An open-label study of chronic polyethylene glycol laxative use in chronic constipation

Pharmacologic Treatment of Chronic Constipation

Chronic constipation is a common disease that can impair the quality of life, with a prevalence of 14% globally and 16.5% in South Korea. Straining, hard stools, the sensation of incomplete evacuation, the sensation of anorectal blockage, and manual maneuvers to facilitate defecation are the related symptoms of chronic constipation. On the other hand, medications commonly referred to as laxatives are the essentials of treatment for constipation compared to non-pharmacological treatment, such as lifestyle modifications, biofeedback, or surgery. Unfortunately, there is still an unmet need to determine if pharmacological treatment for constipation is being administered appropriately. Therefore, there are many disadvantages as to whether the indications and side effects of laxatives are adequately considered and prescribed as the primary treatment modality for constipation in a real clinical situation in Korea. Laxatives are generally recommended as the next step for patients in whom organic causes have been excluded and have not responded to initial non-pharmacologic therapies such as dietary fiber intake and exercise. Laxatives can be classified as bulk-forming laxatives, osmotic laxatives, stimulant laxatives, and other novel laxatives. On the other hand, there are distinct mechanisms underlying constipation, and appropriate administration is the most decisive. Therefore, the present investigators prepared this review to discuss appropriate pharmacological strategies for chronic constipation in Korea. Moreover, this paper also includes suggestions for appropriate pharmacological treatment options for special patient populations.

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.

Consequences of poly(ethylene oxide) and poloxamer P188 on transcription in healthy and stressed myoblasts

Poly(ethylene oxide) (PEO) and poloxamers, a class of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers, have many personal and medical care applications, including the stabilization of stressed cellular membranes. Despite the widespread use, the cellular transcriptional response to these molecules is relatively unknown. C2C12 myoblasts, a model muscle cell, were subjected to short-term Poloxamer 188 (P188) and PEO181 (8,000 g/mol) treatment in culture. RNA was extracted and sequenced to quantify transcriptomic impact. The addition of moderate concentrations (14 µM) of either polymer to unstressed cells caused substantial differential gene expression, including at least twofold modulation of 357 and 588 genes, respectively. In addition, evaluation of the transcriptome response to osmotic stress without polymer treatment revealed dramatic change in RNA expression. Interestingly, the addition of polymer to stressed cells-at concentrations that provide physiological protection-did not yield a significant difference in expression of any gene relative to stress alone. Genome-scale expression analysis was corroborated by single-gene quantitative real-time PCR. Changes in protein expression were measured via western blot, which revealed partial alignment with the RNA results. Collectively, the significant changes to expression of multiple genes and resultant protein translation demonstrates an unexpectedly broad biochemical response to these polymers in healthy myoblasts in vitro. Meanwhile, the lack of substantial transcriptional response to polymer treatment in stressed cells highlights the physical nature of that protective mechanism.

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.

Use of polyethylene glycol in functional constipation and fecal impaction

OBJECTIVE

The objective of this study was to evaluate in an analytical and descriptive manner the evidence published so far on the use of polyethylene glycol (PEG), with or without electrolytes, in the management of functional constipation and the treatment of fecal impaction.

METHODOLOGY

Search on MEDLINE, EMBASE and Cochrane databases until May 2016 of all publications adjusted to the following terms: constipation AND/OR fecal impaction AND (PEG OR polyethylene glycol OR macrogol OR movicol OR idralax OR miralax OR transipeg OR forlax OR golytely OR isocolan OR mulytely) NOT colonoscopy. Critical reading of selected articles (English or Spanish), sorting their description according to group age (adult/pediatric age) and within those, in accordance with study features (efficacy evaluation versus placebo, doses query, safety, comparison with other laxatives, observational studies and monographic review articles of polyethylene glycol or meta-analysis).

