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 close, 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-close 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-close 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-close group versus the split-close 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-close PEG-E was superior to the whole-dose PEG-E and resulted in better colon cleansing, adherence, and tolerance.