Serial monitoring of the physiological effects of the standard Pico-Salax® regimen for colon cleansing in healthy volunteers

Frequency of hyponatremia caused by sodium picosulfate solution when used as a bowel cleansing agent for colonoscopy

Objective:

To determine the frequency of hyponatremia in patients taking Sodium Picosulfate Solution (SPS) solution for bowel preparation prior to colonoscopy and to compare serum sodium levels before and after SPS.

Methods:

This interventional study was conducted at Dr. Ruth K. M. Pfau, Civil Hospital Karachi between June 2019 to November 2019. Patients undergoing colonoscopy were included in the study. All patients were given SPS. Two samples of blood for electrolytes were taken, one 30 minutes before taking SPS solution and another 30 minutes before colonoscopy. Paired sample t-test was used to determine the difference between serum sodium level before taking the colonoscopy solution and serum sodium level before colonoscopy.

Results:

Fifty- four patients fulfilling inclusion criteria were included. Out of the 54 patients 28 (51.9%) were males and 26 (48.1%) were females. Mean sodium levels before taking colonoscopy solution was 139.7 ±3.5 mEq/L and mean sodium level before colonoscopy was 138.9 ±3.8 mEq/L. The difference between serum sodium level before taking SPS colonoscopy solution and before colonoscopy was found to be statistically insignificant (t (53) = 1.308; p = 0.196).

Conclusion:

No serious adverse effects were reported in any of our patients. There was no significant difference in the serum sodium level of patients undergoing colonoscopy before taking SPS bowel preparation solution and serum sodium level before colonoscopy.

The effect of oral intake during the immediate pre-colonoscopy time period on volume depletion in patients who receive sodium picosulfate

Sodium picosulfate, used in combination with magnesium oxide and citric acid for bowel cleansing, can result in dehydration. We investigated whether enhanced carbohydrate fluid intake pre-colonoscopy could mitigate this effect. We enrolled 398 elective colonoscopy patients in a prospective, controlled, single-blinded study. The control group (n=194) fasted routinely (minimum seven hours) whilst the treatment group (n=197) drank 1,200 ml carbohydrate solution leading up to admission (up until two hours pre-colonoscopy). On admission a patient survey was completed, and urine specific gravity obtained. Supine blood pressure and pulse rate were measured, and repeated within three minutes of standing. The carbohydrate group had reduced symptoms and signs of dehydration, including thirst (34% versus 65%, P <0.001), dry mouth (45% versus 59%, P=0.008), dizziness (10% versus 20%, P=0.010), lower mean urine specific gravity (1.007 versus 1.017, P <0.001), lower incidence of orthostatic hypotension (2.6% versus 11%, P <0.001), and lower mean erect pulse rate (78 versus 81 /minute, P=0.047). The postural change in systolic blood pressure was less in the treatment group (mean -0.4 mmHg, median -1 mmHg [interquartile range, IQR -7 to 7]) than in the control group (mean -4.1 mmHg, median -1 mmHg [IQR -12 to 3], P=0.028). These findings indicate that hydration with carbohydrate solution in patients taking sodium picosulfate has clinical benefit.

Single-day sodium picosulfate and magnesium citrate versus split-dose polyethylene glycol for bowel cleansing prior to colonoscopy: A prospective randomized endoscopist-blinded trial

BACKGROUND AND AIM

The intake of polyethylene glycol (PEG) prior colonoscopy is frequently associated with nausea and abdominal discomfort. The aim of this study was to investigate whether sodium picosulfate and magnesium citrate (PMC) is superior to a polyethylene glycol (PEG) preparation in regard to patient acceptance. Furthermore, it investigates possible differences in efficiency and patient safety.

METHODS

In a randomised, prospective, and endoscopist-blinded study patients were 1:1 randomized to either use PMC or 4-L PEG in order to prepare for colonoscopy. Cleansing regimes consisted of a split-dose administration in the PEG arm and standard administration in the PMC arm. Primary end point was proportion of patients evaluating the bowel preparation procedure as "very distressing," defined as ≥ 8 points on a 10-point numeric rating scale (NRS). Secondary end points were quality of bowel preparation and electrolyte parameters.

