American Gastroenterological Association-American College of Gastroenterology Clinical Practice Guideline: Pharmacological Management of Chronic Idiopathic Constipation.

INTRODUCTION: Chronic idiopathic constipation (CIC) is a common disorder associated with significant impairment in quality of life. This clinical practice guideline, jointly developed by the American Gastroenterological Association and the American College of Gastroenterology, aims to inform clinicians and patients by providing evidence-based practice recommendations for the pharmacological treatment of CIC in adults. METHODS: The American Gastroenterological Association and the American College of Gastroenterology formed a multidisciplinary guideline panel that conducted systematic reviews of the following agents: fiber, osmotic laxatives (polyethylene glycol, magnesium oxide, lactulose), stimulant laxatives (bisacodyl, sodium picosulfate, senna), secretagogues (lubiprostone, linaclotide, plecanatide), and serotonin type 4 agonist (prucalopride). The panel prioritized clinical questions and outcomes and used the Grading of Recommendations Assessment, Development, and Evaluation framework to assess the certainty of evidence for each intervention. The Evidence to Decision framework was used to develop clinical recommendations based on the balance between the desirable and undesirable effects, patient values, costs, and health equity considerations. RESULTS: The panel agreed on 10 recommendations for the pharmacological management of CIC in adults. Based on available evidence, the panel made strong recommendations for the use of polyethylene glycol, sodium picosulfate, linaclotide, plecanatide, and prucalopride for CIC in adults. Conditional recommendations were made for the use of fiber, lactulose, senna, magnesium oxide, and lubiprostone. DISCUSSION: This document provides a comprehensive outline of the various over-the-counter and prescription pharmacological agents available for the treatment of CIC. The guidelines are meant to provide a framework for approaching the management of CIC; clinical providers should engage in shared decision making based on patient preferences as well as medication cost and availability. Limitations and gaps in the evidence are highlighted to help guide future research opportunities and enhance the care of patients with chronic constipation.

Comparative profiles of lubiprostone, linaclotide, and elobixibat for chronic constipation: a systematic literature review with meta-analysis and number needed to treat/harm.

OBJECTIVE: To comprehensively evaluate the efficacy, safety, patient symptoms, and quality-of-life (QoL) of lubiprostone, linaclotide, and elobixibat as treatment for chronic constipation (CC). DESIGN: Systematic literature review (SLR) and meta-analysis (MA). Literature searches were conducted on PubMed and Embase using the Ovid platform. METHODS: SLR including randomized controlled trials (RCTs) and observational studies was conducted to identify the overall efficacy and safety of lubiprostone, linaclotide, and elobixibat. Thereafter, MA was performed using only RCTs. The number needed to treat (NNT) and number needed to harm (NNH) analyses were additionally conducted. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was efficacy regarding change in spontaneous bowel movements. Secondary outcomes included safety, constipation-related symptoms, and QoL. RESULTS: Twenty-four studies met the inclusion criteria for the SLR: 17 RCTs, 4 observational studies, and 3 single-arm trials. Feasibility assessment for the MA resulted in 14 studies available for safety data analysis, and 8 available for efficacy analysis, respectively. Three drugs showed similar efficacy in the MA and NNT analysis. However, the NNH analysis revealed distinct safety profiles: lubiprostone, linaclotide, and elobixibat were linked to the highest risk of nausea, diarrhea, and abdominal pain, respectively. CONCLUSION: The current study provides an updated overview of the efficacy, safety, patient symptoms, and QoL of the three drugs with different mechanisms of action for CC treatment.The findings could help physicians adopt an individualized approach for treating patients with CC in clinical practice.

AGA Clinical Practice Guideline on the Pharmacological Management of Irritable Bowel Syndrome With Constipation.

