The Strength of hERG Inhibition by Erythromycin at Different Temperatures Might Be Due to Its Interacting Features with the Channels.

Erythromycin is one of the few compounds that remarkably increase ether-a-go-go-related gene (hERG) inhibition from room temperature (RT) to physiological temperature (PT). Understanding how erythromycin inhibits the hERG could help us to decide which compounds are needed for further studies. The whole-cell patch clamp technique was used to investigate the effects of erythromycin on hERG channels at different temperatures. While erythromycin caused a concentration-dependent inhibition of cardiac hERG channels, it also shifted the steady-state activation and steady-state inactivation of the channel to the left and significantly accelerated the onset of inactivation at both temperatures, although temperature itself caused a profound change in the dynamics of hERG channels. Our data also suggest that the binding pattern to S6 of the channels changes at PT. In contrast, cisapride, a well-known hERG blocker whose inhibition is not affected by temperature, does not change its critical binding sites after the temperature is raised to PT. Our data suggest that erythromycin is unique and that the shift in hERG inhibition may not apply to other compounds.

Cisapride induced hypoglycemia via the KCNH6 potassium channel.

Mutations in KCNH6 has been proved to cause hypoinsulinemia and diabetes in human and mice. Cisapride is a stomach-intestinal motility drug used to treat gastrointestinal dysfunction. Cisapride has been reported to be a potential inhibitor of the KCNH family, but it remained unclear whether cisapride inhibited KCNH6. Here, we discovered the role of cisapride on glucose metabolism, focusing on the KCNH6 potassium channel protein. Cisapride reduced blood glucose level and increased serum insulin secretion in wild-type (WT) mice fed standard normal chow/a high-fat diet or in db/db mice, especially when combined with tolbutamide. This effect was much stronger after 4 weeks of intraperitoneal injection. Whole-cell patch-clamp showed that cisapride inhibited KCNH6 currents in transfected HEK293 cells in a concentration-dependent manner. Cisapride induced an increased insulin secretion through the disruption of intracellular calcium homeostasis in a rat pancreatic ß-cell line, INS-1E. Further experiments revealed that cisapride did not decrease blood glucose or increase serum insulin in KCNH6 ß-cell knockout (Kcnh6-ß-KO) mice when compared with WT mice. Cisapride also ameliorated glucose-stimulated insulin secretion (GSIS) in response to high glucose in WT but not Kcnh6-ß-KO mice. Thus, our data reveal a novel way for the effect of KCNH6 in cisapride-induced hypoglycemia.

hERG block potencies for 5 positive control drugs obtained per ICH E14/S7B Q&As best practices: Impact of recording temperature and drug loss.

According to the ICH S7B guideline, drug candidates are screened for hERG block prior to first-in-human testing to predict the likelihood of delayed repolarization associated with a rare, but life-threatening, ventricular tachyarrhythmia. The new ICH E14 Q&As guideline allows hERG results to be used in later clinical development for decision-making (Q&As 5.1 and 6.1). To pursue this path, the hERG assay should be conducted following the new ICH S7B Q&A 2.1 guideline, which calls for best practice considerations of the recording temperature, voltage protocol, stimulation frequency, recording/data quality, and concentration verification. This study investigated hERG block by cisapride, dofetilide, terfenadine, sotalol, and E-4031 - positive controls commonly used to demonstrate assay sensitivity - using the manual whole cell patch clamp method and an action potential-like voltage protocol presented at 0.2 Hz. Recordings were conducted at room and near physiological temperature. Drug concentrations were measured using samples collected during real patch clamp experiments and satellite experiments. Results showed temperature effects for E-4031, terfenadine, and sotalol, but not cisapride and dofetilide. Cisapride and terfenadine showed substantial concentration losses, largely due to nonspecific binding to the perfusion apparatus. Using concentrations measured from the real and satellite experiments to assess block potencies yielded comparable results, indicating that satellite sample collection may be viable for drugs with nonspecific binding concerns only. In summary, this study provides block potencies for 5 hERG positive controls, and serves as a case study for hERG assays conducted, and results illustrated in accordance with the new ICH E14/S7B Q&As.

High throughput measurement of hERG drug block kinetics using the CiPA dynamic protocol.

The Comprehensive in vitro Proarrhythmic Assay (CiPA) has promoted use of in silico models of drug effects on cardiac repolarization to improve proarrhythmic risk prediction. These models contain a pharmacodynamic component describing drug binding to hERG channels that required in vitro data for kinetics of block, in addition to potency, to constrain them. To date, development and validation has been undertaken using data from manual patch-clamp. The application of this approach at scale requires the development of a high-throughput, automated patch-clamp (APC) implementation. Here, we present a comprehensive analysis of the implementation of the Milnes, or CiPA dynamic protocol, on an APC platform, including quality control and data analysis. Kinetics and potency of block were assessed for bepridil, cisapride, terfenadine and verapamil with data retention/QC pass rate of 21.8% overall, or as high as 50.4% when only appropriate sweep lengths were considered for drugs with faster kinetics. The variability in IC50 and kinetics between manual and APC was comparable to that seen between sites/platforms in previous APC studies of potency. Whilst the experimental success is less than observed in screens of potency alone, it is still significantly greater than manual patch. With the modifications to protocol design, including sweep length, number of repetitions, and leak correction recommended in this study, this protocol can be applied on APC to acquire data comparable to manual patch clamp.

