Clinical trial: single- and multiple-dose pharmacokinetics of polyethylene glycol (PEG-3350) in healthy young and elderly subjects

Does a Preoperative Bowel Regimen Change Time to Bowel Movement? A Randomized Clinical Trial

IMPORTANCE

This study is important because it aimed to assess an intervention to decrease patient discomfort after a robotic sacral colpopexy.

OBJECTIVE

Our primary outcome was to determine whether preoperative use of polyethylene glycol decreases time to first bowel movement postoperatively. Secondary outcomes include degree of pain with first bowel movement and stool consistency.

STUDY DESIGN

This was a randomized controlled trial. The experimental group was assigned polyethylene glycol daily for 7 days before surgery and the control group was not. All patients received polyethylene glycol postoperatively.

RESULTS

There was no statistically significant reduction in the time to first postoperative bowel movement when preoperative polyethylene glycol was used (mean [SD] in days for the control and experimental groups of 2.32 [0.99] and 1.96 [1.00], P = 0.21). There was a statistically significant reduction in pain levels with the first postoperative bowel movement in the experimental group (median [IQR] of 4 [2-5] vs 1 [0-2], P = 0.0007). Postoperative day 1 pain levels were also significantly lower in the experimental group (median [IQR] of 4 [3-6] vs 2 [0-4], P = 0.0484). In addition, patients had decreased average postoperative pain levels over 7 days with an estimated difference in the median pain levels of 1.88 units (95% confidence interval, 0.64-3.12; P = 0.0038).

CONCLUSIONS

Preoperative administration of polyethylene glycol did not decrease time to first postoperative bowel movement. Patients in the experimental group exhibited less pain with their first postoperative bowel movement and had improved pain levels on postoperative day 1.

Diagnostic and therapeutic approach to children with chronic refractory constipation: Consensus report by the SIGENP motility working group

Constipation is a common problem in children, accounting for about 3% of all primary care visits and up to 25% of referrals to paediatric gastroenterologists. Although polyethylene glycol often proves effective, most children require prolonged treatment and about 50% of them have at least one relapse within the first 5 years after initial recovery. When conventional treatment fails, children are considered to have refractory constipation. Children with refractory constipation deserve specialist management and guidance. Over the last decades, there has been a remarkable increase in our knowledge of normal and abnormal colonic and anorectal motility in children, and a number of different techniques to measure transit and motility have been developed. The present review analyses the possible diagnostic investigations for children with refractory constipation, focusing on their actual indications and their utility in clinical practice. Moreover, we have also analytically reviewed medical and surgical therapeutic options, which should be considered in selected patients in order to achieve the best clinical outcome.

A real-time in vivo clearance assay for quantification of glymphatic efflux

Glymphatic fluid transport eliminates metabolic waste from the brain including amyloid-β, yet the methodology for studying efflux remains rudimentary. Here, we develop a method to evaluate glymphatic real-time clearance. Efflux of Direct Blue 53 (DB53, also T-1824 or Evans Blue) injected into the striatum is quantified by imaging the DB53 signal in the vascular compartment, where it is retained due to its high affinity to albumin. The DB53 signal is detectable as early as 15 min after injection and the efflux kinetics are sharply reduced in mice lacking the water channel aquaporin 4 (AQP4). Pharmacokinetic modeling reveal that DB53 efflux is consistent with the existence of two efflux paths, one with fast kinetics (T_1/2 = 50 min) and another with slow kinetics (T_1/2 = 240 min), in wild-type mice. This in vivo methodology will aid in defining the physiological variables that drive efflux, as well as the impact of brain states or disorders on clearance kinetics.

Monitoring Anti-PEG Antibodies Level upon Repeated Lipid Nanoparticle-Based COVID-19 Vaccine Administration

PEGylated lipids are one of the four constituents of lipid nanoparticle mRNA COVID-19 vaccines. Therefore, various concerns have been raised on the generation of anti-PEG antibodies and their potential role in inducing hypersensitivity reactions following vaccination or in reducing vaccine efficacy due to anti-carrier immunity. Here, we assess the prevalence of anti-PEG antibodies, in a cohort of vaccinated individuals, and give an overview of their time evolution after repeated vaccine administrations. Results indicate that, in our cohort, the presence of PEG in the formulation did not influence the level of anti-Spike antibodies generated upon vaccination and was not related to any reported, serious adverse effects. The time-course analysis of anti-PEG IgG showed no significant booster effect after each dose, whereas for IgM a significant increase in antibody levels was detected after the first and third dose. Data suggest that the presence of PEG in the formulation does not affect safety or efficacy of lipid-nanoparticle-based COVID-19 vaccines.

What have we learned about the allergenicity and adverse reactions associated with the severe acute respiratory syndrome coronavirus 2 vaccines: One year later

OBJECTIVE

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to the most rapid response and scale-up in vaccine and therapeutic development in history. We highlight the history of these amazing achievements with a focus on the description of the classification and mechanisms of allergic reactions and adverse events relevant to the allergist and immunologist that have been associated with the SARS-CoV-2 vaccines. Finally, we offer a detailed management approach in the context of a possible allergic reaction.

DATA SOURCES

Using defined search strategy, we identified peer-reviewed articles within PubMed that were published between January 1, 2019, and December 4, 2021.

