Efficacy and recovery of remimazolam versus midazolam in sedated upper gastrointestinal endoscopy: a multicenter randomized controlled trial in Japan (RECOVER Study)

Objectives: Sedation is increasingly essential for gastrointestinal endoscopy. Remimazolam, an ultra-short-acting benzodiazepine, has a shorter pharmacokinetic half-life than midazolam. The aim of this study was to determine whether remimazolam provides superior procedural sedation in Japanese patients. Methods: The cohort of this prospective, multicenter, randomized, single-blind controlled trial comprised adults (18–80 years) scheduled for sedated upper gastrointestinal endoscopy. Participants were randomized to remimazolam and midazolam groups. The primary outcome was the proportion of ambulatory patients 5 min after endoscopy. Secondary outcomes were successful pre-procedure sedation (Modified Observer’s Assessment of Alertness/Sedation ≤ 4), dose of sedative to achieve sedation, time to ambulation, and adverse events. Results: From October 2024 to January 2025, 40 patients were enrolled. After excluding two outliers 38 were analyzed (remimazolam, n = 20; midazolam, n = 18). Ambulation at 5 min occurred in 85.0% (17/20) of the remimazolam versus 0.0% (0/18) of the midazolam group (p < 0.0001). Mean time from procedure end to walking was 4.25 min (range 0.0–10.0) for remimazolam and 35.56 min (10.0–60.0) for midazolam (p < 0.0001). Pre-procedure sedation was successful (MOAA/S ≤ 4) in 100% of both groups. Mean doses to achieve sedation were 4.30 mg (3.0–7.0) for remimazolam and 3.11 mg (2.0–5.0) for midazolam (p = 0.003). Hypoxemia occurred in 5.0% of the remimazolam and 33.3% of the midazolam group (p = 0.038). Conclusions: In upper gastrointestinal endoscopy, remimazolam achieved markedly faster recovery and a lower incidence of hypoxemia than midazolam. Rates of achieving target sedation were equivalent. These findings indicate remimazolam is an effective and potentially safer sedative option for Japanese patients undergoing endoscopy. Trial registration: This research was registered with the Japan Registry of Clinical Trials (trial number jRCTs071240062) on September 26, 2024.