BACKGROUND & AIMS: Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction associated with significant disease burden. This American Gastroenterological Association guideline is intended to support practitioners in decisions about the use of medications for the pharmacological management of IBS-C and is an update of a prior technical review and guideline. METHODS: The Grading of Recommendations Assessment, Development and Evaluation framework was used to assess evidence and make recommendations. The technical review panel prioritized clinical questions and outcomes according to their importance for clinicians and patients and conducted an evidence review of the following agents: tenapanor, plecanatide, linaclotide, tegaserod, lubiprostone, polyethylene glycol laxatives, tricyclic antidepressants, selective serotonin reuptake inhibitors, and antispasmodics. The Guideline Panel reviewed the evidence and used the Evidence-to-Decision Framework to develop recommendations. CONCLUSIONS: The panel agreed on 9 recommendations for the management of patients with IBS-C. The panel made a strong recommendation for linaclotide (high certainty) and conditional recommendations for tenapanor, plecanatide, tegaserod, and lubiprostone (moderate certainty), polyethylene glycol laxatives, tricyclic antidepressants, and antispasmodics (low certainty). The panel made a conditional recommendation against the use of selective serotonin reuptake inhibitors (low certainty).

Factors associated with long-term efficacy of lubiprostone for chronic constipation.

The prevalence of chronic constipation in Japan is increasing, and is presently almost 1 in 5 people. Because constipation is common, especially in older patients, to avoid adverse events and polypharmacy, simple treatments at low doses are generally desired. Although the chloride channel activator lubiprostone is candidate drug that may solve these problems, factors associated with the long-term efficacy of lubiprostone monotherapy for chronic constipation in treatment-naive patients remain unclear. We here retrospectively investigated the clinical characteristics and factors of patients who achieved long-term constipation improvement with lubiprostone monotherapy. Seventy-four patients with chronic constipation treated with lubiprostone monotherapy (24 or 48 µg/day) from January 2017 to August 2018 were reviewed. Patient characteristics and clinical time-courses were compared between those who sustained improvement for 6 months, and those who became refractory to treatment. In 54 patients (76.1%), constipation improved by lubiprostone administration for 6 months. On multivariate analysis, a significant clinical factor associated with sustained improvement was a starting lubiprostone dose of 24 µg/day (odds ratio: 5.791; 95% confidence interval: 1.032-32.498; p = 0.046). A starting lubiprostone dose of 24 µg/day has efficacy to improve chronic constipation and to prevent adverse events of nausea and diarrhea in Japanese patients.

Bowel preparation using 2-L split-dose polyethylene glycol regimen plus lubiprostone versus 4-L split-dose polyethylene glycol regimen: a randomized controlled trial.

BACKGROUND: Colonoscopy is a standard procedure for evaluating colon diseases and screening for colorectal cancer, and bowel cleanliness prior to colonoscopy is key. The aim of this study was to compare the bowel cleansing efficacy of low-volume (2 L) split-dose polyethylene glycol (PEG) plus single-dose (24 µg) lubiprostone (LB) and high-volume (4 L) split-dose PEG. METHODS: Patients scheduled to undergo outpatient colonoscopy between December 2019 and June 2021 at Rajavithi Hospital were enrolled and randomized into two groups: 2 L PEG + LB or 4 L PEG. Colon cleanliness was evaluated using the Boston Bowel Preparation Scale (BBPS) by reviewing images of the colon after completion of colonoscopy. Secondary outcomes comprised cecal intubation rate, procedure time, withdrawal time, polyp detection rate, adenoma detection rate, patient satisfaction, compliance (based on complete ingestion of bowel preparation regimen), willingness to repeat the preparation regimen, and associated adverse events. RESULTS: One hundred and forty patients were included, with 70 in each group. The mean total and segment-specific BBPS scores were not significantly different between groups. However, the rate of adequate bowel preparation was significantly higher in the 2 L PEG + LB group than the 4 L PEG group (100% [95% CI 94.6-100] versus 88.4% [95% CI 78.4-94.9], p = 0.004) in the per-protocol analysis. Colonic polyps were the most common finding. The polyp detection rate, adenoma detection rate, and all secondary outcomes were statistically similar in the two groups (p > 0.05). CONCLUSIONS: The combination of 2 L split-dose PEG plus LB improves bowel cleanliness (based on BBPS scores) to a comparable degree to the standard 4 L split-dose PEG, without additional adverse events and with a lower PEG volume.

Constipation in Cancer Patients - an Update of Clinical Evidence.