STUDY SELECTIONS

All recent articles on COVID-19 published in English were reviewed with focus on the immunogenicity and allergenicity of the current existing COVID-19 vaccines.

RESULTS

Following a detailed literature review, we discuss the evolution and development of the new vaccines for SARS-CoV-2. Furthermore, we provide evidence regarding the significance and mechanisms of allergic reactions associated with the vaccines and offer a management approach for those with an increased risk of presenting an allergic or other relevant vaccine reaction.

CONCLUSION

The international rollout of COVID-19 vaccination started with reports of immediate allergic reactions. Although we still need to understand the mechanisms of these reactions, we can be reassured that patients with underlying allergic disease will not need to avoid SARS-CoV-2 vaccination. In addition, the vast majority of those with a first-dose reaction will tolerate subsequent doses.

Review of the Safety Profiles of Laxatives in Pregnant Women

Chronic constipation is one of the most common complaints seen in the gastroenterology clinic and is particularly prevalent in women. Women who become pregnant may suffer from existing constipation or develop constipation de novo. A thorough understanding of the safety of laxative therapies during pregnancy and the postpartum period is essential to successfully treating these women. Current understanding of the safety of both over the counter and prescription laxatives has not been adequately evaluated. In this article we provide an updated and comprehensive review of the safety profiles of laxatives that are currently used for the treatment of chronic constipation to aid the clinician in risk-benefit discussions with women who are currently or planning to become pregnant.

Estimating the release of chemical substances from consumer products, textiles and pharmaceuticals to wastewater

Chemical emissions from households originate from a wide range of sources and results in highly diverse mixtures. This makes traditional monitoring based on analytical chemistry challenging, especially for compounds that appear in low concentrations. We therefore developed a method for predicting emissions of chemicals from households into wastewater, relying on consumption patterns from multiple data sources. The method was then used to predict the emissions of chemical preparations, chemicals leaching from textiles and prescription pharmaceuticals in Sweden. In total we predicted emissions of 2007 chemicals with a combined emission of 62,659 tonnes per year - or 18 g/person and day. Of the emitted chemicals, 2.0% (w/w) were either classified as hazardous to the environment or were both persistent and mobile. We also show that chemical emissions come from a wide range of uses and that the total emission of any individual chemical is determined primarily by its use pattern, not by the total amount used. This emphasizes the need for continuous updates and additional knowledge generation both on emission factors and excretion rates as well as a need for improved reporting on the intended use of individual chemicals. Finally, we scrutinize the model and its uncertainty and suggest areas that need improvement to increase the accuracy of future emission modelling. We conclude that emission modelling can help guide environmental monitoring and provide input into management strategies aimed at reducing the environmental effect caused by hazardous chemicals.

Efficacy and Safety of Over-the-Counter Therapies for Chronic Constipation: An Updated Systematic Review

INTRODUCTION

Constipation is commonly treated with over-the-counter (OTC) products whose efficacy and safety remain unclear. We performed a systematic review of OTC therapies for chronic constipation and provide evidence-based recommendations.

METHODS

We searched PubMed and Embase for randomized controlled trials of ≥4-week duration that evaluated OTC preparations between 2004 and 2020. Studies were scored using the US Preventive Services Task Force criteria (0-5 scale) including randomization, blinding, and withdrawals. The strengths of evidence were adjudicated within each therapeutic category, and recommendations were graded (A, B, C, D, and I) based on the level of evidence (level I, good; II, fair; or III, poor).

RESULTS

Of 1,297 studies identified, 41 met the inclusion criteria. There was good evidence (grade A recommendation) for the use of the osmotic laxative polyethylene glycol (PEG) and the stimulant senna; moderate evidence (grade B) for psyllium, SupraFiber, magnesium salts, stimulants (bisacodyl and sodium picosulfate), fruit-based laxatives (kiwi, mango, prunes, and ficus), and yogurt with galacto-oligosaccharide/prunes/linseed oil; and insufficient evidence (grade I) for polydextrose, inulin, and fructo-oligosaccharide. Diarrhea, nausea, bloating, and abdominal pain were common adverse events, but no serious adverse events were reported.

DISCUSSION

The spectrum of OTC products has increased and quality of evidence has improved, but methodological issues including variability in study design, primary outcome measures, trial duration, and small sample sizes remain. We found good evidence to recommend polyethylene glycol or senna as first-line laxatives and moderate evidence supporting fiber supplements, fruits, stimulant laxatives, and magnesium-based products. For others, further validation with more rigorously designed studies is warranted.

Using Polyethylene Glycol 3350 Plus Electrolytes in Constipated Hemodialysis Patients: A Case Series

Appropriate management of constipation in hemodialysis patients has not been established, although constipation is the most frequent gastrointestinal complication in dialysis patients. We herein report the efficacy and safety of polyethylene glycol in constipated hemodialysis patients assessed prospectively. Seven patients using stimulant laxatives participated in this study. Polyethylene glycol was administered to reduce stimulant laxatives during the six-week intervention period. The amount of stimulant laxatives decreased and spontaneous bowel movements with ideal stool consistency increased significantly after the intervention. No serious adverse effects were observed throughout this study. In conclusion, polyethylene glycol can be a useful tool for managing constipated hemodialysis patients.

