Colon Cleansing Quality of Polyethylene Glycol Compared With Polyethylene Glycol Plus Ascorbic Acid. (REPREP1)
|Colonoscopy Preparation||Drug: Polyethylene glycol 4000 Drug: Macrogol 3350 plus ascorbic acid||Phase 4|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Investigator)
Primary Purpose: Diagnostic
|Official Title:||Randomized Clinical Trial to Evaluate the Colon Cleansing Quality of Polyethylene Glycol Compared With Polyethylene Glycol Plus Ascorbic Acid in Patients With Past Poor Colonic Preparation|
- Colon cleansing [ Time Frame: 30 days ]Colon cleansing will be assessed just after colonoscopy by the endoscopist in charge of performing the examination and afterwards images were reviewed by a the staff of endoscopists for validation (30 days). For assessing colon cleansing a validated scale (Boston scale) will be used.
- Tolerance of bowel preparation [ Time Frame: Tolerance will be assessed just before colonoscopy by a research assistant ]It will be assessed by using a visual analog scale colon
- Detection of colorectal neoplasia [ Time Frame: 14 months ]Detection rate of adenoma and colorectal cancer will be assessed for both groups (low volume and high volume preparation)
|Study Start Date:||May 2014|
|Study Completion Date:||May 2016|
|Primary Completion Date:||December 2015 (Final data collection date for primary outcome measure)|
Active Comparator: High volume
Drug: Polyethylene glycol 4000
- Polyethylene glycol 4000: 16 envelopes (70 g of powder each). It includes electrolytes and sodium sulfate. These substances make PEG metabolically inert, achieving a suitable osmotic balance, despite having a high molecular weight. The preparation passes along the gastrointestinal tract without causing net absorption of fluid or electrolytes. It is routinely used in clinical practice for bowel cleansing, before abdominal surgery, barium enema and other colorectal and genitourinary tract tests. Participants will divide the whole doses in 4 liters of water taking half the day before the examination starting at 20.00 h and the other half at 6.00 pm on the day of the examination.
Experimental: Low volume
Drug: Macrogol 3350 plus ascorbic acid
- Macrogol 3350 plus ascorbic acid: 4 envelopes, 2 containing 112 g polyethylene glycol and electrolytes and 2 with 2 g of ascorbic acid. The properties of the polyethylene glycol are the same as those mentioned previously, while ascorbic acid generates an osmotic gradient potentiating the effect of polyethylene glycol. It is used routinely as a bowel prep. Participants will divide the doses in 2 liters of water taking half the day before (112 g of PEG and an 11 g of ascorbic acid) the examination at 20.00 h and the other half at 6.00 pm on the day of the examination
Two key quality indicators for colonoscopy are the cecal intubation rate and the percentage of neoplastic lesions detected. Both factors are associated with adequate bowel cleansing. Poor cleansing ranged from 5% to 30% across studies, negatively affecting the efficiency of colonoscopy.
The most important factor associated with poor colonic preparation is the past history of poor bowel preparation. However, there are no recommendations on the proper type of preparation in those patients. In two non-randomized studies inadequate cleansing in the second colonoscopy ranged from 9.8% to 23%. Randomized studies comparing high volume (3-4 liters) with low volume (2 liters) PEG preparations, which are better tolerated by patients, are therefore needed before making any recommendations in this regard.
Please refer to this study by its ClinicalTrials.gov identifier: NCT02073552
|Hospital Universitario de Canarias|
|Santa Cruz de Tenerife, Spain, 38320|
|Principal Investigator:||Antonio Z Gimeno García, MD, PhD||Hospital Universitario de Canarias|