RESULTS

Fifty-eight publications have been chosen for descriptive analysis; of them, 41 are clinical trials, eight are observational studies and nine are systematic reviews or meta-analysis. Twelve clinical trials evaluate PEG efficacy versus placebo, eight versus lactulose, six are dose studies, five compare polyethylene glycol with and without electrolytes, two compare its efficacy with respect to milk of magnesia, and the rest of the trials evaluate polyethylene glycol with enemas (two), psyllium (one), tegaserod (one), prucalopride (one), paraffin oil (one), fiber combinations (one) and Descurainia sophia (one).

CONCLUSIONS

Polyethylene glycol with or without electrolytes is more efficacious than placebo for the treatment of functional constipation, either in adults or in pediatric patients, with great safety and tolerability. These preparations constitute the most efficacious osmotic laxatives (more than lactulose) and are the first-line treatment for functional constipation in the short and long-term. They are as efficacious as enemas in fecal impaction, avoid the need for hospital admission and are well tolerated by patients (mainly when administered without electrolytes).

Safety and Palatability of Polyethylene Glycol 3350 as an Oral Laxative in Cats

Recurrent constipation is a common problem in cats. Laxatives often are the cornerstone for management of recurrent constipation; however, there is a paucity of published research on laxative use in cats. This study investigated the safety and palatability of polyethylene glycol (PEG3350) in normal cats. All cats consumed the PEG3350 laxative for 4 weeks without changes in weight or food intake. In all cats soft stools were achieved. Effective doses varied widely in experimental cats, so individualized dosing is important. Mild, non-clinical hyperkalemia was noted although the cause is unknown.

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).

Guidelines for the Diagnosis and Treatment of Chronic Functional Constipation in Korea, 2015 Revised Edition

The Korean Society of Neurogastroenterology and Motility first published guidelines for chronic constipation in 2005 and was updated in 2011. Although the guidelines were updated using evidence-based process, they lacked multidisciplinary participation and did not include a diagnostic approach for chronic constipation. This article includes guidelines for diagnosis and treatment of chronic constipation to realistically fit the situation in Korea and to be applicable to clinical practice. The guideline development was based upon the adaptation method because research evidence was limited in Korea, and an organized multidisciplinary group carried out systematical literature review and series of evidence-based evaluations. Six guidelines were selected using the Appraisal of Guidelines for Research & Evaluation (AGREE) II process. A total 37 recommendations were adopted, including 4 concerning the definition and risk factors of chronic constipation, 8 regarding diagnoses, and 25 regarding treatments. The guidelines are intended to help primary physicians and general health professionals in clinical practice in Korea, to provide the principles of medical treatment to medical students, residents, and other healthcare professionals, and to help patients for choosing medical services based on the information. These guidelines will be updated and revised periodically to reflect new diagnostic and therapeutic methods.

Polyethylene glycol 3350 in occasional constipation: A one-week, randomized, placebo-controlled, double-blind trial

AIM: To evaluate the efficacy and safety of polyethylene glycol (PEG) 3350 in subjects with self-reported occasional constipation.

METHODS: Eligible subjects ≥ 17 years of age were randomized to receive either placebo or PEG 3350 17 g once daily in this multicenter, double-blind trial. Evaluations were conducted before (baseline) and after a 7-d treatment period. The primary efficacy variable was the proportion of subjects reporting complete resolution of straining and hard or lumpy stools. Secondary efficacy variables assessed the severity of the subjects’ daily bowel movement (BM) symptoms, and preference of laxatives based on diary entries, visual analog scale scores, and questionnaires.

RESULTS: Of the 203 subjects enrolled in the study, 11 had major protocol violations. Complete resolution was noted by 36/98 (36.7%) subjects in the PEG 3350 group and 23/94 (24.5%) in the placebo group (P = 0.0595). The number of complete BMs without straining or lumpy stools was similar between both groups. Subjects receiving PEG 3350 experienced significant relief in straining and reduction in hardness of stools over a 7-d period (P < 0.0001). Subjects reported that PEG 3350 had a better effect on their daily lives, provided better control over a BM, better relief from constipation, cramping, and bloating, and was their preferred laxative. Adverse events (AEs) were balanced between the PEG 3350 and the placebo groups. No deaths, serious AEs, or discontinuations due to AEs were reported. This trial is registered at clinicaltrials.gov as NCT00770432.