Interventions for preventing distal intestinal obstruction syndrome (DIOS) in cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF) is the most common, life-limiting, genetically inherited disease. It affects multiple organs, particularly the respiratory system. However, gastrointestinal problems such as constipation and distal intestinal obstruction syndrome (DIOS) are also important and well-recognised complications in CF. They share similar symptoms e.g. bloating, abdominal pain, but are distinct conditions. Constipation occurs when there is gradual faecal impaction of the colon, but DIOS occurs when there is an accumulation of faeces and sticky mucus, forming a mass in the distal part of the small intestine. The mass may partially block the intestine (incomplete DIOS) or completely block the intestine (complete DIOS). Symptoms of DIOS can affect quality of life and other aspects of CF health, such as airway clearance, exercise, sleep and nutritional status. Treatment of constipation and prevention of complete bowel obstruction are required for gastrointestinal management in CF. However, many different strategies are used in clinical practice and there is a lack of consensus. The importance of this topic was highlighted in a recent research priority setting exercise by the James Lind Alliance. OBJECTIVES: To evaluate the effectiveness and safety of laxative agents of differing types for preventing DIOS (complete and incomplete) in children and adults with CF. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Date of search: 09 September 2021. We also searched online trial registries. Date of last search: 12 October 2021. SELECTION CRITERIA: Randomised and quasi-randomised controlled parallel trials comparing laxative therapy for preventing DIOS (including osmotic agents, stimulants, mucolytics and substances with more than one action) at any dose to placebo, no treatment or an alternative laxative therapy, in people of any age with pancreatic sufficient or insufficient CF and any stage of lung disease. Randomised cross-over trials were judged on an individual basis. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trials for inclusion, extracted outcome data and performed a risk of bias assessment for the included data. We judged the certainty of the evidence using GRADE criteria. MAIN RESULTS: We included one cross-over trial (17 participants) with a duration of 12 months, in which participants were randomly allocated to either cisapride (a gastro-prokinetic agent) or placebo for six months each. The trial had an unclear risk of bias for most domains but had a high risk of reporting bias. Radiograph scores revealed no difference in occurrence of DIOS between cisapride and placebo (narrative report, no data provided). There were no adverse effects. Symptom scores were the only secondary outcome within the review that were reported. Total gastrointestinal symptom scores favoured cisapride with a statistically significant mean difference (MD) of -7.60 (95% confidence interval (CI) -14.73 to -0.47). There was no significant difference at six months between cisapride and placebo for abdominal distension, MD -0.90 (95% CI -2.39 to 0.59) or abdominal pain, MD -0.4 (95% CI -2.05 to 1.25). The global symptom scores (whether individuals felt better or worse) were reported in the paper to favour cisapride and be statistically significant (P < 0.05). We assessed the available data to be very low certainty. There was a great deal of missing data from the included trial and the investigators failed to report numerical data for many outcomes. The overall risk of bias of the trial was unclear and it had a high risk for reporting bias. There was also indirectness; the trial drug (cisapride) has since been removed from the market in several countries due to adverse effects, thus it has no current applicability for preventing DIOS. The included trial also had very few participants, which downgraded the certainty a further level for precision. AUTHORS' CONCLUSIONS: There is an absence of evidence for interventions for the prevention of DIOS. As there was only one included trial, we could not perform a meta-analysis of the data. Furthermore, the included trial compared a prokinetic agent (cisapride) that is no longer licensed for use in a number of countries due to the risk of serious cardiac events, a finding that came to light after the trial was conducted. Therefore, the limited findings from the trial are not applicable in current clinical practice. Overall, a great deal more research needs to be undertaken on gastrointestinal complications in CF, as this is a very poorly studied area compared to respiratory complications in CF.

Pharmacological and surgical interventions for the treatment of gastro-oesophageal reflux in adults and children with asthma.

BACKGROUND: Asthma and gastro-oesophageal reflux disease (GORD) are common medical conditions that frequently co-exist. GORD has been postulated as a trigger for asthma; however, evidence remains conflicting. Proposed mechanisms by which GORD causes asthma include direct airway irritation from micro-aspiration and vagally mediated oesophagobronchial reflux. Furthermore, asthma might precipitate GORD. Thus a temporal association between the two does not establish that GORD triggers asthma. OBJECTIVES: To evaluate the effectiveness of GORD treatment in adults and children with asthma, in terms of its benefits for asthma. SEARCH METHODS: The Cochrane Airways Group Specialised Register, CENTRAL, MEDLINE, Embase, reference lists of articles, and online clinical trial databases were searched. The most recent search was conducted on 23 June 2020. SELECTION CRITERIA: We included randomised controlled trials comparing treatment of GORD in adults and children with a diagnosis of both asthma and GORD versus no treatment or placebo. DATA COLLECTION AND ANALYSIS: A combination of two independent review authors extracted study data and assessed trial quality. The primary outcome of interest for this review was acute asthma exacerbation as reported by trialists. MAIN RESULTS: The systematic search yielded a total of 3354 citations; 23 studies (n = 2872 participants) were suitable for inclusion. Included studies reported data from participants in 25 different countries across Europe, North and South America, Asia, Australia, and the Middle East. Participants included in this review had moderate to severe asthma and a diagnosis of GORD and were predominantly adults presenting to a clinic for treatment. Only two studies assessed effects of intervention on children, and two assessed the impact of surgical intervention. The remainder were concerned with medical intervention using a variety of dosing protocols. There was an uncertain reduction in the number of participants experiencing one or more moderate/severe asthma exacerbations with medical treatment for GORD (odds ratio 0.53, 95% confidence interval (CI) 0.17 to 1.63; 1168 participants, 2 studies; low-certainty evidence). None of the included studies reported data related to the other primary outcomes for this review: hospital admissions, emergency department visits, and unscheduled doctor visits. Medical treatment for GORD probably improved forced expiratory volume in one second (FEV1) by a small amount (mean difference (MD) 0.10 L, 95% CI 0.05 to 0.15; 1333 participants, 7 studies; moderate-certainty evidence) as well as use of rescue medications (MD -0.71 puffs per day, 95% CI -1.20 to -0.22; 239 participants, 2 studies; moderate-certainty evidence). However, the benefit of GORD treatment for morning peak expiratory flow rate was uncertain (MD 6.02 L/min, 95% CI 0.56 to 11.47; 1262 participants, 5 studies). It is important to note that these mean improvements did not reach clinical importance. The benefit of GORD treatment for outcomes synthesised narratively including benefits of treatment for asthma symptoms, quality of life, and treatment preference was likewise uncertain. Data related to adverse events with intervention were generally underreported by the included studies, and those that were available indicated similar rates regardless of allocation to treatment or placebo. AUTHORS' CONCLUSIONS: Effects of GORD treatment on the primary outcomes of number of people experiencing one or more exacerbations and hospital utilisation remain uncertain. Medical treatment for GORD in people with asthma may provide small benefit for a number of secondary outcomes related to asthma management. This review determined with moderate certainty that with treatment, lung function measures improved slightly, and use of rescue medications for asthma control was reduced. Further, evidence is insufficient to assess results in children, or to compare surgery versus medical therapy.

