Induction and maintenance of procedural sedation in adults: focus on remimazolam injection

Toward Model-Informed Precision Dosing for Remimazolam: A Population Pharmacokinetic-Pharmacodynamic Analysis

Remimazolam, widely used for procedural sedation and general anesthesia, is a new ultra short-acting benzodiazepine for intravenous sedation and anesthesia. We aim to characterize the pharmacokinetics/pharmacodynamics (PK/PD) of remimazolam and its metabolite CNS 7054 in healthy Chinese volunteers using population analysis and suggest an optimal dosing regimen for sedation therapy. Data were collected from a single-center, placebo-controlled, randomized, and dose-escalation clinical pharmacology study. Forty-six healthy volunteers received a single infusion dose of remimazolam, while nine healthy subjects received a continuous infusion of remimazolam. A population PK/PD model was established and RxODE and Shiny in R were used to design the remimazolam dosing regimens. A three-compartment model best described the PK of remimazolam and a two-compartment model with one transit compartment was adopted for CNS 7054. The relationship between exposure and the bispectral index was best described using an effect compartment model with an inhibitory sigmoid model. Additionally, a web-based dashboard was developed to provide individualized dosing regimens, complemented by a graphical illustration of the PK/PD profiles of the proposed dosing regimen. The established population PK/PD model characterized the dose-exposure-response relationship of remimazolam well, which could be applied to optimize individual dosing regimens.

Remimazolam versus propofol for sedation in gastrointestinal endoscopic procedures: a systematic review and meta-analysis

BACKGROUND

Propofol has a favourable efficacy profile in gastrointestinal endoscopic procedures, however adverse events remain frequent. Emerging evidence supports remimazolam use in gastrointestinal endoscopy. This systematic review and meta-analysis compares remimazolam and propofol, both combined with a short-acting opioid, for sedation of adults in gastrointestinal endoscopy.

METHODS

We searched MEDLINE, Embase, and Cochrane databases for randomised controlled trials comparing efficacy-, safety-, and satisfaction-related outcomes between remimazolam and propofol, both combined with short-acting opioids, for sedation of adults undergoing gastrointestinal endoscopy. We performed sensitivity analyses, subgroup assessments by type of short-acting opioid used and age range, and meta-regression analysis using mean patient age as a covariate. We used R statistical software for statistical analyses.

RESULTS

We included 15 trials (4516 subjects). Remimazolam was associated with a significantly lower sedation success rate (risk ratio [RR] 0.991; 95% confidence interval [CI] 0.984-0.998; high-quality evidence) and a slightly longer induction time (mean difference [MD] 9 s; 95% CI 4-13; moderate-quality evidence), whereas there was no significant difference between the sedatives in other time-related outcomes. Remimazolam was associated with significantly lower rates of respiratory depression (RR 0.41; 95% CI 0.30-0.56; high-quality evidence), hypotension (RR 0.43; 95% CI 0.35-0.51; moderate-quality evidence), hypotension requiring treatment (RR 0.25; 95% CI 0.12-0.52; high-quality evidence), and bradycardia (RR 0.42; 95% CI 0.30-0.58; high-quality evidence). There was no difference in patient (MD 0.41; 95% CI -0.07 to 0.89; moderate-quality evidence) and endoscopist satisfaction (MD -0.31; 95% CI -0.65 to 0.04; high-quality evidence) between both drugs.

CONCLUSIONS

Remimazolam has clinically similar efficacy and greater safety when compared with propofol for sedation in gastrointestinal endoscopies.

Remimazolam Sedation and Neuraxial Anesthesia in a Patient with Amyotrophic Lateral Sclerosis Undergoing an Open Colectomy: A Case Report

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease involving the upper and lower motor neurons. Perioperative management of patients with ALS can be challenging due to the risk of hemodynamic instability, aspiration, and ventilatory failure. We discuss a 58-year-old male patient with ALS who underwent open abdominal surgery under regional anesthesia utilizing a remimazolam infusion for sedation. While various sedation agents have been used successfully in patients with ALS, remimazolam, a new short-acting benzodiazepine with unique pharmacologic properties and reversible anxiolysis, provides amnesia while avoiding ventilatory depression.