Quantitative Analysis of Antibody Survival across the Infant Digestive Tract Using Mass Spectrometry with Parallel Reaction Monitoring

Orally delivered antibodies may be useful for the prevention of enteric pathogen infection, but to be effective they need to survive intact across digestion through the gastrointestinal tract. As a test case, we fed a recombinant human antibody, palivizumab, spiked into human milk to four infants and collected gastric, intestinal and stool samples. We identified a tryptic peptide from palivizumab (LLIYDTSK) that differs from all endogenous human antibodies and used this for quantitation of the intact palivizumab. To account for dilution by digestive fluids, we co-fed a non-digestible, non-absorbable molecule-polyethylene glycol 28-quantified it in each sample and used this value to normalize the observed palivizumab concentration. The palivizumab peptide, a stable isotope-labeled synthetic peptide and polyethylene glycol 28 were quantified via a highly sensitive and selective parallel-reaction monitoring approach using nano-liquid chromatography/Orbitrap mass spectrometry. On average, the survival of intact palivizumab from the feed to the stomach, upper small intestine and stool were 88.4%, 30.0% and 5.2%, respectively. This approach allowed clear determination of the extent to which palivizumab was degraded within the infant digestive tract. This method can be applied with some modifications to study the digestion of any protein.

From Synthesis to Characterization of Site-Selective PEGylated Proteins

Covalent attachment of therapeutic proteins to polyethylene glycol (PEG) is widely used for the improvement of its pharmacokinetic and pharmacological properties, as well as the reduction in reactogenicity and related side effects. This technique named PEGylation has been successfully employed in several approved drugs to treat various diseases, even cancer. Some methods have been developed to obtain PEGylated proteins, both in multiple protein sites or in a selected amino acid residue. This review focuses mainly on traditional and novel examples of chemical and enzymatic methods for site-selective PEGylation, emphasizing in N-terminal PEGylation, that make it possible to obtain products with a high degree of homogeneity and preserve bioactivity. In addition, the main assay methods that can be applied for the characterization of PEGylated molecules in complex biological samples are also summarized in this paper.

Severe hypernatremia and transient azotemia in a cat following inadvertent intravenous administration of a commercial polyethylene glycol solution

OBJECTIVE

To describe the clinical signs, clinicopathologic abnormalities, treatment, and outcome after IV administration of polyethylene glycol 3350 (PEG3350) in a cat.

CASE SUMMARY

A cat was inadvertently administered 6 g/kg of PEG3350 in electrolyte solution, IV, resulting in severe hypernatremia (203 mmol/L), diffuse encephalopathy, hemolysis, and moderate azotemia. The hemolysis and acute kidney injury observed immediately following PEG3350 administration resolved with supportive care. Administration of IV and oral electrolyte-free water slowly corrected the hypernatremia and the neurologic signs subsequently improved. Complete resolution of clinical signs was documented one month following hospital discharge. The PEG3350 concentrations in serum, plasma, and urine samples confirmed toxic exposure to PEG3350. Efficacy of treatment was evident by decreasing concentrations of PEG3350 in serum after the first 24 hours of treatment. Renal elimination of PEG3350 was significant and PEG3350 was still detected in the urine 17 days after exposure.

NEW INFORMATION PROVIDED

This is the first report to describe the clinical signs and clinicopathologic abnormalities in a cat intoxicated with IV PEG3350. Potential pathophysiologic mechanisms are discussed, and the successful supportive medical treatment is outlined.

Initial researches on neuro-functional status and evolution in chronic ethanol consumers with recent traumatic spinal cord injury

We found differences related to the neuro-functional deficiency and clinical progress, among non-consumers and chronic consumers of ethanol, with recent traumatic spinal cord injury (SCI). We present a synthesis of related data on lesion mechanisms in post-traumatic myelogenous disorders, namely some of the alcohols and their actions on the nervous system, with details on the influences exerted, in such afflictions, by the chronic consumption of ethanol. The subject is not frequently approached - according to a literature review with systematic elements, which we have done before - thus constituting a niche that deserves to be further explored. The applicative component of the article highlights statistical data resulted from a retrospective study regarding the specialized casuistry from the Neuromuscular Recovery Clinic of the "Bagdasar Arseni" Emergency Clinical Hospital, following the comparative analysis of two groups of patients with recent SCI: non-consumers - the control group (n=780) - and chronic ethanol consumers - the study group (n=225) - with the addition of a prospective pilot component. Data processing has been achieved with SPSS 24. The American Spinal Injury Association Impairment Scale (AIS) mean motor scores differ significantly (tests: Mann-Whitney and t) between the control and study group in favor of the second, both at admission (p<0.001) and at discharge (p<0.001). AIS mean sensitive scores differ between the two lots, and also in favor of the study, but statistically significant only at discharge (p=0.048); the difference at admission is not significant (p=0.51) - possibly because of alcoholic-nutritional polyneuropathy. These findings, with numerous related details, later presented in the text, are surprising, which requires further studies and attempts of understanding.