RESULTS

PMC bowel-cleansing procedure was better tolerated compared with PEG (PMC(NRS<8)  = 89.9% vs PEG(NRS<8)  = 79.2%, P = 0.037). Mean declines in serum sodium (ΔSodium(PEG)  = -0.76 ± 3.07 vs ΔSodium(PMC)  = -3.38 ± 3.56 mmol/L; P < 0.001), chloride (ΔChloride(PEG)  = -1.00 ± 3.22 vs ΔChloride(PMC)  = -3.49 ± 3.51 mmol/L; P < 0.001), and osmolality (ΔOsmolality(PEG)  = -4.23 ± 6.82 vs ΔOsmolality(PMC)  = -8.83 ± 7.43 mosmol/kg; P < 0.001) were higher in the PMC arm than in the PEG arm. Hyponatremia after bowel preparation occurred more often in PMC (21.2%) than in PEG (4.0%) (P < 0.001). Successful preparation was achieved more frequently in the PEG arm (42.9% vs 82.2%; P < 0.001).

CONCLUSION

Standard picosulfate/magnesium citrate is better accepted than a split-dose PEG regimen. From the perspective of successful preparation and patients' safety, PEG is superior to PMC.

Serum magnesium concentrations in patients receiving sodium picosulfate and magnesium citrate bowel preparation: an assessment of renal function and electrocardiographic conduction

BACKGROUND

We performed a post hoc analysis of two clinical trials to assess whether sodium picosulfate and magnesium (Mg(2+)) citrate (Prepopik(®) [P/MC]), a dual-action bowel preparation for colonoscopy, has an impact on serum Mg(2+) levels and cardiac electrophysiology. Although rare, hypermagnesemia has been reported in patients consuming Mg(2+)-containing cathartics, especially patients who are elderly and have renal impairment.

METHODS

Data were analyzed from two prospective, Phase III, randomized, assessor-blinded, active-control, multicenter, pivotal studies that investigated split-dose/day-before P/MC. Serum Mg(2+) and creatinine clearance (CrCl) were measured at screening, on the day of colonoscopy, and 24-48 hours, 7 days, and 4 weeks after colonoscopy; electrocardiograms also were obtained at these time points.

RESULTS

In total, 304 patients received split-dose P/MC and 294 patients received day-before P/MC. Only 10% of the patients had serum Mg(2+) above the upper limit of normal (1.05 mmol/L) on the day of colonoscopy. There was a slight inverse correlation between CrCl and Mg(2+) levels on the day of colonoscopy; however, even at the lowest CrCl, serum Mg(2+) remained below clinically significant levels of 2.0 mmol/L. Increases in serum Mg(2+) were transient, with levels returning to baseline within 24-48 hours, regardless of renal function. No patients with elevated Mg(2+) experienced a corrected QT (QTc) interval >500 milliseconds or a QTc interval increase of ≥60 milliseconds from baseline. P/MC had no impact on PR or QRS interval.

CONCLUSION

P/MC produces little impact on serum Mg(2+) levels with no clinically significant effect on cardiac conduction in patients, including those with mild-to-moderate renal impairment.

Prospective, randomized comparison of same-day dose of 2 different bowel cleanser for afternoon colonoscopy: picosulfate, magnesium oxide, and citric acid versus polyethylene glycol

For afternoon colonoscopy, same-day administration of sodium picosulfate, magnesium oxide, and citric acid (PM/Ca) is recommended. However, few studies have evaluated the bowel-cleansing efficacy and safety of this regimen. The aim of this study was to compare the bowel-cleansing efficacy, side effects, and patient's tolerability of a same-day split administration of PM/Ca with polyethylene glycol (PEG) for afternoon colonoscopy. Patients were randomly assigned to a PM/Ca group or a PEG group. The PM/Ca group consumed 1 sachet of PM/Ca at 06:00 and 1 sachet of PM/Ca 4 hours before the colonoscopy. They also took 2 tablets of bisacodyl before sleep on the night before. The PEG group consumed 2 L of PEG at 06:00 and 2 L of PEG 4 hours before the colonoscopy. All subjects were instructed to finish the bowel cleanser or fluid at least 2 hours before colonoscopy. All colonoscopic examinations were performed in the afternoon on the same day. The bowel-cleansing efficacy was scored using 2 scales: the Ottawa Bowel Preparation Scale (OBPS) and the Aronchick scale. Ease of using the bowel cleanser was rated from 1 (very easy) to 5 (very difficult). Two hundred nine patients underwent colonoscopy. The bowel-cleansing scores by OBPS did not differ between groups (5.0 vs 4.9, P = 0.63). Ease of using the bowel cleanser was superior in the PM/Ca group (P < 0.01). The cleansing efficacy of PM/Ca administered on the day of colonoscopy is comparable to that of PEG. Patients prefer PM/Ca.

