Mechanism of action and toxicities of purgatives used for colonoscopy preparation

Cardiac Arrest Following GoLytely Consumption: A Potential Trigger for Hypovolemic Shock

This case report presents a rare but severe complication of polyethylene glycol (PEG) used for colonoscopic bowel preparation. A 71-year-old male developed cardiac arrest secondary to hypovolemic shock following consumption of GoLytely. Despite being hemodynamically stable prior to ingestion, the patient experienced extreme weakness, dizziness, and orthostatic hypotension post-consumption. Evaluation ruled out other causes of arrest. While serious complications from PEG are rare, this case underscores the importance of vigilance. Further investigation is warranted to elucidate the relationship between PEG use and cardiac events and to identify potential risk factors for adverse outcomes associated with bowel preparation regimens.

Risks, indications and technical aspects of colonoscopy in elderly or frail patients. Position paper of the Societat Catalana de Digestologia, the Societat Catalana de Geriatria i Gerontologia and the Societat Catalana de Medicina de Familia i Comunitaria

Colonoscopy (CS) is an invasive diagnostic and therapeutic technique, allowing the study of the colon. It is a safe and well tolerated procedure. However, CS is associated with an increased risk of adverse events, insufficient preparation and incomplete examinations in the elderly or frail patient (PEA/F). The objective of this position paper was to develop a set of recommendations on risk assessment, indications and special care required for CS in the PEA/F. It was drafted by a group of experts appointed by the SCD, SCGiG and CAMFiC that agreed on eight statements and recommendations, between them to recommend against performing CS in patients with advanced frailty, to indicate CS only if the benefits clearly outweigh the risks in moderate frailty and to avoid repeating CS in patients with a previous normal procedure. We also recommended against performing screening CS in patients with moderate or advanced frailty.

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

Background

Colonoscopy is a standard procedure for evaluating colon diseases and screening for colorectal cancer, and bowel cleanliness prior to colonoscopy is key. The aim of this study was to compare the bowel cleansing efficacy of low-volume (2 L) split-dose polyethylene glycol (PEG) plus single-dose (24 µg) lubiprostone (LB) and high-volume (4 L) split-dose PEG.

Methods

Patients scheduled to undergo outpatient colonoscopy between December 2019 and June 2021 at Rajavithi Hospital were enrolled and randomized into two groups: 2 L PEG + LB or 4 L PEG. Colon cleanliness was evaluated using the Boston Bowel Preparation Scale (BBPS) by reviewing images of the colon after completion of colonoscopy. Secondary outcomes comprised cecal intubation rate, procedure time, withdrawal time, polyp detection rate, adenoma detection rate, patient satisfaction, compliance (based on complete ingestion of bowel preparation regimen), willingness to repeat the preparation regimen, and associated adverse events.

Results

One hundred and forty patients were included, with 70 in each group. The mean total and segment-specific BBPS scores were not significantly different between groups. However, the rate of adequate bowel preparation was significantly higher in the 2 L PEG + LB group than the 4 L PEG group (100% [95% CI 94.6–100] versus 88.4% [95% CI 78.4–94.9], p = 0.004) in the per-protocol analysis. Colonic polyps were the most common finding. The polyp detection rate, adenoma detection rate, and all secondary outcomes were statistically similar in the two groups (p > 0.05).

Conclusions

The combination of 2 L split-dose PEG plus LB improves bowel cleanliness (based on BBPS scores) to a comparable degree to the standard 4 L split-dose PEG, without additional adverse events and with a lower PEG volume.

Novel frontiers of agents for bowel cleansing for colonoscopy

The incidence of colorectal cancer (CRC) is characterized by rapid declines in the wake of widespread screening. Colonoscopy is the gold standard for CRC screening, but its accuracy is related to high quality of bowel preparation (BP). In this review, we aimed to summarized the current strategy to increase bowel cleansing before colonoscopy. Newly bowel cleansing agents were developed with the same efficacy of previous agent but requiring less amount of liquid to improve patients’ acceptability. The role of the diet before colonoscopy was also changed, as well the contribution of educational intervention and the use of adjunctive drugs to improve patients’ tolerance and/or quality of BP. The review also described BP in special situations, as lower gastrointestinal bleeding, elderly people, patients with chronic kidney disease, patients with inflammatory bowel disease, patients with congestive heart failure, inpatient, patient with previous bowel resection, pregnant/lactating patients. The review underlined the quality of BP should be described using a validate scale in colonoscopy report and it explored the available scales. Finally, the review explored the possible contribution of bowel cleansing in post-colonoscopy syndrome that can be related by a transient alteration of gut microbiota. Moreover, the study underlined several points needed to further investigations.

Polyethylene glycol combined with linaclotide is an effective and well-tolerated bowel preparation regimen for colonoscopy: an endoscopist-blinded, randomized, controlled trial

BACKGROUND AND AIM

Bowel preparation is an important determinant of the quality of colonoscopy. The traditional split-dose regimen of 4 L polyethylene glycol (PEG) solutions for bowel preparation is effective but poorly tolerated. The aim of this was to study the efficacy and tolerability of using linaclotide as an adjunctive agent with low-volume PEG for bowel preparation.