CONCLUSION: Oral administration of 17 g PEG 3350 once daily for a week is effective, safe, and well tolerated in subjects with occasional constipation.

Comparison of the effectiveness of polyethylene glycol with and without electrolytes in constipation: a systematic review and network meta-analysis

Background

Polyethylene glycol is commonly used to manage constipation and is available with or without electrolytes. The addition of electrolytes dates back to its initial development as lavage solutions in preparation for gastrointestinal interventions. The clinical utility of the addition of electrolytes to polyethylene glycol for the management of constipation is not established.

The objective of this systematic review and network meta-analysis (NMA) was to assess the relative effectiveness of polyethylene glycol with (PEG + E) or without electrolytes (PEG) in the management of functional constipation in adults.

Methods

A systematic review was conducted to identify randomised controlled clinical trials that assessed the use of polyethylene glycol in functional constipation. The primary outcome was the mean number of bowel movements per week.

Results

Nineteen studies were included in the NMA (PEG N = 9, PEG + E N = 8, PEG versus PEG + E N = 2; involving 2247 patients). PEG and PEG + E are both effective, increasing the number of bowel movements per week by 1.8 (95 % Crl 1.0, 2.8) and 1.9 (95 % Crl 0.9, 3.0) respectively versus placebo and by 1.8 (95 % Crl 0.0, 3.5) and 1.9 (95 % Crl 0.2, 3.6) respectively versus lactulose. There was no efficacy difference between PEG + E and PEG (0.1, 95 % Crl −1.1, 1.2) and there were no differences in safety or tolerability.

Conclusions

Polyethylene glycol with and without electrolytes are effective and safe treatments for constipation in adults. The addition of electrolytes to polyethylene glycol does not appear to offer any clinical benefits over polyethylene glycol alone in the management of constipation.

Opioids and the gastrointestinal tract - a case of narcotic bowel syndrome and literature review

The worldwide use of opiates is increasing yet there is little evidence that in long-term, non-cancer patients, they have an efficacious effect on functional outcomes and quality of life measures. Although it seems paradoxical, chronic opiate use may lead to a pro-nociceptive state. Mechanisms for the development of the hyperalgesic state include activation of the opiate bimodal regulatory systems, dynorphin and spinal cord glia. A potential consequence of chronic opiate usage is the development of narcotic bowel syndrome, which is characterized by chronic or intermittent colicky abdominal pain or discomfort that worsens after the narcotic effects of opiates wear off. It is likely that this is an under-recognized diagnosis. We describe here a case of 26-year old female who had visited our institution multiple times with intractable chronic abdominal pain in the context of normal findings on haematological, biochemical, metabolic, endoscopic and radiological investigations. She had been treated with a multitude of opioid agonists with escalating doses. A diagnosis of narcotic bowel syndrome was made. On elective admission her daily analgesic requirements were 150 µg/hr fentanyl, 100 mg oramorph and 400 mg tramadol (equating to 740 mg oral morphine/24 hr). A detoxification regimen was prescribed which included rapid opiate withdrawal couple with the commencement of methadone, lorazepam, clonidine and duloxetine. She was discharged opiate free, with no abdominal pain, 14 days after admission. Clinicians must be aware of narcotic bowel syndrome, which is often erroneously labelled as a functional gastrointestinal disorder, in patients who have been on long-term opiates.