Procedural sedation in pediatric dentistry: a narrative review

Procedural sedation and analgesia are now considered standard care for managing pain and anxiety in pediatric dental patients undergoing diagnostic and therapeutic procedures outside of the operating room. Anxiolysis, which combines both pharmacologic and non-pharmacologic approaches, plays a significant role in procedural sedation. Non-pharmacologic interventions such as Behavior Management Technology can help reduce preprocedural agitation, ease the transition to sedation, reduce the required amount of medication for effective sedation, and decrease the occurrence of adverse events. As the introduction of novel sedative regimen and methods in pediatric dentistry, the potential role of mainstay sedatives administered by new routes, for new indications, and with new delivery techniques, should be considered. The purpose of this paper is to examine and discuss the current state of sedation techniques in pediatric dentistry.

Efficacy and safety of remimazolam-based sedation for intensive care unit patients undergoing upper gastrointestinal endoscopy: a cohort study

BACKGROUND

Remimazolam is a novel ultra-short-acting sedative, but its safety and adverse events (AEs) in high-risk patients in the intensive care unit (ICU) setting remain unknown.

METHODS

This was a single-center, retrospective study that compared remimazolam to propofol and midazolam in patients undergoing upper gastrointestinal endoscopy. The primary outcome was the incidence of treatment-related AEs. The secondary outcomes were the time to extubation, the length of ICU stay, and the average cost of sedative per case.

RESULTS

Of the 88 patients analyzed, 47 were treated with remimazolam (mean dose, 7.90±4.84 mg), and 41 were treated with propofol (21.19±17.98 mg) or midazolam (3.08±2.17 mg). There was no statistically significant difference in the average duration of the endoscopic procedure (35.89±13.37 min vs. 44.51±21.68 min, P=0.133) or the time to extubation (15.00±9.75 h vs. 20.59±18.71 h, P=0.211) in the remimazolam group (group I) compared to the propofol or midazolam group (group II). ICU stays (5.40±2.93 d vs. 4.63±3.31 d, P=0.072) and treatment-related AEs (48.61% vs. 51.38%, P=0.056) were similar between groups. The average cost of sedative per case was significantly lower in the group I than in the group II (RMB 16.07±10.58 yuan vs. RMB 24.37±15.46 yuan, P=0.016).

CONCLUSION

Remimazolam-based sedation was noninferior to the classic sedatives and had lower average cost per case, indicating that it may be used as a promising sedative for high-risk patients during endoscopic procedures in the ICU setting.

Remimazolam: An Updated Review of a New Sedative and Anaesthetic

Remimazolam (CNS7056) is a novel benzodiazepine for intravenous sedation; it has an ultra-short duration of action and was recently approved for use in procedural sedation and general anaesthesia. It acts on γ-aminobutyric acid type A receptors and is rapidly converted into an inactive metabolite by tissue esterase enzymes. Remimazolam has been successfully used in endoscopic inspection or surgery and general anaesthesia induction and maintenance with fast and predictable onset and recovery times, high procedure success rates, and minor respiratory and hemodynamic fluctuations and without serious drug-related adverse reactions. If needed, the effects of remimazolam can be reversed by flumazenil, which allows prompt termination of sedation. Although remimazolam has great potential for sedation in patients admitted to intensive care units, future studies are needed to evaluate its efficacy and safety in patients requiring sedation for a long period, and numerous studies are warranted to explore the optimal dose in different application scenarios. The review aimed to provide an introduction to the process of remimazolam synthesis and its current clinical uses and future clinical developments.

