Safety evaluation of lubiprostone in the treatment of constipation and irritable bowel syndrome

Post-marketing safety assessment of constipation drugs: a real-world pharmacovigilance study based on FAERS database

BACKGROUND

Laxatives are widely used in the treatment of constipation, but they also have brought many adverse reactions to patients.

METHODS

We conducted a pharmacovigilance analysis based on the United States Food and Drug Administration Adverse Event Reporting System (FAERS) database to analyze the adverse events of six constipation drugs (linaclotide, lubiprostone, prucalopride, naloxegol, naldemedine, and plecanatide) and to search for clinically meaningful adverse reaction signals. We used disproportionality analysis as the main analysis method to detect pharmacovigilance signals, which includes Frequentist methods and Bayesian methods.

RESULTS

Among the reports of the six drugs, more adverse reactions were reported from females than males, and the number of adverse reactions reported was higher in the group of 60-89 years. Linaclotide had the lowest proportion of serious adverse event reports (4.38%), while naldemedine had the highest proportion of serious adverse event reports (25.57%). According to the classification of system organ classification (SOC), the number of gastrointestinal adverse events (N = 8321) was the largest.

CONCLUSIONS

The adverse reactions of constipation drugs were mainly gastrointestinal symptoms such as diarrhea, abdominal pain and abdominal distension. Linaclotide has the highest safety, and more studies are needed to analyze the cardiovascular safety of lubiprostone.

Efficacy and safety of lubiprostone for the treatment of chronic idiopathic constipation: A phase 3, randomized, placebo-controlled study

INTRODUCTION

Chronic idiopathic constipation (CIC) negatively impacts quality of life and increases healthcare costs. Lubiprostone stimulates the secretion of intestinal fluid, in turn facilitating the passage of stools and alleviating associated symptoms. Lubiprostone has been available in Mexico since 2018, but its clinical efficacy has not been studied in a Mexican population.

AIM

To evaluate the efficacy of lubiprostone, assessed by changes in spontaneous bowel movement (SBM) frequency after one week of treatment with 24 μg oral lubiprostone (b.i.d.), as well as its safety, over four weeks of treatment.

STUDY

Randomized, double-blind, placebo-controlled study on 211 adults with CIC in Mexico.

RESULTS

The increase in SBM frequency, after one week of treatment, was significantly higher in the lubiprostone group than in the placebo group (mean: 4.9 [SD: 4.45] vs. 3.0 [3.14], p = 0.020). Secondary efficacy endpoints revealed a significantly higher proportion of SBM frequency/week in the lubiprostone group at weeks 2, 3, and 4. There was a better response within 24 h after the first dose with lubiprostone vs. placebo (60.0% vs. 41.5%; OR: 2.08, CI95%: [1.19, 3.62], p = 0.009) and the lubiprostone group also had significant improvement, with respect to straining, stool consistency, abdominal bloating, and Satisfaction Index. The main adverse events were gastrointestinal disorders in 13 (12.4%) lubiprostone-treated subjects and 4 (3.8%) control subjects.

CONCLUSIONS

Our data confirm the efficacy and safety of lubiprostone for the treatment of CIC in a Mexican population. Lubiprostone treatment induces relief from the most bothersome symptoms associated with constipation.

Myths and misconceptions about childhood constipation

Many widely held beliefs and assumptions concerning childhood constipation continue to interfere with rational management of childhood constipation. Although many still believe that constipation is not a common disease, about 9.5% of the world's children suffer from chronic constipation. Most of these children live in non-Western countries. There are major misconceptions about the etiology of constipation as a significant proportion of clinicians still believe that constipation is caused by some form an organic pathology, whereas in reality, the majority have functional constipation. Contrary to a commonly held belief that children outgrow constipation without long-term problems, there is evidence that constipation leads to significant bowel and psychological consequences and has a major impact on the quality of life which detrimentally affects future health and education. Finally, ineffective management strategies such as increasing fiber and water in the diet, and short duration of treatment owing to the fear that long-term laxative treatment leads to colonic dysfunction, interfere with effective therapeutic strategies.   Conclusions: It is apparent that myths and misconception often lead to wrong assumptions regarding the distribution of the disease, its etiology, pathophysiology, and management leading to ordering incorrect investigations and ineffective therapeutic strategies while spending large sums of public funds unnecessarily. Poorly treated constipation leads to deleterious psychological consequences predisposing children to develop significant psychological damage and bowel dysfunctions. This review aims to challenge these myths about various elements of constipation by exploring the existing literature and encouraging clinicians to have a fresh look at old concepts that could interfere with the well-being of children with constipation. What is Known: • Childhood constipation is a growing problem in the world leading to significant suffering and high healthcare expenditure • Myths and misconceptions lead to poor management strategies causing psychological and bowel damage What is New: • Organic, systemic, and bowel disorders leading to constipation are uncommon, and in the majority, it arises due to deliberate fecal withholding and most investigations ordered by clinicians are not very helpful in the management • Most non-pharmacological interventions are not effective in the day-to-day management of childhood constipation. The use of laxatives is considered to be the first-line management strategy.

