Effect of alosetron on bowel urgency and global symptoms in women with severe, diarrhea-predominant irritable bowel syndrome: analysis of two controlled trials

2025 Seoul Consensus on Clinical Practice Guidelines for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a chronic, disabling, and functional bowel disorder that significantly affects social functioning and reduces quality of life and increases social costs. The Korean Society of Neurogastroenterology and Motility published clinical practice guidelines on the management of IBS based on a systematic review of the literature in 2017, and planned to revise these guidelines in light of new evidence on the pathophysiology, diagnosis, and management of IBS. The current revised version of the guidelines is consistent with the previous version and targets adults diagnosed with or suspected of having IBS. These guidelines were developed using a combination of de novo and adaptation methods, with analyses of existing guidelines and discussions within the committee, leading to the identification of key clinical questions. Finally, the guidelines consisted of 22 recommendations, including 3 concerning the definition and risk factors of IBS, 4 regarding diagnostic modalities and strategies, 2 regarding general management, and 13 regarding medical treatment. For each statement, the advantages, disadvantages, and precautions were thoroughly detailed. The modified Delphi method was used to achieve expert consensus to adopt the core recommendations of the guidelines. These guidelines serve as a reference for clinicians (including primary care physicians, general healthcare providers, medical students, residents, and other healthcare professionals) and patients, helping them to make informed decisions regarding IBS management.

Personalisation of therapy in irritable bowel syndrome: a hypothesis

Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction characterised by symptoms of abdominal pain, occurring at least 1 day per week, and a change in stool frequency or form. Individuals with IBS are usually subtyped according to their predominant bowel habit, which is used to direct symptom-based treatment. However, this approach is probably an oversimplification of a complex and multidimensional condition, and other factors, such as psychological health, are known to influence symptom severity and prognosis. We have previously used latent class analysis, a method of mathematical modelling, to show that people with IBS can be classified into seven unique clusters based on a combination of gastrointestinal symptoms, abdominal pain, extraintestinal symptoms, and psychological comorbidity. The clusters can be used to predict the prognosis of IBS (eg, symptom severity), health-care use (eg, consultation behaviour, prescribing, and costs), and impact (eg, quality of life, work and productivity, activities of daily living, and income). These clusters could also be used to increase the personalisation of IBS treatment that better recognises the heterogenous nature of the condition. We present new data providing additional validation of our seven-cluster model and conduct a comprehensive evidence-based review of IBS management. Based on this evidence, we propose a framework of first-line and second-line treatments according to IBS cluster. Finally, we discuss what further research is needed to implement this approach in clinical practice, including the need for randomised trials comparing cluster-based treatment with conventional treatment according to stool subtype.

Evidence-Based Clinical Guidelines for Chronic Diarrhea 2023

The Japan Gastroenterological Association (JGA) published the first version of clinical guidelines for chronic diarrhea 2023. These guidelines describe the definition, classification, diagnostic criteria, diagnostic testing methods, epidemiology, pathophysiology, and treatment of chronic diarrhea, and provide flowcharts for the diagnosis and treatment of chronic diarrhea based on the latest evidence. Treatment for chronic diarrhea begins by distinguishing secondary chronic constipation with a clear etiology, such as drug-induced diarrhea, food-induced diarrhea, systemic disease-associated diarrhea, infection-associated diarrhea, organic disease-associated diarrhea, and bile acid diarrhea. The first line of treatment for chronic diarrhea in the narrow sense, defined in these guidelines as functional diarrhea in routine medical care, is lifestyle modification and dietary therapy. The first medicines to be considered for oral treatment are probiotics for regulating the gut microbiome and anti-diarrheals. Other medications, such as 5HT3 receptor antagonists, anticholinergics, Kampo medicine, psychotherapy, antibiotics, bulking agents, adrenergic agonists, and somatostatin analogs, lack sufficient evidence for their use, highlighting a challenge for future research. This Clinical Guidelines for Chronic Diarrhea 2023, which provides the best clinical strategies for treating chronic diarrhea in Japan, will also be useful for medical treatment worldwide.

Defecation symptoms in primary health care patients with irritable bowel syndrome

BACKGROUND

The objectives of the present study were to (a) measure the prevalence of defecation symptoms in IBS, (b) investigate the relationship between stool consistency and defecation symptoms in IBS, and (c) investigate the association of defecation symptoms with health-related quality of life (HRQL) and self-reported stress in patients with IBS cared for in a primary health care setting.

METHODS

Ten primary health care centres joined the study. 282 patients with IBS as well as 372 non-IBS controls filled in gastrointestinal symptom diaries prospectively for two weeks as well as the Perceived Stress Scale-14 (PSS14) and the EuroQol barometer to measure perceived stress and HRQL, respectively.

RESULTS

Incomplete evacuation was present in 51% vs. 21% of the stools among the IBS patients and the non-IBS controls, respectively. The need to strain during defecation was existing in 41% vs. 33% of the stools for the IBS patients and the non-IBS controls, respectively. Urgency was experienced in 37% of the stools in the IBS patients compared with 18% of the stools in the non-IBS controls. Patients with IBS experienced in a significant higher degree of overlapping symptoms per stool (p < 0.001 to p = 0.007). The occurrence of all defecation symptoms in the same patient was related to decreased HRQL, and increased stress (p = 0.001 to p < 0.001).

CONCLUSIONS

An overlap between IBS and symptoms from the anorectal region related to defecation was found in a primary health care population. Defecation symptoms are very common in primary care IBS-patients, it co-occurs with increased self-perceived stress, and decreased HRQL.

Rifaximin Treatment for Individual and Multiple Symptoms of Irritable Bowel Syndrome With Diarrhea: An Analysis Using New End Points

PURPOSE

Rifaximin is indicated for the treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults. The current aim was to evaluate rifaximin efficacy on individual and composite IBS-D symptoms using definitions not previously examined.

METHODS

Phase III post hoc analyses of two randomized, double-blind, placebo-controlled trials and the open-label phase of a randomized, double-blind, placebo-controlled trial were conducted. Adults with IBS-D received a 2-week course of rifaximin 550 mg TID. Individual and composite responses for abdominal pain (mean weekly improvements from baseline of ≥30%, ≥40%, or ≥50%), bloating (mean weekly improvements from baseline of ≥1 or ≥2 points; or ≥30%, ≥40%, or ≥50%), stool consistency (mean weekly average stool consistency score <3 or <4), and urgency (improvement from baseline of ≥30% or ≥40% in percentage of days with urgency) for ≥2 of the first 4 weeks after treatment, and weekly for 12 weeks, were assessed.

FINDINGS

Overall, 1258 patients from the double-blind trials (rifaximin [n = 624]; placebo [n = 634]) and 2438 from an open-label trial were analyzed. The percentage of bloating or urgency responders was significantly greater with double-blind rifaximin versus placebo (P ≤ 0.03). A significantly greater percentage of the double-blind group were composite abdominal pain and bloating responders versus placebo for all thresholds analyzed (P < 0.05). A significantly greater percentage of the double-blind group were tri-symptom composite end point responders (abdominal pain, bloating, and fecal urgency) versus placebo (P = 0.001). A significantly greater percentage of patients achieved response (≥30% composite tri-symptom threshold) with double-blind rifaximin versus placebo as early as 1 week posttreatment, with significance maintained through ≥5 weeks after treatment. Open-label results were consistent with those of the double-blind study.

IMPLICATIONS

Rifaximin significantly improved multiple, concurrent IBS-D symptoms, using clinically relevant definitions of treatment response. Using a novel tri-symptom composite end point (ie, abdominal pain, bloating, fecal urgency), adults with IBS-D treated with a 2-week course of rifaximin were significantly more likely to be composite end point responders than those receiving placebo (≥30% or ≥40% threshold) for the three symptoms. Thus, rifaximin not only met current standard thresholds used for adjudication of responders in clinical trials but also achieved higher thresholds for many of these symptoms, suggesting potential for even more robust clinical improvements.

