Safety and efficacy of remimazolam in induction and maintenance of general anesthesia in high-risk surgical patients (ASA Class III): results of a multicenter, randomized, double-blind, parallel-group comparative trial

Purpose: Remimazolam, an ultra-short-acting benzodiazepine sedative is equally effective as propofol in induction and maintenance of general anesthesia with improved hemodynamic stability in American Society of Anesthesiologists (ASA) Class I and II patients. This trial investigated remimazolam’s efficacy and safety in vulnerable patients (ASA Class III) undergoing elective general surgery. Methods: A multicenter, randomized, double-blind, parallel-group trial in 67 adult surgical patients undergoing general anesthesia with two remimazolam induction doses (6 mg kg⁻¹ h⁻¹—group A and 12 mg kg⁻¹ h⁻¹—group B) has been conducted in 6 trials sites in Japan. Remimazolam was infused up to 2 mg kg⁻¹ h⁻¹ for maintenance of anesthesia in both groups. Results: The functional anesthetic capability of the investigated drug was 100% in both arms. The mean time to loss of consciousness (LoC) was significantly shorter in group B (81.7 s) compared to group A (97.2 s), p = 0.0139. The mean bispectral index (BIS) value during maintenance of anesthesia ranged from 46.0 to 68.0 and from 44.7 to 67.5 in group A and B, respectively. There was no statistically significant difference between the remimazolam arms concerning the incidence of blood pressure (BP) decrease (67.7% in group B vs. 54.8% in group A), recovery profile or the incidence or severity of adverse events (AEs) or adverse drug reactions (ADRs). Conclusion: Both induction regimens (6 and 12 mg kg⁻¹ h⁻¹) were equally efficacious and safe in surgical patients ASA Class III. A significantly shorter time to LoC was observed with the higher remimazolam dosage. Clinical trial registration This trial is registered with the Japan Pharmaceutical Information Center—Clinical Trials Information (JapicCTI). JapicCTI number: 121977.