Analysis of the impact on efficacy of lubiprostone dose reduction to manage adverse events in the treatment of chronic constipation in Japan

OBJECTIVE

To compare outcomes between two doses of lubiprostone in patients with chronic constipation (CC), to assess whether dose reduction affects efficacy.

METHODS

This open-label exploratory study involved 146 patients with CC treated initially with lubiprostone 24 mcg twice daily for a planned duration of 4 weeks. Patients who experienced adverse events (AEs) had their dose reduced to 12 mcg twice daily (for 4 weeks).

RESULTS

Lubiprostone dose was unchanged in 104 patients and reduced due to AEs in 42 patients. Significant differences in the mean number of bowel movements per week favored the dose-reduced group at Week 1 and end of follow-up. No between-group differences were observed over time for mean number of days per week with bowel movements or mean Bristol Stool Form Scale scores. Symptoms of abdominal bloating, strained defecation, and sensation of incomplete evacuation improved in both groups. Before dose reduction, nausea was reported by 64.3% and diarrhea by 45.2% of patients in the dose-reduced group; after dose reduction, no patients reported nausea and one patient reported diarrhea.

CONCLUSION

Dose reduction of lubiprostone reduced the incidence of AEs, with no compromise to efficacy, and may be a suitable approach for patients who develop AEs during treatment.

Evaluation of efficacy and safety of lubiprostone in patients with chronic constipation

OBJECTIVES

Lubiprostone is an apical type 2 chloride channel activator approved for the treatment of chronic constipation (CC), and nausea is the most common adverse symptom. However, the associated factors with the efficacy and the precise mechanism of nausea remain unclear. The aim of this study is to characterize clinical backgrounds related with the efficacy and the adverse symptoms of lubiprostone.

MATERIALS AND METHODS

Subjects were patients with CC who were prescribed lubiprostone from April 2017 to October 2019. The efficacy and safety of lubiprostone were retrospectively examined using the electronic medical record.

RESULTS

Hundred and fifty-five patients (76 men, and mean age 69) were evaluated. Lubiprostone was effective in 74 patients (47.8%), and the discontinuation due to adverse in 34 patients (21.9%). including nausea, diarrhea and abdominal pain in 16, 12 and 3 patients, respectively. The efficacy was significantly associated with gender, age, body mass index (BMI), diabetes mellitus, hypertension, calcium channel blockers and antipsychotics. In multivariate analysis, the efficacy was significantly associated with men (odds ratio [OR], 3.21; 95% confidence interval (CI), 1.42-7.27) and BMI (OR, 1.14; 95% CI, 1.02-1.28). The incidence of nausea was higher in patients under 65 years old, and hypertension was the significant protective factor for nausea.

CONCLUSIONS

Lubiprostone was effective for men patients with CC, and hypertension seems to be the protective factor for nausea.

Open-label study to evaluate the treatment continuation rate after a dose reduction of lubiprostone due to onset of adverse events

OBJECTIVE

To investigate the continuation rate with a reduced lubiprostone dose (12 mcg twice daily, BD) after the onset of adverse events (AEs) in patients with chronic constipation (CC).

METHODS

In this exploratory, open-label, multicenter study, patients with CC received lubiprostone 24 mcg BD and the dose was reduced to 12 mcg BD in subjects experiencing AEs. The primary objective was the continuation rate after dose reduction due to nausea/vomiting. Secondary objectives included the continuation rate after dose reduction due to diarrhea/any AE and efficacy, including changes in number of weekly bowel movements and Bristol Stool Form Scale.

RESULTS

Of the 146 patients included in the study, 42 (28.8%) received lubiprostone 12 mcg BD (dose-reduced group) due to any AE. Thirty-six (85.7%) subjects in the dose-reduced group continued treatment and completed the study. 22/27 (81.5%) and 17/19 (89.5%) patients in whom the dose was reduced due to nausea/vomiting or diarrhea, respectively, continued treatment. There was no clinically relevant difference in efficacy after dose reduction.