METHODS

This was an endoscopist-blinded, randomized, controlled trial of 432 patients randomly assigned to three groups: 2 L PEG, 4 L PEG and 2 L PEG + 290 µg linaclotide (2 L PEG + L group). The primary outcome measure was efficacy of bowel preparation according to the Boston Bowel Preparation Scale (BBPS), with secondary outcomes of patients' tolerance, defecating frequency, complications, sleeping quality, cecal intubation rate, preparation-to-colonoscopy interval, withdrawal time, cecal intubation time, and adenoma and polyp detection rates.

RESULTS

The percentage of adequate bowel preparation in the 2 L PEG + L group was higher than that of the 2 L PEG group (87.9% vs. 77.0%; P = 0.017), but not the 4 L PEG group (87.9% vs. 91.4%; P = 0.339). In terms of the mean (SD) BBPS score for the total and segmental colons, the bowel cleansing efficacy of 2 L PEG + L was superior to that of 2 L PEG and similar to that of 4 L PEG. Patient's tolerance (including complications, willingness to repeat and sleeping quality) were compatible between the 2 L and 2 L + L group, and the 4 L group was the worst among these three groups.

CONCLUSION

Two liters of PEG combined with 290 µg linaclotide was an effective and well-tolerated bowel preparation regimen.

Evaluating lubiprostone for effective bowel preparation before colonoscopy

Background

Colon preparation is a fundamental step for performing a successful colonoscopy. We aimed to evaluate the effectiveness of administering lubiprostone (LB) added to a single dose of oral polyethylene glycol (PEG) solution in achieving satisfactory colon cleanliness and decreasing the side effects.

Results

One-hundred percent of the control group patients reported that the experienced taste was worse than expected, while in the intervention group half of the patients (50%) said that the taste was natural and 48% experienced taste worse than expected (p<0.0001). Regarding Boston bowel preparation scale (BBPS), there was a significant difference in the overall Boston scale (p=0.02) with more efficacy in the intervention group as 66% of patients in the intervention group had good bowel preparation (5–7) and 24% excellent preparation (8–9). On the other hand, the overall Boston scale in the control group showed that 54% of patients were between 5 and 7, and only 16% of patients had overall Boston scale 8–9. In terms of the side effects of the preparation in both arms, the majority of cases in the intervention arm did not complain of any side effects (78%), while the majority of the complaints were vomiting in 16% of the intervention cases.

Conclusion

The current evidence suggested that adding LB to the colon preparation significantly improved the tolerability and efficacy.

Efficacy and Safety of TJP-008 Compared to 2 L PEG with Ascorbate in Colon Cleansing: A Randomized Phase 3 Trial

Background/Aims

Polyethylene glycol (PEG)-based bowel preparations are effective cleansing agents for colonoscopy. However, they require relatively large volumes to be used even with agents such as 2 L PEG with ascorbate (2LPEG). This phase 3, randomized, single-blinded, multicenter, parallel-group study compared the efficacy of 1 L PEG with high-dose ascorbate, TJP-008, to 2LPEG.

Methods

Patients undergoing colonoscopy were randomized (111) to receive TJP-008 as 1-day split dose (TJP-008-1) or 2-day split dose (TJP-008-2) regimen or to receive 2LPEG as a 2-day split dose regimen. Cleansing efficacy was evaluated using the Harefield Cleansing Scale. The primary endpoint was overall bowel cleansing success. Full analysis set (FAS) and per protocol set (PPS) analyses were performed.

Results

Of the 314 screened patients, efficacy was assessed in the following patient numbers (FAS/PPS) total (293/285), TJP-008-1 (98/94), TJP-008-2 (97/95), and 2LPEG (98/96). FAS revealed noninferiority between TJP-008 and 2LPEG with regard to overall success (TJP-008-2, 99.0%; TJP-008-1, 95.9%; 2LPEG, 94.9%; p=0.100 and p=0.733, respectively). PPS also showed noninferiority (p=0.721 and p=0.211, respectively). However, the PPS analyses showed a higher bowel cleansing score for TJP-008-2 for high-quality cleansing in the right colon (TJP-008-2 83.2% vs 2LPEG 62.5%; p=0.005).

Conclusions

TJP-008 is a new low-volume cleansing agent with a colon cleansing efficacy comparable to that of standard 2LPEG that exhibits significant safety and tolerability.

Lethal Complication From Inappropriately Prepared Polyethylene Glycol (Golytely) in a Pediatric Patient

Polyethylene glycol with electrolytes (PEG-ELS, Golytely) is a widely used osmotic solution for colonic preparation in adults who are undergoing colonoscopy or colon surgeries. In pediatric patients, It is approved for the same indications and as a treatment for severe chronic constipation. PEG-ELS has an acceptable safety profile and minimal side effects. The most common adverse effects are nausea and abdominal cramps. Golytely is known to cause minimal electrolyte disturbances with no major sequelae. A few case reports have been published describing the effect of PEG-ELS on the electrolytes.