OPINION STATEMENT: Constipation is one of the most frequent problems in cancer patients, and its etiology is multifactorial. It leads to decreased quality of life and impedes optimal pain treatment. Despite the high prevalence, constipation is frequently underdiagnosed mainly because of lack of validated diagnostic criteria or widely accepted definition of constipation in cancer patients. All cancer patients should be evaluated regularly for constipation, and concomitant causes and risk factors were assessed. Opioids are responsible for a much of the secondary constipation in cancer patients. The management of constipation in cancer patients should be multifaceted, addressing dietary and behavioral issues and optimizing pharmacological interventions. Prevention of opioid-induced constipation (OIC) is pivotal, as treatment is often unsatisfactory or inefficient. Dietary and behavioral interventions should be considered. Non-pharmacological measures include hydration and nutrition, ensuring privacy during defecation, using a commode or footstool, and the availability of a caregiver. Abdominal massage may be of value. Traditional laxatives are recommended in prevention but not in the treatment of OIC. Peripherally acting mu-opioid receptor antagonists (PAMORA) appear the first choice in the treatment and an alternative to laxatives in some recent clinical practice guidelines in preventing OIC. Naldemedine, naloxegol, and methylnaltrexone are supported by quality evidence for OIC management. Naloxone or naltrexone, taken orally in combined formulations with opioids, may be valuable in preventing or reducing OIC symptoms.

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.

Risk Factors for Adverse Events in Patients with Chronic Constipation Following Lubiprostone Administration.

INTRODUCTION: Lubiprostone is an effective treatment of chronic constipation (CC). However, as with other stimulant or osmotic laxatives, adverse events (AEs) can make it difficult to continue treatment. This article investigates AE risk factors associated with lubiprostone. METHODS: We retrospectively analyzed all 1,338 Japanese patients with CC treated at our hospital from October 2013 to July 2017. All patients were diagnosed with constipation as defined by the Roma III criteria. Enrolled patients received lubiprostone orally (24 or 48 µg daily), after which we investigated the incidence of AEs. The causative factors for diarrhea and nausea, the most common AEs, were examined by the backward logistic regression model. RESULTS: Two hundred eight (15.5%) experienced at least 1 AE. No serious AEs were associated with the study drug. The AEs reported by >1% of patients overall were diarrhea (6.1%) and nausea (4.2%). We performed a multivariate logistic regression using a backward variable selection method to investigate AE risk factors. Factors associated with higher incidence of diarrhea were patient age of 65 years or more (odds ratio: [95% confidence interval]; p value) (2.09: [1.05-4.16]; 0.035). Factors associated with greater likelihood of nausea included female gender (1.99: [1.10-3.61]; 0.023), and the chief complaint was a patient complaining of abdominal pain and fullness (2.07: [1.01-4.22]; 0.046). CONCLUSIONS: Understanding AE risk factors can help avoid unnecessary AEs and promote more effective treatment.

Real-World Comparison of Elobixibat and Lubiprostone Treatment in Patients with Chronic Constipation: A Propensity Score-Matched Analysis.

INTRODUCTION: Elobixibat is a new laxative, but its efficacy and adverse events (AEs) are insufficiently examined compared with those of other laxatives. Hence, by propensity score (PS) matching, we compared the effects and AEs between elobixibat and lubiprostone. METHODS: We retrospectively analyzed 1,887 Japanese patients with chronic constipation (CC) treated at our hospital between October 2013 and April 2020. Enrolled patients were divided into three treatment groups, namely, elobixibat (10 mg daily) (E10 group, n = 293), lubiprostone (24 µg daily) (L24 group, n = 772), and lubiprostone (48 µg daily) (L48 group, n = 822), as their first treatment. We then investigated the changes on the weekly average number of spontaneous bowel movements, stool consistency scores (SCSs), and AEs starting from the baseline until the end of the 2-week treatment. To adjust for patients' background, we performed one-to-one nearest neighbor matching without replacement between elobixibat- and lubiprostone-treated patients according to the individual estimated PSs. RESULTS: After treatment, for SCSs, both the L24 and L48 groups significantly improved compared with the E10 group (p < 0.05), but their stools were soft (Bristol Stool Form Scale: 4.8). Notably, the E10 group had less frequent AEs than the L24 group (26 [9.0%] vs. 43 [14.8%], p = 0.03). Particularly, nausea was significantly less in the E10 group than that in the L48 group (2 [0.7%] vs. 7 [2.4%], p = 0.01). CONCLUSION: Elobixibat is a beneficial drug for patients with mildly symptomatic CC and is safe to use, given its few AEs.