CONCLUSION

These results suggest that treatment withdrawal due to AEs associated with lubiprostone 24 mcg BD could be minimized in patients with CC after dose reduction to 12 mcg BD, thus resulting in improved long-term outcomes.

CLINICAL TRIAL REGISTRATION

Japan Registry of Clinical Trials (https://jrct.niph.go.jp/latest-detail/jRCTs031180069).

Irritable Bowel Syndrome: News from an Old Disorder

Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder, which can affect all members of a society, regardless of age, sex, race or socioeconomic status. Because of its high prevalence and chronic nature, it represents a significant economic burden. In fact, these patients have a relevant impairment of their quality of life, which limits their work productivity and daily social activities, especially when it is associated with other disorders, such as anxiety and depression. The diagnosis of IBS relies on symptom-based diagnostic criteria with normal results on a limited number of complementary tests that rule out other possible diagnoses. The aetiology of this condition is incompletely established. However, evidence suggests that it is a multifactorial disorder with several different mechanisms that have been implicated as responsible for the symptoms. Since the treatment strategy is usually based on predominant symptoms and their severity, it is important to recognise the underlying mechanisms in order to successfully relief the visceral pain and altered bowel habits. The aim of this non-systematic review of the literature was to explore the pathophysiology and treatment options of IBS, highlighting the most recent evidence, from the new Rome IV criteria to the new drug armamentarium.

Analysis of Nausea in Clinical Studies of Lubiprostone for the Treatment of Constipation Disorders

BACKGROUND

Lubiprostone is a ClC-2 chloride channel activator approved for the treatment of chronic idiopathic constipation (CIC) and opioid-induced constipation (OIC) in adults and irritable bowel syndrome with constipation (IBS-C) in women. Lubiprostone is generally well tolerated, with nausea being the most common adverse event.

AIMS

To characterize nausea with lubiprostone using pooled results from clinical studies in patients with CIC, OIC, or IBS-C.

METHODS

Data from three 3- and 4-week placebo-controlled studies and three long-term open-label studies were pooled for the CIC analysis. The OIC and IBS-C analyses each used pooled data from three 12-week placebo-controlled studies and one 36-week open-label extension study.

RESULTS

The populations included the following numbers of patients: CIC, 316 (placebo) and 1113 (lubiprostone 24 mcg twice daily [BID]); OIC, 652 (placebo) and 889 (lubiprostone 24 mcg BID); and IBS-C, 435 (placebo) and 1011 (lubiprostone 8 mcg BID). The incidence of nausea in lubiprostone-treated patients ranged from 11.4 to 31.1%, with the highest incidence in patients with CIC. Among patients with any nausea, most reported only mild or moderate severity (96.5-99.1% across indications) and only one event (83.6-88.7%); most events occurred within the first 5 days of treatment.

CONCLUSIONS

Nausea was the most common adverse event following the treatment with lubiprostone. Event rates varied by indication and dose, and the majority of nausea adverse events were mild to moderate in severity. Nausea events predominantly occurred early in the treatment period in all of the pooled study populations.

Opioid-Induced Constipation and Bowel Dysfunction: A Clinical Guideline

OBJECTIVE

To formulate timely evidence-based guidelines for the management of opioid-induced bowel dysfunction.

SETTING

Constipation is a major untoward effect of opioids. Increasing prescription of opioids has correlated to increased incidence of opioid-induced constipation. However, the inhibitory effects of opioids are not confined to the colon, but also affect higher segments of the gastrointestinal tract, leading to the coining of the term "opioid-induced bowel dysfunction."

METHODS

A literature search was conducted using Medline, EMBASE, and EMBASE Classic, and the Cochrane Central Register of Controlled Trials. Predefined search terms and inclusion/exclusion criteria were used to identify and categorize relevant papers. A series of statements were formulated and justified by a comment, then labeled with the degree of agreement and their level of evidence as judged by the Strength of Recommendation Taxonomy (SORT) system.

RESULTS

From a list of 10,832 potentially relevant studies, 33 citations were identified for review. Screening the reference lists of the pertinent papers identified additional publications. Current definitions, prevalence, and mechanism of opioid-induced bowel dysfunction were reviewed, and a treatment algorithm and statements regarding patient management were developed to provide guidance on clinical best practice in the management of patients with opioid-induced constipation and opioid-induced bowel dysfunction.