In this report, we present a case of an inappropriate preparation of Golytely administered to a pediatric patient leading to severe electrolyte disturbances and death.

Comparison of 1L Adjuvant Auxiliary Preparations with 2L Solely Polyethylene Glycol plus Ascorbic Acid Regime for Bowel Cleaning: A Meta-analysis of Randomized, Controlled Trials

The effectiveness of additional usage of adjuvants for bowel preparation is still unclear. This study compared 1L polyethylene glycol plus ascorbic acid with adjuvant drug regimens (1L PEG-AA, lower volume) with 2L polyethylene glycol plus ascorbic acid (2L PEG-A, low volume) to evaluate whether the adjuvants can be used to reduce the standard dosage of purgative further. The PubMed/MEDLINE, EMBASE, Cochrane Library, and Web of Science database were searched for randomized controlled trials (RCTs). The primary outcome was the efficacy of bowel preparation, and the secondary outcomes were patients' tolerability and complication rate. The overall quality of evidence was assessed using the GRADEpro guideline development tool. Five RCTs with a total of 1013 patients from Korea were included. The majority of patients were outpatients from different hospitals. The pooled data showed no significant difference in the adequate bowel preparation rate (89.3% versus 89.4%, RR 1, 95% CI 0.95-1.05, I ² = 47%) as well as in the complication rate (RR for nausea 1.22, 95% CI 0.89-1.65, I ² = 49%; RR for bloating 0.96, 95% CI 0.73-1.28, I ² = 0%; RR for vomiting 0.69, 95% CI 0.32-1.50, I ² = 33%; RR for abdominal pain 1.01, 95% CI 0.61-1.69, I ² = 0%). But a significantly higher willingness rate was observed in the lower volume (85.1% versus 67.9%, RR 1.25, 95% CI 1.14-1.38, I ² = 46%). The quality of primary outcome evidence was moderate. The findings of this meta-analysis revealed that 1L PEG-AA may be a viable alternative to 2L PEG-A, with comparable effectiveness, better patient preference, and no statistically significant adverse event occurrence.

New Ultra Low Volume Bowel Preparation and Overview of Existing Bowel Preparations

BACKGROUND

Adequate bowel cleansing is essential in achieving a good quality colonoscopy. However, one of the barriers to achieving high-quality bowel cleansing is the patient's tolerability. Different bowel preparations have been developed to improve tolerability while maintaining adequate bowel cleansing.

OBJECTIVES

We aim to explore the pros and cons of commonly used bowel preparations, particularly highlighting the new ultra-low volume bowel preparation.

METHODS

Extensive literature search was carried out on various databases to evaluate the effectiveness and side effects of different bowel cleansing agents, including findings of recent clinical trials on ultra-low bowel preparation.

RESULTS

Polyethylene glycol (PEG) has been commonly used as a bowel prep. Due to its high volume required to ingest to achieve an adequate effect, it has been combined with various adjuncts to reduce the volume to make it more tolerable. Magnesium and phosphate-based preps can achieve low volume, but they can be associated with multiple side effects, mainly electrolyte disturbances. Ultra low volume prep (NER1006) was achieved by combing PEG with ascorbic acid, and its efficacy and side effects were demonstrated in three noninferiority studies.

CONCLUSION

It is important to consider patient preferences, co-morbidities and tolerability, and efficacy and side effect profiles when choosing bowel prep for patients undergoing colonoscopy. New ultra-low bowel prep showed promising results in initial clinical trials, but further real-world post-marketing data will inform its value in clinical practice.

Bowel Preparation for Colonoscopy in 2020: A Look at the Past, Present, and Future

PURPOSE OF THIS REVIEW

Colorectal cancer is the third most common cancer in the USA. Colonoscopy is considered the gold standard for colorectal cancer screening and can offer both diagnosis and therapy. The bowel preparation remains a significant barrier for patients who need to undergo colonoscopy and is often cited as the most dreaded aspect of the colonoscopy process. Inadequate bowel preparations still occur in 10-25% of colonoscopies, and this in turn can lead to increased procedural times, lower cecal intubation rates, and shorter interval between colonoscopies. From a quality standpoint, it is imperative that we do what we can to decrease the rate of inadequate bowel preparations. This review will focus on recent data regarding bowel preparation and offers a glimpse into what may be coming in the future.

RECENT FINDINGS

Recent advances in the field have been made to improve tolerability of bowel preparations and allow for more adequate colonoscopies. Newer, lower volume, flavored preparations, the use of adjuncts, and using split-dose preparations all can help with tolerability, compliance, and, in turn, preparation quality. Edible bowel preparations may become available in the near future. Early data on the use of artificial intelligence for assessment of preparation quality has been promising. Additionally, utilization of smartphone technology for education prior to the bowel preparation has also been shown to improve the adequacy of bowel preparations.