Remimazolam besylate for the sedation of postoperative patients undergoing invasive mechanical ventilation in the ICU: a prospective dose‒response study

This single-center study aimed to determine the effective dose and safety of remimazolam besylate for the sedation of postoperative patients undergoing invasive mechanical ventilation in the intensive care unit (ICU). Mechanically ventilated patients admitted to the ICU after surgery were included. The Narcotrend index (NTI) was used to assess the depth of sedation, and the Richmond Agitation-Sedation Scale (RASS) score was also recorded. Remimazolam besylate was administered initially at a loading dose of 0.02 mg/kg, followed by a gradual increase of 0.005 mg/kg each time until the targeted depth of sedation was achieved (NTI 65-94). A maintenance dose of remimazolam besylate was administered starting at 0.2 mg/kg/h, followed by increments or subtractions of 0.05 mg/kg/h each time until a satisfactory depth of sedation was achieved and maintained for at least 30 min. The demographic data, anesthesia, surgery types, hemodynamics and respiratory parameters were recorded. Adverse events and adverse drug reactions were monitored for safety. Twenty-three patients were eventually included in this study covering a period of 1 year. A satisfactory depth of sedation was achieved by a single intravenous infusion of remimazolam besylate at a loading dose of 0.02-0.05 mg/kg followed by a maintenance dose of 0.20-0.35 mg/kg/h. There were no significant changes in hemodynamic and respiratory parameters within 10 min after the administration of remimazolam besylate. In addition, a significant correlation was observed between the NTI and the RASS score for assessing sedation (r = 0.721, P < 0.001). The NTI showed a predictive probability for a RASS score of 0.817. Remimazolam besylate was effective for mild/moderate sedation of invasively mechanically ventilated postoperative patients in the ICU while maintaining excellent respiratory and hemodynamic stability. The NTI can be used as a good tool for the objective evaluation of the depth of sedation and agitation.

Safety and efficacy of remimazolam besylate in patients undergoing colonoscopy: A multicentre, single-blind, randomized, controlled, phase Ⅲ trial

Study objective: The objective of the study was to evaluate the safety and efficacy of remimazolam besylate versus propofol injection in patients undergoing colonoscopy.

Design: A multicenter, randomized, non-inferiority, single-blind, parallel-controlled clinical trial.

Setting: Operating room.

Patients: Patients aged 18–65 years (American Society of Anesthesiologists [ASA] classification I-III) undergoing a diagnostic or therapeutic colonoscopy.

Interventions: Patients were administered intravenous injection of remimazolam besylate or propofol (active comparator) for sedation.

Measurements: Modified Observer’s Assessment of Alertness/Sedation [MOAA/S] scores of the included patients were assessed before dosing, 1, 1.5, 2, 2.5, and 3 min after the start of dosing, and then every 1 min until the MOAA/S score reached 5 on three consecutive occasions.

Main Results: A total of 360 patients received remimazolam and 120 patients received propofol. The incidence of adverse events (67.8% vs. 84.2%, p = 0.001) was significantly lower in patients administered remimazolam compared to propofol. There was no significant difference in sedation success rates (full analysis set [FAS]: 98.9% vs. 99.2%; remimazolam vs. propofol). Remimazolam had a significantly longer onset of action, but the difference was not considered clinically significant (1.45 min vs. 1.24 min, remimazolam vs. propofol). Propofol achieved a deeper level of sedation (mean MOAA/S score 0.5 vs. 0.2; remimazolam vs. propofol). Mean time to discharge after the end of the last administration of study drug (20.3 vs. 21.8 min, p = 0.020) and incidence of injection pain was significantly lower in patients administered remimazolam (2.3% vs. 35.3%, p < 0.0001). Incidence of oxygen desaturation was significantly higher in patients administered propofol compared to patients administered remimazolam (6.7% vs. 1.1%, p = 0.001). Similarly, incidence of hypotension was more frequent in patients administered propofol compared to patients administered remimazolam (29.2% vs. 10.6%, p < 0.0001).

Conclusion: Remimazolam besylate had a better safety and tolerability profile and similar sedative efficacy to propofol in patients undergoing a diagnostic or therapeutic colonoscopy in China, suggesting that remimazolam besylate has potential as a sedative agent for colonoscopy.

The Efficacy and Safety of Remimazolam Tosilate Versus Dexmedetomidine in Outpatients Undergoing Flexible Bronchoscopy: A Prospective, Randomized, Blind, Non-Inferiority Trial

Purpose: This study aimed to compare the efficacy and safety of remimazolam tosilate-remifentanil (RT-RF) vs dexmedetomidine-remifentanil (Dex-RF) for outpatients undergoing fiberoptic bronchoscopy (FB).

