Irritable bowel syndrome medications side effects survey

NHE3 inhibitor tenapanor maintains intestinal barrier function, decreases visceral hypersensitivity, and attenuates TRPV1 signaling in colonic sensory neurons

The pathogenesis of irritable bowel syndrome (IBS) is multifactorial, characterized in part by increased intestinal permeability, and visceral hypersensitivity. Increased permeability is associated with IBS severity and abdominal pain. Tenapanor is FDA-approved for the treatment of IBS with constipation (IBS-C) and has demonstrated improvements in bowel motility and a reduction in IBS-related pain; however, the mechanism by which tenapanor mediates these functions remains unclear. Here, the effects of tenapanor on colonic pain signaling and intestinal permeability were assessed through behavioral, electrophysiological, and cell culture experiments. Intestinal motility studies in rats and humans demonstrated that tenapanor increased luminal sodium and water retention and gastrointestinal transit versus placebo. A significantly reduced visceral motor reflex (VMR) to colonic distension was observed with tenapanor treatment versus vehicle in two rat models of visceral hypersensitivity (neonatal acetic acid sensitization and partial restraint stress; both P < 0.05), returning VMR responses to that of nonsensitized controls. Whole cell voltage patch-clamp recordings of retrogradely labeled colonic dorsal root ganglia (DRG) neurons from sensitized rats found that tenapanor significantly reduced DRG neuron hyperexcitability to capsaicin versus vehicle (P < 0.05), an effect not mediated by epithelial cell secretions. Tenapanor also attenuated increases in intestinal permeability in human colon monolayer cultures caused by incubation with proinflammatory cytokines (P < 0.001) or fecal supernatants from patients with IBS-C (P < 0.005). These results support a model in which tenapanor reduces IBS-related pain by strengthening the intestinal barrier, thereby decreasing permeability to macromolecules and antigens and reducing DRG-mediated pain signaling.NEW & NOTEWORTHY A series of nonclinical experiments support the theory that tenapanor inhibits IBS-C-related pain by strengthening the intestinal barrier. Tenapanor treatment reduced visceral motor responses to nonsensitized levels in two rat models of hypersensitivity and reduced responses to capsaicin in sensitized colonic nociceptive dorsal root ganglia neurons. Intestinal permeability experiments in human colon monolayer cultures found that tenapanor attenuates increases in permeability induced by either inflammatory cytokines or fecal supernatants from patients with IBS-C.

Effectiveness of Rifaximin on the Outcomes of Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Irritable bowel syndrome (IBS) is a prevalent gastrointestinal disorder that impacts the lives of many individuals worldwide. We conducted a systemic review and meta-analysis of randomized controlled trials (RCTs) to assess both the effectiveness of rifaximin in alleviating IBS symptoms and its potential adverse effects. PubMed, Web of Science, Embase, the Cochrane Library, Scopus, and Google Scholar were searched from inception until August 20, 2023, for studies comparing rifaximin with placebo in the resolution of symptoms among IBS patients. Risk ratios (RRs) and their corresponding 95% confidence intervals (CIs) were derived for all the outcomes of interest. Six RCTs were pooled in this analysis. The results showed improved abdominal distension with rifaximin over the control group. Overall symptom relief at the end of the treatment period and follow-up period was also observed in the patients receiving rifaximin. However, no significant differences were found between the rifaximin group and the control group for the outcomes of abdominal pain, nausea, headache, vomiting, diarrhea, sinusitis, bronchitis, and upper respiratory tract infection. The results of our meta-analysis support the use of rifaximin in the treatment of IBS, owing to its safety and effectiveness. Future RCTs should be conducted to assess this topic of interest more extensively.