CLINICALTRIALS

gov identifiers: NCT00731679, NCT00724126, and NCT01543178. (Clin Ther. 2023;45:XXX-XXX) © 2023 Elsevier HS Journals, Inc.

Comparative effectiveness of 5-hydroxytryptamine 3 receptor antagonists in irritable bowel syndrome: a network meta-analysis of randomized controlled studies

BACKGROUND

There is evidence demonstrating the beneficial effects of 5-hydroxytryptamine 3 receptor antagonists (5-HT3) for the treatment of non-constipated irritable bowel syndrome (NC-IBS). We aimed to determine the comparative effectiveness of 5-HT3 antagonists in NC-IBS, as evidenced by the results of a network meta-analysis (NWM) of published relevant randomized controlled trials (RCTs).

METHODS

We searched the PubMed/Medline, EMBASE, and Cochrane Library databases for relevant RCTs through September 2020 and data from each selected RCT were extracted. A Bayesian NWM was then performed to investigate the efficacy of 5-HT3 antagonists and to explore the effectiveness rank order in treating NC-IBS patients.

RESULTS

Twenty-one eligible RCTs were identified and entered into this NWM. They included a total of 10,421 NC-IBS patients, randomized to alosetron, cilansetron, ondansetron, ramosetron, placebo, and mebeverine. The cumulative ranking probability for each intervention at the end of treatment period, was evaluated by means of surfaces under cumulative ranking (SUCRA) values. These results showed that alosetron had the best performance for global symptom improvement (SUCRA 0.82), cilansetron showed the best performance (SUCRA 0.90) for abdominal pain/discomfort improvement, while ondansetron (SUCRA 0.98) was by far the best choice concerning bowel habits/consistency improvement. The control regimens (mebeverine and placebo) represented the least efficacious interventions.

CONCLUSIONS

This NWM showed that 5-HT3 receptor antagonists performed better in comparison to control drugs. Consequently, this class of drugs may play an important role in improving the debilitating symptoms in NC-IBS patients, in particular those with diarrhea.

Bimodal Release Ondansetron Improves Stool Consistency and Symptomatology in Diarrhea-Predominant Irritable Bowel Syndrome: A Randomized, Double-Blind, Trial

INTRODUCTION

Previous, small studies have suggested that ondansetron has beneficial effects in diarrhea-predominant irritable bowel syndrome (IBS-D). This randomized, double-blind study evaluated the efficacy and safety of daily 12 mg RHB-102, an investigational bimodal release ondansetron tablet, in IBS-D.

METHODS

Men and women with IBS-D by the Rome III criteria, Bristol Stool Scale ≥6 on 2 or more days weekly, and average daily worst pain intensity ≥3/10 were randomized 60:40 to RHB-102 or placebo once daily for 8 weeks. The primary end point was overall stool consistency response for at least 4 of 8 weeks. Secondary end points included overall worst abdominal pain and overall composite response, defined as response on both abdominal pain and stool consistency end points.

RESULTS

Overall stool consistency response rates were 56.0% and 35.3% (RHB-102 vs placebo, P = 0.036) and similar among male and female patients. Overall pain response (50.7% vs 39.2%) and composite response rates (40.0% vs 25.5%) favored RHB-102, although these differences were not statistically significant. Stool consistency response rates were enhanced in patients with baseline C-reactive protein above the median (2.09 mg/L), 59.5%, vs 23.1% (P = 0.009). Overall rates of adverse events were similar, with a higher rate of constipation in RHB-102 patients (13.3% vs 3.9%) that resolved rapidly on withholding treatment.

DISCUSSION

RHB-102 was effective and safe in the treatment of men and women with IBS-D. Baseline C-reactive protein seemed to be predictive of response.

Abnormalities of mucosal serotonin metabolism and 5-HT3 receptor subunit 3C polymorphism in irritable bowel syndrome with diarrhoea predict responsiveness to ondansetron

BACKGROUND

Irritable bowel syndrome with diarrhoea (IBS-D) is a common condition, greatly reducing the quality of life with few effective treatment options available.

AIM

To report the beneficial response shown in our trial with the 5-hydroyxtryptamine (5-HT) receptor 3 antagonist, ondansetron in IBS-D METHODS: A randomised, placebo-controlled, cross-over trial of 5 weeks of ondansetron versus placebo in 125 patients meeting modified Rome III criteria for IBS-D as previously described. Patients were compared to 21 healthy controls. 5-HT and 5-HIAA were measured in rectal biopsies. Whole gut transit time was assessed using a radio-opaque marker technique. Whole blood DNA was genotyped for an insertion polymorphism in the promoter region of the serotonin transporter gene SLC6A4, as well as single nucleotide polymorphisms (SNPs) of the tryptophan hydroxylase gene TPH1 and 5-HT₃ receptor genes HTR3A, C and E.

RESULTS

Patients' biopsies showed significantly higher 5-HIAA levels (2.1 (1.2-4.2) pmol/mg protein vs 1.1 (0.4-1.5) in controls, P < .0001). 39 patients used < 4 mg/d ("super-responders") while 55 required ≥ 4 mg/d. 5-HT concentrations in rectal biopsies were significantly lower in super-responders (21.3 (17.0-31.8) vs 37.7 (21.4-61.4), P = .0357) and the increase in transit time on ondansetron was significantly greater (15.6 (1.8-31) hours vs 3.9 (-5.1-17.9) hours). Stool consistency responders were more likely to carry the CC genotype of the SNP p.N163K rs6766410 of the HTR3C gene (33% vs 14%, P = .0066).

CONCLUSION

IBS-D patients have significant abnormalities in mucosal 5-HT metabolism. Those with the lowest concentration of 5-HT in rectal biopsies showed the greatest responsiveness to ondansetron.

Treatment of irritable bowel syndrome with diarrhoea using titrated ondansetron (TRITON): study protocol for a randomised controlled trial

BACKGROUND

Irritable bowel syndrome with diarrhoea (IBS-D) affects up to 4% of the general population. Symptoms include frequent, loose, or watery stools with associated urgency, resulting in marked reduction of quality of life and loss of work productivity. Ondansetron, a 5HT3 receptor antagonist, has had an excellent safety record for over 20 years as an antiemetic, yet is not widely used in the treatment of IBS-D. It has, however, been shown to slow colonic transit and in a small randomised, placebo-controlled, cross-over pilot study, benefited patients with IBS-D.

METHODS

This trial is a phase III, parallel group, randomised, double-blind, multi-centre, placebo-controlled trial, with embedded mechanistic studies. Participants (n = 400) meeting Rome IV criteria for IBS-D will be recruited from outpatient and primary care clinics and by social media to receive either ondansetron (dose titrated up to 24 mg daily) or placebo for 12 weeks. Throughout the trial, participants will record their worst abdominal pain, worst urgency, stool frequency, and stool consistency on a daily basis. The primary endpoint is the proportion of "responders" in each group, using Food and Drug Administration (FDA) recommendations. Secondary endpoints include pain intensity, stool consistency, frequency, and urgency. Mood and quality of life will also be assessed. Mechanistic assessments will include whole gut transit, faecal tryptase and faecal bile acid concentrations at baseline and between weeks 8 and 11. A subgroup of participants will also undergo assessment of sensitivity (n = 80) using the barostat, and/or high-resolution colonic manometry (n = 40) to assess motor patterns in the left colon and the impact of ondansetron.

DISCUSSION

The TRITON trial aims to assess the effect of ondansetron across multiple centres. By defining ondansetron's mechanisms of action we hope to better identify patients with IBS-D who are likely to respond.

TRIAL REGISTRATION

ISRCTN, ISRCTN17508514 , Registered on 2 October 2017.

Fecal urgency is common in constipated patients and is associated with anxiety

BACKGROUND

Fecal urgency is a symptom generally associated with diarrhea but is also reported by patients with constipation. Our aim was to (a) assess the prevalence and burden of fecal urgency in constipated patients (b) evaluate gastrointestinal and psychiatric predictors of moderate to severe fecal urgency in these patients.