The approach to diagnosis and treatment of chronic constipation: suggestions for a general practitioner

Chronic constipation is a frequent complaint. Symptoms of obstructive defecation (straining, hard and lumpy stools, or incomplete evacuation) are more frequent and bothersome than the frequency of bowel movements. Patient assessment is clinically based on the presence or absence of red flags. Commonly used therapies (eg, bulk-forming agents, stool softeners and stimulant laxatives) have only been evaluated in small studies of short duration. Polyethylene glycol was shown to be effective and safe in several rigorous trials with durations of more than one year. New drugs (prucalopride, lubiprostone and linaclotide) were shown to be effective and safe in well-designed and rigorous studies. Trials conducted in primary care patients are lacking for all therapies. Biofeedback and behavioural therapies are effective, but should be reserved for selected patients after proper diagnostic evaluation. A practical management algorithm is proposed using a multistep approach favouring early introduction of combined therapies and long-term step-down strategy to the lowest satisfactory regimen.

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.

Physical therapy combined with a laxative fruit drink for treatment of chagasic megacolon

CONTEXT

The treatment of Chagas' disease colopathy is limited to clinical management in the initial of the process, and for patients for whom surgery is not indicated or is not possible, anti-constipation diets are used, along with judicious administration of laxatives and enemas.

OBJECTIVE

To evaluate over time the effects of physical-therapy interventions combined with daily ingestion of a laxative fruit drink in the treatment of chagasic megacolon.

METHOD

In a quantitative, prospective, and comparative study, 12 patients of both sexes and with a mean age of 67 ± 12 years were clinically evaluated to receive 12 sessions of physical therapy twice a week, along with fruit drink, and were evaluated for intestinal constipation before and after treatment.

RESULTS

A significant difference (P<0.0022) was observed in the constipation scores before and after 6 weeks of intervention in 91.7% of the patients, and in 72.7% after 12 months, with reduction of laxative medications, softer stools, and increased number of bowel movements. With respect to gender, age, and whether or not the patient had received surgical treatment, there was no significant difference (P>0.05).

CONCLUSION

The proposed protocol is easy to implement, safe, non-invasive, and low-cost, with the potential to be deployed in health care by providing benefits independent of gender, age, or whether the participant has undergone surgery, improving the condition of patients with chagasic megacolon.

Current and future therapies for chronic constipation

In this article, traditional and novel therapies for chronic constipation are reviewed. Traditional laxatives are effective at inducing bowel movements, but efficacy in long-term management and efficacy on constipation-associated abdominal symptoms are less well established, with the exception of polyethylene glycol, for which long-term studies confirm sustained efficacy. Recently approved drugs include the colonic secretagogue lubiprostone and the 5-HT4 agonist prucalopride. In controlled trials in chronic constipation, these drugs were shown to significantly improve constipation and its associated symptoms, with a favourable safety record. Methylnaltrexone, a subcutaneously administered peripherally acting mu opioid receptor antagonist, has recently been approved for opioid-induced constipation in terminally ill patients. New agents under evaluation include the 5-HT4 agonists velusetrag and naronapride, the guanylate cyclase-C receptor agonist linaclotide and the peripherally acting mu opioid receptor antagonist alvimopan.

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.

Pharmacologic management of chronic constipation

Chronic constipation is a common digestive problem in North America, with significant psychosocioeconomic implications. Dietary and lifestyle measures and low-cost traditional over-the-counter laxatives are usually the first line of therapy but help only half of the patients. Several newer agents that act by increasing colonic peristalsis, altering colonic secretion, and/or antagonizing enteric opioid receptors have been developed that are effective in treating constipation and its related symptoms as well as improving quality of life. This article focuses on the pharmacology of traditional and newer agents for the treatment of constipation.

Comparison of polyethylene glycol with and without electrolytes in the treatment of constipation in elderly institutionalized patients: a randomized, double-blind, parallel-group study

BACKGROUND

Polyethylene glycol (PEG) is a commonly used osmotic laxative. PEG with electrolytes is mixed with water, but PEG without electrolytes can also be mixed with, for example, juice, coffee or tea, making it more palatable. Laxatives, including PEG, are commonly used by the elderly, particularly those living in institutions. Few clinical studies, however, have investigated the use of PEG in this population.

