Efficacy of premedication with activated Dimethicone or N-acetylcysteine in improving visibility during upper endoscopy

AIM: To assess the efficacy of N-acetylcysteine (NAC) and activated Dimethicone in improving endoscopic mucosal visibility. METHODS: A total of 148 patients were randomly allocated into four groups to receive one of the following premedications: group A: 100 mL water alone; group B: activated Dimethicone plus water (up to 100 mL); group C: NAC plus water (up to 100 mL); and group D: activated Dimethicone and NAC plus water (up to 100 mL). A single endoscopist blinded to the patients group assessed the gastric mucosal visibility scores (range 1-4) at four sites. The sum of the scores from the four sites was considered as the total mucosal visibility score (TMVS). RESULTS: The patients in group B showed a significantly lower TMVS than those of groups A and C (P < 0.001). The TMVS in patients of group D was significantly lower than that of groups A and C (P < 0.001). The TMVS did not significantly differ between groups B and D (P > 0.05). The difference between TMVS of groups C and A was not significant (P > 0.05). CONCLUSION: Premedication with activated Dimethicone 20 min prior to the upper endoscopy leads to the best visibility. NAC does not improve visualization by itself.