METHODS

Patients presenting consecutively to a tertiary outpatient gastroenterology clinic with constipation were included. Patients were considered to have moderate to severe fecal urgency if ≥50% of bowel movements (BMs) in the past 3 months were associated with fecal urgency. Anxiety, depression, and sleep disturbance were diagnosed using a Patient-Reported Outcomes Measurement Information System (PROMIS) t-score of ≥60. Abdominal pain and constipation severity were also assessed using PROMIS questionnaires. Univariable and stepwise logistic regression were used to identify predictors of moderate to severe fecal urgency.

KEY RESULTS

Of 139 constipated patients, 70.8% reported experiencing fecal urgency in the past 3 months and 25.8% reported being significantly bothered by it. Moderate to severe fecal urgency was reported by 27% of 139 patients. Frequency of loose stools (OR 1.5, 95% CI 1.1, 2.0) and presence of anxiety (OR 2.3, 95% CI 1.1, 5.0) were independent predictors of moderate to severe fecal urgency.

CONCLUSIONS AND INFERENCES

Fecal urgency is common in patients with constipation and is frequently bothersome to many patients. We identified clinical and psychiatric factors associated with moderate to severe fecal urgency in constipated patients with potential therapeutic implications if validated in future studies.

Alosetron versus traditional pharmacotherapy in clinical practice: effects on resource use, health-related quality of life, safety and symptom improvement in women with severe diarrhea-predominant irritable bowel syndrome

OBJECTIVE

Severe diarrhea-predominant irritable bowel syndrome (IBS-D) is associated with decreased health-related quality of life (HRQOL) and increased health care costs. Treatment recommendations for IBS-D often start with traditional pharmacotherapy (TP), with escalation to alosetron, rifaximin or eluxadoline if there is no success. There has been no previous head-to-head clinical trial comparing IBS-D treatment outcome for alosetron versus TP. This study, GSK protocol S3B30020, evaluated resource use, work productivity, health-related quality of life and global symptom response in women with IBS-D who were treated with alosetron or TP.

METHODS

A total of 1956 patients who met criteria for severe IBS-D were randomized to treatment with alosetron 1 mg twice daily (BID) or only TP for up to 24 weeks. Work productivity and resource use were evaluated by standard questionnaires, HRQOL by the IBSQOL instrument and IBS symptoms by the Global Improvement Scale (GIS).

RESULTS

Compared to only TP, alosetron-treated patients reported: (1) fewer clinic/office visits for any health problem (p = .0181) or for IBS-D (p = .0004); (2) reduced use of over-the-counter medications for IBS-D (p < .0001); (3) fewer days of lost work productivity (p < .0001); (4) decreased restriction of social and outdoor activities (p < .0001); and (5) greater global improvement in IBS-D symptoms (p < .0001). Alosetron treatment improved HRQOL scores for all domains (p < .0001). Incidence of adverse events during alosetron use was not remarkable and was similar to that previously reported.

CONCLUSIONS

Alosetron 1 mg BID significantly reduced health care utilization and lost productivity, and significantly improved global IBS symptoms, HRQOL, and participation in outdoor and social activities compared with treatment response to TP.

Acupuncture for Diarrhoea-Predominant Irritable Bowel Syndrome: A Network Meta-Analysis

Background

The objective of this study was to compare the efficacy and side effects of acupuncture, sham acupuncture, and drugs in the treatment of diarrhoea-predominant irritable bowel syndrome.

Methods

Randomized controlled trials (RCTs) assessing the effects of acupuncture and drugs were comprehensively retrieved from electronic databases (such as PubMed, Cochrane Library, Embase, CNKI, Wanfang Database, VIP Database, and CBM) up to December 2017. Additional references were obtained from review articles. With document quality evaluations and data extraction, Network Meta-Analysis was performed using a random-effects model under a frequentist framework.

Results

A total of 29 studies (n = 9369) were included; 19 were high-quality studies, and 10 were low-quality studies. NMA showed the following: (1) the ranking of treatments in terms of efficacy in diarrhoea-predominant irritable bowel syndrome is acupuncture, sham acupuncture, pinaverium bromide, alosetron = eluxadoline, ramosetron, and rifaximin; (2) the ranking of treatments in terms of severity of side effects in diarrhoea-predominant irritable bowel syndrome is rifaximin, alosetron, ramosetron = pinaverium bromide, sham acupuncture, and acupuncture; and (3) the treatment of diarrhoea-predominant irritable bowel syndrome includes common acupoints such as ST25, ST36, ST37, SP6, GV20, and EX-HN3.

Conclusion

Acupuncture may improve diarrhoea-predominant irritable bowel syndrome better than drugs and has the fewest side effects. Sham acupuncture may have curative effect except for placebo effect. In the future, it is necessary to perform highly qualified research to prove this result. Pinaverium bromide also has good curative effects with fewer side effects than other drugs.

Alosetron use in clinical practice: significant improvement in irritable bowel syndrome symptoms evaluated using the US Food and Drug Administration composite endpoint

BACKGROUND

Alosetron is approved to treat women with severe IBS and diarrhea (IBS-D) who have failed standard therapy. In our study, we aimed to evaluate alosetron efficacy using new US Food and Drug Administration (FDA) endpoints and utilization in clinical practice.

METHODS

This prospective, open-label, multicenter, observational 12-week study evaluated women with severe IBS-D enrolled in the alosetron prescribing program. The coprimary FDA endpoints were changes from baseline in stool consistency and abdominal pain severity. Responders achieved a 30% decrease compared with baseline in weekly average of the worst abdominal pain in the past 24 h, and a 50% or greater reduction from baseline in the number of days/week with at least one stool of type 6 (mushy) or type 7 (watery) consistency. Secondary endpoints included changes from baseline in stool frequency, fecal urgency and fecal incontinence.

RESULTS

Enrolled patients (n = 192) were primarily White (90.6%), with a mean age of 44.5 years. Patient and physician rating of IBS severity was between moderate and severe (85.9% concordance, Spearman coefficient 0.429, p < 0.0001). Alosetron 0.5 mg twice daily (82.8%) was the most common dosing regimen. A total of 152 alosetron-treated patients completed the study. Of 105 fully evaluable patients, 45% met the FDA composite endpoint responder criteria for ⩾50% of the study period. Improvements in all individual symptoms were statistically significant compared with baseline. There were no serious adverse events, cases of colonic ischemia, or complications of constipation.

CONCLUSION

In a clinical practice setting study, alosetron demonstrated treatment success using a rigorous FDA composite endpoint and also improved multiple other IBS symptoms, including fecal urgency and incontinence in women with severe IBS-D [ClinicalTrials.gov identifier: NCT01257477].

Efficacy and safety of 5-hydroxytryptamine 3 receptor antagonists in irritable bowel syndrome: A systematic review and meta-analysis of randomized controlled trials

AIM

We assessed the efficacy and safety of 5-hydroxytryptamine (5-HT3) receptor antagonists in adults with non-constipated irritable bowel syndrome (IBS) or diarrhea-predominant IBS (IBS-D).

METHODS

We searched PubMed, MEDLINE, EMBASE, and the Cochrane Controlled Trials Register for randomized controlled trials (RCTs) involving adults with non-constipated IBS or IBS-D that compared 5-HT3 receptor antagonists with placebo or other conventional treatment. Dichotomous symptom data were pooled to obtain the relative risk (RR) and 95% confidence intervals (CIs) for improving global IBS symptoms, abdominal pain and abnormal bowel habits, or stool consistency symptoms after therapy, and adverse events, including constipation. Meta- analysis was performed with Mantel Haenszel method using Revman 5.3 software.