CONCLUSIONS

Ongoing efforts to improve the tolerability and palatability of colonoscopy bowel preparations are important from a quality improvement standpoint to ensure the adequacy of colonoscopy. Incorporating patient-specific factors and comorbidities is also an essential aspect of improving the quality of bowel preparation. Leveraging technology to better communicate with and educate patients on the bowel preparation process is likely to play a larger role in the coming years.

Nanostructured cochleates: a multi-layered platform for cellular transportation of therapeutics

Among lipid-based nanocarriers, multi-layered cochleates emerge as a novel delivery system because of prevention of oxidation of hydrophobic and hydrophilic drugs, enhancement in permeability, and reduction in dose of drugs. It also improves oral bioavailability and increases the safety of a drug by targeting at a specific site with less side effects. Nanostructured cochleates are used as a carrier for the delivery of water-insoluble or hydrophobic drugs of anticancer, antiviral and anti-inflammatory action. This review article focuses on different methods for preparation of cochleates, mechanism of formation of cochleates, mechanism of action like cochleate undergoes macrophagic endocytosis and release the drug into the systemic circulation by acting on membrane proteins, phospholipids, and receptors. Advanced methods such as calcium-substituted and β-cyclodextrin-based cochleates, novel techniques include microfluidic and modified trapping method. Cochleates showed enhancement in oral bioavailability of amphotericin B, delivery of factor VII, oral mucosal vaccine adjuvant-delivery system, and delivery of volatile oil. In near future, cochleate will be one of the interesting delivery systems to overcome the stability and encapsulation efficiency issues associated with liposomes. The current limiting factors for commercial preparation of cochleates involve high cost of manufacturing, lack of standardization, and specialized equipments.

Bowel preparation for colonoscopy: what is best and necessary for quality?

PURPOSE OF REVIEW

Colonoscopy is recognizably, the best colon cancer prevention test, provided the quality of the preparation is adequate for detection of precancerous polyps but also allowing for accurate identification of margins, thereby facilitating complete endoscopic resection. As there are many aspects effecting colon prep outcomes, it is timely to review new standards for optimizing outcomes, including product selection based on patient demographics.

RECENT FINDINGS

New national guidelines have set a minimum quality threshold for adequacy and also defined a split day delivery for oral options as the "standard of care". Several new prep options have been recently released and these data are discussed.

SUMMARY

Optimizing the quality of colon preps has major implications for clinical practice. Clinicians must recognize new targets for standard of care, providing the best approach for each individual patient, considering variable factors which may otherwise compromise success.

Comparative safety of bowel cleansers: protocol for a systematic review and network meta-analysis

INTRODUCTION

The US Food and Drug Administration has withdrawn the bowel cleansing kit HalfLytely (PEG 3500) with 10 mg bisacodyl tablets due to an increased risk of ischaemic colitis compared with the same kit with only 5 mg bisacodyl. This is of interest in Canada given that the bowel cleansing kit Bi-Peglyte (PEG 3500) with 15 mg bisacodyl is currently approved for use. The objective is to assess the comparative safety of various bowel cleansers with or without bisacodyl, with a primary interest inpolyethylene glycol (PEG)-based and sodium-picosulfate-based products.

METHODS AND ANALYSIS

Given the existing volume of the literature, the review will be conducted in two stages. Stage 1 will consist of a scoping exercise by searching MEDLINE, Embase and the Cochrane Library (up to 21 November 2017) to identify randomised controlled trials, quasirandomised studies and non-randomised studies in which any bowel cleanser regimens were compared among persons undergoing colonoscopy. The outcomes will be mapped to establish a listing of the studies and their comparisons and outcomes currently available in the literature. From this, a data synthesis plan will be determined. In stage 2, a systematic review with meta-analyses will be pursued, focused on the bowel cleanser comparisons and outcomes of interest identified in stage 1. Two reviewers will screen, extract and quality assess the articles. Outcomes of interest include ischaemic colitis, electrolyte imbalances and their consequences, seizures, bowel perforation and patient tolerability. If sufficient data exist and studies are of sufficient homogeneity, network meta-analyses (NMAs) will be performed.

ETHICS AND DISSEMINATION

Ethics approval was not necessary due to study design. Updating the safety profile of bowel cleansers among the generally healthy population undergoing colonoscopy is pertinent given recent approval changes. This will be the first NMA within this population. Policy considerations may be reconsidered to minimise risk during bowel cleanser use.

PROSPERO REGISTRATION NUMBER

CRD42018084720.