Absorption, distribution, metabolism and excretion of the biomaterials used in Nanocarrier drug delivery systems

Nanocarriers (NCs) are a type of drug delivery system commonly used to regulate the pharmacokinetic and pharmacodynamic properties of drugs. Although a wide variety of NCs has been developed, relatively few have been registered for clinical trials and even fewer are clinically approved. Overt or potential toxicity, indistinct mechanisms of drug release and unsatisfactory pharmacokinetic behavior all contribute to their high failure rate during preclinical and clinical testing. These negative characteristics are not only due to the NCs themselves but also to the materials of the drug nanocarrier system (MDNS) that are released in vivo. In this article, we review the main analytical techniques used for bioassay of NCs and MDNS and their pharmacokinetics after administration by various routes. We anticipate our review will serve to improve the understanding of MDNS pharmacokinetics and facilitate the development of NC drug delivery systems.

Polyethylene glycol 3350 plus electrolytes for chronic constipation: a 2-week, randomized, double-blind, placebo-controlled study with a 52-week open-label extension

BACKGROUND

Although polyethylene glycol 3350 plus electrolytes (PEG3350 + E) is the most widely used osmotic laxative in Europe, prospective data on its long-term (over 6 months) safety and efficacy are not available to date.

METHODS

Japanese patients with chronic constipation were randomized to receive PEG3350 + E or placebo for 2 weeks orally. Following this, the patients received PEG3350 + E in the 52-week extension study. The starting dose was 13.7 g/day dissolved in 125 mL of water, and dose titration was allowed (upper limit 41.1 g/day) according to the patient's bowel condition. The primary efficacy endpoint was the change from baseline in frequency of spontaneous bowel movements (SBMs) at week 2 in the double-blind study. Secondary endpoints and adverse events were assessed. Safety and efficacy were also assessed in the extension study.

RESULTS

Among 204 patients who provided informed consent, 156 were randomized and included in the full analysis. The frequency of SBMs was significantly higher with PEG3350 + E [least squares mean (LSM) 4.3, 95% confidence interval (CI) 3.6-4.9] compared with placebo (LSM 1.6, 95% CI 1.2-2.1; P < 0.0001). A total of 153 patients entered the extension study; PEG3350 + E led to a sustained improvement in bowel function. The common adverse drug reactions during the entire study period were mild gastrointestinal disorders (abdominal pain 4.5%, diarrhea 3.8%, nausea 3.2%, abdominal distension 2.6%).

CONCLUSIONS

Treatment with PEG3350 + E resolved constipation in the short term, was well tolerated, and led to sustained improvement in bowel function in the long-term treatment of Japanese patients with chronic constipation.

CLINICAL TRIAL REGISTRATION NUMBER

Japic CTI-163167.

Chronic Functional Constipation in Infants and Children

Functional constipation is a common problem among children. The prevalence worldwide is about 3% and it is accounting for about 3-5% of all visits to pediatricians implicating a significant impact on health care cost. In most children presenting with the symptom constipation no underlying medical disease responsible for the symptom can be found; this is the so-called functional constipation. Functional constipation is characterized by infrequent bowel movements, hard and/or large stools, painful defecation, sometimes in combination with fecal incontinence, and is often accompanied by abdominal pain, without evidence of a structural or biochemical explanation.The recommendation for the management of FC includes a normal intake of fibers and fluids, normal physical activity, and an additional pharmacologic treatment for fecal disimpaction followed by a pharmacologic maintenance therapy.In infants constipation is treated somewhat differently as compared with children. When constipation presents early in life, the risk of an underlying organic disease is increased compared to older children.

Macrogol (polyethylene glycol) 4000 without electrolytes in the symptomatic treatment of chronic constipation: a profile of its use

Macrogol 4000, a biologically inert, non-absorbable osmotic laxative, is a highly effective and well-tolerated first-line option for the treatment of the symptoms of chronic idiopathic/functional constipation in children and adults. High-molecular-weight (HMW) macrogols ± electrolytes have generally similar efficacy profiles; however, the taste of macrogol 4000 is generally preferred over that of macrogol 3350 + electrolytes. Macrogol 4000 is more effective than lactulose in improving stool frequency and consistency, and is associated with less vomiting and flatulence. Comparisons with other osmotic and bulk-forming laxatives are limited, with macrogol 4000 being at least as, or more effective than, psyllium hydrocolloid and magnesium hydroxide in treating chronic constipation. Current clinical treatment guidelines recommend the use of HMW macrogols over the use of lactulose and bulk-forming laxative in the symptomatic treatment of constipation in children and adults.

Adverse eff ects of polymeric nanoparticle poly(ethylene glycol)- block-polylactide methyl ether (PEG-b-PLA) on steroid hormone secretion by porcine granulosa cells

Objectives. Development of nanoparticles (NPs) for biomedical applications, including medical imaging and drug delivery, is currently undergoing a dramatic expansion. Diverse effects of different type NPs relating to mammalian reproductive tissues have been demonstrated. Th e objective of this study was to explore the in vitro effects of polymeric nanoparticle poly(ethylene glycol)-blockpolylactide methyl ether (PEG-b-PLA NPs) on functional state and viability of ovarian granulosa cells (GCs), which play an important role in maintaining ovarian function and female fertility.