RESULTS

We included 21 RCTs; 16 were high quality (Jadad score ≥ 4). The pooled RR of global IBS symptoms improved by 5-HT3 receptor antagonists versus placebo or mebeverine was 1.56 (95% CI: 1.43-1.71); alosetron, ramosetron, and cilansetron had similar treatment effects. The pooled RR of abdominal pain relieved by 5-HT3 receptor antagonists versus placebo was 1.33 (95% CI: 1.26-1.39). The pooled RR showed that 5-HT3 receptor antagonists improved abnormal bowel habits or stool consistency symptoms (RR = 1.63, 95% CI: 1.33, 1.99). The pooled RR of adverse events following 5-HT3 receptor antagonist treatment was 1.15 (95% CI: 1.08, 1.22). Subgroup analysis indicated that alosetron had a high rate of adverse effects (RR = 1.16, 95% CI: 1.08, 1.25); adverse events following ramosetron treatment were not statistically significantly different. 5-HT3 receptor antagonists were likelier to cause constipation: the pooled RR of constipation developing with 5-HT3 receptor antagonist versus placebo was 3.71 (95% CI: 2.98-4.61). However, constipation was likelier in patients with non-constipated IBS after taking 5-HT3 receptor antagonists than in patients with IBS-D only (non-constipated IBS and IBS-D: RR = 5.28 [95% CI: 3.93, 7.08] vs. IBS-D only 3.24 [2.54, 4.12]).

CONCLUSIONS

Ramosetron, cilansetron, ondansetron, and alosetron are effective for treating non-constipated IBS and IBS-D. Our systematic review found rare serious adverse events.

Randomised clinical trial: exploratory phase 2 study of ONO-2952 in diarrhoea-predominant irritable bowel syndrome

BACKGROUND

ONO-2952 is a novel and selective inhibitor of translocator protein 18 kDa that reduces stress-induced defecation and visceral hyperalgesia in rat models.

AIM

To evaluate the efficacy and safety of ONO-2952 in females with irritable bowel syndrome with diarrhoea in an exploratory proof-of-concept study.

METHODS

A randomised, double-blind, placebo-controlled study was conducted at 49 US centres. Two hundred subjects with irritable bowel syndrome with diarrhoea (Rome III criteria) were randomised to ONO-2952 20 mg, or 60 mg, or placebo. Subjects recorded irritable bowel syndrome symptoms daily during a 2-week baseline period, the 4-week treatment period and for 4 weeks post-treatment. The co-primary endpoints were change from baseline to week 4 in abdominal pain, stool consistency and stool frequency.

RESULTS

Improvements in irritable bowel syndrome symptoms were seen with ONO-2952 over placebo in per-protocol analyses for all three co-primary endpoints, but these did not reach statistical significance at the 5% level. The largest improvement was seen with ONO-2952 60 mg. ONO-2952 was well tolerated with a safety profile similar to that of placebo. Most adverse events were mild or moderate in severity and not treatment related.

CONCLUSION

ONO-2952 showed evidence of clinical efficacy in reducing irritable bowel syndrome-related symptoms in female subjects with irritable bowel syndrome with diarrhoea, and further evaluation is, therefore, warranted to assess its potential as a treatment for irritable bowel syndrome with diarrhoea (NCT01844180).

Eluxadoline for the treatment of diarrhoea-predominant irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome (IBS) treatment is challenging physicians because of its multifactorial physiopathology. In particular, abdominal pain and diarrhea management lack one unique effective pharmacological remedy. Opioid receptors, present in the central nervous system (CNS) and the enteric nervous system (ENS), are involved in visceral sensitivity and gastrointestinal motility control. To date only a few opioid receptor modulators are currently in use for the treatment of IBS but with dosage limitations due to the early development of severe constipation.

AREAS COVERED

In this drug evaluation manuscript we review the irritable bowel syndrome therapeutic needs and chemistry, pharmacokinetics and -dynamics, clinical study results with the new opioid receptor ligand eluxadoline for the treatment of diarrhea-predominant irritable bowel syndrome (IBS-D).

EXPERT OPINION

Eluxadoline shows a peculiar pharmacological profile with μ-opioid agonism and δ-opioid antagonism actions. Its efficacy over placebo for the treatment of abdominal pain and diarrhea in IBS-D has been demonstrated in short- and long-term clinical studies in humans. Its safety has been evaluated in the same studies. Interestingly, eluxadoline showed a low rate of constipation development in IBS patients in comparison with known effects of other opioid receptor modulators. Patients with a history of acute pancreatitis should not be treated with eluxadoline.

Irritable bowel syndrome: new insights into symptom mechanisms and advances in treatment

Despite being one of the most common conditions leading to gastroenterological referral, irritable bowel syndrome (IBS) is poorly understood. However, recent years have seen major advances. These include new understanding of the role of both inflammation and altered microbiota as well as the impact of dietary intolerances as illuminated by magnetic resonance imaging (MRI), which has thrown new light on IBS. This article will review new data on how excessive bile acid secretion mediates diarrhea and evidence from post infectious IBS which has shown how gut inflammation can alter gut microbiota and function. Studies of patients with inflammatory bowel disease (IBD) have also shown that even when inflammation is in remission, the altered enteric nerves and abnormal microbiota can generate IBS-like symptoms. The efficacy of the low FODMAP diet as a treatment for bloating, flatulence, and abdominal discomfort has been demonstrated by randomized controlled trials. MRI studies, which can quantify intestinal volumes, have provided new insights into how FODMAPs cause symptoms. This article will focus on these areas together with recent trials of new agents, which this author believes will alter clinical practice within the foreseeable future.

Eluxadoline for Irritable Bowel Syndrome with Diarrhea

Background Effective and safe treatments are needed for patients who have irritable bowel syndrome (IBS) with diarrhea. We conducted two phase 3 trials to assess the efficacy and safety of eluxadoline, a new oral agent with mixed opioid effects (μ- and κ-opioid receptor agonist and δ-opioid receptor antagonist), in patients with IBS with diarrhea. Methods We randomly assigned 2427 adults who had IBS with diarrhea to eluxadoline (at a dose of 75 mg or 100 mg) or placebo twice daily for 26 weeks (IBS-3002 trial) or 52 weeks (IBS-3001 trial). The primary end point was the proportion of patients who had a composite response of decrease in abdominal pain and improvement in stool consistency on the same day for at least 50% of the days from weeks 1 through 12 and from weeks 1 through 26. Results For weeks 1 through 12, more patients in the eluxadoline groups (75 mg and 100 mg) than in the placebo group reached the primary end point (IBS-3001 trial, 23.9% with the 75-mg dose and 25.1% with the 100-mg dose vs. 17.1% with placebo; P=0.01 and P=0.004, respectively; IBS-3002 trial, 28.9% and 29.6%, respectively, vs. 16.2%; P<0.001 for both comparisons). For weeks 1 through 26, the corresponding rates in IBS-3001 were 23.4% and 29.3% versus 19.0% (P=0.11 and P<0.001, respectively), and the corresponding rates in IBS-3002 were 30.4% and 32.7% versus 20.2% (P=0.001 and P<0.001, respectively). The most common adverse events associated with 75 mg of eluxadoline and 100 mg of eluxadoline, as compared with placebo, were nausea (8.1% and 7.5% vs. 5.1%), constipation (7.4% and 8.6% vs. 2.5%), and abdominal pain (5.8% and 7.2% vs. 4.1%). Pancreatitis developed in 5 (2 in the 75-mg group and 3 in the 100-mg group) of the 1666 patients in the safety population (0.3%). Conclusions Eluxadoline is a new therapeutic agent that reduced symptoms of IBS with diarrhea in men and women, with sustained efficacy over 6 months in patients who received the 100-mg dose twice daily. (Funded by Furiex Pharmaceuticals, an affiliate of Allergan; IBS-3001 and IBS-3002 ClinicalTrials.gov numbers, NCT01553591 and NCT01553747 , respectively.).