Patients and methods: We conducted a double-blind, randomized, prospective study involving a total of 146 outpatients undergoing FB divided into two groups. The RT-RF (RR) group (n = 73) received an initial dose of 12 mg/kg/h of RT for 10 min followed by a maintenance dose of 1–2 mg/kg/h, while the Dex-RF (DR) group (n = 73) received an initial dose of 0.5 μg/kg of Dex for 10 min followed by a maintenance dose of 0.2–0.7 μg/kg/h. All outpatients also received 0.05–0.2 μg/kg/min RF to maintain the Modified Observer’s Assessment of Alertness and Sedation (MOAA/S) scale <3. The primary outcome was rate of successful FB completed. Secondary outcomes were time metrics, hemodynamics, intubating conditions, oxygen saturation, coughing severity, number of remedies, total dose of fentanyl, RF, RT, and Dex, incidence of dreaming, patient and bronchoscopist satisfaction, willingness to repeat bronchoscopy, and adverse events.

Results: The FB successful completion rate was 94.52% (95% CI: 89.20–99.90) in the RR group and 91.78% (95% CI: 85.30–98.20) in the DR group. Compared with patients in the DR group, the onset time, time to fully alert, and hospital discharge were all significantly shorter in the RR group (p < 0.01), and hemodynamics were more stable in the RR group. Intubating conditions, clinically acceptable intubating conditions, lowest oxygen saturation, coughing severity, consumption of fentanyl and RF, number of remedies, and patient and bronchoscopist satisfaction were similar between the groups (p > 0.05), as were demographic characteristics, incidence of dreaming, willingness to repeat bronchoscopy, and adverse events (p > 0.05).

Conclusion: RT-RF has non-inferior efficacy, better time metrics and hemodynamic stability for outpatients undergoing FB than Dex-RF.

Systematic Review Registration: [http://www.chictr.org.cn/showproj.aspx?proj=66673], identifier [ChiCTR2000041524].

Remimazolam tosilate compared with propofol for gastrointestinal endoscopy in elderly patients: a prospective, randomized and controlled study

Background

Remimazolam tosilate (HR7056, RT), a novel ultrashort-acting benzodiazepine, can be used for procedural sedation and general anaesthesia. However, few studies have focused on the sedative effect of RT during gastrointestinal endoscopy in elderly patients. The purpose of this study is to compare the sedative effect of RT and propofol for gastrointestinal endoscopy in elderly patients.

Methods

A total of 82 patients aged ≥65 years with an American Society of Anaesthesiologists (ASA) grade I-II and a body mass index (BMI) of 18.0 to 30.0 kg/m² who were scheduled for gastrointestinal endoscopy from Jan 2021 to Aug 2021 were selected and randomly divided into a RT group and a propofol group. Alfentanil 5 μg/kg was used for analgesia in both groups. The RT group was given remimazolam tosilate 0.15 mg/kg with supplemental doses of 0.05 mg/kg as need, while the propofol group was given propofol 1.5 mg/kg with supplemental doses of 0.5 mg/kg. The supplemental doses were determined by the modified observational alertness/sedation assessment (MOAA/S) score and the patients’ body movements. Sedative effects, such as the time to loss of consciousness (LOC) (MOAA/S score ≤ 1), successful sedation in one dose, number of supplemental doses after successful induction, and recovery time, were evaluated. Sedation-related side effects, such as injection pain, haemodynamic events and respiratory depression, were also noted. Postoperative nausea and vomiting (PONV), visual analogue scale (VAS) scores at rest, remedial analgesics, and dizziness or headache were recorded. In addition, patients’ satisfaction and physician’s satisfaction of the procedure were compared between the two groups.

Results

Data from 77 patients were analysed. The success rate of sedation in both groups was 100%. The time to LOC (MOAA/S score ≤ 1) in the RT group was longer than that in the propofol group (20.7 ± 6.1s vs. 13.2 ± 5.2s, P < 0.001). There were fewer patients in the RT group reporting injection pain than that in the propofol group (0/39 vs. 5/38, P = 0.025). Haemodynamic events and respiratory depression in the RT group were less frequent than those in the propofol group ((6/39 vs. 17/38, P = 0.005), (2/39 vs. 9/38, P = 0.026), respectively). The number of supplemental doses after successful induction in the RT group was greater than that in the propofol group (4/9/11/13/1/1 vs. 8/4/18/6/2/0 requiring 0, 1, 2, 3, 4 or 5 supplemental doses, P = 0.014). The characteristics of the patients enrolled, postoperative parameters of the patients, and patients’ and physician’s satisfaction of the procedure were comparable in the two groups.

