The Effect of Pre-Treatment with a Proton Pump Inhibitor On the Incidence and Severity of GI Adverse Events Associated with a 4L Polyethylene Glycol + Electrolytes (PEG) Purgative for Colonoscopy

Abstract

Background: Safe and effective, PEG is a commonly prescribed purgative for colonoscopy. Unfortunately, PEG is associated with a high incidence of GI adverse events including abdominal pain, bloating, nausea, and vomiting. These symptoms also occur with upper GI tract disorders such as GERD, non-ulcer dyspepsia (dyspepsia), and gastroparesis. Acid suppression therapy is highly effective for GERD, and may be beneficial for dyspepsia. Purpose: To evaluate the effect of pre-treatment with a proton pump inhibitor (PPI) on the incidence and severity of PEG-related GI adverse events. Methods: A single center, prospective, double-blind, randomized, placebo control study evaluating the effect of a PPI (40 mg esomeprazole, daily) on PEG-related GI adverse events. Eligible patients (pts) were scheduled for elective outpatient colonoscopy and were not taking acid suppression therapy. Pts received placebo or PPI for 7 consecutive days ending on the day of colonoscopy. Cherry flavored PEG (NuLYTELY®) was taken the evening prior to colonoscopy. Symptom (abdominal pain, bloating, nausea, vomiting) incidence and severity, using a 10 point Likert scale, was measured at baseline and immediately prior to colonoscopy. A validated quality of life (QOL) scale (QOLRAD) was administered at baseline and before colonoscopy. Logistic regression models for post-treatment symptoms (adjusted odds ratios), and linear models for symptom severity (difference in least squares means), controlled for treatment assignment and pre-treatment symptoms. Multivariate modeling considered QOL scale, age, gender, BMI, and personal history of colonoscopy. This study was approved by the TJU IRB. Results: 539 pts were enrolled between 3/04-12/06, and 339 (PPI = 166,Placebo = 173) were included in this analysis. The two groups were well matched for age (mean = 54 yrs), gender (∼50% female), BMI (28), and baseline GI symptoms (both incidence and severity). As expected, a marked increase in all symptoms occurred after PEG. Pre-treatment with a PPI did not affect the incidence or severity of PEG-related GI symptoms. This finding was consistent for individual symptoms, and for the presence of any one symptom. However, pre-medication with a PPI was associated with significantly better pre-colonoscopy (after PEG ingestion) scores for overall QOL (OR 0.58, 95% CI (0.33, 0.99), p = 0.05) and QOL related to food and drink (OR 0.50, 95% CI (0.28, 0.86), p = 0.01). Conclusion: Pre-treatment with a PPI before ingesting PEG does not lessen the incidence or severity of GI symptoms. In pts with food or drink related problems at baseline (nearly 50% of all pts), PPI pre-treatment does significantly improve quality of life.