LOW-VOLUME PEG PLUS ASCORBIC ACID AS BOWEL PREPARATION FOR COLONOSCOPY USING MORNING-ONLY DOSING REGIMEN COMPARED TO STANDARD SPLIT-DOSING: MULTICENTER SINGLE-BLIND RANDOMIZED PARALLEL-GROUP CONTROLLED STUDY
BACKGROUND. According to guidelines the optimal delay between the last dose of purgative and colonoscopy is no longer than 2-4 hours. Morning-only dosing of polyethyleneglycol solution (PEG) prior to colonoscopy versus standard split-dosing with nocturnal pause may be more acceptable for patient. AIM. To compare the efficacy, safety and tolerability of morning-only dosing regimen of 2 liter PEG plus ascorbic acid solution (PEG + Asc) 2 L to split-dose PEG + Asc 2 L for bowel preparation prior to colonoscopy. METHODS. This was a multicenter prospective endoscopist-blinded randomized non-inferiority study comparing morning-only to split dosing with nocturnal pause regimen of PEG + Asc 2 L (MOVIPREP<sup>®</sup>) for the bowel preparation prior to colonoscopy. The primary endpoint was successful colon cleansing where «Success» represented grades of bowel cleansing А and В according to Harefield Cleansing Scale© (HCS©). Clinically relevant non-inferiority margin was set at -15 % with one-sided significance level of 5 %. Secondary endpoints were general satisfaction/acceptability ofpatients with the preparationfor colonoscopy, as well as patient compliance and safety of the study drug. RESULTS. Overall 140 patients from 6 centers were enrolled in the study and randomized into two groups of 70 each. ITT analysis showed successful colon cleansing in 94,3 % in the morning-only group versus 91,4 % in the split-dose group. An estimated treatment difference was 2,9 %, 95 % lower confidence limit for the difference -9,7 % with the prespecified non-inferiority margin -15 % (p for non-inferiority <0.001). Furthermore 71,4 % ofpatients had the highest grade A colon cleansing according to HCS© in each group. In patients in the morning-only intake group, the time to first bowel motion following the first liter of PEG + Asc 2 L was shorter, with a median time of 1.08 hours, compared with 1.58 hours in the split-dose group (p<0,001). Nearly all of the patients treated in the morning-only dosing group (69/70) and in the split-dose group (67/70) received the study medication as planned. In general, the study drug was well tolerated in patients of both groups. At least one treatment-emergent adverse event was reported by 58,6 % of patients in the morning-only dosing group and by 61,4 % of patients in the split dosing group. The most frequently reported adverse events were typical gastrointestinal disorders (53,5 % of patients) and changes in laboratory tests (12,1 % of patients). No serious adverse events were reported in this study. CONCLUSION. Morning-only dosing regimen of PEG + Asc 2 L is non-inferior to split-dosing regimen in terms of colon cleansing and is safe and convenient for use as a bowel preparation prior to colonoscopy.