiographic procedures, or mortality during hospitalization. During a mean follow-up of 22 months, rebleeding was significantly lower (log-rank test; p < 0.01) in ischemic colitis cases (5.3%) than in other LGIB cases (19.4%) after discharge. During the mean follow-up period of 29 months, 1 patient (1.8%) with ischemic colitis and 18 patients (5.8%) with other LGIB died (log-rank test; p = 0.41).

CONCLUSIONS

Outpatient-onset ischemic colitis patients usually had left-sided colitis, recovered with conservative short-term treatment and had lower transfusion requirements and further bleeding compared with other LGIB patients. After discharge, patients with outpatient-onset ischemic colitis had lower recurrence over the long term than other LGIB patients.

Pseudomembranous Colitis: Not Always Caused by Clostridium difficile

Although classically pseudomembranous colitis is caused by Clostridium difficile, it can result from several etiologies. Certain medications, chemical injury, collagenous colitis, inflammatory bowel disease, ischemia, and other infectious pathogens can reportedly cause mucosal injury and subsequent pseudomembrane formation. We present the case of a middle-aged woman with vascular disease who was incorrectly diagnosed with refractory C. difficile infection due to the presence of pseudomembranes. Further imaging, endoscopy, and careful histopathology review revealed chronic ischemia as the cause of her pseudomembranous colitis and diarrhea. This case highlights the need for gastroenterologists to consider non-C. difficile etiologies when diagnosing pseudomembranous colitis.

Lubiprostone: pharmacokinetic, pharmacodynamic, safety and regulatory aspects in the treatment of constipation-predominant irritable bowel syndrome

INTRODUCTION

Lubiprostone acts locally (apical membrane of human intestinal epithelial cells) as a highly selective type-2 chloride channel activator. It was approved in the USA for chronic idiopathic constipation (January 2006) and in women aged ≥ 18 years suffering from irritable bowel syndrome with constipation (IBS-C) (April 2008). So far, the only other pro-secretory medication approved in IBS-C and currently available in USA and Europe (since August and November 2012, respectively) is linaclotide.

AREAS COVERED

This review outlines the regulatory history, pharmacokinetic, pharmacodynamic and safety data in the treatment of IBS-C with a European perspective. It is based on publicly available data, namely, published literature, drug labels and the FDA's spontaneous reporting system.

EXPERT OPINION

Although interesting pharmacodynamic data suggest that lubiprostone may have additional mechanisms of action, its beneficial effects in IBS-C must be confirmed in the actual clinical scenario taking into account the new version of European Medicines Agency's guideline. This is especially important with regard to duration of studies (recommended to be at least 6 months) to adequately assess long-term sustained efficacy, withdrawal, rebound and safety. Further research is warranted in uncertain areas (i.e., males, pediatric and elderly patients). On the basis of current data, it is still too early to draw definite conclusions on the overall risk-benefit balance for IBS-C.

A review of ischemic colitis: is our clinical recognition and management adequate?

Ischemic colitis is a common cause of hospital admissions; however it is frequently confused intellectually with mesenteric ischemia and often misdiagnosed as infectious diarrhea or Clostridium difficile colitis. Ischemic colitis is caused by non-occlusive insult to the small vessels supplying the colon without a clear precipitating factor. It is more common in females and in patients above 60 years of age. The classic presentation includes sudden onset of lower abdominal pain followed by the urge to defecate and bloody diarrhea. Focal right-sided ischemic colitis has more pain and a worse prognosis. Choosing the correct diagnostic studies is challenging and requires proficient knowledge of the disease. Management is usually conservative, however around 10-20% of the patients will require surgery. Acute ischemic colitis usually resolves; nevertheless some patients may develop chronic segmental colitis or a stricture. One ischemic colitis caveat is that it may be the first sign of undiagnosed cardiac disease. A firm grasp on this common yet little discussed condition is valuable to a gastrointestinal consultant and hospitalist alike.

Ischaemic colitis associated with oral contraceptive and bisacodyl use

A woman with a history of hip replacement presented 3 days prior to revision of the hip with abdominal pain, diarrhoea and haematochezia. These symptoms began 6 h after she began taking bisacodyl in preparation for her upcoming surgery. She was on low-dose estradiol for hormone replacement therapy (HRT). Subsequent colonoscopy and biopsies were consistent with acute colonic ischaemia (CI). She was treated with intravenous fluids and antibiotics and discharged and told to stop HRT and bisacodyl. Follow-up colonoscopy 1 month after discharge was normal. This case adds to the three other previously reported cases of bisacodyl-associated CI.