Gut microbiota modulates visceral sensitivity through calcitonin gene-related peptide (CGRP) production

Abdominal pain is common in patients with gastrointestinal disorders, but its pathophysiology is unclear, in part due to poor understanding of basic mechanisms underlying visceral sensitivity. Accumulating evidence suggests that gut microbiota is an important determinant of visceral sensitivity. Clinical and basic research studies also show that sex plays a role in pain perception, although the precise pathways are not elucidated. We investigated pain responses in germ-free and conventionally raised mice of both sexes, and assessed visceral sensitivity to colorectal distension, neuronal excitability of dorsal root ganglia (DRG) neurons and the production of substance P and calcitonin gene-related peptide (CGRP) in response to capsaicin or a mixture of G-protein coupled receptor (GPCR) agonists. Germ-free mice displayed greater in vivo responses to colonic distention than conventional mice, with no differences between males and females. Pretreatment with intracolonic capsaicin or GPCR agonists increased responses in conventional, but not in germ-free mice. In DRG neurons, gut microbiota and sex had no effect on neuronal activation by capsaicin or GPCR agonists. While stimulated production of substance P by DRG neurons was similar in germ-free and conventional mice, with no additional effect of sex, the CGRP production was higher in germ-free mice, mainly in females. Absence of gut microbiota increases visceral sensitivity to colorectal distention in both male and female mice. This is, at least in part, due to increased production of CGRP by DRG neurons, which is mainly evident in female mice. However, central mechanisms are also likely involved in this process.

Improving Medication Tolerance: A Pilot Study in Disorders of Gut-brain Interaction Treated With Tricyclic Antidepressants

OBJECTIVES

Tricyclic antidepressants (TCAs) are commonly used to treat disorders of gut-brain interaction (DGBI). However, these medications are often associated with side effects that lead to early treatment discontinuation. Research in other chronic medical conditions suggests that many TCA side effects may be caused by nocebo (negative placebo) effects. The current study tests a brief, verbal intervention aimed at improving tolerance of TCAs in DGBI by providing education about nocebo effects.

MATERIALS AND METHODS

This pilot randomized controlled trial was performed in a tertiary care gastroenterology clinic. Participants with DGBI were randomized "standard information," describing the benefits and risks of TCAs, or "augmented information," which included an additional <30-second education about nocebo effects. Two weeks after their visit, participants were emailed a survey evaluating the number and bothersomeness of side effects, adequate relief, global improvement, and treatment satisfaction.

RESULTS

Thirty-one patients were randomized and 22 responded to the survey. The average age was 40% and 59% were women. Although not statistically significant, the augmented group attributed nominally fewer symptoms to TCAs than the standard group, with a medium effect size (1.5 vs. 4.2, effect size d=0.56, P=0.212) and reported being significantly less bothered by those symptoms (13.4 vs. 38.1, P=0.037). A nominally larger percentage of the augmented group reported adequate relief of symptoms after 2 weeks of treatment compared with the standard group (55% vs. 27%, respectively).

CONCLUSIONS

This pilot study demonstrates that a brief (≈30 s) clinical intervention addressing nocebo effects may improve tolerance of TCAs. These findings provide support for future, fully powered studies to evaluate the impact of framing on clinical outcomes, especially in chronic conditions.

Complementary and Alternative Medicine Use in Pediatric Functional Abdominal Pain Disorders at a Large Academic Center

OBJECTIVE

To describe the use of complementary and alternative medicine (CAM) in pediatric functional abdominal pain disorders at a large Midwestern pediatric gastroenterology center.

STUDY DESIGN

A survey of patients attending a follow-up visit for functional abdominal pain disorders was completed. Data were collected on demographics, quality of life, use of conventional therapies, patient's opinions, and perception of provider's knowledge of CAM.

RESULTS

Of 100 respondents (mean age, 13.3 ± 3.5 years), 47 (60% female) had irritable bowel syndrome, 29 (83% female) had functional dyspepsia, 18 (67% female) had functional abdominal pain, and 6 (83% female) had abdominal migraine (Rome III criteria). Ninety-six percent reported using at least 1 CAM modality. Dietary changes were undertaken by 69%. Multivitamins and probiotics were the most common supplements used by 48% and 33% of respondents, respectively. One-quarter had seen a psychologist. Children with self-reported severe disease were more likely to use exercise (P < .05); those with active symptoms (P < .01) or in a high-income group (P < .05) were more likely to make dietary changes; and those without private insurance (P < .05), or who felt poorly informed regarding CAM (P < .05), were more likely to use vitamins and supplements. Seventy-seven percent of patients described their quality of life as very good or excellent.

