Effectiveness of oral phloroglucinol as a premedication for unsedated esophagogastroduodenoscopy: A prospective, double-blinded, placebo-controlled, randomized trial

Background Anti-spasmodic agents are commonly injected during esophagogastroduodenoscopy (EGD) to improve visualization of the gastric mucosa by inhibiting gastrointestinal (GI) peristalsis. The availability of oral anti-spasmodic agents would increase convenience. In this study, we evaluated the effectiveness of oral phloroglucinol (Flospan®) as a premedication for unsedated EGD. Methods A prospective, double-blinded, placebo-controlled, randomized controlled trial was conducted in a tertiary hospital. Individuals scheduled to undergo unsedated EGD were randomly assigned to receive either oral phloroglucinol or matching placebo 15 min before EGD. The primary outcome was the rate of complete gastric peristalsis suppression. Outcomes were assessed by independent investigators according to the classification of gastric peristalsis and ease of intragastric observation at the beginning (Period A) and end (Period B) of EGD. Results Overall, 71 phloroglucinol-treated and 71 placebo-treated participants (n = 142 total) were included. The phloroglucinol group showed significantly higher proportions of participants with complete gastric peristalsis suppression than the placebo group (22.5% vs. 9.9%, P = 0.040). The ease of intragastric observation was significantly better in the phloroglucinol group than in the placebo group at Periods A (P < 0.001) and B (P = 0.005). Patients in both groups had comparable adverse events and showed willingness to take the premedication at their next examination. Conclusions Oral phloroglucinol significantly suppressed gastrointestinal peristalsis during unsedated EGD compared with placebo (Clinical trial registration number: NCT03342118).