Effect of Low-Volume Split-Dose Purgative on the Quality of Bowel Prep for Colonoscopy on the Hospitalized Patient

Although colon cancer is preventable, it is still the second leading cause of cancer death in both men and women in the United States (). Colonoscopy is as yet the gold standard for colon cancer prevention (). The success of colonoscopy is dependent upon the quality of the bowel prep. The problem addressed in this study was the impact of hospitalization on bowel prep quality. The participants in this study were 54 consecutive inpatients older than 18 years and 52 consecutive outpatients older than 18 years who were scheduled for colonoscopy in the Endoscopy Lab at Santa Barbara Cottage Hospital. Convenience sampling was used to collect sample data utilizing the Boston Bowel Prep Scale (BBPS). The study group contained 48.1% of the inpatients who had a BBPS of less than seven (out of nine total possible points with a score of nine representing the most optimal prep outcome) compared to 19.2% of the outpatients. Efforts to improve bowel prep palatability, decrease cost, and decrease side effects while improving quality should be continued. Split-dosing is a best practice recommendation. This researcher hypothesized that an intervention in the form of a lower-volume, split-dosage prep would improve the quality of bowel prep in the inpatient population. There was a statistically significant improvement noted with the intervention group in the follow-up study, which indicates potential for improving the quality of bowel prep for screening colonoscopy, thus a possibility for better colon health surveillance.

Optimal Bowel Cleansing for Colonoscopy in the Elderly Patient

Colonoscopy is an important diagnostic and screening tool for colorectal cancer detection and prevention, and adequate bowel preparation is critical for successful colonoscopy. Complications related to colonoscopy, either directly or indirectly related to the procedure, are increased in elderly patients, and the risks and benefits of colonoscopy procedures need to be carefully considered in these patients. Recent studies have shown that 4 L polyethylene glycol with a split preparation is safe and effective for elderly patients, and is the preferred preparation for patients with medical comorbidities. Preparations containing sodium phosphate are generally not recommended for the elderly because of increased renal complications. In addition, a low-residue diet may aid in tolerance and willingness to undergo the procedure compared with a clear liquid diet, with comparable bowel preparation adequacy. Risk factors for inadequate bowel preparations include poor adherence to split preparation instructions or volume of solution ingested, and certain patient-related medications and comorbidities, such as diabetes, elevated body mass index, and antidepressant or narcotic use. Methods for achieving safe and adequate bowel preparations in the elderly include clear instructions, reminder calls, and case management for potential confounding patient-related factors.

A new approach in bowel preparation before colonoscopy in patients with constipation: A prospective, randomized, investigator-blinded trial

OBJECTIVE

Enema administration in the morning of routine colonoscopy is known to be useless. However, the potential bowel cleansing effects of distal colon emptying with enema prior to purgatives are not known. The aim of this study is to investigate the effects of enema use before purgatives in preparation for colonoscopy.

MATERIAL AND METHODS

Two hundred twenty-seven patients were randomly assigned into three groups; enema before purgative use, enema after purgative use, and no enema. Patients were compared in terms of age, sex, BMI, Rome III constipation criteria, history of abdominal surgery, tolerance to the preparation procedure, complications during preparation such as nausea, vomiting, headache and dizziness, cecal insertion time, total duration of colonoscopy, polyp determination rate and colonic cleansing based on the Boston Bowel Preparation Scale.

RESULTS

One hundred two (44.9%) patients were male and 125 (55.1%) female. The mean age and BMI was 55.4±11.8 years and 28.8±4.7, respectively. No difference was observed between the groups in terms of sex, age, or BMI. The number of fulfilled Rome criteria and of previous abdominal surgeries were significantly higher in females than in men. Right colon Boston Bowel Preparation Scale score was higher in the group using enemas before purgatives than the scores of other groups. This improvement was statistically significant in the female patient group with higher constipation rate.

CONCLUSIONS

Use of enemas before purgatives in patients with constipation significantly improves adequacy of right colon cleansing.

"Bowel prep hyponatremia" - a state of acute water intoxication facilitated by low dietary solute intake: case report and literature review

Background

Symptomatic hyponatremia is considered a rare complication of oral bowel preparation for colonoscopy. The pathophysiology underlying this phenomenon has been widely regarded as a mere sequela of excessive arginine vasopressin (AVP) release.

Case presentation

This case describes a 61-year old woman who developed acute hyponatremic encephalopathy when preparing for elective outpatient lower endoscopy. She had had negligible oral solute intake for two days and ingested four liters of clear fluid within two hours. On admission, the patient was agitated and had slurred speech. Treatment with hypertonic saline lead to full recovery. A brisk aquaresis confirmed acute dilutional hyponatremia.

Conclusion

Apart from elevated AVP-levels, the amount and speed of fluid intake and concomitant low-solute intake constitute important risk factors in the development of clinically relevant hyponatremias in patients undergoing colonoscopies. Understanding that the cause of sodium imbalance in this scenario is multifactorial and complex is pivotal to recognizing and ideally preventing this complication, for which we propose the term “bowel prep hyponatremia”.

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

Background

Adequate bowel preparation is an essential prerequisite for complete mucosal visualization during colonoscopy. Polyethylene glycol (PEG) solutions are commonly used. However the large volume of the solution is often poorly tolerated. Addition of Lubiprostone (LB) could improve the adequacy of standard PEG preparation & reduce requirement. The aims to assess adequacy of PEG preparation with addition of single dose LB (24mcg) vs placebo and efficacy of reduced dose PEG + LB compared with full dose PEG + LB.