CONCLUSIONS

The use of CAM in children with functional abdominal pain disorders is common, with a majority reporting a high quality of life. Our study underscores the importance of asking about CAM use and patient/family knowledge of these treatments.

Does Irritable Bowel Syndrome Exist? Identifiable and Treatable Causes of Associated Symptoms Suggest It May Not

Significant shortcomings in irritable bowel syndrome (IBS) diagnosis and treatment may arise from IBS being an “umbrella” diagnosis that clusters several underlying identifiable and treatable causes for the same symptom presentation into one classification. This view is compatible with the emerging understanding that the pathophysiology of IBS is heterogeneous with varied disease mechanisms responsible for the central pathological features. Collectively, these converging views of the pathophysiology, assessment and management of IBS render the traditional diagnosis and treatment of IBS less relevant; in fact, they suggest that IBS is not a disease entity per se and posit the question “does IBS exist?” The aim of this narrative review is to explore identifiable and treatable causes of digestive symptoms, including lifestyle, environmental and nutritional factors, as well as underlying functional imbalances, that may be misinterpreted as being IBS.

Efficacy, safety, and tolerability of plecanatide in patients with irritable bowel syndrome with constipation: results of two phase 3 randomized clinical trials

OBJECTIVES

Two identical, phase 3, randomized, double-blind, placebo-controlled trials evaluated the efficacy and safety of plecanatide in patients with irritable bowel syndrome with constipation (IBS-C).

METHODS

Adults meeting Rome III criteria for IBS-C were randomized (1:1:1) to placebo or plecanatide (3 or 6 mg) for 12 weeks. The primary efficacy end point was the percentage of overall responders (patients reporting ≥30% reduction from baseline in worst abdominal pain plus an increase of ≥1 complete spontaneous bowel movement (CSBM)/week from baseline in the same week for ≥6 of 12 treatment weeks). Safety was assessed by adverse events (AEs).

RESULTS

Overall, 2189 individuals were randomized across the two studies and 1879 completed the studies. Demographic and baseline characteristics were similar across treatment groups and between studies. The percentage of overall responders in Study 1 was 30.2% and 29.5% for plecanatide 3 and 6 mg, respectively, vs. 17.8% placebo (P < 0.001 for each dose vs. placebo), and in Study 2 was 21.5% (P = 0.009) and 24.0% (P < 0.001) for plecanatide 3 and 6 mg, respectively, compared to 14.2% for placebo. The percentage of sustained efficacy responders (overall responders plus weekly responders for ≥2 of last 4 weeks of the 12-week treatment period) was significantly greater for both doses of plecanatide vs. placebo across both studies. All secondary end points (stool frequency/consistency, straining, abdominal symptoms) showed statistically significant improvements compared with placebo. The most common AE was diarrhea (3 mg, 4.3%; 6 mg, 4.0%; placebo, 1.0%). Discontinuation due to diarrhea was infrequent (3 mg, 1.2%; 6 mg, 1.4%; placebo, 0).

CONCLUSIONS

Plecanatide significantly improved both abdominal pain and constipation symptoms of IBS-C with minimal associated side effects and high levels of tolerability.

Tenapanor Treatment of Patients With Constipation-Predominant Irritable Bowel Syndrome: A Phase 2, Randomized, Placebo-Controlled Efficacy and Safety Trial

OBJECTIVES

Tenapanor is a first-in-class, small-molecule inhibitor of the gastrointestinal sodium/hydrogen exchanger NHE3. This study assessed the efficacy and safety of tenapanor in patients with constipation-predominant irritable bowel syndrome (IBS-C).

METHODS

In this phase 2, double-blind study, patients with IBS-C (Rome III criteria) were randomized (1:1:1:1) to receive tenapanor 5 mg, 20 mg, or 50 mg b.i.d., or placebo b.i.d. for 12 weeks. The primary end point was the complete spontaneous bowel movement (CSBM) responder rate, defined as the proportion of patients reporting an increase from baseline of ≥1 CSBM/week for ≥6/12 treatment weeks. Secondary end points included abdominal symptom responder rates (≥30% score improvement from baseline for ≥6/12 weeks) and a composite responder rate (CSBM and abdominal pain response in the same week for ≥6/12 weeks).