RANKL-induced osteoclastogenesis in bone marrow-derived macrophages is suppressed by cisapride.

Cisapride is a selective 5-hydroxytryptamine (5-HT)4 receptor (5-HT4R) agonist. However, the effects of cisapride on osteoclasts and osteoblasts have not been fully explored. We therefore examined the effects of cisapride on osteoclastogenesis in cultured primary bone marrow-derived macrophages (BMMs), and on osteoblast differentiation in cultured primary calvarial pre-osteoblasts. Cisapride significantly inhibited tartrate-resistant acid phosphatase (TRAP)-positive multinuclear osteoclasts and F-actin ring formation during receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis. No cytotoxicity was observed. Cisapride also suppressed RANKL-induced expression of NF-ATc1, TRAP, and cathepsin K genes in BMMs. In addition, cisapride significantly stimulated apoptotic cell death of osteoclasts. However, cisapride had no effect on osteoblast differentiation, as assessed by alkaline phosphatase (ALP) activity and mineralized nodule formation in the cultured primary pre-osteoblasts. Overall, our findings suggest that cisapride may improve the clinical management of metabolic bone diseases such as osteoporosis.

Effects of preoperative cisapride on postoperative aspiration pneumonia in dogs with laryngeal paralysis.

OBJECTIVES: Retrospective evaluation of a preoperative prokinetic protocol using a constant-rate infusion of a serotonin 5-HT4 receptor agonist, cisapride, and its association with frequency of postoperative aspiration pneumonia in dogs undergoing unilateral arytenoid lateralisation as compared to a historical population at the same institution. MATERIALS AND METHODS: Medical records of dogs undergoing unilateral arytenoid lateralisation for laryngeal paralysis were reviewed for historical findings, imaging findings, anaesthesia and surgery durations, perioperative medications and if surgery was performed as an emergency. Aspiration pneumonia events in the first 72 hours after surgery were recorded. The study group received a preoperative cisapride constant-rate infusion; historical 'controls' did not receive the cisapride protocol. RESULTS: One of 50 dogs in the cisapride group and six of 52 dogs in the historical group developed aspiration pneumonia within the immediate postoperative period. The cisapride protocol was largely well tolerated. A markedly lower rate of aspiration pneumonia in patients administered butorphanol with acepromazine preoperatively and buprenorphine postoperatively was noted, but the overall low frequency of aspiration pneumonia and variation in case management protocols precluded definitive conclusions with respect to optimal perioperative drug choices. CLINICAL SIGNIFICANCE: Laryngeal paralysis is commonly treated by unilateral arytenoid lateralisation, and aspiration pneumonia is one of the most serious potential complications of this procedure. This study suggests that further investigation of a cisapride constant-rate infusion to prevent this complication is warranted.

Acupuncture for symptomatic gastroparesis.

