A Randomized Clinical Study Evaluating the Safety and Efficacy of a New, Reduced-Volume, Oral Sulfate Colon-Cleansing Preparation for Colonoscopy

OBJECTIVES: We sought to evaluate a new, low-volume, oral sulfate solution as a bowel preparation for colonoscopy in adult patients. METHODS: The investigations were designed as two multicenter, single-blind, randomized, non-inferiority studies to show that the sulfate regimen would effect cleansing that is acceptable and equivalent to polyethylene glycol electrolyte solution with ascorbic acid (PEG-EA), and would be suitable for colonoscopy. One study evaluated same-day administration; the other compared the two study preparations given by split-dose administration in which the first portion was taken the evening before colonoscopy and the second portion on the morning of the procedure. The primary efficacy variable was based on bowel cleansing graded by an investigator who was unaware of the preparation method received. RESULTS: Study 1 randomized 408 outpatients scheduled for colonoscopy for routine indications, with 387 subjects taking the preparation. In all, 364 subjects were randomized and took the preparation in study 2. The demographics of the enrolled subjects were similar across both treatment groups in the two studies, including gender, race, and ethnic characteristics. The primary efficacy analysis supports the conclusion that the oral sulfate solution produces the same degree of cleansing as PEG-EA. Successful preparations were seen in 82.4 % and 80.3 % in study 1 and 97.2 % and 95.6 % in study 2 for the oral sulfate solution and the PEG-EA regimen, respectively. Although no difference in excellent preparations was seen in the 1-day preparation, split-dose administration resulted in more excellent preparations in the sulfate group than in the PEG-EA group (63.3 vs. 52.5 %, P = 0.043). Preparation-related symptoms of cramping, bloating, nausea, and vomiting were generally mild and infrequent. Sulfate subjects reported slightly increased gastrointestinal events and higher vomiting scores (P = 0.009) in the 1-day preparation but not in the split-dose regimen. There were no other differences for adverse events or clinically significant laboratory findings, including no increased creatinine. CONCLUSIONS: The new 960-ml oral sulfate solution is effective for colonoscopy cleansing and has an acceptable safety profile.