Efficacy and safety of different doses of remimazolam tosylate for colonoscopy: single-center, prospective, randomized, double-blind, parallel trial.

Background: Remimazolam tosylate is a new sedative combining the advantages of etomidate with remifentanil. Remimazolam tosylate shows effective in colonoscopy, but the optimal dose is not confirm. In this study, a single-center, prospective, randomized, double-blind, parallel trial were performed to compare the efficacy and safety of different doses of remimazolam tosylate for colonoscopy. Methods: Before colonoscopy, 120 recruited patients were randomized with a 1:1:1 ratio into 3 treatment groups: group A, 0.1 mg/kg remimazolam tosylate; group B, 0.15 mg/kg remimazolam tosylate; group C, 0.2 mg/kg remimazolam tosylate. Patients received 1 µg/kg fentanyl by intravenous injection over 30 s followed by the respective induction dose of remimazolam tosylate over 1 min (±5 s). When adequate sedation was achieved, colonoscopy was performed. Sedation was maintained at Modified Observer's Assessment of Alertness/Sedation (MOAA/S) ≤4 during the procedure. The additional administration of remimazolam tosylate (0.05 mg/kg per time) was permitted when necessary. Results: Forty-one patients, 39 patients and 40 patients were respectively analyzed in group A, group B and group C. The procedural success rate was 80.49%, 87.18% and 95.00% in group A, group B and group C, respectively. During the induction period, patients in group A required additional doses of remimazolam tosylate more frequently than in group B and group C, but less during the maintenance period (all P<0.05). There was no significant difference in the induction time or time to recovery among the three groups. Incidence of adverse events (such as hypotension, hyoxemia and bucking) was similar among the three groups. Conclusions: The initial loading doses of 0.1, 0.15, and 0.2 mg/kg remimazolam tosylate were all efficacy and safety for patients undergoing colonoscopy, and fewer times of the drug was re-administered. Trial Registration: Chinese Clinical Trial Registry ChiCTR2000041331.