Defining the role of CFTR channel blocker and ClC-2 activator in DNBS induced gastrointestinal inflammation.

In the present study, we have investigated and/or compared the role of glibenclamide, G as cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor, and lubiprostone, L as chloride channel-2 (ClC-2) activator in the 2,4-dinitrobenzene sulfonic acid (DNBS)-induced gastrointestinal inflammation. GI inflammation was induced by intrarectal administration of DNBS. Rats were randomly allocated in 5 groups as sham control, distilled water + DNBS, sulfasalazine (S) + DNBS, G + DNBS, and L + DNBS. All the groups were pre-treated successively for five days before the induction of colitis. One day before and the first four days after DNBS administration various parameters were studied. Later, blood chemistry, colon's gross structure, histology, and the antioxidant load was examined. Pre-treatment with G significantly protected the change induced by DNBS concerning the change in body weight, food intake, diarrhea, occult blood in the feces, wet weight of the colon, and spleen. G because of its anti-inflammatory property down-regulated the neutrophil and WBC count and up-regulated the lymphocyte number. Moreover, G efficiently ameliorates the oxidative stress in the colon and declines the level of myeloperoxidase and malondialdehyde and up-regulated the level of superoxide dismutase and glutathione. Lubiprostone has not shown any promising effects, in fact, it causes an increase in diarrheal frequency. Our findings from this study represent that G has good potential to ameliorate GI inflammation induced by DNBS by its multiple actions including CFTR blockage and reducing the release of inflammatory markers from the MCs, anti-inflammatory and free radical scavenging property.

Lubiprostone protects esophageal mucosa from acid injury in porcine esophagus.

Esophageal injury from acid exposure related to gastroesophageal reflux disease is a common problem and a risk factor for development of Barrett's esophagus and esophageal adenocarcinoma. Our previous work highlights the benefits of using porcine esophagus to study human esophageal disease because of the similarities between porcine and human esophagus. In particular, esophageal submucosal glands (ESMGs) are present in human esophagus and proximal porcine esophagus but not in rodent esophagus. Although CFTR is expressed in the ducts of ESMGs, very little is known about CFTR and alternate anion channels, including ClC-2, in the setting of acid-related esophageal injury. After finding evidence of CFTR and ClC-2 in the basal layers of the squamous epithelium, and in the ducts of the ESMGs, we developed an ex vivo porcine model of esophageal acid injury. In this model, esophageal tissue was placed in Ussing chambers to determine the effect of pretreatment with the ClC-2 agonist lubiprostone on tissue damage related to acid exposure. Pretreatment with lubiprostone significantly reduced the level of acid injury and significantly augmented the recovery of the injured tissue (P < 0.05). Evaluation of the interepithelial tight junctions showed well-defined membrane localization of occludin in lubiprostone-treated injured tissues. Pretreatment of tissues with the Na+-K+-2Cl- cotransporter inhibitor bumetanide blocked lubiprostone-induced increases in short-circuit current and inhibited the reparative effect of lubiprostone. Furthermore, inhibition of ClC-2 with ZnCl2 blocked the effects of lubiprostone. We conclude that ClC-2 contributes to esophageal protection from acid exposure, potentially offering a new therapeutic target.NEW & NOTEWORTHY This research is the first to describe the presence of anion channels ClC-2 and CFTR localized to the basal epithelia of porcine esophageal mucosa and the esophageal submucosal glands. In the setting of ex vivo acid exposure, the ClC-2 agonist lubiprostone reduced acid-related injury and enhanced recovery of the epithelial barrier. This work may ultimately provide an alternate mechanism for treating gastroesophageal reflux disease.

Effect of lubiprostone on vinca alkaloid-induced constipation in patients with hematological malignancies: a propensity score-matched analysis.