Irritable bowel syndrome: modern concepts and management options

Irritable bowel syndrome is the most common functional gastrointestinal disorder, manifesting as abdominal pain/discomfort and altered bowel function. Despite affecting as many as 20% of adults, a lack of understanding of etiopathogenesis and evaluation strategies results in diagnostic uncertainty, and in turn frustration of both the physician and the patient. This review summarizes the current literature on the diagnosis and management of irritable bowel syndrome, with attention to evidence-based approaches. A 4-step treatment strategy that has been used successfully in our tertiary referral practice is presented and should lead to successful therapeutic outcomes in the majority of patients with irritable bowel syndrome.

American college of gastroenterology monograph on the management of irritable bowel syndrome

This editorial reviews a recently published guideline on management of irritable bowel syndrome. The guideline illustrates problems arising from the quality of clinical trials used in systematic reviews and the potential impact of the inherent weaknesses of those trials on rating the strength of evidence and the resulting recommendations.

A 9-year evaluation of temporal trends in alosetron postmarketing safety under the risk management program

OBJECTIVES

Adverse events (AEs) of ischemic colitis (IC) and complications of constipation (CoC) associated with alosetron are rare and have been adjudicated during the first 5.5 years of the risk management program (RMP); however, changes in incidence rates relative to reductions in AE reports and increases in alosetron prescriptions over the 9-year RMP have not been evaluated. The authors aim to evaluate temporal trends in alosetron postmarketing safety over the 9-year RMP.

METHODS

The alosetron safety database was searched to identify cases of IC, CoC, and related AEs from 20 November 2002 to 31 December 2011. Adjudication of IC and CoC cases were based on US Food and Drug Administration-defined criteria. Incidence rates were calculated using the number of AEs and alosetron prescriptions (expressed as cases/1000 patient-years exposure).

RESULTS

A total of 29 cases were adjudicated as probable/possible IC and 7 cases were adjudicated as CoC. Cumulative adjudicated incidence rate of IC (1.03 cases/1000 patient-years) is low and stable, while that of CoC (0.25 cases/1000 patient-years) is low, declining progressively over time. Decreases in the incidence rates of potential symptoms of IC (abdominal pain with bloody diarrhea/hematochezia) and CoC (constipation) were also observed.

CONCLUSIONS

Over the 9-year RMP period, incidence rates of IC and CoC remain rare. Substantial reductions over time were observed in the incidence of CoC and in symptoms suggestive of IC or CoC, while IC incidence has been stable at approximately 1.0 case/1000 patient-years. Decreases in AEs and serious outcomes associated with IC and CoC since the reintroduction of alosetron are likely attributable to the RMP.

Managing irritable bowel syndrome

Irritable bowel syndrome (IBS), characterized by abdominal pain or discomfort associated with a change in bowel patterns, is one of the most common functional gastrointestinal disorders. Because no single drug effectively relieves all IBS symptoms, management relies on dietary and lifestyle modifications, as well as pharmacologic and nonpharmacologic therapies. The authors review current approaches to treatment and discuss nursing implications.

Alosetron: an effective treatment for diarrhea-predominant irritable bowel syndrome

Serotonin (5-HT) is one of the key mediators of gut motility, secretion and sensation. Most 5-HT is localized in the gastrointestinal tract. Particularly important for gut function and regulation are the 5-HT(1P), 5-HT(3) and 5-HT(4) receptors. These receptors have been the focus of research evaluating the pathophysiologic mechanisms of irritable bowel syndrome (IBS) as well as targets for the development of novel agents to treat irritable bowel syndrome. Alosetron is one of three 5-HT(3) antagonists currently available. The other two, ondansetron and granisetron, are primarily used in the treatment of chemotherapy-induced nausea and vomiting. Alosetron, which slows gut transit, has been approved for the treatment of severe diarrhea-predominant IBS (IBS-D) in women. This review will examine the common, yet therapeutically challenging, disorder IBS, as well as the role of alosetron in the treatment of IBS-D.

Randomised clinical trial: alosetron improves quality of life and reduces restriction of daily activities in women with severe diarrhoea-predominant IBS

BACKGROUND

Patients with irritable bowel syndrome with diarrhoea (IBS-D) experience restriction in daily activities and decreased health-related quality of life (QOL).

AIM

To investigate effects of alosetron on patient-reported health-related QOL, satisfaction and productivity in women with severe IBS-D.

METHODS

A total of 705 women (severe IBS-D, Rome II criteria) randomised to alosetron 0.5 mg QD, 1 mg QD, 1 mg BID, or placebo for 12 weeks were studied. IBSQOL, treatment satisfaction, daily activities, and lost workplace productivity (LWP) were evaluated at randomisation and Week 12.

RESULTS

One or more doses of alosetron significantly improved all IBSQOL domains except for sexual function from baseline vs. placebo. The magnitude of IBSQOL changes was consistent with a clinically meaningful effect. Alosetron 0.5 mg QD and 1 mg BID significantly reduced IBS interference with social/leisure activities and LWP from baseline vs. placebo [social/leisure (mean ±S.E.) days lost: -6.7 ± 0.8, -7.0 ± 0.9, P < 0.01; LWP (mean ± S.E.) h lost: -11.0 ± 3.3, -21.1 ± 4.1, P < 0.05 respectively]. Significantly more patients treated with alosetron reported satisfaction vs. placebo. Improvements in IBSQOL, LWP, and treatment satisfaction significantly correlated with global improvement of IBS symptoms. The incidence of adverse events with alosetron was low with constipation being the most commonly reported event. A single case of ischaemic colitis occurred, in a patient receiving alosetron 0.5 mg QD.

CONCLUSIONS

In women with severe IBS-D, alosetron treatment, including 0.5 mg QD, resulted in statistically significant and clinically relevant improvements in health-related QOL, restriction of daily activities and treatment satisfaction over placebo. IBS symptom improvement corresponded with positive changes in IBSQOL, LWP and treatment satisfaction.

Functional diarrhea

Chronic diarrhea is a frequent and challenging problem in clinical medicine. In a considerable subgroup of these, no underlying cause is identified and this is referred to as functional diarrhea. A consensus definition for functional diarrhea is based on loose stool consistency and chronicity and absence of coexisting irritable bowel syndrome. Underlying pathophysiology includes rapid intestinal transit, which may be worsened by stress or be triggered by a preceding infectious gastroenteritis. Diagnostic work-up aims at exclusion of underlying organic disease. Treatment starts with dietary adjustments, aiming at decreasing nutrients that enhance transit and stool and at identifying precipitating food items.

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.

[Guidelines for the treatment of irritable bowel syndrome]

Traditional symptom-based therapies of irritable bowel syndrome (IBS) are directed at the relief of individual IBS symptoms, but they are often of limited efficacy in addressing the entire symptom complex. Combinations of drugs to target bothersome symptoms are suggested as the first-line pharmacologic treatment. Increasing knowledge of the pathophysiology and molecular mechanisms of IBS has resulted in the development of several new therapeutic approaches. Thirteen consensus statements for the treatment of IBS were developed using the modified Delphi approach. Exclusion diets have modest efficacy in improving symptoms in some IBS patients. Symptom-based therapies with dietary fiber, bulking agents, laxatives, antispasmodics and laxatives are effective in the improvement of some individual symptoms, e.g. dietary fiber and bulking agents for constipation, laxatives for constipation, antispasmodics for abdominal pain and discomfort, antidiarrheals for diarrhea. 5HT3 receptor antagonists and 5HT((4)) receptor agonists are effective in the relief of global IBS symptoms and individual symptoms such as abdominal pain and abnormal bowel habits. A short term course of nonabsorbable antibiotics may improve global IBS symptoms, particularly in patients with diarrhea- predominant IBS. Some probiotics appear to have the potential benefit in improving global IBS symptoms. Selective C-2 chloride channel activator is more effective than placebo at relieving global IBS symptoms in patients with constipation-predominant IBS. Both tricyclic antidepressants and selective serotonin reuptake inhibitors are equally effective in relieving global IBS symptoms, and have some benefits in treating abdominal pain. Certain types of psychologic therapy may be effective in improving global symptoms in some IBS patients. Further studies are strongly needed to develop better treatment strategies for Korean patients with IBS.

