Braintree Laboratories, Inc. Braintree, MA, United States
Matthew L. Walker, PhD1, John McGowan, MPH1, Mark V. Cleveland, PhD1, Cynthia Zamora, MD2 1Braintree Laboratories, Inc., Braintree, MA; 2Worldwide Clinical Trials, San Antonio, TX
Introduction: Clinical studies reported in the literature have described inferior bowel cleansing efficacy of first generation sodium picosulfate-based preps compared to other split-dose preps, including oral sulfate solution (OSS) and 4L PEG-ELS (Rex, 2014, Pisera, 2019). Since studies are conducted under varying conditions and often utilize different cleansing assessment scales, the reason for this efficacy disparity is unclear. Patel, et al (2009) established methods to evaluate stool output and clarity (% solids) following administration of a bowel prep. These methods informed the development of FDA-approved sulfate-based preps, including the recently approved oral sulfate tablets (OST). A second generation sodium picosulfate and magnesium citrate (SPMC) liquid prep was recently approved. Using the methods developed by Patel for testing OSS, we evaluated the SPMC powder and liquid, along with OST for stool output and clarity.
Methods: In a series of experiments, 29 healthy males (18-50 yoa) were confined to the clinic and administered the bowel preps according to FDA split-dose (PM/AM) labeling (19 OST, 5 SPMC powder, 5 SPMC liquid). Ad-libitum water was provided. Post-dose bowel movements (BMs) were collected and measured, ending 8 hrs after dose 2. Stool clarity was assessed in BMs occurring after dose 2.
Results: Mean stool output for subjects given OST was 2.8 L ±0.4 with % solids of 4% ±6. These values are comparable to those reported by Patel for OSS (2.9 L ±0.1, % solids = 1.5 ±0.2).
Stool output for the SPMC powder (1.3 L ±0.2) was less than half of that seen with the sulfate-based preps, with a higher % of stool solids (7% ±3). Output for the SPMC liquid (1.6 L ±0.2) was slightly better than the powder, but still more than a liter lower than OSS/OST, with a higher % solids (12% ±5).
Discussion: Subjects given OST produced stool output and % solids comparable to OSS. This similarity is reflected in their cleansing scores in pivotal studies, where both have repeatedly achieved > 90% successful preps. In contrast, subjects given SPMC powder and the new SPMC liquid produced less stool output, by more than a liter, compared to OSS/OST, and higher stool solids. These results may contribute to SPMC preps failing to reach 90% cleansing success in colonoscopy studies.
This difference in stool profiles between the SPMC and sulfate-based preps offers a possible explanation for the lower cleansing success rates seen in clinical studies of SPMC preps
Matthew Walker: Braintree Laboratories Inc. – Employee.
John McGowan: Braintree Laboratories Inc. – Employee.
Mark Cleveland: Braintree Laboratories – Consultant.
Matthew L. Walker, PhD1, John McGowan, MPH1, Mark V. Cleveland, PhD1, Cynthia Zamora, MD2. P2232 - Sulfate-Based Bowel Preparations Produce Greater Stool Output Compared to Sodium Picosulfate - Magnesium Citrate Preparations, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.