OBJECTIVE

To test whether PEG 4000 without electrolytes (hypotonic PEG) is at least as effective and safe as PEG 4000 with electrolytes (isotonic PEG) in elderly institutionalized constipated patients. The acceptability of the treatments was also compared.

METHODS

This randomized, double-blind, parallel-group study was conducted at ten private assisted-living facilities or communal nursing homes in Finland. Eligible patients were required to have used isotonic PEG at a stable dose without any other treatment for constipation (except for Plantago ovata seeds) for at least 2 weeks prior to a run-in period. After the 1-week run-in, 62 patients (mean age 86 years; range 66-99 years) were randomly either switched to receive hypotonic PEG or continued to receive isotonic PEG, both dissolved in water, 12 g once or twice daily or once every other day, for 4 weeks. Stool frequency, stool consistency, stool straining and gastrointestinal symptoms were recorded. Safety laboratory tests were conducted before and after the treatment period. Acceptability was assessed at the end of the study.

RESULTS

At week 4, mean (SD) weekly stool frequencies in the hypotonic and isotonic PEG groups were 8.5 (4.5) and 8.4 (3.6), respectively. The mean stool frequency ratio (95% CI) was 0.90 (0.74, 1.10); thus, the PEG products were considered equally effective. At week 4, the proportion of patients with soft or normal stool consistency was higher in the hypotonic PEG group than in the isotonic PEG group (70% vs 52%), but this difference was not statistically significant. There were no differences between the groups in stool straining or gastrointestinal symptoms. In the safety laboratory tests, no clinically significant differences between the groups were detected, although plasma sodium level was statistically significantly lower in the hypotonic PEG group at the end of the study (137.7 vs 138.9 mmol/L, respectively; p = 0.012). Most patients were willing to continue their study treatment (85% in the hypotonic PEG and 63% in the isotonic PEG group; p = 0.070). Compared with only 12% of the patients receiving hypotonic PEG, however, 31% of the patients in the isotonic PEG group rated the taste of the study treatment as bad or very bad (p = 0.101).

CONCLUSION

Hypotonic PEG solution is as effective as isotonic PEG in the treatment of constipation in elderly institutionalized patients. Both treatments appear safe, well tolerated and, when dissolved in water, well accepted by the majority of the patients. When desired, switching from isotonic to hypotonic PEG can safely take place in elderly individuals without compromising efficacy.

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

BACKGROUND

The pharmacokinetics of polyethylene glycol 3350 (PEG-3350) have not been fully described because of lack of a sufficiently sensitive analytical method.

AIM

To describe the pharmacokinetics of PEG-3350 in humans.

METHODS

A highly sensitive, high performance liquid chromatography with mass spectrometry (HPLC/MS/MS) method was developed for PEG-3350 in urine, plasma and faeces with quantification limits of 30 ng/mL, 100 ng/mL and 500 microg/g respectively. Noncompartmental pharmacokinetics methods were used and the effects of gender, age, renal status and dosing frequency were examined after the oral administration of 17 g to healthy volunteers.

RESULTS

Peak PEG-3350 plasma concentrations occurred at 2-4 h and declined to nonquantifiable levels usually within 18 h after single and multiple doses, with a half-life of about 4-6 h. Steady state was reached within 5 days of dosing. Mean urinary excretion of the administered dose ranged from 0.19% to 0.25%. Age, gender or mild kidney impairment did not alter the pharmacokinetics of PEG-3350. Mean faecal excretion of the administered dose was 93% in young subjects.

CONCLUSIONS

For the first time, a highly sensitive assay allowed comprehensive pharmacokinetics studies of PEG-3350 in humans. These studies confirmed that orally administered PEG-3350 is minimally absorbed, rapidly excreted and primarily eliminated via faeces.