[Irritable bowel syndrome, levator ani syndrome, proctalgia fugax and chronic pelvic and perineal pain]

OBJECTIVES

To define functional gastrointestinal pain, irritable bowel syndrome (IBS), levator ani syndrome, proctalgia fugax, the pathophysiology of these syndromes and the treatments that can be proposed.

MATERIAL AND METHODS

Review of articles published on the theme based on a Medline (PubMed) search and consensus conferences selected according to their scientific relevance.

RESULTS

IBS is very common. Patients report abdominal pain and/or discomfort, bloating, and abnormal bowel habit (diarrhoea, constipation or both), in the absence of any structural or biochemical abnormalities. IBS has a complex, multifactorial pathophysiology, involving biological and psychosocial interactions resulting in dysregulation of the brain-gut axis associated with disorders of intestinal motility, hyperalgesia, immune disorders and disorders of the intestinal bacterial microflora and autonomic and hormonal dysfunction. Many treatments have been proposed, ranging from diet to pharmacology and psychotherapy.

DISCUSSION

Patients with various types of chronic pelvic and perineal pain, especially those seen in urology departments, very often report associated IBS. This syndrome is also part of a global and integrated concept of pelviperineal dysfunction, avoiding a rigorous distinction between the posterior segment and the midline and anterior segments of the perineum.

Alosetron for severe diarrhea-predominant irritable bowel syndrome: improving patient outcomes

BACKGROUND

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder often diagnosed and managed by primary care physicians (PCPs). Despite the high prevalence of IBS, symptom severity is often underappreciated and inadequately managed. The goal of this review is to discern IBS treatment gaps and identify opportunities for improving its management in the primary care setting, as well as describe the most current clinical experience with alosetron, a targeted treatment for severe diarrhea-predominant IBS (IBS-D) in women.

SCOPE

PubMed was searched for English language articles using combinations of the following key words: 'irritable bowel syndrome,' 'diarrhea-predominant irritable bowel syndrome,' 'diagnosis,' 'guidelines,' 'general practice,' 'primary care,' 'quality of life,' 'burden,' 'prevalence,' 'patient satisfaction,' 'patient survey,' 'severe,' 'severity,' and 'alosetron.'

FINDINGS

Establishing the diagnosis of IBS in primary care represents a clinical challenge for many healthcare professionals. While many patients seek care for IBS symptoms in the primary care setting, evidence shows that PCPs are often unaware of established diagnostic criteria for IBS. Establishing the severity of IBS is also problematic, given the lack of consensus guidelines defining severe IBS, which in turn complicates treatment decisions. Severe IBS is often inferred after inadequate response to conventional agents; the level of disease impact on quality of life and patient functioning also defines severity. The selective 5-HT(3) antagonist alosetron has been shown to provide improvement across multiple symptom domains, and the incidence of adverse events continues to be low since the implementation of the Prescribing Program for Lotronex. Alosetron is the only agent approved by the US Food and Drug Administration for treatment of severe IBS-D in women.

CONCLUSION

PCPs often are required to evaluate and treat suspected IBS. The diagnosis and management of IBS in the primary care setting could be optimized through the use of published diagnostic criteria, adequate assessment of symptom severity, and a thorough knowledge of the therapeutic agents that have provided evidence of effectiveness. In the subset of women who suffer from IBS-D, targeted serotonergic therapy with alosetron has been shown to provide symptom relief across multiple domains, including improvement of the patient's quality of life.

Optimizing outcomes with alosetron hydrochloride in severe diarrhea-predominant irritable bowel syndrome

Irritable bowel syndrome (IBS) is a highly prevalent functional gastrointestinal disorder that causes a range of symptoms. Currently, alosetron hydrochloride (Lotronex®), a selective serotonin type 3 receptor antagonist, is the only medication approved for the treatment of severe diarrhea-predominant irritable bowel syndrome (IBS-D) in women who have inadequately responded to conventional therapy. Alosetron has demonstrated efficacy compared with placebo in clinical trials and has been shown to improve overall health-related quality of life (HRQoL). However, rare instances of ischemic colitis and severe complications of constipation have been reported. As a result, in 2000 alosetron was voluntarily withdrawn from the market but was reintroduced in 2002 with a more restricted indication and a requirement that clinicians and patients follow a prescribing program. Although the efficacy and benefit of alosetron has been clearly demonstrated, it has been used sparingly since its reintroduction. This brief review describes the history of alosetron, efficacy of alosetron in the treatment of IBS, the impact of severe IBS on HRQoL, safety considerations, the risk evaluation and mitigation strategy program under which alosetron is now prescribed, and an update on postmarketing surveillance data.

Ischemic colitis and complications of constipation associated with the use of alosetron under a risk management plan: clinical characteristics, outcomes, and incidences

OBJECTIVES

Alosetron is a potent, selective 5-HT(3) receptor antagonist prescribed for women with severe diarrhea-predominant irritable bowel syndrome (IBS-D) under a risk management plan (RMP). The RMP was implemented following cases of ischemic colitis (IC) and complications of constipation (CoC) associated with the use of alosetron. The objectives of this study were to characterize IC and CoC clinical features, outcomes, and incidence rates in the new restricted patient population to evaluate the effectiveness of the RMP in the prevention of serious outcomes.

METHODS

Safety data from adverse event reporting from November 2002 through June 2008 were reviewed for probable and possible IC and CoC using the US Food and Drug Administration/sponsor-defined criteria and definitions. Evidence for IC included medical documentation, colonoscopy, and sigmoidoscopy+/-biopsy. Evidence for CoC included medical history and confirmation from health-care professionals.

RESULTS

Within the inclusion dates, 29,072 patients received 203,939 alosetron prescriptions. Although the absolute numbers of IC and CoC cases have declined, the incidence rates for IC and CoC (0.95 and 0.36 cases per 1,000 patient-years, respectively) were similar to rates during the postmarketing cycle before alosetron withdrawal. In patients with severe IBS-D receiving alosetron (n=998) or placebo (n=411) in clinical trials since reintroduction, incidence rates for IC were 4 and 2 cases per 1,000 patients, respectively. Rates for CoC were 2 and 0 cases per 1,000 patients in the alosetron and placebo groups, respectively. No mesenteric ischemia, surgeries, transfusions, or deaths occurred in patients with IC and no cases of CoC were associated with toxic megacolon, perforation, surgeries, transfusions, or deaths. IC and CoC cases were typically of short duration and all improved on prompt withdrawal of alosetron.

CONCLUSIONS

Serious outcomes associated with IC and CoC appear to be mitigated since introduction of alosetron under the RMP.

Alosetron for severe diarrhea-predominant irritable bowel syndrome: safety and efficacy in perspective

Irritable bowel syndrome affects 5-10% of North Americans, with an estimated one-third having a diarrhea-predominant form. Alosetron hydrochloride (Lotronex) is a serotonin receptor type 3 antagonist approved in early 2000 for use in women with diarrhea-predominant irritable bowel syndrome (IBS-D). Initial use was widespread, but infrequent serious adverse events of ischemic colitis and severe constipation-related complications prompted alosetron's voluntary withdrawal from the US market in November 2000. Unprecedented public request prompted its reintroduction in 2002 under a Risk Management Plan, including a more restricted indication and a Prescribing Program for Lotronex. Despite these measures, the use of alosetron has been very limited since its reintroduction. Possible deterrents to its use include concerns over safety and the possible medical-legal implications raised by the Risk Management Plan. It is also possible that changes in the natural history and/or diagnosis of IBS-D have reduced the target population. Given the unique regulatory history of alosetron, these issues continue to engender controversy. This article profiles these concerns and reviews the pharmacology, clinical efficacy and safety, and post-marketing experience with alosetron. Myths and misconceptions related to alosetron use, or lack thereof, are addressed to provide the reader with the evidence needed to make informed treatment decisions for their female patients with severe IBS-D.