Targeted therapies for diarrhea-predominant irritable bowel syndrome

Irritable bowel syndrome (IBS) causes gastrointestinal symptoms such as abdominal pain, bloating, and bowel pattern abnormalities, which compromise patients’ daily functioning. Common therapies address one or two IBS symptoms, while others offer wider symptom control, presumably by targeting pathophysiologic mechanisms of IBS. The aim of this targeted literature review was to capture clinical trial reports of agents receiving the highest recommendation (Grade 1) for treatment of IBS from the 2009 American College of Gastroenterology IBS Task Force, with an emphasis on diarrhea-predominant IBS. Literature searches in PubMed captured articles detailing randomized placebo-controlled trials in IBS/diarrhea-predominant IBS for agents receiving Grade I (strong) 2009 American College of Gastroenterology IBS Task Force recommendations: tricyclic antidepressants, nonabsorbable antibiotics, and the 5-HT₃ receptor antagonist alosetron. Studies specific for constipation-predominant IBS were excluded. Tricyclic antidepressants appear to improve global IBS symptoms but have variable effects on abdominal pain and uncertain tolerability; effects on stool consistency, frequency, and urgency were not adequately assessed. Nonabsorbable antibiotics show positive effects on global symptoms, abdominal pain, bloating, and stool consistency but may be most efficacious in patients with altered intestinal microbiota. Alosetron improves global symptoms and abdominal pain and normalizes bowel irregularities, including stool frequency, consistency, and fecal urgency. Both the nonabsorbable antibiotic rifaximin and the 5-HT₃ receptor antagonist alosetron improve quality of life. Targeted therapies provide more complete relief of IBS symptoms than conventional agents. Familiarization with the quantity and quality of evidence of effectiveness can facilitate more individualized treatment plans for patients with this heterogeneous disorder.

Targeted therapies for diarrhea-predominant irritable bowel syndrome

Irritable bowel syndrome (IBS) causes gastrointestinal symptoms such as abdominal pain, bloating, and bowel pattern abnormalities, which compromise patients' daily functioning. Common therapies address one or two IBS symptoms, while others offer wider symptom control, presumably by targeting pathophysiologic mechanisms of IBS. The aim of this targeted literature review was to capture clinical trial reports of agents receiving the highest recommendation (Grade 1) for treatment of IBS from the 2009 American College of Gastroenterology IBS Task Force, with an emphasis on diarrhea-predominant IBS. Literature searches in PubMed captured articles detailing randomized placebo-controlled trials in IBS/diarrhea-predominant IBS for agents receiving Grade I (strong) 2009 American College of Gastroenterology IBS Task Force recommendations: tricyclic antidepressants, nonabsorbable antibiotics, and the 5-HT(3) receptor antagonist alosetron. Studies specific for constipation-predominant IBS were excluded. Tricyclic antidepressants appear to improve global IBS symptoms but have variable effects on abdominal pain and uncertain tolerability; effects on stool consistency, frequency, and urgency were not adequately assessed. Nonabsorbable antibiotics show positive effects on global symptoms, abdominal pain, bloating, and stool consistency but may be most efficacious in patients with altered intestinal microbiota. Alosetron improves global symptoms and abdominal pain and normalizes bowel irregularities, including stool frequency, consistency, and fecal urgency. Both the nonabsorbable antibiotic rifaximin and the 5-HT(3) receptor antagonist alosetron improve quality of life. Targeted therapies provide more complete relief of IBS symptoms than conventional agents. Familiarization with the quantity and quality of evidence of effectiveness can facilitate more individualized treatment plans for patients with this heterogeneous disorder.

The risk of ischaemic colitis in irritable bowel syndrome patients treated with serotonergic therapies

Ischaemic colitis (IC) is the most common form of ischaemic injury to the gastrointestinal (GI) tract. IC typically presents with the sudden onset of lower abdominal pain, cramping and rectal bleeding, and is usually self-limited with low morbidity, although it may cause gangrenous or fulminant colitis, especially when the right colon is involved. Multiple medical conditions, as well as several pharmacological agents, are associated with IC, including irritable bowel syndrome (IBS) and drugs used for its treatment that act on gut serotonin 5-HT receptors. These include the selective 5-HT(3) receptor antagonist alosetron, currently approved for the treatment of severe diarrhoea-predominant IBS in women who fail to respond to conventional treatment, and cilansetron, another 5-HT(3) receptor antagonist that is no longer in clinical development. In addition, the 5-HT(4) receptor partial agonist tegaserod, which was approved for the treatment of constipation-predominant IBS in women, was associated with IC in the postmarketing setting, as was renzapride, a 5-HT(4) agonist/5-HT(3) antagonist. Although several hypotheses have been proposed, the pathophysiological basis for development of IC with 5-HT(3) receptor antagonists or 5-HT(4) receptor agonists remains unknown. Of interest, several population-based studies demonstrated that a diagnosis of IBS (independent of serotonergic therapies) increases the risk of developing IC 2- to 4-fold. As a result, IBS patients with the acute onset of abdominal pain, tenderness, diarrhoea or lower intestinal bleeding, especially those with predisposing conditions or medications, should be evaluated promptly for IC. The management of IC remains supportive; most cases of non-gangrenous IC, as seen in the alosetron and tegaserod databases, have been transient and have resolved spontaneously without complications or death. Despite the small number of deaths associated with alosetron in patients with complications of constipation and because of the ongoing requirement to prescribe alosetron under a risk management plan, misconceptions persist regarding the definition, incidence, severity and outcome of IC in clinical trials and the postmarketing setting. In this article, the frequency and clinical characteristics of IC associated with the use of alosetron and other serotonergic agents are examined, evidence of an association between IC and IBS is reviewed, and a scoring system to aid in the diagnosis of IC in any clinical situation is proposed.

Ischemic colitis of the left colon in a diabetic patient

Diabetes mellitus may affect the gastrointestinal tract possibly as a result of autonomic neuropathy. Here we present a 68-year-old male with non-insulin-dependent diabetes mellitus who presented with prolonged watery diarrhea and in whom imaging studies demonstrated ischemic colitis of the left colon. Resection of the affected colon resulted in sustained disappearance of symptoms.