Methods

Single center prospective double blind randomized controlled trial. Part I: 442 patients for colonoscopy randomized to receive placebo (GrA) or single dose of LB (GrB) prior to PEG preparation. Quality of bowel preparation graded 0–9 according to Boston Bowel Preparation Scale (BBPS). BBPS-9: excellent and BBPS 0–4: repeat procedure.

Part II: 146 patients randomized to receive LB + 1.5 L PEG (GrC; 75) or LB + 1 L PEG (GrD; 71). BBPS score compared with GrB (2 L PEG).

Results

Part I: 442 patients (221 GrA & 221 Gr B). LB resulted in significant improvement in total BBPS (7.44 + 0.14 vs. 6.36 + 0.16, p < 0.0001). 66.5 % Gr B vs 38 % Gr A had excellent prep; 42.5 % GrB vs 24 % GrA had adequate prep. Repeat procedure needed 9.5 % Gr B vs 16.7 % Gr A (P < 0.01).

Part II: No difference in BBPS scores with lower doses (Gr C&D) compared to standard (GrB) (Mean BBPS 7.44 + 0.14 GrA,7.30 + 0.25 GrC;7.25 + 0.26 GrD;p >0.05).

Conclusion

Single dose LB prior to PEG significantly enhanced bowel preparation compared to PEG alone. There was no significant difference in quality of preparation with lower doses of PEG when combined with LB.

Trial registration

The study protocol was approved by institutional review board and the trial was registered on March 22, 2011 with clinicaltrials.gov (NCT01324284).

Systematic review and meta-analysis: sodium picosulfate/magnesium citrate vs. polyethylene glycol for colonoscopy preparation

BACKGROUND AND AIMS

Previous studies comparing sodium picosulfate/magnesium citrate (SPMC) with polyethylene glycol (PEG) drew inconsistent conclusions. We conducted a meta-analysis to compare the performance of the two agents for colonoscopy preparation.

METHODS

A search of randomized controlled trials (RCTs) up to July 2015 was acquired, using MEDLINE, EMBASE, the Cochrane Library, and Google Scholar. We calculated the pooled estimates of bowel cleanliness, polyp/adenoma detection rate (PDR/ADR), completion of preparation, willingness to repeat identical bowel preparation, and adverse events by using relative risk (RR) with random-effects models. A non-inferiority analysis was performed, comparing SPMC to PEG for bowel cleaning efficacy.

RESULTS

A total of 25 RCTs were qualified for analysis. There was no statistically significant difference between the two agents in bowel cleanliness, but the effect direction showed a trend in favor of PEG (RR 0.93; 95 % CI 0.86-1.01, P = 0.07). The non-inferiority analysis demonstrated the non-inferiority of SPMC by retaining at least 90 % of the effect of PEG. Similarly, there was no significant difference between the two agents in PDR (RR 0.94; 95 % CI 0.82-1.08, P = 0.37) and ADR (RR 0.88; 95 % CI 0.74-1.05, P = 0.16). However, a higher proportion of patients were likely to complete SPMC preparation (RR 1.08; 95 % CI 1.04-1.13, P < 0.001) and were willing to repeat SPMC preparation (RR 1.44; 95 % CI 1.25-1.67, P < 0.001). The total number of adverse events was significantly lower in the SPMC group (RR 0.78; 95 % CI 0.66-0.93, P = 0.004).

CONCLUSIONS

SPMC, with better tolerability and less frequent adverse events, demonstrated non-inferior bowel cleaning efficacy than that of the PEG. Large-scale, well-organized, head-to-head studies are warranted.

Impact of the quality of bowel cleansing on the efficacy of colonic cancer screening: a prospective, randomized, blinded study

OBJECTIVES

Efficacy of two low volume bowel cleansing preparations, polyethylene glycol plus ascorbate (PEG + Asc) and sodium picosulfate/magnesium citrate (NaPic/MgCit), were compared for polyp and adenoma detection rate (PDR and ADR) and overall cleansing ability. Primary endpoint was PDR (the number of patients with ≥ 1 polypoid or flat lesion recorded by the colonoscopist).

METHODS

Diagnostic, surveillance or screening colonoscopy patients were enrolled into this investigator-blinded, multi-center Phase IV study and randomized 1:1 to receive PEG + Asc (administered the evening before and the morning of colonoscopy, per label) or NaPic/MgCit (administered in the morning and afternoon the day before colonoscopy, per label). The blinded colonoscopist documented any lesion and assessed cleansing quality (Harefield Cleansing Scale).