Post-infectious irritable bowel syndrome

Post-infectious irritable bowel syndrome (PI-IBS) is a common disorder wherein symptoms of IBS begin after an episode of acute gastroenteritis. Published studies have reported incidence of PI-IBS to range between 5% and 32%. The mechanisms underlying the development of PI-IBS are not fully understood, but are believed to include persistent sub-clinical inflammation, changes in intestinal permeability and alteration of gut flora. Individual studies have suggested that risk factors for PI-IBS include patients’ demographics, psychological disorders and the severity of enteric illness. However, PI-IBS remains a diagnosis of exclusion with no specific disease markers and, to date, no definitive therapy exists. The prognosis of PI-IBS appears favorable with spontaneous and gradual resolution of symptoms in most patients.

Chronic pelvic pain

Chronic pelvic pain affects both men and women; there are probably common mechanisms that involve the central nervous system. In many cases, the symptoms may be localised to a single end organ. However, the involvement of the central nervous system may result in a complex regional pain syndrome affecting the whole pelvis and as a consequence, multiple-organ symptomatology. The initial trigger may be relatively benign but a predisposed individual may develop a range of significant sensory and efferent functional abnormalities. Stimuli not normally reaching threshold may be perceived and normal sensations may be magnified to become dysphoric or painful. Problems of emptying viscera and maintaining continence may occur. Significant musculoskeletal disability may arise as well as abnormalities of the autonomic nervous system. There is an association with systemic disorders. Also, psychological, behavioural, sexual and social problems arise. In the chronic pelvic pain syndromes, treatment of the end organ has a limited role, and multidisciplinary as well as interdisciplinary management is essential.

New treatments for irritable bowel syndrome in women

The estimated prevalence of irritable bowel syndrome (IBS) in Western countries is 7-15%, with a female:male ratio of 2-2.5:1 in IBS patients who seek healthcare services; however, the female predominance is lower in the general population. IBS has a significant impact on health-related quality of life and is associated with a significant healthcare and economic burden. Management of IBS is comprised of general measures and pharmacologic and nonpharmacologic treatment. However, there are ongoing efforts to find more effective therapeutic approaches. As advancements in the understanding of the pathophysiology of IBS continue to grow, new and effective treatments with novel mechanisms of action that have the potential to improve relief of IBS symptoms over current treatments are likely to be developed. This article provides an overview of current and emerging therapies for IBS and also highlights sex and gender differences in clinical trials and treatment response.

Challenges to the therapeutic pipeline for irritable bowel syndrome: end points and regulatory hurdles

Recent advances in our understanding of basic neuroenteric mechanisms and the role of effectors and transmitters in the brain-gut axis have provided opportunities to develop new therapeutic agents for irritable bowel syndrome (IBS). Furthermore, human pharmacodynamic studies utilizing transit, colonic, or rectal sensitivity and brain imaging have been useful in determining therapeutic efficacy (particularly for drugs that act on motor function). This review provides an overview of medications that have not yet been approved for treatment of patients with IBS yet have shown promise in phase IIB trials. These include drugs that act on the serotonin receptor and transporter system: antidepressants, norepinephrine reuptake inhibitors, opioids, cholecystokinin antagonists, neurokinin-antagonists, chloride channel activators, guanylate cyclase C agonists, atypical benzodiazepines, probiotics, and antibiotics. The changing landscape in the regulatory approval process has impacted the development of IBS drugs. Guidance documents from regulatory agencies in Europe and the United States have focused on patients' reported outcomes and associated quality of life. After a decade of experience with different end points that have generated some data on psychometric validation and unprecedented information about responsiveness of the binary or global end points to drug therapy, it is necessary to pursue further validation studies before or during pivotal phase IIB or III trials. The hope of providing relief to patients should galvanize all parties to achieve these goals.

Predictors of patient-assessed illness severity in irritable bowel syndrome

BACKGROUND

Conceptual models suggest that "irritable bowel syndrome (IBS) severity" is a multidimensional outcome that is related to, yet distinct from, health-related quality of life (HRQOL). Existing severity questionnaires are largely based on physician rather than patient-based ratings. Since severity is a patient-centered outcome, it is essential that future instruments are based on patients' self-perceptions of severity. We measured patient-derived predictors of severity in a large cohort of IBS patients.

METHODS

We performed a cross-sectional analysis in 755 IBS patients recruited at a university-based center. Subjects completed a bowel symptom questionnaire, SCL-90, and SF-36. The main outcome was patient-assessed "overall severity of gastrointestinal symptoms," as measured on a 0-20 scale (20 = most severe). We first developed a conceptual model of IBS, and then performed bivariate analyses to identify biopsychosocial predictors of severity. We then entered significant predictors into a multivariable model to measure the independent association of each predictor with severity.

RESULTS

Six factors predicted severity: (a) abdominal pain rating (P < 0.001); (b) belief that "something serious is wrong with body" (P < 0.001); (c) straining with defecation (P= 0.001); (d) myalgias (P= 0.02); (e) urgency with defecation (P= 0.03); and (f) bloating (P= 0.05). Severity correlated highly with HRQOL in bivariate, but not multivariate, analysis.

CONCLUSION

Patient-derived severity in IBS is related to, yet distinct from, generic HRQOL. IBS severity is predicted by abdominal pain, bloating, straining, urgency, myalgias, and disease-related concern. These symptoms fall along both poles of the "brain-gut axis," indicating that a full assessment of patient severity must include a balanced biopsychosocial history.

Efficacy and tolerability of alosetron for the treatment of irritable bowel syndrome in women and men: a meta-analysis of eight randomized, placebo-controlled, 12-week trials

BACKGROUND

Stimulated 5-hydroxytryptamine-3 (5-HT(3)) receptors promote intestinal motility, secretion, and sensation, effects that are related to the known pathophysiology of irritable bowel syndrome (IBS). A previous meta-analysis of 6 randomized controlled trials of the 5-HT(3)-receptor antagonist alosetron found that this agent was associated with global improvement in symptoms, pain, and discomfort in patients with IBS.

OBJECTIVE

This was a meta-analysis of randomized, placebo-controlled trials that evaluated the efficacy and tolerability of alosetron for the management of IBS. It updated and expanded on the previous meta-analysis.

METHODS

PubMed, EMBASE, SCOPUS, Web of Science, and the cochrane central Register of controlled Trials were searched from 1966 through September 2007 for placebo-controlled trials that examined the efficacy and tolerability of alosetron in the management of IBS. The search terms were alosetron, 5-HT, irritable bowel, functional bowel diseases, and irritable colon. No language restriction was applied. The data were analyzed in terms of 2 main outcomes: global improvement in IBS symptoms and adequate relief of IBS pain and discomfort.

RESULTS

Eight multicenter, randomized, placebo-controlled, 12-week clinical trials met the criteria for inclusion in the meta-analysis. The studies included 4,170 patients with IBS (80% female) who were randomized to receive either alosetron or placebo. All patients met the Rome criteria for IBS, and all subtypes of IBS were represented. Most patients had diarrhea-predominant IBS; only 2.6% of patients had constipation-predominant IBS. In the 3 trials included in the analysis of global improvement in symptoms, alosetron was significantly more effective than placebo (relative risk [RR] = 1.60; 95% CI, 1.44-1.76; P <0.001). In the 6 trials included in the analysis of adequate relief of IBS pain and discomfort, there was also a significant difference in favor of alosetron (RR = 1.31; 95% CI, 1.20-1.43; P < 0.001). Analysis of adequate relief of IBS pain and discomfort by sex also indicated significant differences between alosetron and placebo in both sexes (female: RR = 1.34 [95% cI, 1.21-1.48]; male: RR = 1.23 [95% CI, 1.02-1.47]). The analysis of tolerability, which was based on data from 7 studies, found a significant difference between alosetron and placebo (RR = 1.19; 95% cI, 1.07-1.31; P<0.001). The only adverse events that occurred with a significantly higher incidence in those treated with alosetron compared with placebo were constipation in 8 trials (RR = 4.35; 95% CI, 3.01-6.26; P < 0.001) and abdominal pain and discomfort in 5 trials (RR = 1.96; 95% CI, 1.46-2.64; P < 0.001). In the alosetron group, there were 4 cases of ischemic colitis (0.16%) and 2 cases of serious complications of constipation (0.08%); neither of these was reported in the placebo group. Alosetron was not associated with any deaths.