BACKGROUND: Gastroparesis, a state of delayed gastric emptying in the absence of mechanical obstruction of the stomach, has a substantial impact on people's daily function and quality of life when symptomatic. Current treatment options are based on limited evidence of benefits. Acupuncture is widely used to manage gastrointestinal disorders, although its role in people with symptomatic gastroparesis is unclear. We therefore undertook a systematic review of the evidence. OBJECTIVES: To assess the benefits and harms of acupuncture, in comparison with no treatment, sham acupuncture, conventional medicine, standard care, or other non-pharmacological active interventions for symptom management in people with gastroparesis. SEARCH METHODS: On 26 March 2018, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL Plus, PsycINFO, AMED, Korean medical databases (including Korean Studies Information, DBPIA, Korea Institute of Science and Technology Information, Research Information Centre for Health Database, KoreaMed, and the National Assembly Library), and Chinese databases (including the China Academic Journal). We also searched two clinical trials registries for ongoing trials. We imposed no language limitations. SELECTION CRITERIA: We selected all randomised controlled trials comparing the penetrating type of acupuncture with no treatment, sham acupuncture, conventional medicine, standard care, and other non-pharmacological active interventions for people with symptomatic gastroparesis of any aetiology (i.e. surgical, diabetic, or idiopathic). Trials reporting outcomes at least four weeks from baseline (short-term outcomes) were eligible. We defined long-term outcomes as those measured after 12 weeks from baseline. The primary outcome was improvement of gastroparesis symptoms in the short term. Secondary outcomes were: improvement of symptoms measured after three months, change in the rate of gastric emptying, quality of life, use of medication, and adverse events in the short and long term. DATA COLLECTION AND ANALYSIS: Two review authors independently selected eligible trials based on predefined selection criteria. Two review authors independently extracted data and evaluated the risk of bias. The review authors contacted investigators to obtain missing information wherever possible. MAIN RESULTS: We included 32 studies that involved a total of 2601 participants. Acupuncture was either manually stimulated (24 studies) or electrically stimulated (8 studies). The aetiology of gastroparesis was diabetes (31 studies) or surgery (1 study). All studies provided data on the proportion of people with symptoms 'improved', although the definition or categorisation of improvement varied among the studies. Most measured only short-term outcomes (28 studies), and only one study employed validated instruments to assess subjective changes in symptoms or reported data on quality of life or the use of medication. Reporting of harm was incomplete; minor adverse events were reported in only seven trials. Most studies had unclear risk of bias in terms of allocation concealment (29/32), outcome assessor blinding (31/32) and selective reporting (31/32), as well as high risk of bias in terms of participant/personnel blinding (31/32). Acupuncture was compared with sham acupuncture (needling on non-acupuncture points), three different types of gastrokinetic drugs (domperidone, mosapride, cisapride), and a histamine H2 receptor antagonist (cimetidine).There was low-certainty evidence that symptom scores of participants receiving acupuncture did not differ from those of participants receiving sham acupuncture at three months when measured by a validated scale.There was very low-certainty evidence that a greater proportion of participants receiving acupuncture had 'improved' symptoms in the short term compared to participants who received gastrokinetic medication (4 to 12 weeks) (12 studies; 963 participants; risk ratio (RR) 1.25; 95% confidence interval (CI) 1.17 to 1.33, I² = 8%). Short-term improvement in overall symptom scores favouring acupuncture was also reported in five studies with considerable heterogeneity.Acupuncture in combination with other treatments, including gastrokinetics, non-gastrokinetics and routine care, was compared with the same treatment alone. There was very low-certainty evidence in favour of acupuncture for the proportion of participants with 'improved' symptoms in the short term (4 to 12 weeks) (17 studies; 1404 participants; RR 1.22; 95% CI 1.16 to 1.28; I² = 0%). Short-term improvement in overall symptom scores, favouring acupuncture, were also reported (two studies, 132 participants; MD -1.96, 95% CI -2.42 to -1.50; I² = 0%).Seven studies described adverse events, including minor bleeding and hematoma, dizziness, xerostomia, loose stool, diarrhoea, abdominal pain, skin rash and fatigue. The rest of the trials did not report whether adverse events occurred.Subgroup analyses revealed that short-term benefits in terms of the proportion of people with 'improved' symptoms did not differ according to the type of acupuncture stimulation (i.e. manual or electrical). The sensitivity analysis revealed that use of a valid method of random sequence generation, and the use of objective measurements of gastric emptying, did not alter the overall effect estimate in terms of the proportion of people with 'improved' symptoms. The asymmetric funnel plot suggests small study effects and publication bias towards positive reporting. AUTHORS' CONCLUSIONS: There is very low-certainty evidence for a short-term benefit with acupuncture alone or acupuncture combined with gastrokinetic drugs compared with the drug alone, in terms of the proportion of people who experienced improvement in diabetic gastroparesis. There is evidence of publication bias and a positive bias of small study effects. The reported benefits should be interpreted with great caution because of the unclear overall risk of bias, unvalidated measurements of change in subjective symptoms, publication bias and small study reporting bias, and lack of data on long-term outcomes; the effects reported in this review may therefore differ significantly from the true effect. One sham-controlled trial provided low-certainty evidence of no difference between real and sham acupuncture in terms of short-term symptom improvement in diabetic gastroparesis, when measured by a validated scale. No studies reported changes in quality of life or the use of medication.Due to the absence of data, no conclusion can be made regarding effects of acupuncture on gastroparesis of other aetiologies. Reports of harm have remained largely incomplete, precluding assessments of the safety of acupuncture in this population. Future research should focus on reducing the sources of bias in the trial design as well as transparent reporting. Harms of interventions should be explicitly reported.