Patients receiving vinca alkaloids for hematological malignancies frequently experience constipation that is unresponsive to laxatives. Research on treatment of vinca alkaloid-induced constipation is limited. This study aimed to determine whether the chloride channel activator lubiprostone ameliorates vinca alkaloid-induced constipation in patients with hematological malignancies. In this retrospective cohort study, vinca alkaloid-induced constipation (grade ≥ 3 using the Common Terminology Criteria for Adverse Events) was investigated in patients treated for hematological malignancies between July 2014 and June 2019 who had already been prescribed osmotic laxatives and additionally received either a stimulant laxative or lubiprostone. Univariate and multivariate analyses were performed to identify the risk factors for persistent constipation after introduction of the second laxative. A propensity score model was used to match 67 patients taking a stimulant laxative and 67 treated with lubiprostone, and the occurrence of intractable constipation was compared between groups. Overall, 203 patients were included, among whom 50 (25%) had constipation. On multivariate analysis, body mass index, opioid use, and addition of lubiprostone were independently associated with constipation. Patients treated with lubiprostone were significantly less likely to experience intractable constipation than did those treated with stimulant laxatives (10% vs. 34%, P = 0.002). Moreover, post-constipation diarrhea was significantly less frequent among patients treated with lubiprostone (42% vs. 63%, P = 0.024). Lubiprostone was more effective than stimulant laxatives at treating vinca alkaloid-induced intractable constipation in patients with hematological malignancies, and its use could enable safe vinca alkaloid chemotherapy.

The Efficacy and Safety of Lubiprostone for Constipation in Cancer Patients Compared with Non-cancer Patients: A Retrospective Cohort Study.

Lubiprostone is an effective drug for various types of constipation in patients without cancer; however, there is no report on its efficacy and safety in patients with cancer. Our purpose was to evaluate the efficacy and safety of lubiprostone for constipation in cancer patients. We retrospectively studied 124 patients (cancer, N = 67) who were treated with lubiprostone for constipation in our hospital between June 2013 and May 2016. The number of bowel movements (BMs) increased in the both the cancer and non-cancer groups. The mean change in BM frequency did not differ between the two groups. Approximately 70% of patients in both groups had an initial BM within 24 h after administration of lubiprostone. The most common lubiprostone-related adverse events in both groups were diarrhea (38.8 vs. 14%), and nausea (22.4 vs. 8.8%). No lubiprostone-related serious adverse events occurred. Discontinuation due to the side effects of lubiprostone was more frequent in cancer patients (p = 0.023). Logistic regression analysis showed that the risk of discontinuation of lubiprostone in cancer patients was high in patients with a body-mass index (BMI) <22, and low in patients using opioids and magnesium oxide dosage ≥1000 mg/d. Our study showed that while lubiprostone was as effective in cancer patients as in non-cancer patients, in cancer patients it was associated with a high incidence of diarrhea and nausea side effects and warranted caution, especially in patients with a low BMI.

Differences in efficacy and safety of lubiprostone used for idiopathic vs opioid-induced constipation: meta-analysis of East Asian and Western populations.

Several secretagogues, such as lubiprostone, have been developed for the treatment of constipation in the last 10 years. It is unclear whether the efficacy of lubiprostone for spontaneous bowel movement (SBM) and the adverse events are similar between idiopathic and opioid-induced constipation and between East-Asian and Western populations. We conducted a meta-analysis to compare efficacy and safety of lubiprostone in two populations with idiopathic vs opioid-induced constipation. The PubMed and Cochrane databases were searched for relevant randomized control trials (RCTs) investigating the efficacy and safety that were published in English up to March 2019. Compared with the placebo groups in idiopathic and opioid-induced constipation, the lubiprostone groups significantly improved in 24-h SBM frequency [relative risk: 1.28, 95% confidence interval, 1.11-1.49, and 1.23, 1.14-1.32] and weekly frequency >3 SBM/week (1.68, 1.41-2.01, and 1.43, 1.01-2.04), respectively. Although the incidence of adverse events was similar between idiopathic and opioid-induced constipation, the incidence of nausea in Western populations with idiopathic constipation was significantly higher (29.2%) than that in East-Asian populations (10.0%, p<0.001). In conclusion, lubiprostone effectively improved SBM frequency, irrespective of the etiology of constipation and population. The incidence of nausea was significantly higher in Western populations.

Evaluation and Comparison of Daiokanzoto and Lubiprostone for Constipation: A Retrospective Cohort Study.