Methods. The GCs isolated from porcine ovarian follicles were incubated with the different concentrations of PEG-b-PLA NPs (PEG average Mn=350 g/mol and PLA average Mn=1000 g/mol; 0.2-100 μg/ml) or poly(ethylene glycol) with an average molecular weight of 300 (PEG-300; 0.2- 40 mg/ml) in the presence or absence of stimulators, follicle-stimulating hormone (FSH; 1 μg/ml), androstenedione (100 nM), forskolin (10 μM) or 8Br-cAMP (100 μM), for different time periods (24, 48, 72 h). At the end of the incubation, progesterone and estradiol levels produced by GCs were measured in the culture media by radioimmunoassay. Th e viability of GCs was determined by the method using a colorimetric assay with MTT.

Results. Treatment of GCs with PEG-b-PLA NPs induced a significant decrease in basal as well as FSH-stimulated progesterone secretion above the concentration of 20 and 4 μg/ml, respectively. Moreover, PEG-b-PLA NPs reduced forskolin-stimulated, but not cAMP-stimulated progesterone production by GCs. A dose-dependent inhibition of androstenedione-stimulated estradiol release by GCs was found by the action of PEG-b-PLA NPs. Incubation of GCs with PEG-300 significantly inhibited basal as well as FSH-stimulated progesterone secretion above the concentration of 40 mg/ml. PEG-b-PLA NPs and PEG-300 significantly reduced the viability of GCs at the highest tested concentrations (100 μg/ml and 40 mg/ml, respectively).

Conclusions. The obtained results indicate that polymeric NPs PEG-b-PLA might induce alterations in steroid hormone production by ovarian GCs and thereby could modify reproductive functions.

Gastrointestinal Dysfunctions in Parkinson's Disease: Symptoms and Treatments

A diagnosis of Parkinson's disease is classically established after the manifestation of motor symptoms such as rigidity, bradykinesia, and tremor. However, a growing body of evidence supports the hypothesis that nonmotor symptoms, especially gastrointestinal dysfunctions, could be considered as early biomarkers since they are ubiquitously found among confirmed patients and occur much earlier than their motor manifestations. According to Braak's hypothesis, the disease is postulated to originate in the intestine and then spread to the brain via the vagus nerve, a phenomenon that would involve other neuronal types than the well-established dopaminergic population. It has therefore been proposed that peripheral nondopaminergic impairments might precede the alteration of dopaminergic neurons in the central nervous system and, ultimately, the emergence of motor symptoms. Considering the growing interest in the gut-brain axis in Parkinson's disease, this review aims at providing a comprehensive picture of the multiple gastrointestinal features of the disease, along with the therapeutic approaches used to reduce their burden. Moreover, we highlight the importance of gastrointestinal symptoms with respect to the patients' responses towards medical treatments and discuss the various possible adverse interactions that can potentially occur, which are still poorly understood.

A Way Forward for Cancer Chemoprevention: Think Local

As cells progress through carcinogenesis, the associated exponential expansion of genetic and molecular aberrations and resultant heterogeneity make therapeutic success increasingly unattainable. Therapeutic intervention at early stages of carcinogenesis that occurs within the primary organ and in the face of a lower burden of molecular aberrations, constitutes a basic tenet of cancer chemoprevention, and provides a situation that favors a greater degree of therapeutic efficacy compared with that of advanced cancer. A longstanding barrier to chemoprevention relates to the requirement for essentially no systemic toxicity, and the fact that when large numbers of people are treated, the emergence of systemic toxicity is almost universal. A rational means to address this in fact relates to a second basic tenet of the chemopreventive strategy: the focus of therapeutic intervention is to disrupt a process that is in essence localized to a single organ. Based upon this consideration, a strategy which is based upon local delivery of therapeutics to an at-risk organ will achieve therapeutic efficacy while avoiding systemic delivery and its associated toxicity. This article will review the rationale for undertaking such an approach, describe successful clinical achievements based on this strategy, describe ongoing efforts to expand the impact of this approach, and together will highlight the high impact that this approach has already had on the field as well as its extremely high potential for future impact. Cancer Prev Res; 10(1); 14-35. ©2016 AACR.

Safety of polyethylene glycol 3350 solution in chronic constipation: randomized, placebo-controlled trial

Purpose

To evaluate the safety and tolerability of aqueous solution concentrate (ASC) of polyethylene glycol (PEG) 3350 in patients with functional constipation.

Patients and methods

The patients who met Rome III diagnostic criteria for functional constipation were randomized in this multicenter, randomized, placebo-controlled, single-blind study to receive once daily dose of PEG 3350 (17 g) ASC or placebo solution for 14 days. The study comprised a screening period (visit 1), endoscopy procedure (visits 2 and 3), and followup telephone calls 30 days post-treatment. Safety end points included adverse events (AEs), clinical laboratory evaluations, vital signs, and others. The primary end points were the proportion of patients with abnormalities of the oral and esophageal mucosa, detected by visual and endoscopic examination of the oral cavity and esophagus, respectively, compared with placebo. A secondary objective was to compare the safety and tolerability of ASC by evaluating AEs or adverse drug reactions.