Interventions for preventing distal intestinal obstruction syndrome (DIOS) in cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF) is the most common, life-limiting, genetically inherited disease. It affects multiple organs, particularly the respiratory system. However, gastrointestinal problems such as constipation and distal intestinal obstruction syndrome (DIOS) are also important and well-recognised complications in CF. They share similar symptoms e.g. bloating, abdominal pain, but are distinct conditions. Constipation occurs when there is gradual faecal impaction of the colon, but DIOS occurs when there is an accumulation of faeces and sticky mucus, forming a mass in the distal part of the small intestine. The mass may partially block the intestine (incomplete DIOS) or completely block the intestine (complete DIOS). Symptoms of DIOS can affect quality of life and other aspects of CF health, such as airway clearance, exercise, sleep and nutritional status. Treatment of constipation and prevention of complete bowel obstruction are required for gastrointestinal management in CF. However, many different strategies are used in clinical practice and there is a lack of consensus. The importance of this topic was highlighted in a recent research priority setting exercise by the James Lind Alliance. OBJECTIVES: To evaluate the effectiveness and safety of laxative agents of differing types for preventing DIOS (complete and incomplete) in children and adults with CF. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Date of search: 22 May 2018.We also searched online trial registries. Date of last search: 10 June 2018. SELECTION CRITERIA: Randomised and quasi-randomised controlled parallel trials comparing laxative therapy for preventing DIOS (including osmotic agents, stimulants, mucolytics and substances with more than one action) at any dose to placebo, no treatment or an alternative laxative therapy, in people of any age with pancreatic sufficient or insufficient CF and any stage of lung disease. Randomised cross-over trials were judged on an individual basis. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trials for inclusion, extracted outcome data and performed a risk of bias assessment for the included data. We judged the quality of the evidence using GRADE criteria. MAIN RESULTS: We included one cross-over trial (17 participants) with a duration of 12 months, in which participants were randomly allocated to either cisapride (a gastro-prokinetic agent) or placebo for six months each. The trial had an unclear risk of bias for most domains but had a high risk of reporting bias.Radiograph scores revealed no difference in occurrence of DIOS between cisapride and placebo (narrative report, no data provided). There were no adverse effects. Symptom scores were the only secondary outcome within the review that were reported. Total gastrointestinal symptom scores favoured cisapride with a statistically significant mean difference (MD) of -7.60 (95% confidence interval (CI) -14.73 to -0.47). There was no significant difference at six months between cisapride and placebo for abdominal distension, MD -0.90 (95% CI -2.39 to 0.59) or abdominal pain, MD -0.4 (95% CI -2.05 to 1.25). The global symptom scores (whether individuals felt better or worse) were reported in the paper to favour cisapride and be statistically significant (P < 0.05).We assessed the available data to be very low quality. There was a great deal of missing data from the included trial and the investigators failed to report numerical data for many outcomes. The overall risk of bias of the trial was unclear and it had a high risk for reporting bias. There was also indirectness; the trial drug (cisapride) has since been removed from the market in several countries due to adverse effects, thus it has no current applicability for preventing DIOS. The included trial also had very few participants, which downgraded the quality a further level for precision. AUTHORS' CONCLUSIONS: There is an absence of evidence for interventions for the prevention of DIOS. As there was only one included trial, we could not perform a meta-analysis of the data. Furthermore, the included trial compared a prokinetic agent (cisapride) that is no longer licensed for use in a number of countries due to the risk of serious cardiac events, a finding that came to light after the trial was conducted. Therefore, the limited findings from the trial are not applicable in current clinical practice.Overall, a great deal more research needs to be undertaken on gastrointestinal complications in CF, as this is a very poorly studied area compared to respiratory complications in CF.

The in vitro pharmacology and non-clinical cardiovascular safety studies of a novel 5-HT4 receptor agonist, DSP-6952.

The pharmacological activity of DSP-6952, a novel compound was investigated, compared to that of clinically efficacious gastrointestinal (GI) prokinetic 5-hydroxytryptamine4 (5-HT4) receptor agonists. DSP-6952 had a strong affinity of Ki = 51.9 nM for 5-HT4(b) receptor, and produced contraction in the isolated guinea pig colon with EC50 of 271.6 nM and low intrinsic activity of 57%, similar to tegaserod and mosapride. In the development of the 5-HT4 receptor agonists, cardiovascular risk was deliberately evaluated, because some related prokinetics were reported to cause with cardiovascular adverse events, such as ventricular arrhythmias or ischemia. DSP-6952 showed minimal effects up to 100 µM in human ether-a-go-go-related gene (hERG) channels or guinea pig cardiomyocytes. In telemetered conscious monkeys, DSP-6952 did not affect blood pressure or any electrocardiogram (ECG) up to 180 mg/kg, p.o.; however, DSP-6952 transiently increased heart rate, as well as in anesthetized dogs. The positive chronotropic effects of DSP-6952 were completely antagonized by a 5-HT4 receptor antagonist, and another 5-HT4 receptor agonist, TD-5108 also increased heart rate. These effects are considered a class effect seen in clinically developing and marketed 5-HT4 receptor agonists, and have not been regarded as a critical issue in clinical use. DSP-6952 did not induce contraction in the rabbit coronary artery up to 100 µM, which differed from tegaserod or sumatriptan. These results show that DSP-6952 does not have cardiac ischemic risk via coronary vasoconstriction. In conclusion, DSP-6952 is a promising GI prokinetic compound with partial 5-HT4 receptor agonistic activity as well as a favorable cardiovascular safety profile.

Virtual Screening of DrugBank Reveals Two Drugs as New BCRP Inhibitors.

The breast cancer resistance protein (BCRP) is an ABC transporter playing a crucial role in the pharmacokinetics of drugs. The early identification of substrates and inhibitors of this efflux transporter can help to prevent or foresee drug-drug interactions. In this work, we built a ligand-based in silico classification model to predict the inhibitory potential of drugs toward BCRP. The model was applied as a virtual screening technique to identify potential inhibitors among the small-molecules subset of DrugBank. Ten compounds were selected and tested for their capacity to inhibit mitoxantrone efflux in BCRP-expressing PLB985 cells. Results identified cisapride (IC50 = 0.4 µM) and roflumilast (IC50 = 0.9 µM) as two new BCRP inhibitors. The in silico strategy proved useful to prefilter potential drug-drug interaction perpetrators among a database of small molecules and can reduce the amount of compounds to test.

Pharmacokinetic-pharmacodynamic modelling of drug-induced QTc interval prolongation in man: prediction from in vitro human ether-à-go-go-related gene binding and functional inhibition assays and conscious dog studies.

BACKGROUND AND PURPOSE: Functional measures of human ether-à-go-go-related gene (hERG; Kv 11.1) channel inhibition have been prioritized as an in vitro screening tool for candidate molecules. However, it is unclear how these results can be translated to humans. Here, we explore how data on drug binding and functional inhibition in vitro relate to QT prolongation in vivo. Using cisapride, sotalol and moxifloxacin as paradigm compounds, we assessed the relationship between drug concentrations, binding, functional measures and in vivo effects in preclinical species and humans. EXPERIMENTAL APPROACH: Pharmacokinetic-pharmacodynamic modelling was used to characterize the drug effects in hERG functional patch clamp, hERG radio-labelled dofetilide displacement experiments and QT interval in conscious dogs. Data were analysed in parallel to identify potential correlations between pharmacological activity in vitro and in vivo. KEY RESULTS: An Emax model could not be used due to large variability in the functional patch clamp assay. Dofetilide displacement revealed that binding curves are unrelated to the in vivo potency estimates for QTc prolongation in dogs and humans. Mean in vitro potency estimates ranged from 99.9 nM for cisapride to 1030 µM for moxifloxacin. CONCLUSIONS AND IMPLICATIONS: The lack of standardized protocols for in vitro assays leads to significant differences in experimental conditions, making the assessment of in vitro-in vivo correlations unreliable. Identification of an accurate safety window during the screening of candidate molecules requires a quantitative framework that disentangles system- from drug-specific properties under physiological conditions, enabling translation of the results to humans. Similar considerations will be relevant for the comprehensive in vitro pro-arrhythmia assay initiative.