Polyethylene glycol vs sodium picosulfate/magnesium citrate for colonoscopy preparation

BACKGROUND AND STUDY AIMS

Polyethylene glycol-based electrolyte solutions (PEG-ELS) and the combination of sodium picosulfate/magnesium citrate (SPMC) are commonly used bowel preparation agents. The aim of the present study was to compare the two agents with regard to cleansing efficacy and tolerance among individuals scheduled for outpatient colonoscopy.

MATERIALS AND METHODS

The 368 colonoscopy outpatients at three Norwegian hospitals were randomized to bowel lavage with either PEG-ELS or SPMC. Compliance and patient tolerance were evaluated using a patient questionnaire. Bowel cleansing was evaluated using the Ottawa Bowel Preparation Quality Scale (OBPS), a validated scoring system with scores between 0 (best) and 14.

RESULTS

There was no difference in the cleansing quality between the PEG-ELS and SPMC groups (median OBPS 5.0 in both groups). The group that received SPMC reported better overall patient tolerance than the PEG-ELS group (72.6 % vs 59.0 % reporting no or slight discomfort, P < 0.01). Compliance with the recommended total fluid intake (4 L) was better in the SPMC group than in the PEG-ELS group (94.2 % vs 81.2 % respectively, P < 0.01); moreover, the polyp detection rate was superior (34.3 % vs 23.3 %, P = 0.02).

CONCLUSION

PEG-ELS and SPMC are equally effective in cleansing efficacy, but SPMC was better tolerated by patients and resulted in superior patient compliance and polyp detection rate.

CLINICAL TRIAL REGISTRATION

NCT01624454.

Effectiveness of Sodium Picosulfate/Magnesium Citrate (PICO) for Colonoscopy Preparation

Purpose

Bowel preparation with sodium phosphate was recently prohibited by the U.S. Food and Drug Administration. Polyethylene glycol (PEG) is safe and effective; however, it is difficult to drink. To identify an easy bowel preparation method for colonoscopy, we evaluated three different bowel preparation regimens regarding their efficacy and patient satisfaction.

Methods

In this randomized, comparative study, 892 patients who visited a secondary referral hospital for a colonoscopy between November 2012 and February 2013 were enrolled. Three regimens were evaluated: three packets of sodium picosulfate/magnesium citrate (PICO, group A), two packets of PICO with 1 L of PEG (PICO + PEG 1 L, group B), and two packets of PICO with 2 L of PEG (PICO + PEG 2 L, group C). A questionnaire survey regarding the patients' preference for the bowel preparation regimen and satisfaction was conducted before the colonoscopies. The quality of bowel cleansing was scored by the colonoscopists who used the Aronchick scoring scale and the Ottawa scale.

Results

The patients' satisfaction rate regarding the regimens were 72% in group A, 64% in group B, and 45.9% in group C. Nausea and abdominal bloating caused by the regimens were more frequent in group C than in group A or group B (P < 0.01). Group C showed the lowest preference rate compared to the other groups (P < 0.01). Group C showed better right colon cleansing efficacy than group A or group B.

Conclusion

Group A exhibited a better result than group B or group C in patient satisfaction and preference. In the cleansing quality, no difference was noted between groups A and C.

The modern bowel preparation in colonoscopy

Adequate bowel preparation is essential for optimal colonoscopy. Suboptimal bowel preparation occurs in 25% to 40% of cases and is associated with canceled procedures, prolonged procedure time, incomplete examination, increased cost, and missed pathology. There are several effective formulations for colon cleansing with a good safety profile. Split dosing should be implemented whenever possible in an effort to enhance tolerance and adherence, and improve mucosal visibility and overall quality of the examination. In this review, modern bowel preparations are discussed including their mechanism of action, mode of use, safety, and how to optimize outcomes.