Daiokanzoto (DKT) and lubiprostone (LPS) are drugs used for constipation, but few studies have compared them. This study examined the effectiveness, adverse events, and medical economic efficiency of DKT and LPS for constipation. Patients who received DKT (DKT group) and those who received LPS (LPS group) during admission to Ogaki Municipal Hospital between November 2012 and May 2016 were enrolled. Drug efficacy was evaluated based on the median value of bowel movement frequency over 1 week before and after drug administration, and their safety was evaluated by the presence or absence of diarrhea, abdominal pain, nausea, and vomiting. To assess medical economic efficiency, drug costs for constipation per week were calculated. The median values (quartile ranges) of bowel movement frequency at 1 week after drug administration were 8.5 (6.0-12.0) in the DKT group and 5 (3.0-7.0) in the LPS group, which was significantly different (p < 0.01). Diarrhea occurred significantly less often in the DKT group (4 cases) than in the LPS group (17 cases) (p < 0.01). The median cost of drugs administered for constipation for 1 week was significantly lower in the DKT group (631 [quartile range, 513-653] yen) than in the LPS group (1431 [1135-2344] yen) (p < 0.01). DKT had a higher immediate effect on constipation and was associated with more frequent bowel movement and fewer adverse events of diarrhea than LPS, suggesting that it may be effective and safe for treating constipation, and DKT is inexpensive.

Identification of the fatty acid activation site on human ClC-2.

Fatty acids (including lubiprostone and cobiprostone) are human ClC-2 (hClC-2) Cl- channel activators. Molecular and cellular mechanisms underlying this activation were examined. Role of a four-amino acid PKA activation site, RGET691, of hClC-2 was investigated using wild-type (WT) and mutant (AGET, RGEA, and AGAA) hClC-2 expressed in 293EBNA cells as well as involvement of PKA, intracellular cAMP concentration ([cAMP]i), EP2, or EP4 receptor agonist activity. All fatty acids [lubiprostone, cobiprostone, eicosatetraynoic acid (ETYA), oleic acid, and elaidic acid] caused significant rightward shifts in concentration-dependent Cl- current activation (increasing EC50s) with mutant compared with WT hClC-2 channels, without changing time and voltage dependence, current-voltage rectification, or methadone inhibition of the channel. As with lubiprostone, cobiprostone activation of hClC-2 occurred with PKA inhibitor (myristoylated protein kinase inhibitor) present or when using double PKA activation site (RRAA655/RGEA691) mutant. Cobiprostone did not activate human CFTR. Fatty acids did not increase [cAMP]i in hClC-2/293EBNA or T84 cells. Using T84 CFTR knockdown cells, cobiprostone increased hClC-2 Cl- currents without increasing [cAMP]i, while PGE2 and forskolin-IBMX increased both. Fatty acids were not agonists of EP2 or EP4 receptors. L-161,982, a supposed EP4-selective inhibitor, had no effect on lubiprostone-activated hClC-2 Cl- currents but significantly decreased T84 cell barrier function measured by transepithelial resistance and fluorescent dextran transepithelial movement. The present findings show that RGET691 of hClC-2 (possible binding site) plays an important functional role in fatty acid activation of hClC-2. PKA, [cAMP]i, and EP2 or EP4 receptors are not involved. These studies provide the molecular basis for fatty acid regulation of hClC-2.

Opioid-Related Constipation in Patients With Non-cancer Pain Syndromes: a Review of Evidence-Based Therapies and Justification for a Change in Nomenclature.

PURPOSE OF REVIEW: Opioids are a mainstay in the treatment of chronic non-cancer pain syndromes, but their analgesic benefits come at a cost as opioid-related constipation occurs in 40-80% of individuals taking chronic opioids. Furthermore, as 10-20% of the population suffers from constipation at baseline, it should be expected that while a proportion of individuals will develop constipation as a direct consequence of opioids (OIC), others will experience it as an exacerbation of their baseline constipation (OEC). Herein, we review the evidence-based data for treatments directed at opioid-related constipation focusing on individuals with non-cancer pain syndromes and provide a template for the development of differentiated treatment algorithms for OIC and OEC. RECENT FINDINGS: Historical and current treatment protocols recommend traditional laxatives, but these are ineffective in up to 50%, due in part to the heterogeneous pathogenesis of constipation. Therapeutic decisions must be tailored to account for this overlapping pathogenesis. OIC and OEC are distinct entities. As such, additional research and guidelines should address these as different patient populations.