Abnormal layering of muscularis propria as a cause of chronic intestinal pseudo-obstruction: A case report and literature review.

Visceral myopathy is one of the causes of chronic intestinal pseudo-obstruction. Most cases pathologically reveal degenerative changes of myocytes or muscularis propia atrophy and fibrosis. Abnormal layering of muscularis propria is extremely rare. We report a case of a 9-mo-old Thai male baby who presented with chronic intestinal pseudo-obstruction. Histologic findings showed abnormal layering of small intestinal muscularis propria with an additional oblique layer and aberrant muscularization in serosa. The patient also had a short small bowel without malrotation, brachydactyly, and absence of the 2(nd) to 4(th) middle phalanges of both hands. The patient was treated with cisapride and combined parenteral and enteral nutritional support. He had gradual clinical improvement and gained body weight. Subsequently, the parenteral nutrition was discontinued. The previously reported cases are reviewed and discussed.

The Link between Inactivation and High-Affinity Block of hERG1 Channels.

Block of human ether-à-go-go-related gene 1 (hERG1) K(+) channels by many drugs delays cardiac repolarization, prolongs QT interval, and is associated with an increased risk of cardiac arrhythmia. Preferential block of hERG1 channels in an inactivated state has been assumed because inactivation deficient mutant channels can exhibit dramatically reduced drug sensitivity. Here we reexamine the link between inactivation gating and potency of channel block using concatenated hERG1 tetramers containing a variable number (0-4) of subunits harboring a point mutation (S620T or S631A) that disrupts inactivation. Concatenated hERG1 tetramers containing four wild-type subunits exhibited high-affinity block by cisapride, dofetilide, and MK-499, similar to wild-type channels formed from hERG1 monomers. A single S620T subunit within a tetramer was sufficient to fully disrupt inactivation gating, whereas S631A suppressed inactivation as a graded function of the number of mutant subunits present in a concatenated tetramer. Drug potency was positively correlated to the number of S620T subunits contained within a tetramer but unrelated to mutation-induced disruption of channel inactivation. Introduction of a second point mutation (Y652W) into S620T hERG1 partially rescued drug sensitivity. The potency of cisapride was not altered for tetramers containing 0 to 3 S631A subunits, whereas the potency of dofetilide was a graded function of the number of S631A subunits contained within a tetramer. Together these findings indicate that S620T or S631A substitutions can allosterically disrupt drug binding by a mechanism that is independent of their effects on inactivation gating.

Sudden cardiac death & the Reverse Dodo Verdict.

Adverse effects of treatment on cardiac QT intervals were first reported 50 years ago. A clear link to sudden death was established, but the problem remained relatively unknown. The issue of treatment related effects on the heart, and the contribution this might make to sudden cardiac deaths in general, came more clearly into focus 20 years ago, linked to regulatory actions. In an era of polypharmacy, and mixing of prescribed and non-prescribed pharmacologically active agents it is now becoming increasingly clear that unanticipated cardiac effects may be common and a significant cause of mortality. There is likely underreporting and also underdiagnosis, as recognition requires a timely ECG. This paper proposes two methods to handle the problem.

Rehabilitating drug-induced long-QT promoters: in-silico design of hERG-neutral cisapride analogues with retained pharmacological activity.

BACKGROUND: The human ether-a-go-go related gene 1 (hERG1), which codes for a potassium ion channel, is a key element in the cardiac delayed rectified potassium current, IKr, and plays an important role in the normal repolarization of the heart's action potential. Many approved drugs have been withdrawn from the market due to their prolongation of the QT interval. Most of these drugs have high potencies for their principal targets and are often irreplaceable, thus "rehabilitation" studies for decreasing their high hERG1 blocking affinities, while keeping them active at the binding sites of their targets, have been proposed to enable these drugs to re-enter the market. METHODS: In this proof-of-principle study, we focus on cisapride, a gastroprokinetic agent withdrawn from the market due to its high hERG1 blocking affinity. Here we tested an a priori strategy to predict a compound's cardiotoxicity using de novo drug design with molecular docking and Molecular Dynamics (MD) simulations to generate a strategy for the rehabilitation of cisapride. RESULTS: We focused on two key receptors, a target interaction with the (adenosine) receptor and an off-target interaction with hERG1 channels. An analysis of the fragment interactions of cisapride at human A2A adenosine receptors and hERG1 central cavities helped us to identify the key chemical groups responsible for the drug activity and hERG1 blockade. A set of cisapride derivatives with reduced cardiotoxicity was then proposed using an in-silico two-tier approach. This set was compared against a large dataset of commercially available cisapride analogs and derivatives. CONCLUSIONS: An interaction decomposition of cisapride and cisapride derivatives allowed for the identification of key active scaffolds and functional groups that may be responsible for the unwanted blockade of hERG1.

Management of faecal incontinence and constipation in adults with central neurological diseases.