RESULTS

Overall, 356 patients were randomized (mean age: 45.7 years; 86.8% women) and 304 completed the study. The CSBM responder rate was significantly higher in the tenapanor 50 mg b.i.d. group than in the placebo group (60.7 vs. 33.7%; P<0.001), as was the composite responder rate (50.0 vs. 23.6%; P<0.001). Responder rates for abdominal symptoms (pain, discomfort, bloating, cramping, and fullness) were significantly higher in the tenapanor 50 mg b.i.d. group than in the placebo group (all P<0.05). Diarrhea was the most frequent adverse event (tenapanor b.i.d.: 20 mg, 12.4%; 50 mg, 11.2%).

CONCLUSIONS

Tenapanor 50 mg b.i.d. significantly increased stool frequency and reduced abdominal symptoms in patients with IBS-C. Further research into tenapanor as a potential treatment for these patients is justified.

Irritable bowel syndrome and other gastrointestinal disorders: evaluating self-medication in an Asian community setting

BACKGROUND

Gastrointestinal disorders frequently present symptoms which are often self-treated.

OBJECTIVE

To record demographic profile of patients visiting community pharmacies for self-treatment with medications for gastrointestinal disorders, the number of these patients who fulfilled irritable bowel syndrome diagnostic criteria, and to judge the appropriateness of their treatment requests.

SETTING

Singapore community pharmacies.

METHOD

The multicentre study was conducted using ROME III adapted criteria on adults above 18 years who have self-selected medicinal products for treatment of irritable bowel syndrome or gastrointestinal symptoms in the community pharmacy.

RESULTS

Among those seeking self-medication, 36.8 % fulfilled criteria for irritable bowel syndrome, with irritable bowel syndrome-mixed (16.3 %) being the most prevalent subtype. For patients not fulfilling criteria for irritable bowel syndrome diagnosis, rates for other functional gastrointestinal disorders were constipation (20.5 %), dyspepsia (16.3 %), gastroesophageal reflux disease (12.1 %), diarrhoea (8.9 %), bloating (4.2 %), and heartburn (3.2 %). There were more females with gastrointestinal complaints. Overall, 21.6 % of the total participants had recently sought medical attention for their gastrointestinal complaint. 20 % of patients selected inappropriate medication for their gastrointestinal complaints, and the antacids class had the highest incidence of inappropriate medication use. Possible co-existing relationships were seen between gastroesophageal reflux disease with dyspepsia, irritable bowel syndrome with gastroesophageal reflux disease, irritable bowel syndrome with dyspepsia, and diarrhoea with constipation.

CONCLUSION

Patients who fulfilled criteria for irritable bowel syndrome had a high tendency to self-treat their gastrointestinal symptoms. Constipation complaints were also common. Around one in five patients self-medicated gastrointestinal symptoms inappropriately, with antacids being the most common.

Lubiprostone: evaluation of the newest medication for the treatment of adult women with constipation-predominant irritable bowel syndrome

Irritable bowel syndrome (IBS) is a chronic disorder that affects primarily female patients and is thought also to afflict approximately 7%-10% of the population of the Western World. Although bowel habits may change over the course of years, patients with IBS are characterized according to their predominant bowel habit, constipation (IBS-C), diarrhea (IBS-D), or mixed type (IBS-M), and treatments are focused toward the predominant symptom. Current treatments for IBS-C have included fiber, antispasmodics, osmotic and stimulant laxatives, and the now severely limited 5-HT(4) agonist tegaserod. No one agent has been universally successful in the treatment of this bothersome syndrome and the search for new agents continues. Lubiprostone (Amitiza(®)), a novel compound, is a member of a new class of agents called prostones and was approved for the treatment of chronic idiopathic constipation in 2006 at a dose of 24 μg twice daily and then in 2008 for the treatment of IBS-C in women only at a dose of 8 μg twice daily. Its purported mechanism is as a type 2 chloride channel activator, but recent evidence suggests that it may also work at the cystic fibrosis transport receptor. This article will compare the newly proposed mechanism of action of this compound to the purported mechanism and review the structure, pharmacology, safety, efficacy, and tolerability of this new therapeutic option. Clinical trial data leading to the approval of this agent for the treatment of IBS-C and the gender-based understanding of IBS, as well as this agent's place among existing and emerging therapies, will be examined.

