Efficacy and safety of a ready-to-drink bowel preparation for colonoscopy: a randomized, controlled, non-inferiority trial

Abstract

Background: We performed a randomized, controlled, assessor-blinded, multicenter, non-inferiority (NI) study to compare the safety and efficacy of a ready-to-drink formulation of sodium picosulfate, magnesium oxide, and citric acid (SPMC oral solution) with a powder formulation (P/MC powder) for oral solution.

Methods: Eligible participants (adults undergoing elective colonoscopy) were randomized 1:1 to split-dose SPMC oral solution or P/MC powder. The primary efficacy endpoint assessed overall colon-cleansing quality with the Aronchick Scale (AS), and the key secondary efficacy endpoint rated quality of right colon cleansing with the Boston Bowel Preparation Scale (BBPS). Assessments were performed by a treatment-blinded endoscopist. Tolerability was assessed using the Mayo Clinic Bowel Prep Tolerability Questionnaire. Safety assessments included adverse events and laboratory evaluations.

Results: The study included 901 participants: 448 for SPMC oral solution; 453 for P/MC powder. SPMC oral solution demonstrated non-inferiority to P/MC powder {87.7% (393/448) responders versus 81.5% (369/453) responders [difference (95% confidence interval): 6.3% (1.8, 10.9)]}. The key secondary efficacy objective assessing the right colon was also met. According to the prespecified hierarchical testing, after meeting the primary and key secondary objectives, SPMC oral solution was tested for superiority to P/MC powder for the primary endpoint (p = 0.0067). SPMC oral solution was well tolerated. Most common adverse events were nausea (3.1% versus 2.9%), headache (2.7% versus 3.1%), hypermagnesemia (2.0% versus 5.1%), and vomiting (1.3% versus 0.7%) for SPMC oral solution and P/MC powder, respectively.

Conclusions: Ready-to-drink SPMC oral solution showed superior efficacy of overall colon cleansing compared with P/MC powder, with similar safety and tolerability.[ClinicalTrials.gov identifier: NCT03017235.].

Keywords: bowel preparation; colon cleansing; inadequate bowel preparation; oral solution; screening colonoscopy.

Conflict of interest statement

Conflict of interest statement: The authors declare that there is no conflict of interest.

Figures

Figure 1.

CONSORT diagram of study population. GI, gastrointestinal; mITT, modified intent to treat; PP, per protocol; PI, prinicipal investigator; P/MC, sodium picosulfate, magnesium oxide, and citric acid; SPMC, sodium picosulfate, magnesium oxide, and citric acid.

Figure 2.

Forest plots showing the treatment difference between SPMC oral solution and P/MC powder bowel preparations on several efficacy endpoints in the mITT population. Error bars depict the 95% CI, given in brackets. The CI for treatment difference was calculated using stratified (by site) proportion difference, where the weights are Cochran–Mantel–Haenszel weights for site. AS, Aronchick Scale; BBPS, Boston Bowel Preparation Scale; CI, confidence interval; mITT, modified intent to treat; P/MC, picosulfate, magnesium oxide, and citric acid powder; SPMC, sodium picosulfate, magnesium oxide, and citric acid.

Figure 3.

Responses to the Mayo Clinic Bowel Prep Tolerability Questionnaire for the mITT population. Participants tolerated SPMC oral solution well, with most (a) saying that the bowel preparation was ‘easy’ or ‘acceptable’, (b) willing to use this preparation again, and (c) not bothered or only mildly bothered by a bad taste; (d) of the participants who had a previous screening colonoscopy (n = 261 for SPMC oral solution, n = 281 for P/MC powder), most stated that the tolerability of the study bowel preparation was better than the previous bowel preparation. mITT, modified intent to treat; P/MC, picosulfate, magnesium oxide; SPMC, sodium picosulfate, magnesium oxide, and citric acid.