BACKGROUND: People with central neurological disease or injury have a much higher risk of both faecal incontinence and constipation than the general population. There is often a fine line between the two symptoms, with any management intended to ameliorate one risking precipitating the other. Bowel problems are observed to be the cause of much anxiety and may reduce quality of life in these people. Current bowel management is largely empirical, with a limited research base. This is an update of a Cochrane review first published in 2001 and subsequently updated in 2003 and 2006. The review is relevant to individuals with any disease directly and chronically affecting the central nervous system (post-traumatic, degenerative, ischaemic or neoplastic), such as multiple sclerosis, spinal cord injury, cerebrovascular disease, Parkinson's disease and Alzheimer's disease. OBJECTIVES: To determine the effects of management strategies for faecal incontinence and constipation in people with a neurological disease or injury affecting the central nervous system. SEARCH METHODS: We searched the Cochrane Incontinence Group Trials Register (searched 8 June 2012), which includes searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and MEDLINE In-Process as well as handsearching of journals and conference proceedings; and all reference lists of relevant articles. SELECTION CRITERIA: Randomised and quasi-randomised trials evaluating any type of conservative or surgical intervention for the management of faecal incontinence and constipation in people with central neurological disease or injury were selected. Specific therapies for the treatment of neurological diseases that indirectly affect bowel dysfunction were also considered. DATA COLLECTION AND ANALYSIS: At least two review authors independently assessed the risk of bias of eligible trials and independently extracted data from the included trials using a range of pre-specified outcome measures. MAIN RESULTS: Twenty trials involving 902 people were included. Oral medications There was evidence from individual small trials that people with Parkinson's disease had a statistically significant improvement in the number of bowel motions or successful bowel care routines per week when fibre (psyllium) (mean difference (MD) -2.2 bowel motions, 95% confidence interval (CI) -3.3 to -1.4) or oral laxative (isosmotic macrogol electrolyte solution) (MD 2.9 bowel motions per week, 95% CI 1.48 to 4.32) are used compared with placebo. One trial in people with spinal cord injury showed statistically significant improvement in total bowel care time comparing intramuscular neostigmine-glycopyrrolate (anticholinesterase plus an anticholinergic drug) with placebo (MD 23.3 minutes, 95% CI 4.68 to 41.92).Five studies reported the use of cisapride and tegaserod in people with spinal cord injuries or Parkinson's disease. These drugs have since been withdrawn from the market due to adverse effects; as they are no longer available they have been removed from this review. Rectal stimulants One small trial in people with spinal cord injuries compared two bisacodyl suppositories, one polyethylene glycol-based (PGB) and one hydrogenated vegetable oil-based (HVB). The trial found that the PGB bisacodyl suppository significantly reduced the mean defaecation period (PGB 20 minutes versus HVB 36 minutes, P < 0.03) and mean total time for bowel care (PGB 43 minutes versus HVB 74.5 minutes, P < 0.01) compared with the HVB bisacodyl suppository.Physical interventions There was evidence from one small trial with 31 participants that abdominal massage statistically improved the number of bowel motions in people who had a stroke compared with no massage (MD 1.7 bowel motions per week, 95% CI 2.22 to 1.18). A small feasibility trial including 30 individuals with multiple sclerosis also found evidence to support the use of abdominal massage. Constipation scores were statistically better with the abdominal massage during treatment although this was not supported by a change in outcome measures (for example the neurogenic bowel dysfunction score).One small trial in people with spinal cord injury showed statistically significant improvement in total bowel care time using electrical stimulation of abdominal muscles compared with no electrical stimulation (MD 29.3 minutes, 95% CI 7.35 to 51.25).There was evidence from one trial with a low risk of bias that for people with spinal cord injury transanal irrigation, compared against conservative bowel care, statistically improved constipation scores, neurogenic bowel dysfunction score, faecal incontinence score and total time for bowel care (MD 27.4 minutes, 95% CI 7.96 to 46.84). Patients were also more satisfied with this method.Other interventions In one trial in stroke patients, there appeared to be a short term benefit (less than six months) to patients in terms of the number of bowel motions per week with a one-off educational intervention from nurses (a structured nurse assessment leading to targeted education versus routine care), but this did not persist at 12 months. A trial in individuals with spinal cord injury found that a stepwise protocol did not reduce the need for oral laxatives and manual evacuation of stool.Finally, one further trial reported in abstract form showed that oral carbonated water (rather than tap water) improved constipation scores in people who had had a stroke. AUTHORS' CONCLUSIONS: There is still remarkably little research on this common and, to patients, very significant issue of bowel management. The available evidence is almost uniformly of low methodological quality. The clinical significance of some of the research findings presented here is difficult to interpret, not least because each intervention has only been addressed in individual trials, against control rather than compared against each other, and the interventions are very different from each other.There was very limited evidence from individual trials in favour of a bulk-forming laxative (psyllium), an isosmotic macrogol laxative, abdominal massage, electrical stimulation and an anticholinesterase-anticholinergic drug combination (neostigmine-glycopyrrolate) compared to no treatment or controls. There was also evidence in favour of transanal irrigation (compared to conservative management), oral carbonated (rather than tap) water and abdominal massage with lifestyle advice (compared to lifestyle advice alone). However, these findings need to be confirmed by larger well-designed controlled trials which should include evaluation of the acceptability of the intervention to patients and the effect on their quality of life.

Management of faecal incontinence and constipation in adults with central neurological diseases.