How do physician assessments of patient preferences for colorectal cancer screening tests differ from actual preferences? A comparison in Canada and the United States using a stated-choice survey

BACKGROUND

Patient preferences can affect colorectal cancer (CRC) screening test use. We compared utility-based preferences for alternative CRC screening tests from a stated-preference discrete-choice survey of the general population and physicians in Canada and the United States.

METHODS

General population respondents (Canada, n = 501; US, n = 1087) participated in a survey with 12 choice scenarios and 9 CRC screening test attributes. Physicians (n = 100, both Canada and US) reported expected patient preferences. We estimated relative importance of attributes using bivariate probit regression analysis and calculated willingness-to-pay for various CRC screening tests.

RESULTS

In 28 and 31% of scenarios, Canadian and US respondents, respectively, chose no screening over a hypothetical test. Canadian (45%) and US (46%) physicians expected patients to choose no screening more often. For all groups the most important attribute was sensitivity, but physicians' perception of patients' preferences are significantly different from actual preferences. Other key attributes are those related to test performance or the testing process. Fecal DNA, colonoscopy, and virtual colonoscopy were the most preferred tests by all groups, but respondents were willing-to-pay more than physicians predicted.

CONCLUSION

Physicians' perception of patients' preferences are quite different from those of the general population. However, among general population and physicians, Canadian and US preferences were similar.

Treatment of irritable bowel syndrome using complementary and alternative medicine

The therapeutic objectives for irritable bowel syndrome (IBS) patients are to improve their functioning in society. Accordingly, recommended management is to develop a logical strategy including a positive diagnosis, consideration of the patient's agenda and emotional state, critical appraisal of the efficacies of various drugs and a graded therapeutic response. Unfortunately, none of the currently available drugs (e.g. antispasmodics, antidiarrheals, osmotics, cathartics, bulking agents, tranquilizers, sedatives) are globally effective in treating all IBS symptoms, and the advanced receptor-targeted drugs are not always successfully and safely marketed. Consequently, more than half of patients may seek complementary and alternative medicine (CAM) to treat the annoying bowel symptoms. Physicians have considered these CAM measures to have an "enhanced placebo effect". For example, many herbal medicine and plant products are globally used to treat IBS, whereas their efficacies are often inconclusive because of small sample sizes, inadequate data analyses and lack of standardized preparations. Meta-analyses do not establish their true efficacy. Acupuncture has long been employed by patients themselves to treat functional gastrointestinal disorders with satisfactory response, but its effect on IBS does not seem to be promising. Peppermint oil, melatonin and clay-like materials are effective in treating some IBS symptoms, while their true pharmacology remains enigmatic. In conclusion, IBS treatment is usually tailored to the individual's manifestations, ranging from reassurance to psychotherapy. Apart from conventional medications, CAM may be considered individually as a supplement or alternative to treat IBS patients that is at least equal in effect to placebo if patients do not exhibit any intolerable or serious side effects.

Extra digestive manifestations of irritable bowel syndrome: intolerance to drugs?