CONCLUSIONS

In recent years, more insight has been gained in the pathophysiology of this "entity"; new treatment approaches have been developed, but guidelines on clinical best practice are still lacking. Current knowledge is insufficient regarding management of the opioid side effects on the upper gastrointestinal tract, but recommendations can be derived from what we know at present.

Novel pharmacological therapies for irritable bowel syndrome

Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disorder, which represents a major cost to healthcare services. Current pharmacological treatment includes fibre supplements, antispasmodics, laxatives, loperamide and antidepressants. This article reviews the novel pharmacological treatments already or recently approved for patients with IBS-C (lubiprostone, linaclotide) and IBS-D (alosetron, ramosetron, rifaximin, eluxadoline). Furthermore, results for drugs in development (plecanatide, ibudutant and ebastine) or used in chronic constipation or for other indications, with potential application in IBS (prucalopride, elobixibat, mesalazine, ondansetron and colesevelam) are also reviewed.

Phase II drugs under clinical investigation for the treatment of chronic constipation

INTRODUCTION

Chronic constipation (CC) is a common gastrointestinal (GI) motility disorder that significantly impairs the quality of life in affected subjects. As almost half of the patients suffering from CC are not satisfied with currently available medicines, there is a need to develop new molecules with better effectiveness and tolerability.

AREAS COVERED

The authors include all experimental and clinical trials (up to Phase II) about new investigational drugs for the treatment of CC. The article identifies nine new agents: mitemcinal, TD-8954, YKP10811, itopride, RM-131, KWA-0711, elobixibat, velusetrag, and naronapride. All nine agents have shown prokinetic effects in different stages of the development. The mechanisms of new developing drugs include: the activation of 5-hydroxytryptamine type-4 (5-HT4), ghrelin and motilin receptors, antagonizing dopamine type-2 (D2) receptors, inhibition of ileal bile acid reabsorption and acetylcholine esterase, as well as water absorption from the GI tract.

EXPERT OPINION

At this current point in time, new generations of 5-HT4 receptor agonists (velusetrag, noranopride and YKP10811) are hoped to progress, further in the future, due to better efficiency and safety. However, it is not possible to make a concise conclusion at this current time due to a lack of evidence. Further clinical trials with a longer duration and a larger sample size are warranted.

The safety of novel drugs used to treat irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome (IBS) is a chronic gastrointestinal (GI) disorder with a high prevalence. Besides efficacy, the safety of each drugs used to treat GI disorders is an important issue in the drug development process.

AREAS COVERED

This article reviews all Phase I to IV clinical trials or case reports with results related to the safety of novel GI drugs. The drugs are currently approved or under evaluation for approval.

EXPERT OPINION

Most of the reported adverse events were related to the GI tract with mild-to-moderate severity. Diarrhea was significantly higher versus placebo following use of linaclotide and renzapride, similar to that of constipation with ramosetron. Lubiprostone, linaclotide and rifaximin with low systemic bioavailability have less adverse events and exert more advantageous results. Asimadoline acts peripherally on κ-opioid receptors and is not associated with CNS side effects. As lubiprostone and linaclotide cause dose-dependent adverse events, starting the treatment with the lowest effective doses is advised. Ramosetron is under evaluation for diarrhea-predominant IBS due to its acceptable safety and tolerability, besides its efficacy. Rifaximin, asimadoline and renzapride are still in need of more long-term studies regarding their safety.

New treatment targets for the management of irritable bowel syndrome

PURPOSE OF REVIEW

Irritable bowel syndrome (IBS) and chronic idiopathic constipation (CIC) are highly prevalent medical conditions that reduce quality of life and represent a substantial economic burden on healthcare cost. Until recently, no specific treatment options were available. This review will provide an update of the most recent randomized clinical trials data showing efficacy and safety of novel, targeted treatment modalities in IBS and CIC with gastrointestinal receptor and ion channel agonists.

RECENT FINDINGS

Recent discoveries of peptides and small molecules targeting gastrointestinal receptors and ion channels resulted in novel, specific pharmacological therapies of IBS and CIC. The bicyclical fatty acid lubiprostone and the synthetic 14-amino acid peptide linaclotide were identified to selectively activate a Chloride Channel-2 and the Guanylin Cyclase-C receptor, respectively, and demonstrate efficacy in the treatment of IBS with constipation and CIC.

