Efficacy and Recovery of Remimazolam Versus Midazolam in Sedated Colonoscopy: A Multicenter Randomized Controlled Trial in Japan

OBJECTIVES: Sedation during colonoscopy is becoming increasingly important. Remimazolam, an ultra-short-acting benzodiazepine, has a shorter pharmacokinetic half-life than that of midazolam. This study examined whether remimazolam provides superior sedation during colonoscopy in Japanese patients. METHODS: This prospective, multicenter, randomized, single-blind, controlled trial included adults (18-80 years) scheduled for sedated colonoscopy. Participants were randomized to the remimazolam and midazolam groups. The primary outcome was the proportion of ambulatory patients 5 min after colonoscopy. Secondary outcomes were successful pre-procedure sedation (Modified Observer's Assessment of Alertness/Sedation [MOAA/S] ≤ 4), recovery time, total sedative dose, and adverse events. RESULTS: Forty patients were enrolled and analyzed (remimazolam, n = 19; midazolam, n = 21). At 5 min post-colonoscopy, ambulation was achieved in 100% (19/19) of remimazolam patients and 19.1% (4/21) of midazolam patients (p < 0.0001). The median time [interquartile range (IQR)] from procedure end to full alertness (MOAA/S = 5) was 0 [0-0] min for remimazolam and 10 [5-20] min for midazolam (p < 0.0001). The median time [IQR] from procedure end to independent ambulation was 0 [0-5] min for remimazolam and 20 [10-30] min for midazolam (p < 0.001). Pre-procedure sedation was successful (MOAA/S ≤ 4) in 100% of both groups. The median amount [IQR] of total sedative dose was 5 [4-6] mg for remimazolam and 3 [3] mg for midazolam. Hypoxemia occurred in 5.3% and 9.5% of patients in the remimazolam and midazolam groups, respectively. CONCLUSIONS: Compared with midazolam, remimazolam resulted in significantly faster recovery after colonoscopy in Japanese patients, with comparable achievement of target sedation and a low incidence of hypoxemia. CLINICAL REGISTRATION: Trial number: jRCTs071240062.