CONCLUSIONS

Alosetron was effective in these men and women with IBS. constipation was the most frequently reported adverse event associated with alosetron therapy. Ischemic colitis and serious complications of constipation were reported in a small number of patients treated with alosetron.

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.

Effects of 5-hydroxytryptamine (serotonin) type 3 antagonists on symptom relief and constipation in nonconstipated irritable bowel syndrome: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND & AIMS

We performed a systematic review and meta-analyses to estimate treatment efficacy and constipation rate of 5-hydroxytryptamine (serotonin) (5-HT(3)) antagonists in patients with nonconstipated (NC) or diarrhea-predominant (D)-irritable bowel syndrome (IBS).

METHODS

Two reviewers independently searched MEDLINE, EMBASE, and Web of Science (January 1, 1966 to December 15, 2006) for randomized controlled trials of 5-HT(3) antagonists in IBS reporting clinical end points of the IBS symptom complex and safety parameters. Study characteristics, markers of methodologic quality, and outcomes for the intention-to-treat population for each randomized controlled trial were extracted independently.

RESULTS

We found 14 eligible randomized controlled trials of alosetron (n = 3024) or cilansetron (n = 1116) versus placebo (n = 3043) or mebeverine (n = 304). Random-effects meta-analyses found 5-HT(3) antagonists more effective than the comparators in achieving global improvement in IBS symptoms (pooled relative risk, 1.60; 95% confidence interval [CI], 1.49-1.72; I(2) = 0%) and relief of abdominal pain and discomfort (pooled relative risk, 1.30; 95% CI, 1.22-1.39; I(2) = 22%). Benefit was apparent for both agents, in patients of either sex. These agents were more likely to cause constipation (pooled relative risk, 4.28; 95% CI, 3.28-5.60, I(2) = 65%); there was less constipation with 5-HT(3) antagonists in D-IBS patients than in mixed populations (NC-IBS and D-IBS; relative risk ratio, 0.65; 95% CI, 0.41-0.99). Nine patients (0.2%) using 5-HT(3) antagonists had possible ischemic colitis versus none in control groups.

CONCLUSIONS

5-HT(3) antagonists significantly improve symptoms of NC-IBS or D-IBS in men and women. There is an increased risk of constipation with 5-HT(3) antagonists, although the risk is lower in those with D-IBS.

A randomized, double-blind, placebo-controlled study to assess efficacy and safety of 0.5 mg and 1 mg alosetron in women with severe diarrhea-predominant IBS

OBJECTIVE

Alosetron is indicated for women with chronic, severe diarrhea-predominant IBS (d-IBS) who have not responded adequately to conventional therapy. Constipation is the most common adverse event with alosetron treatment. Multiple dosing regimens were assessed in a randomized, double-blind, placebo-controlled study (S3B30040) to determine efficacy, tolerability, and evaluate constipation rate.

METHODS

705 women with severe d-IBS were randomized to placebo, alosetron 0.5 mg once daily, 1 mg once daily, or 1 mg twice daily for 12 wk. The primary end point was the proportion of week 12 responders (patients with moderate or substantial improvement in IBS symptoms) on the 7-point Likert Global Improvement Scale (GIS). Secondary end points were average rate of adequate relief of IBS pain and discomfort, and bowel symptom improvements.

RESULTS

The proportion of GIS responders at week 12 (primary time point) was significantly greater in all alosetron groups compared with placebo (54/176 [30.7%], 90/177 [50.8%], 84/175 [48%], and 76/177 [42.9%] for placebo, 0.5, 1 mg once daily, and 1 mg twice daily alosetron groups, respectively; P< or = 0.02). Results were similar for the average adequate relief rate (treatment effects > or =12%, P< or = 0.038). Bowel symptoms were improved in all alosetron groups. Constipation was the most common adverse event (9%, 16%, and 19% patients in the 0.5 mg, 1 mg once daily, and 1 mg twice daily groups, respectively). One event of intestinal obstruction and one of ischemic colitis occurred in the 0.5 mg group, and one event of fecal impaction occurred in the 1 mg twice-daily group. All were self-limited and resolved without sequelae.

CONCLUSION

Alosetron 0.5 mg and 1 mg once daily as well as 1 mg twice daily are effective in providing global improvement in IBS symptoms, adequate relief of IBS pain and discomfort, and improvement in bowel symptoms in women with severe d-IBS. Lower dosing regimens resulted in a decreased constipation rate.

Primary endpoints for irritable bowel syndrome trials: a review of performance of endpoints

The choice of primary endpoint for a clinical trial is one of the most important determinants of the ability of a clinical trial to demonstrate efficacy of therapeutic agents. Although there are still no clear, universally accepted guidelines on the definition of clinical benefit for irritable bowel syndrome (IBS), consensus guidelines stress the importance of using validated endpoints. This article reviews the evidence available in the literature on the psychometric validation and performance of the 3 endpoints recommended by the Rome III Committee for use as primary endpoints in treatment trials of IBS. The Rome III Committee recommends 2 types of measures: binary endpoints addressing the construct of relief (that is, adequate relief and satisfactory relief) and an integrative symptom questionnaire that addresses the change in severity of a representative group of symptoms of IBS (that is, the IBS Severity Scale). The current evidence suggests that at present, adequate relief should be recognized by regulatory authorities as an acceptable primary endpoint in clinical trials. This analysis also suggests that data from individual clinical trials should be pooled and undergo meta-analysis, and that prospective studies should be considered to further characterize the performance of available endpoints as outcome measures in pharmacotherapeutic trials in IBS.

Testosterone Treatment for Hypoactive Sexual Desire Disorder in Postmenopausal Women

INTRODUCTION

The reduced levels of testosterone in postmenopausal women are associated with loss of libido, decreased sexual activity, diminished feelings of physical well-being, and fatigue. A bilateral oophorectomy can lead to decreases in sexual desire in 50% of cases by removing ovarian contribution to the circulating levels of testosterone. Testosterone therapy is an option for the restoration of sexual drive.

AIM

Transdermal testosterone administration may bypass the effects of first pass hepatic metabolism. To this end a series of studies have been carried out using a novel transdermal testosterone system. A review of the results from these studies are presented here.

MAIN OUTCOME MEASURES

A key feature of these studies was the use of validated study instruments to measure sexual function: Sexual Activity Log (SAL), Profile of Female Sexual Function (PFSF) and Personal Distress Scale.

METHODS

The data from the Phase III studies, known as the Investigation of Natural Testosterone in Menopausal women Also Taking Estrogen in Surgically Menopausal women (INTIMATE SM) 1 and 2 were reviewed and the salient information is presented here.

RESULTS

Both INTIMATE 1 and 2 showed a significant increase in total satisfying sexual activity, via the SAL in those women receiving testosterone, compared with those women in the placebo group. Total satisfying sexual activity increased by 74% and 51% for INTIMATE 1 and 2, respectively. The PFSF instrument demonstrated significant improvements in INTIMATE 1 and 2 in all domains of sexual function in testosterone-treated women compared with the placebo patients. In both studies, personal distress decreased in those patients receiving testosterone, compared with the placebo group. The most commonly reported adverse events were application site reactions. Eight-five percent of patients said they would probably or definitely continue treatment. Conclusions. The transdermal testosterone patch is an effective treatment for hypoactive sexual desire disorder in surgically postmenopausal women receiving concomitant estrogen therapy. The treatment has a favorable safety profile.

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.