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.

Lubiprostone for Opioid-Induced Constipation Does Not Interfere with Opioid Analgesia in Patients with Chronic Noncancer Pain.

OBJECTIVE: To determine whether lubiprostone 24 µg twice daily (BID), administered to relieve opioid-induced constipation (OIC), affects opioid analgesia in patients with chronic noncancer pain. METHODS: Data were pooled from 3 randomized, double-blind, placebo-controlled trials of lubiprostone in adults with chronic noncancer pain receiving stable opioid analgesia and who had documented OIC. In each study, lubiprostone 24 µg BID or placebo was administered for 12 weeks for relief of OIC using a common protocol. The Brief Pain Inventory short form (BPI-SF) was administered, and opioid use (expressed as morphine-equivalent daily dose [MEDD]) was recorded at baseline and months 1, 2, and 3. The BPI-SF provided patient scores for pain severity, the worst pain experienced in the past 24 hours, and pain interference with daily life. RESULTS: The pooled patient population (N = 1300) was predominately female (62.5%) and white (82.1%), with a mean age of 50.5 years. The MEDD was 97.5 mg (range, 5 to 3656 mg) in patients receiving placebo and 112.5 mg (range, 4 to 7605 mg) in patients treated with lubiprostone. Lubiprostone 24 µg BID treatment did not appear to affect opioid use or pain scores; changes from baseline were not significantly different with placebo vs. lubiprostone 24 µg BID at months 1, 2, and 3 for MEDD (P ≥ 0.435) and for BPI-SF scores for pain interference, pain severity, and worst pain (P ≥ 0.402). DISCUSSION: Lubiprostone 24 µg BID administered for relief of OIC in patients with chronic noncancer pain does not interfere with opioid analgesia.

Addition of Lubiprostone to polyethylene glycol(PEG) enhances the quality & efficacy of colonoscopy preparation: a randomized, double-blind, placebo controlled trial.

BACKGROUND: Adequate bowel preparation is an essential prerequisite for complete mucosal visualization during colonoscopy. Polyethylene glycol (PEG) solutions are commonly used. However the large volume of the solution is often poorly tolerated. Addition of Lubiprostone (LB) could improve the adequacy of standard PEG preparation & reduce requirement. The aims to assess adequacy of PEG preparation with addition of single dose LB (24mcg) vs placebo and efficacy of reduced dose PEG + LB compared with full dose PEG + LB. METHODS: Single center prospective double blind randomized controlled trial. Part I: 442 patients for colonoscopy randomized to receive placebo (GrA) or single dose of LB (GrB) prior to PEG preparation. Quality of bowel preparation graded 0-9 according to Boston Bowel Preparation Scale (BBPS). BBPS-9: excellent and BBPS 0-4: repeat procedure. Part II: 146 patients randomized to receive LB + 1.5 L PEG (GrC; 75) or LB + 1 L PEG (GrD; 71). BBPS score compared with GrB (2 L PEG). RESULTS: Part I: 442 patients (221 GrA & 221 Gr B). LB resulted in significant improvement in total BBPS (7.44 + 0.14 vs. 6.36 + 0.16, p < 0.0001). 66.5 % Gr B vs 38 % Gr A had excellent prep; 42.5 % GrB vs 24 % GrA had adequate prep. Repeat procedure needed 9.5 % Gr B vs 16.7 % Gr A (P < 0.01). Part II: No difference in BBPS scores with lower doses (Gr C&D) compared to standard (GrB) (Mean BBPS 7.44 + 0.14 GrA,7.30 + 0.25 GrC;7.25 + 0.26 GrD;p >0.05). CONCLUSION: Single dose LB prior to PEG significantly enhanced bowel preparation compared to PEG alone. There was no significant difference in quality of preparation with lower doses of PEG when combined with LB. TRIAL REGISTRATION: The study protocol was approved by institutional review board and the trial was registered on March 22, 2011 with clinicaltrials.gov ( NCT01324284 ).