Results

A total of 65 patients were enrolled in this study, 31 were randomized to PEG 3350 ASC and 34 were randomized to placebo, of which 62 patients completed the study. No patients in either group showed abnormalities in inflammation of the oral mucosa during visit 2 (before treatment) or visit 3 (after treatment). Fewer abnormalities of the esophageal mucosa were observed in the PEG 3350 ASC group than in the placebo group on visit 3, with no significant difference in the proportion of abnormalities between the treatment groups. Overall, 40 treatment-emergent AEs were observed in 48.4% of patients treated with PEG 3350 ASC, and 41 treatment-emergent AEs were observed in 55.9% of patients treated with placebo – nonsignificant difference of −7.5% (95% CI: −21.3, 6.3) between treatment groups. No serious AEs or deaths were reported, and no patient discontinued because of an AE.

Conclusion

PEG 3350 ASC is safe and well tolerated in patients with functional constipation (NCT01885104).

Use of Polyethylene Glycol Electrolyte Solution Expedites Return of Bowel Function and Facilitates Early Discharge after Kidney Transplantation

BACKGROUND

Delay in the return of bowel function often prolongs hospitalization after kidney transplantation, leading to increased patient morbidity and health care costs. Polyethylene glycol (PEG) solution has been observed to aid the return of bowel function in postoperative patients undergoing abdominal surgery.

STUDY DESIGN

Using a 2-arm, single-surgeon, nonrandomized study, we compared the addition of PEG along with early resumption of diet with a control group using only early resumption of diet in kidney transplantation patients.

RESULTS

There were 51 subjects in the control group and 47 subjects in the PEG intervention group. The primary outcomes measure, time to bowel movement, was significantly shorter than the control group by an entire day (2.9 ± 1.1 days vs 4.0 ± 1.3 days; p < 0.001). In propensity score analysis, patients receiving PEG had bowel movements sooner (-1.06 ± 0.25 days; p < 0.001) and decreased lengths of stay (-1.16 ± 0.27 days; p < 0.001).

CONCLUSIONS

Polyethylene glycol significantly reduced time to return of bowel function and postoperative length of stay. By adding PEG to the postoperative protocol, we can help to reduce costs of hospitalization and improve overall outcomes in renal transplantation patients.

Quantitative analysis of polyethylene glycol (PEG) and PEGylated proteins in animal tissues by LC-MS/MS coupled with in-source CID

The covalent conjugation of polyethylene glycol (PEG, typical MW > 10k) to therapeutic peptides and proteins is a well-established approach to improve their pharmacokinetic properties and diminish the potential for immunogenicity. Even though PEG is generally considered biologically inert and safe in animals and humans, the slow clearance of large PEGs raises concerns about potential adverse effects resulting from PEG accumulation in tissues following chronic administration, particularly in the central nervous system. The key information relevant to the issue is the disposition and fate of the PEG moiety after repeated dosing with PEGylated proteins. Here, we report a novel quantitative method utilizing LC-MS/MS coupled with in-source CID that is highly selective and sensitive to PEG-related materials. Both (40K)PEG and a tool PEGylated protein (ATI-1072) underwent dissociation in the ionization source of mass spectrometer to generate a series of PEG-specific ions, which were subjected to further dissociation through conventional CID. To demonstrate the potential application of the method to assess PEG biodistribution following PEGylated protein administration, a single dose study of ATI-1072 was conducted in rats. Plasma and various tissues were collected, and the concentrations of both (40K)PEG and ATI-1072 were determined using the LC-MS/MS method. The presence of (40k)PEG in plasma and tissue homogenates suggests the degradation of PEGylated proteins after dose administration to rats, given that free PEG was absent in the dosing solution. The method enables further studies for a thorough characterization of disposition and fate of PEGylated proteins.

Aspiration pneumonitis caused by polyethylene glycol-electrolyte solution treated with conservative management

Polyethylene glycol (PEG) electrolyte solution, Golytely, is an osmotic laxative commonly used in preoperative bowel cleansing. In this case report, a 9-year-old boy developed aspiration pneumonitis following accidental infusion of PEG solution into his right lung following migration of his nasogastric tube (NGT). Hypoxemia and tachypnea without respiratory failure were observed after infusion. Because PEG is a nonabsorbable toxic material, previous case reports have advocated for the performance of bronchoalveolar lavage (BAL) in the treatment of PEG pneumonitis. With close monitoring, our patient was able to be successfully treated without the need for invasive interventions including BAL or intubation. Generalizations about PEG absorption in the lung based on its permeability in the gastrointestinal tract should not deter the use of more conservative treatment in the appropriate patient.

Pharmacokinetics, metabolism and distribution of PEGs and PEGylated proteins: quo vadis?

The pharmacokinetics (PK), metabolism and biodistribution of polyethylene glycol (PEG) in PEGylated proteins are important to understand the increased cellular vacuolation reported in various tissues in animals. The tissue distribution profile of PEGylated proteins and 'metabolic' PEG is guided largely by absolute PEG load, PEG molecular weight and, where applicable, receptor-mediated uptake via the protein moiety. High molecular weight PEGs show slow renal clearance, and consequently have a greater potential to accumulate within cells. The intracellular nonbiodegradable PEG can accumulate within the lysosome ultimately causing distension and vacuolation observed by standard histological examinations. Improved bioanalytical methodologies will contribute to the identification of specific PK parameters including distribution behavior to support development of PEGylated proteins as therapeutics.