Patients with IBS frequently complain of medication side effects. The goals of this study were to assess the prevalence of drug intolerance as an extra GI manifestation in patients with IBS and to verify the association between drug intolerance and psychological comorbidity. Female patients followed in a tertiary care center completed questionnaires assessing the presence of drug intolerance as well as somatic and psychological extra GI conditions. IBS patients (Rome II criteria; n = 71) were compared to inflammatory bowel disease patients (IBD; n = 96) or to healthy controls (HC; n = 67). The relationship to psychological comorbidity was verified in two different paradigms: (1) by looking at the statistical correlation between drug intolerance and the psychological extra GI symptoms in our IBS patients, and (2) by comparing in a meta-analysis the side effects to placebo (the nocebo effect is presumably increased due to hypervigilance or amplification in psychological disorders) in IBS patients or in patients with comparable medical conditions included in various drug trials approved by Health Canada. Our results show that prevalence of drug intolerance was significantly more elevated in IBS (41% patients) than in HC (7%) or in IBD (27%); somatic and psychological extra GI symptoms were also markedly increased in IBS. In addition, drug intolerance in our IBS patients was significantly associated with somatic comorbidities such as fatigue or multiple symptoms (P < 0.001), but not with psychological factors such as depression, anxiety, mood instability, or sleep disorder. A meta-analysis revealed that the nocebo effect was not different in patients with IBS than in control patients. In conclusion, drug intolerance is a frequent extra GI manifestation of IBS that is not associated with psychological comorbidity; thus, a somatic origin must be explored.

The trials and tribulations of drug development for functional gastrointestinal disorders

Functional gastrointestinal disorders (FGID) are common conditions seen in primary care and specialty practices but many affected individuals report a lack of satisfaction with available treatments. Despite the unmet need for more effective pharmacotherapy, drug development for these conditions can be challenging on many levels. This review will discuss the rationale and challenges of drug development for FGID. The reasons for engaging in drug development include that these conditions are highly prevalent, associated with a significant economic and healthcare burden, and associated with a lack of satisfaction with current therapies. The challenges include the lack of perception that FGID are legitimate disorders, the multidimensional and complex pathophysiology of FGID, the lack of a biological marker for diagnosis and treatment response, the heterogeneity of the patient population, the lack of consensus regarding the best outcome measures for clinical trials and the perceived increased risk-benefit ratio associated with drugs for FGID. Ongoing efforts are being taken to work towards a better understanding of pathophysiology, illness severity, patient-reported outcome measures, and benefit : risk assessment, and towards increasing education and communication amongst patients, clinicians, investigators, industry and regulatory agencies which will hopefully help optimize drug development strategies for FGID.

Review article: the role of antibiotics vs. conventional pharmacotherapy in treating symptoms of irritable bowel syndrome

BACKGROUND

The concept of augmenting the management of irritable bowel syndrome with antibiotics is evolving, and many questions remain regarding this therapy relative to known and hypothesized irritable bowel syndrome pathophysiology. The clinical evidence of small intestinal bacterial overgrowth as an important aetiology of irritable bowel syndrome continues to accumulate. Clinical symptoms of bacterial overgrowth and irritable bowel syndrome are similar; however, a definitive cause-and-effect relationship remains unproven. It is unclear whether motility dysfunction causes bacterial overgrowth or gas products of enteric bacteria affect intestinal motility in irritable bowel syndrome.

AIM

To discusses the efficacy and tolerability of current symptom-directed pharmacotherapies and of antibiotics in the treatment of irritable bowel syndrome.

METHODS

A computerized search of PubMed was performed with search terms "IBS", "pharmacotherapy" and "antibiotics". Relevant articles were selected, and the reference list of selected articles was reviewed to identify additional references.

RESULTS

Antibiotic treatment benefits a subset of irritable bowel syndrome patients. The non-absorbed antibiotic rifaximin has a favourable safety and tolerability profile compared with systemic antibiotics and demonstrates a therapeutic efficacy comparable with symptom-based irritable bowel syndrome pharmacotherapies.

CONCLUSION

Rifaximin is the only antibiotic with demonstrated sustained benefit beyond therapy cessation in irritable bowel syndrome patients in a placebo-controlled trial. Whether antibiotics can improve quality of life in patients with irritable bowel syndrome warrants further research.

Predictors of premature antidepressant discontinuation in functional gastrointestinal disorders

OBJECTIVES

To identify factors responsible for premature antidepressant discontinuation that would assist in designing management strategies for patients with functional gastrointestinal disorders. Antidepressants are being used increasingly to manage patients with functional gastrointestinal disorders; poor patient adherence to treatment regimens, particularly in the period shortly after antidepressant initiation, is common and interferes with success.