RESULTS

Of 394 patients who completed the study, 393 (PEG + Asc, N = 200; NaPic/MgCit, N = 193) had a colonoscopy. Overall PDR for PEG+Asc versus NaPic/MgCit was 51.5% versus 44.0%, p = 0.139. PDR and ADR on the right side of the bowel were significantly higher with PEG + Asc versus NaPic/MgCit (PDR: 56[28.0%] versus 32[16.6%], p = 0.007; ADR: 42[21.0%] versus 23[11.9%], p = 0.015), as was detection of flat lesions (43[21.5%] versus 25[13.0%], p = 0.025). Cleansing quality was better with PEG + Asc than NaPic/MgCit (98.5% versus 57.5% considered successful cleansing). Overall, there were 132 treatment-emergent adverse events (93 versus 39 for PEG+Asc and NaPic/MgCit, respectively). These were mainly mild abdominal symptoms, all of which were reported for higher proportions of patients in the PEG+Asc than NaPic/MgCit group. Twice as many patients in the NaPic/MgCit versus the PEG + Asc group reported tolerance of cleansing solution as 'very good'.

CONCLUSIONS

Compared with NaPic/MgCit, PEG + Asc may be more efficacious for overall cleansing ability, and subsequent detection of right-sided and flat lesions. This is likely attributable to the different administration schedules of the two bowel cleansing preparations, which may positively impact the detection and prevention of colorectal cancer, thereby improving mortality rates.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01689792.

Adjuncts to colonic cleansing before colonoscopy

Pre-procedural cleansing of the bowel can maximize the effectiveness and efficiency of colonoscopy. Yet, efficacy of the current gold standard colonic preparation method - high-volume oral administration of purgative agents 12-24 h prior to the procedure - is limited by several factors, such as patient compliance (due to poor palatability and inconvenience of the dosing regimen) and risks of complications (due to drug interactions or intolerance). Attempts to resolve these limitations have included providing adjunctive agents and methods to promote the colonic cleansing ability of the principal purgative agent, with the aim of lessening unpleasant side effects (such as bloating) and reducing the large ingested volume requirement. Several promising adjunctive agents are bisacodyl, magnesium citrate, senna, simethicone, metoclopramide, and prokinetics, and each are being investigated for their potential. This review provides an up to date summary of the reported investigations into the potencies and weaknesses of the key adjuncts currently being applied in clinic as supplements to the traditional bowel preparation agents. While the comparative analysis of these adjuncts showed that no single agent or method has yet achieved the goal of completely overcoming the limitations of the current gold standard preparation method, they at least provide endoscopists with an array of alternatives to help improve the suboptimal efficacy of the main cleansing solutions when used alone. To aid in this clinical endeavor, a subjective grade was assigned to each adjunct to indicate its practical value. In addition, the systematic review of the currently available agents and methods provides insight into the features of each that may be overcome or exploited to create novel drugs and strategies that may become adopted as effective bowel cleansing adjuncts or alternatives.

Split-dose administration of a dual-action, low-volume bowel cleanser for colonoscopy: the SEE CLEAR I study

BACKGROUND

New bowel cleansers for colonoscopy that lead to improved efficacy, safety, and tolerability are needed.

OBJECTIVE

This study evaluated a nonphosphate, dual-action, low-volume, orange-flavored preparation containing sodium picosulfate and magnesium citrate (P/MC).

DESIGN

Multicenter, assessor-blinded, randomized, noninferiority study.

SETTING

University hospitals, academic medical centers, and private clinics across the United States.

PATIENTS

Adults preparing for colonoscopy.

INTERVENTIONS

P/MC versus 2 L of polyethylene glycol solution (2L PEG-3350) and two 5-mg bisacodyl tablets.

MAIN OUTCOME MEASUREMENTS

This phase 3 study investigated the efficacy, safety, and tolerability of split-dose administration of P/MC versus day-before dosing of 2L PEG-3350 and two 5-mg bisacodyl tablets (SEE CLEAR I study). Efficacy was evaluated by using the Aronchick and Ottawa scales; noninferiority and superiority analyses were performed. Safety was assessed by monitoring adverse events (AEs). Tolerability was measured via a patient questionnaire.

RESULTS

The intent-to-treat population consisted of 601 patients who self-administered P/MC (n = 304) or 2L PEG-3350 and bisacodyl tablets (n = 297). P/MC was superior to 2L PEG-3350 and bisacodyl tablets in overall colon cleansing (84.2% vs 74.4%; 1-sided 97.5% confidence interval [CI], 3.4) (Aronchick scores of excellent or good) and in cleansing of the ascending (89.5% vs 78.8%; 1-sided 97.5% CI, 4.9), mid (transverse and descending) (92.4% vs 85.9%; 1-sided 97.5% CI, 1.6), and rectosigmoid (92.4% vs 87.2%; 1-sided 97.5% CI, 0.4) segments of the colon (Ottawa scores of excellent, good, or fair). Commonly reported AEs related to the bowel preparations were nausea, vomiting, headache, and chills. Patient-reported tolerability, including ease of consumption and taste, was significantly higher for P/MC than 2L PEG-3350 and bisacodyl tablets (P < .0001).

LIMITATIONS

Because of differences in administration and volume of the bowel preparations, the study was designed to be a single-assessor, blinded study.

CONCLUSIONS

The bowel-cleansing effects and patient acceptability of split-dose P/MC were superior to day-before dosing with 2L PEG-3350 and bisacodyl tablets.