IBD medications during pregnancy and lactation

IBD often affects patients during their peak reproductive years. Several drugs are available for the treatment of IBD and new drugs are continuously in the pipeline. As long-term administration of medications is often necessary, the safety of drug therapy during pregnancy and breast-feeding needs to be considered in daily clinical practice. The aim of this Review is to summarize the latest information concerning the safety of medications used to treat IBD during pregnancy and lactation, as well as their effect on fertility. Although only thalidomide and methotrexate are absolutely contraindicated during pregnancy and breast-feeding, alternatives to ciprofloxacin, natalizumab and sodium phosphate should also be considered for pregnant women. Breast-feeding is also discouraged while on treatment with ciclosporin, metronidazole and ciprofloxacin. However, therapy with 5-aminosalicylic acid preparations, glucocorticoids, thiopurines and TNF inhibitors are acceptable during pregnancy and lactation. Pregnant women who have symptomatic IBD or who require therapy should have the opportunity to discuss any associated risks to their pregnancy and infant with the appropriate consultants. By ensuring that the patient and her family are informed, the clinical outcome might be optimized.

Prospective evaluation of 1-day polyethylene glycol-3350 bowel preparation regimen in children

OBJECTIVES

The aim of the present study was to evaluate efficacy, safety, and tolerability of a pediatric colonoscopy bowel preparation regimen composed of polyethylene glycol-3350 (PEG-3350) and a sports drink completed in a few hours.

METHODS

A prospective, open-label trial of a colonoscopy bowel preparation in children ages 8 to 18 years that included 238 g of PEG-3350 mixed with 1.9 L of Gatorade completed in a few hours. Efficacy was determined using the Boston Bowel Preparation Scale. Basic metabolic profiles and questionnaires were obtained that assessed for safety, adverse effects, tolerability, and patient acceptability.

RESULTS

Forty-six patients completed the study. Patients were predominately boys (56.5%) with a mean age of 14.50 years (SD ± 2.9 years). Forty-three (93.5%) were able to complete the regimen. All of the colonoscopies were completed to the cecum and 84% had terminal ileum visualization. Seventy-seven percent were found to be effective preparations. Nausea/vomiting were the most common reported adverse effect (60%) followed by abdominal pain/cramping (44%) and fatigue/weakness (40%). Overall, the regimen was acceptable with 1 exception being the large volume to drink. There were no clinically significant changes in basic metabolic profiles, although there was a statistically significant decrease in the mean potassium (0.16 mEq/L; P = 0.016), blood urea nitrogen (2.68 mg/dL; P < 0.0001), and carbon dioxide (1.89 mmol/L; P < 0.0001).

CONCLUSIONS

This study demonstrated that PEG-3350 + Gatorade administered in a few hours is an effective, safe, and moderately tolerable bowel preparation regimen for colonoscopy in children.

Laxative treatment with polyethylene glycol does not affect lipid absorption in rats

OBJECTIVES

Polyethylene glycol (PEG) is a frequently used laxative agent. It is unknown, however, whether PEG affects the absorptive capacity of the intestine. Reduced lipid (dietary fat and cholesterol) absorption induced by long-term PEG treatment could negatively affect growth in children. We tested whether PEG accelerates gastrointestinal transit and alters lipid absorption and plasma lipid levels.

METHODS

Wistar rats were administered drinking water with or without PEG (7%) for 2 weeks. We studied whole gut transit time by recording the first appearance of red feces after intragastric carmine red administration. We measured plasma concentrations of cholesterol and triglycerides, dietary fat absorption by 48-hour fat balance and by plasma appearance of intragastrically administered stable-isotope labeled fats, and cholesterol absorption with a dual stable isotope technique.

RESULTS

PEG decreased whole gut transit time by 20% (P=0.028) without causing diarrhea. PEG treatment did neither affects overall dietary fat balance nor fat uptake kinetics, cholesterol absorption, or plasma lipid concentrations.

CONCLUSIONS

PEG does not affect lipid absorption nor steady-state plasma lipid levels in rats, although it accelerates the gastrointestinal transit.

Bioanalytical aspects of clinical mass balance studies in oncology

Clinical mass balance studies aim to investigate the absorption, distribution, metabolism and excretion (ADME) of a(n) (often radiolabeled) drug, following a single administration to humans. They are perfectly suited to determine the disposition and major metabolic pathways of a drug, the exposure to the parent drug and its metabolites, and the rate and route of elimination. A mass balance study, however, poses interesting challenges to the analysis of parent drug and metabolites in different biological matrices. Using recent clinical mass balance studies in oncology as an example, this review focuses on the aspects of mass balance studies, from bioanalytical assay development, analysis of clinical samples to reporting of study results. Along the way, it discusses bioanalytical problems and practical solutions.

Expediting return of bowel function after colorectal surgery

BACKGROUND

Postoperative ileus is the main determinant of the length of hospital stay after colorectal surgery. Our objective was to analyze modifiable factors, including polyethylene glycol administration, associated with the return of bowel function.

METHODS

A retrospective review of all patients who underwent elective open partial colectomy from 2004 to 2006 at a single institution.

RESULTS

The time to the first bowel movement with and without oral intake within 48 hours postoperatively was 76 hours versus 134 hours (P < .001); with and without polyethylene glycol administration it was 73 hours versus 94 hours (P = .001); and with and without frequent ambulation it was 78 hours versus 95 hours (P = .012). With postoperative nasogastric tube drainage, the time to the first bowel movement was 22 hours longer (P = .002).