METHODS

Clinical records were reviewed from 172 outpatients who attended a university-based practice and who had been prescribed antidepressants to manage their functional gastrointestinal symptoms. Survival analysis methods were used to determine independent predictors of premature antidepressant discontinuation (within 6 months of initiation). Logistic regression analyses were used to see if the same predictors were responsible for side effects or poor treatment response.

RESULTS

Premature antidepressant discontinuation occurred in 41 (23.8%) subjects. Somatization features (state or trait) and history of depression or an anxiety disorder were the most significant predictors of premature discontinuation (p < or = .01 for each). Advancing age and female sex also were independent predictors (p < .05 for each). Somatization features and psychiatric illness were each linked to poor treatment response, whereas somatization features most consistently were associated with antidepressant side effects.

CONCLUSIONS

Failure to maintain treatment occurs in nearly a quarter of outpatients given antidepressants for functional gastrointestinal disorders. Somatization features and history of depression or anxiety most significantly interfered with treatment by predicting side effects, poor treatment response, and premature antidepressant discontinuation. Management algorithms should include specific strategies targeted at patients with these risk factors for poor treatment adherence.

Cilansetron: A New Selective Serotonin Type 3 (5-HT3)-Receptor Antagonist for the Treatment of Irritable Bowel Syndrome in Males and Females

Irritable Bowel Syndrome (IBS) is a significant problem that affects a large proportion of the US population. The past several years have seen advances in our understanding of the pathophysiology associated with IBS and the development of new therapies. Older therapies have few well-designed clinical studies to support their use. The older studies tended to evaluate the impact of therapy on only one symptom and were ineffective at improving the overall symptomology in this functional disorder. In addition, the older drugs tended to produce side effects that often led to discontinuation of the therapy. Newer therapies, such as the FDA approved serotonergic agents (eg, alosetron and tegaserod), target abnormalities in gut physiology seen in IBS and not just the symptomatic presentation of the disease. In women, these medications have shown to be effective treatments for IBS with diarrhea (IBS-D) and IBS with constipation (IBS-C). Pending FDA approval, cilansetron represents the second 5-HT3 antagonist for the treatment of IBS-D. It has shown promising results in both men and women, which is an improvement over alosetron, since it is only approved for use in females. Similar to alosetron, the most common side effect seen with cilansetron therapy is constipation. Few cases of ischemic colitis, like those seen during alosetron therapy, have been reported in the cilansetron clinical trials and all have resolved without complication. A thorough review of the available data regarding cilansetron will be discussed in this article.

Systematic review: the efficacy of treatments for irritable bowel syndrome--a European perspective

BACKGROUND

Irritable bowel syndrome (IBS) is a common, chronic disorder, characterized by abdominal pain/discomfort, bloating and altered bowel habit.

AIM

To conduct a systematic evidence-based review of pharmacological therapies currently used, or in clinical development, for the treatment of IBS in Europe. The safety and tolerability of these therapies are the subject of an accompanying review.

METHODS

A literature search was completed for randomized controlled studies which included adult patients with IBS and an active or placebo control, assessed IBS symptoms, and were published in English between January 1980 and June 2005. The level of evidence for efficacy was graded according to the quality of the trial design and the study outcome.

RESULTS

There is some evidence for improvement of individual IBS symptoms with antidiarrhoeals (diarrhoea), antispasmodics (abdominal pain/discomfort), bulking agents (constipation), tricyclic antidepressants (abdominal pain/discomfort) and behavioural therapy. In contrast, there is strong evidence for the improvement of global IBS symptoms with two new serotonergic agents: the 5-HT4 selective agonist tegaserod (IBS with constipation) and the 5-HT3 antagonist alosetron (IBS with diarrhoea). Further data are required for the 5-HT3 antagonist, cilansetron, and the mixed 5-HT3 antagonist/5-HT4 agonist renzapride before their utility in IBS can be appraised.

CONCLUSIONS

There is limited evidence for the efficacy, safety and tolerability of therapies currently available in Europe for the treatment of IBS. Overall, there is an absence of pharmacological agents licensed specifically for the treatment of IBS subtypes, and new agents are awaited in Europe that will allow changes in clinical practice to focus on and improve global IBS symptoms.