SUMMARY

Novel molecules including the bicyclical fatty acid lubiprostone and the synthetic 14-amino acid peptide linaclotide represent new treatment modalities for IBS with constipation and CIC with proven efficacy and acceptable side-effect profiles.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Physiology, signaling, and pharmacology of opioid receptors and their ligands in the gastrointestinal tract: current concepts and future perspectives

Opioid receptors are widely distributed in the human body and are crucially involved in numerous physiological processes. These include pain signaling in the central and the peripheral nervous system, reproduction, growth, respiration, and immunological response. Opioid receptors additionally play a major role in the gastrointestinal (GI) tract in physiological and pathophysiological conditions. This review discusses the physiology and pharmacology of the opioid system in the GI tract. We additionally focus on GI disorders and malfunctions, where pathophysiology involves the endogenous opioid system, such as opioid-induced bowel dysfunction, opioid-induced constipation or abdominal pain. Based on recent reports in the field of pharmacology and medicinal chemistry, we will also discuss the opportunities of targeting the opioid system, suggesting future treatment options for functional disorders and inflammatory states of the GI tract.

Constella™(EU)-Linzess™(USA): the last milestone in the long journey of the peptide linaclotide and its implications for the future of peptide drugs

Irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC) are highly prevalent gastrointestinal disorders associated with health, economical and social problems. Recently, after a long journey of preclinical studies and clinical trials, linaclotide, a first-in-class GC-C receptor peptide agonist, has received the approval in the USA and Europe for the treatment of IBS-C and CIC. This article provides an overview of clinical, economic and biological aspects of IBS-C and CIC and covers the current and emerging therapeutic agents for treating these conditions. Particularly, the pharmacodynamic and pharmacokinetic properties of linaclotide, a small, disulfide-rich peptide, and its implications in the future of peptide drug discovery and development are discussed.

Lubiprostone Increases Small Intestinal Smooth Muscle Contractions Through a Prostaglandin E Receptor 1 (EP1)-mediated Pathway

Background/Aims

Lubiprostone, a chloride channel type 2 (ClC-2) activator, was thought to treat constipation by enhancing intestinal secretion. It has been associated with increased intestinal transit and delayed gastric emptying. Structurally similar to prostones with up to 54% prostaglandin E₂ activity on prostaglandin E receptor 1 (EP₁), lubiprostone may also exert EP₁-mediated procontractile effect on intestinal smooth muscles. We investigated lubiprostone's effects on intestinal smooth muscle contractions and pyloric sphincter tone.

Methods

Isolated murine small intestinal (longitudinal and circular) and pyloric tissues were mounted in organ baths with modified Krebs solution for isometric recording. Basal muscle tension and response to electrical field stimulation (EFS; 2 ms pulses/10 V/6 Hz/30 sec train) were measured with lubiprostone (10^-10-10^-5 M) ± EP₁ antagonist. Significance was established using Student t test and P < 0.05.

Results

Lubiprostone had no effect on the basal tension or EFS-induced contractions of longitudinal muscles. With circular muscles, lubiprostone caused a dose-dependent increase in EFS-induced contractions (2.11 ± 0.88 to 4.43 ± 1.38 N/g, P = 0.020) that was inhibited by pretreatment with EP₁ antagonist (1.69 ± 0.70 vs. 4.43 ± 1.38 N/g, P = 0.030). Lubiprostone had no effect on circular muscle basal tension, but it induced a dose-dependent increase in pyloric basal tone (1.07 ± 0.01 to 1.97 ± 0.86 fold increase, P < 0.05) that was inhibited by EP₁ antagonist.

Conclusions

In mice, lubiprostone caused a dose-dependent and EP₁-mediated increase in contractility of circular but not longitudinal small intestinal smooth muscles, and in basal tone of the pylorus. These findings suggest another mechanism for lubiprostone's observed clinical effects on gastrointestinal motility.

A critical appraisal of lubiprostone in the treatment of chronic constipation in the elderly

Chronic constipation is a common disorder in the general population, with higher prevalence in the elderly, and is associated with worse quality of life and with greater health care utilization. Lubiprostone is an intestinal type-2 chloride channel activator that increases intestinal fluid secretion, small intestinal transit, and stool passage. Lubiprostone is currently approved by the US Food and Drug Administration for the treatment of chronic idiopathic constipation and of irritable bowel syndrome with predominant constipation. This review outlines current approaches and limitations in the treatment of chronic constipation in the elderly and discusses the results, limitations, and applicability of randomized, controlled trials of lubiprostone that have been conducted in the general and elderly population, with additional focus on the use of lubiprostone in constipation in Parkinson's disease and in opioid-induced constipation, two clinical entities that can be comorbid in elderly patients.