CONCLUSIONS

These data confirm previous findings supporting no nasogastric tube drainage, early feeding, and frequent ambulation after colorectal surgery. Additionally, our data suggest a strong association (P = .001) between the use of polyethylene glycol and the early return of bowel function.

Over-the-counter laxative polyethylene glycol 3350: an evidence-based appraisal

OBJECTIVE

To explore the clinical dimensions of chronic constipation and the role played in its treatment by laxatives in general and by polyethylene glycol 3350 (MiraLAX * ) in particular. * MiraLAX is a registered trade name of Schering-Plough HealthCare Products, Inc., Memphis, TN, USA, a subsidiary of Merck & Co., Inc.

RESEARCH DESIGN AND METHODS

Published reports of clinical trials involving polyethylene glycol 3350, together with published articles examining the epidemiology, demographics, etiology, evaluation, and management of chronic constipation, were identified in a literature search through November 2009 using PubMed. Congress proceedings and guideline databases of leading national and international gastroenterology associations were also explored for relevant recommendations and evaluations.

MAIN OUTCOME MEASURES

Constipation, often defined differently by patients and physicians, is typically associated with excessive straining, hard stools, infrequent bowel movements, and sensations of incomplete evacuation. Specific criteria are available to aid physicians in making a diagnosis of functional constipation. Initial patient management typically involves dietary and lifestyle changes, although this approach is supported by limited clinical evidence and is often a source of considerable patient frustration. A laxative is needed when these changes do not sufficiently relieve constipation. Multiple agents from several different laxative classes are available, differing in mechanism of action, safety and efficacy profile, and clinical evidence supporting their use.

RESULTS

Twenty-one studies involving a total of 1949 patients were included in the overall review of polyethylene glycol 3350. Fifteen studies used randomized designs, eight were comparative trials, seven were conducted in pediatric populations, and three had elderly components.

LIMITATIONS

Limitations of this review included lack of comparability among the various patient populations described; focus on a single agent; potential publication bias; non-systematic review.

CONCLUSIONS

Polyethylene glycol 3350, an osmotic laxative available over the counter, has been shown to be safe and effective in treating chronic constipation in children and adults, including the elderly, across multiple clinical trials, with a safety profile comparable to that of placebo. Polyethylene glycol 3350 received a grade A recommendation for improving stool frequency and consistency from the American College of Gastroenterology Task Force on Chronic Constipation.

A randomized, double-blind, placebo-controlled trial of polyethylene glycol effects on fasting and postprandial rectal sensitivity and symptoms in hypersensitive constipation-predominant irritable bowel syndrome

AIM

To assess the effect of polyethylene glycol 3350 (PEG) on fasting and postprandial (PP) perception of rectal distension and symptoms in hypersensitive constipation-predominant irritable bowel syndrome (IBS-C).

METHODS

Forty-two patients meeting Rome II criteria for IBS-C and with a pain threshold of < 32 mmHg were included in a randomized, double-blind, placebo-controlled trial. Patients received either oral PEG, 3.45 g t.i.d. orally for 30 days or placebo. Rectal sensitivity was assessed before and after treatment with a barostat using the ascending method of limits, during basal and PP periods.

RESULTS

No changes in fasting and PP rectal tone and thresholds for first sensation, gas sensation, urge to defecate, and pain was observed with PEG in relation to placebo. In both groups, pressure at which patients crossed the thresholds for noxious (PEG: from 28 ± 8.8 to 22 ± 6.9 mmHg) and non noxious (PEG: from 16 ± 4.9 to 12 ± 3.6 mmHg) stimuli decreased compared with pretreatment values. PEG improved consistency of faeces and showed a trend to diminish blood in faeces. PEG and placebo increased bowel movements per week (P < 0.001), and relieved symptoms without significant side-effects.

CONCLUSIONS

Both PEG 3350 and placebo were clinically useful in patients with IBS-C, an effect that cannot be explained by changes in rectal tone and sensation. The results support the concept that visceral sensitivity is not stable and has a heterogeneous response to drugs, and suggest the existence of a post healing hypersensitivity state.

The safety of osmotically acting cathartics in colonic cleansing

Efficient cleansing of the colon before a colonoscopy or a radiological examination is essential. The osmotically acting cathartics (those given the Anatomical Therapeutic Chemical code A06AD) currently used for this purpose comprise products based on three main substances: sodium phosphate, combinations of polyethylene glycol and electrolyte lavage solutions (PEG-ELS), and magnesium citrate. All these preparations give adequate cleansing results and have similar profiles in terms of the frequency and type of mild to moderate adverse effects. However, serious adverse events, such as severe hyperphosphatemia and irreversible kidney damage owing to acute phosphate nephropathy, have been reported after use of sodium-phosphate-based products. The aim of this Review is to provide an update on the potential safety issues related to the use of osmotically acting cathartics, especially disturbances of renal function and water and electrolyte balance. The available evidence indicates that PEG-ELS-based products are the safest option. Magnesium-citrate-based, hypertonic products should be administered with caution to elderly individuals and patients who are prone to develop disturbances in water and electrolyte balance. Sodium-phosphate-based products can occasionally cause irreversible kidney damage and should not be routinely used in bowel-cleansing procedures.