Systematic review: the safety and tolerability of pharmacological agents for treatment of irritable bowel syndrome--a European perspective

AIM

To use an evidence-based approach to evaluate the safety and tolerability of the treatments available for irritable bowel syndrome (IBS), or in clinical development, in Europe. A separate review appraises the evidence for the efficacy of these therapies.

METHODS

A literature search (for 1980 to 2005) was completed for all relevant clinical trial data and other articles which included safety information on the use of pharmacological IBS therapies. Clinical trials were scored according to the level of safety information, and adverse event incidence reported when possible.

RESULTS

The tolerability of many of the agents used to treat IBS in Europe is poorly understood. However, serotonergic agents, such as tegaserod and alosetron, which are currently unavailable in Europe, have undergone rigorous assessment in IBS and their benefits have been established. Following initial marketing of alosetron for use in patients with IBS with diarrhoea, concerns about severe constipation and ischaemic colitis resulted in restriction of its use to women with severe IBS symptoms. This highlights the importance of post-marketing surveillance and post-marketing studies in refining the therapeutic indication of new IBS therapies, which will help to identify appropriate recipients for the drug and establish the impact of adverse reactions in clinical practice.

CONCLUSIONS

There is a significant lack of data on the safety and tolerability of the therapies currently used routinely to treat IBS in Europe. The newer agents have undergone rigorous assessment, such that their benefits and risks in treating IBS are established. Defining their place among the spectrum of available therapies remains challenging when the benefits and risks of the older treatments are so poorly characterized.

The spectrum of irritable bowel syndrome: A clinical review

BACKGROUND

Irritable bowel syndrome (IBS) is associated with a substantial burden on individual patients, health care systems, and society as a whole.

OBJECTIVES

This review article provides an overview of the disease state and discusses treatment options.

METHODS

The MEDLINE database was searched for original research and review articles published in English (from 1966 to July 2005) using the medical subject heading irritable bowel syndrome and the following subheadings: diagnosis, economics, pathophysiology, and therapy. Preference was given to articles that focused on new insights regarding pathophysiology and to those that addressed global symptom improvement for IBS.

RESULTS

Symptoms of IBS vary with each patient and disease episode. Although improvement in individual IBS symptoms is desirable, the overall goal in managing patients with IBS is to achieve global symptom improvement. Traditional IBS therapies (ie, psychotherapy/behavioral therapy, bulking agents, antidiarrheals, antispasmodics, and tricyclic antidepressants) have lacked demonstrable efficacy in randomized controlled trials. Recent improvements in the understanding of IBS pathophysiology, particularly regarding the role of neurotransmitters and hormones in gastrointestinal motility, secretion, and visceral perception, have resulted in the development of novel treatments for IBS. In clinical trials, IBS-specific treatments (ie, agents that affect serotonergic pathways) have been associated with significant improvements in global symptoms. However, the added cost of treatment with these agents and the potential risks of serious adverse events (eg, severe constipation, severe diarrhea, ischemic colitis) may preclude their widespread use. Initial cost-effectiveness analyses with the novel IBS-specific agents suggest the benefits may outweigh the added costs. From a managed care perspective, the costs incurred by IBS-specific therapies may be offset by subsequent reductions in health care resource utilization by patients with IBS.

CONCLUSIONS

IBS-specific agents offer an opportunity for patients with IBS to achieve global symptom improvement. However, when weighing the costs and potential risks against the potential benefits, clinicians should consider the nature and severity of the patient's symptoms, the degree of functional impairment, and the presence of psychosocial comorbidities.

Hyperammonemia with Valproic Acid: Colonic Ischemia Associated with “Triptan” Use Visual Side Effects with Pegylated Interferon: Alopecia Areata with Infliximab: Adverse Effects Seen with Medications Used for Irritable Bowel Syndrome

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In 2004, ISMP is celebrating the 10th anniversary of its incorporation as a nonprofit organization. The Institute represents more than 20 years of experience in helping health care practitioners keep patients safe, and continues to lead efforts to improve the medication use process.