BACKGROUND: People with central neurological disease or injury have a much higher risk of both faecal incontinence and constipation than the general population. There is often a fine line between the two symptoms, with any management intended to ameliorate one risking precipitating the other. Bowel problems are observed to be the cause of much anxiety and may reduce quality of life in these people. Current bowel management is largely empirical, with a limited research base. This is an update of a Cochrane review first published in 2001 and subsequently updated in 2003 and 2006. The review is relevant to individuals with any disease directly and chronically affecting the central nervous system (post-traumatic, degenerative, ischaemic or neoplastic), such as multiple sclerosis, spinal cord injury, cerebrovascular disease, Parkinson's disease and Alzheimer's disease. OBJECTIVES: To determine the effects of management strategies for faecal incontinence and constipation in people with a neurological disease or injury affecting the central nervous system. SEARCH METHODS: We searched the Cochrane Incontinence Group Trials Register (searched 8 June 2012), which includes searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and MEDLINE In-Process as well as handsearching of journals and conference proceedings; and all reference lists of relevant articles. SELECTION CRITERIA: Randomised and quasi-randomised trials evaluating any type of conservative or surgical intervention for the management of faecal incontinence and constipation in people with central neurological disease or injury were selected. Specific therapies for the treatment of neurological diseases that indirectly affect bowel dysfunction were also considered. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the risk of bias of eligible trials and independently extracted data from the included trials using a range of pre-specified outcome measures. MAIN RESULTS: Twenty trials involving 902 people were included.Oral medicationsThere was evidence from individual small trials that people with Parkinson's disease had a statistically significant improvement in the number of bowel motions or successful bowel care routines per week when fibre (psyllium) (mean difference (MD) -2.2 bowel motions, 95% confidence interval (CI) -3.3 to -1.4) or oral laxative (isosmotic macrogol electrolyte solution) (MD 2.9 bowel motions per week, 95% CI 1.48 to 4.32) are used compared with placebo. One trial in people with spinal cord injury showed statistically significant improvement in total bowel care time comparing intramuscular neostigmine-glycopyrrolate (anticholinesterase plus an anticholinergic drug) with placebo (MD 23.3 minutes, 95% CI 4.68 to 41.92).Five studies reported the use of cisapride and tegaserod in people with spinal cord injuries or Parkinson's disease. These drugs have since been withdrawn from the market due to adverse effects; as they are no longer available they have been removed from this review.Rectal stimulantsOne small trial in people with spinal cord injuries compared two bisacodyl suppositories, one polyethylene glycol-based (PGB) and one hydrogenated vegetable oil-based (HVB). The trial found that the PGB bisacodyl suppository significantly reduced the mean defaecation period (PGB 20 minutes versus HVB 36 minutes, P < 0.03) and mean total time for bowel care (PGB 43 minutes versus HVB 74.5 minutes, P < 0.01) compared with the HVB bisacodyl suppository.Physical interventionsThere was evidence from one small trial with 31 participants that abdominal massage statistically improved the number of bowel motions in people who had a stroke compared with no massage (MD 1.7 bowel motions per week, 95% CI 2.22 to 1.18). A small feasibility trial including 30 individuals with multiple sclerosis also found evidence to support the use of abdominal massage. Constipation scores were statistically better with the abdominal massage during treatment although this was not supported by a change in outcome measures (for example the neurogenic bowel dysfunction score).One small trial in people with spinal cord injury showed statistically significant improvement in total bowel care time using electrical stimulation of abdominal muscles compared with no electrical stimulation (MD 29.3 minutes, 95% CI 7.35 to 51.25).There was evidence from one trial with a low risk of bias that for people with spinal cord injury transanal irrigation, compared against conservative bowel care, statistically improved constipation scores, neurogenic bowel dysfunction score, faecal incontinence score and total time for bowel care (MD 27.4 minutes, 95% CI 7.96 to 46.84). Patients were also more satisfied with this method.Other interventionsIn one trial in stroke patients, there appeared to be a short term benefit (less than six months) to patients in terms of the number of bowel motions per week with a one-off educational intervention from nurses (a structured nurse assessment leading to targeted education versus routine care), but this did not persist at 12 months. A trial in individuals with spinal cord injury found that a stepwise protocol did not reduce the need for oral laxatives and manual evacuation of stool.Finally, one further trial reported in abstract form showed that oral carbonated water (rather than tap water) improved constipation scores in people who had had a stroke. AUTHORS' CONCLUSIONS: There is still remarkably little research on this common and, to patients, very significant issue of bowel management. The available evidence is almost uniformly of low methodological quality. The clinical significance of some of the research findings presented here is difficult to interpret, not least because each intervention has only been addressed in individual trials, against control rather than compared against each other, and the interventions are very different from each other.There was very limited evidence from individual trials in favour of a bulk-forming laxative (psyllium), an isosmotic macrogol laxative, abdominal massage, electrical stimulation and an anticholinesterase-anticholinergic drug combination (neostigmine-glycopyrrolate) compared to no treatment or controls. There was also evidence in favour of transanal irrigation (compared to conservative management), oral carbonated (rather than tap) water and abdominal massage with lifestyle advice (compared to lifestyle advice alone). However, these findings need to be confirmed by larger well-designed controlled trials which should include evaluation of the acceptability of the intervention to patients and the effect on their quality of life.

Clinical recovery of chronic intestinal pseudo-obstruction with cisapride in a complex pediatric patient.

Cisapride is a gastrointestinal prokinetic that facilitates or restores motility along the entire gastrointestinal tract. It has been used successfully to treat acute and chronic intestinal pseudo-obstructions (CIPs) in adults, but there is a paucity of literature surrounding the treatment of CIP in pediatric patients and therapies for CIP are limited and their impact is often unsatisfactory. This case report presents the use of cisapride in the management of pseudo-obstruction. Treatment with cisapride substantially improved the patient's symptoms and improved feeding tolerance. It improved his prognosis remarkably and prevented the need for end-of-life care. He experienced no adverse effects throughout the course of therapy. The treatment regimen is discussed in this case report.