A Randomized, Controlled, Double-blind Trial of the Adjunct Use of Tegaserod in Whole-dose or Split-dose Polyethylene Glycol Electrolyte Solution for Colonoscopy Preparation

Background: Problems of compliance, quality, and safety of colon preparation regimens have prompted continued investigation with alternative forms of cleansing.

Objective: To evaluate the efficacy of tegaserod as an adjunct to a polyethylene glycol electrolyte solution (PEG-E), given as a whole dose or split dose, in colonoscopy preparation.

Design: Randomized, placebo-controlled, double-blind trial.

Setting: A single university-based hospital.

Patients: Patients who were undergoing elective colonoscopy.

Interventions: A 4-arm randomization scheme that compared tegaserod with a placebo, each with whole-dose or split-dose PEG-E preparation.

Main Outcome Measurements: Efficacy of colon cleansing was the primary outcome. Secondary outcomes included adherence, tolerability, adverse effects, and patient perceptions of their preparation quality.

Results: A total of 382 patients completed the trial. Patients who received the split-dose preparation had significantly better colon cleansing than those who received the whole-dose preparation (88.9% vs 42.6%, P < .001). The addition of tegaserod did not significantly improve the overall colonoscopy preparation quality compared with a placebo. However, there were fewer poor preparations in the whole-dose PEG-E group (12.4% vs 1.1%, P = .002, Bonferroni correction removes significance) and more excellent preparations in the split-dose group (53.3% vs 38.3%, P = .035, Bonferroni correction removes significance) in favor of tegaserod. Interobserver and intraobserver variability analysis showed substantial agreement among endoscopists. Adherence was significantly lower in the whole-dose group versus the split-dose PEG-E group (68.8% vs 91%, P < .001), independent of the use of tegaserod. Adverse effects were not different between study groups.

Limitations: A 4-arm randomization and the single-center nature of the study.

Conclusions: Tegaserod has a marginal effect on the quality of colonoscopy preparation when used as an adjuvant to PEG-E. The split-dose PEG-E was superior to the whole-dose PEG-E and resulted in better colon cleansing, adherence, and tolerance.