A dual-action, low-volume bowel cleanser administered the day before colonoscopy: results from the SEE CLEAR II study

OBJECTIVES

Optimal bowel preparation is vital for the efficacy and safety of colonoscopy. The inconvenience, discomfort, required consumption of large volumes of product, and potential adverse effects associated with some bowel preparations deter patients from colonoscopy and may provide inadequate cleansing. A dual-action, non-phosphate, natural orange-flavored, low-volume preparation containing sodium picosulfate and magnesium citrate (P/MC) is currently being reviewed for bowel cleansing.

METHODS

This was a phase 3, randomized, multicenter, assessor-blinded, prespecified non-inferiority, head-to-head study to investigate the efficacy, safety, and tolerability of day-before administration of P/MC vs. 2L polyethylene glycol solution and two 5-mg bisacodyl tablets (2L PEG-3350 and bisacodyl tablets (HalfLytely and Bisacodyl Tablets Bowel Prep Kit)) in adult patients preparing for colonoscopy (SEE CLEAR II Study). The primary objective of the study was to demonstrate the non-inferiority of P/MC to 2L PEG-3350 and bisacodyl tablets in overall colon cleansing using a modified Aronchick scale. In addition, efficacy in the ascending, mid (transverse and descending), and recto-sigmoid segments of colon was evaluated using a modified Ottawa scale. Patient acceptability and tolerability of the bowel preparations were assessed via a standard questionnaire. Safety was assessed based on the monitoring of adverse events (AEs) and meaningful findings on clinical evaluations including physical examinations, vital sign measurements, and electrocardiograms (ECGs).

RESULTS

A total of 603 patients were randomized to receive either P/MC (n = 300) or 2L PEG-3350 and bisacodyl tablets (n = 303). Based on the Aronchick scale, successful overall cleansing was similar in patients receiving P/MC (83.0%) and patients receiving 2L PEG-3350 and bisacodyl tablets (79.7%). P/MC demonstrated non-inferiority to 2L PEG-3350 and bisacodyl tablets in overall cleansing of the colon, as measured by the Aronchick scale. Similarly, the efficacy of P/MC, as measured by the Ottawa scale, was non-inferior to 2L PEG-3350 and bisacodyl tablets in cleansing the ascending, mid, and recto-sigmoid segments of the colon. Patient-reported acceptability and tolerability for each item examined on the questionnaire was significantly greater for P/MC compared with 2L PEG-3350 and bisacodyl tablets (P<0.0001).Treatment-emergent AEs related to the bowel preparation reported by 1% of patients receiving P/MC or 2L PEG-3350 and bisacodyl tablets were nausea (3.0% vs. 4.3%), vomiting (1.4% vs. 2.0%), and headache (2.7% vs. 1.7%). No clinically meaningful changes were noted in either treatment arm in data collected from physical examinations, vital sign measurements, and ECGs.

CONCLUSIONS

When administered as a day-before dose, the bowel cleansing effects of P/MC were non-inferior compared with 2L PEG-3350 and bisacodyl tablets using the clinician-rated Aronchick and Ottawa scales. Treatment acceptability was significantly more favorable in patients receiving P/MC than in patients receiving 2L PEG-3350 and bisacodyl tablets.

Colonoscopy preparation: polyethylene glycol with Gatorade is as safe and efficacious as four liters of polyethylene glycol with balanced electrolytes

BACKGROUND

Four liters of polyethylene glycol 3350 (PEG) with balanced electrolytes for colonoscopy preparation has had poor acceptance. Another approach is the use of electrolyte-free PEG combined with 1.9 L of Gatorade. Despite its widespread use, there are no data on metabolic safety and minimal data on efficacy. Our aim was to assess the efficacy and electrolyte safety of these two PEG-based preparations.

METHODS

This was a prospective, randomized, single-blind, non-inferiority trial. Patients were randomized to 238 g PEG + 1.9 L Gatorade or 4 L of PEG-ELS containing 236 g PEG. Split dosing was not performed. On procedure day blood was drawn for basic chemistries. The primary outcome was preparation quality from procedure photos using the Boston Bowel Preparation Scale.

RESULTS

We randomized 136 patients (66 PEG + Gatorade, 70 PEG-ELS). There were no differences in preparation scores between the two agents in the ITT analysis (7.2 ± 1.9 for PEG-ELS and 7.0 ± 2.1 for PEG + Gatorade; p = 0.45). BBPS scores were identical for those who completed the preparation and dietary instructions as directed (7.4 ± 1.7 for PEG-ELS, and 7.4 ± 1.8 for PEG + Gatorade; p = 0.98). There were no statistical differences in serum electrolytes between the two preparations. Patients who received PEG + Gatorade gave higher overall satisfaction scores for the preparation experience (p = 0.001), and had fewer adverse effects.

CONCLUSIONS

Use of 238 g PEG + 1.9 L Gatorade appears to be safe, better tolerated, and non-inferior to 4 L PEG-ELS. This preparation may be especially useful for patients who previously tolerated PEG-ELS poorly.