Conclusions

Compared with propofol, RT can be safely and effectively used for gastrointestinal endoscopy sedation in elderly patients, and the incidence of sedation-related adverse reactions, especially haemodynamic events and respiratory depression, is lower. When RT is used, the number of supplemental doses after successful induction may increase slightly.

Trial registration

Chictr.org.cn ChiCTR2000040498. Retrospectively registered (date of registration: December 1, 2020).

Design, synthesis, and evaluation of phenylpiperazine-phenylacetate derivatives as rapid recovery hypnotic agents

In this paper, we designed and synthesized a series of novel phenylpiperazine-phenylacetate derivatives as rapid recovery hypnotic agents. The best compound 10 had relatively high affinity for the GABAA receptor and low affinity for thirteen other off-target receptors. In three animal models (mice, rats, and rabbits), compound 10 exerted potent hypnotic effects (HD50 = 5.2 mg/kg in rabbits), comparable duration of the loss of righting reflex (LORR), and significant shorter recovery time (time to walk) than propanidid. Furthermore, compound 10 (TI = 18.1) showed higher safety profile than propanidid (TI = 14.7) in rabbits. Above results suggested that compound 10 may have predictable and rapid recovery profile in anesthesia.

Remimazolam: pharmacological characteristics and clinical applications in anesthesiology

A novel ultra-short-acting benzodiazepine (BDZ), remimazolam (CNS 7056), has been designed by ‘soft drug’ development to achieve a better sedative profile than that of the current drugs. Notably, the esterase linkage in remimazolam permits rapid hydrolysis to inactivate metabolites by non-specific tissue esterase and induces a unique and favorable pharmacological profile, including rapid onset and offset of sedation and a predictable duration of action. Similar to other BDZs, its sedative effects can be reversed using flumazenil, a BDZ antagonist. The pharmacokinetics and pharmacodynamics of remimazolam are characterized by relatively high clearance, small steady-state volume of distribution, short elimination half-life, short context-sensitive half-life, and fast onset and recovery, indicating rapid elimination, minimal tissue accumulation, and good control. In addition, remimazolam possesses a superior safety profile, including low liability for cardiorespiratory depression and injection pain, making it a preferred hypnotic agent in various clinical settings. Early clinical investigations suggest that remimazolam is well tolerated and effective for procedural sedation and for induction and maintenance of general anesthesia. To date, however, the clinical use of remimazolam has been confined to a few volunteer studies and a limited number of clinical investigations. Therefore, further studies regarding its recovery issues or postoperative complications, characteristics of electroencephalogram changes, and cost-benefit analyses are required to facilitate its widespread use.

The Efficacy and Safety of Remimazolam Tosilate versus Etomidate-Propofol in Elderly Outpatients Undergoing Colonoscopy: A Prospective, Randomized, Single-Blind, Non-Inferiority Trial

Objective

The optimal sedation regime during endoscopy remains controversial, especially for elderly outpatients. In this study, we compared the efficacy and safety between remimazolam tosilate (RT) and etomidate-propofol (EP) in elderly outpatients undergoing colonoscopy.

Methods

A total of 260 elderly outpatients undergoing sedative colonoscopy were randomized into two groups. Patients in the RT group received a 0.075-mg/kg maintenance dose of remimazolam following an initial dose of 0.15 mg/kg, whereas patients in the EP group (10 mL:20 mg etomidate plus 10 mL:100 mg propofol) received a 0.05-mL/kg maintenance dose following an initial dose of 0.1 mL/kg to maintain a Modified Observer’s Assessment of Alertness/Sedation score of ≤3 during the procedure. The primary endpoint was the success of the procedure. Secondary endpoints included time metrics, hemodynamics, consumption of fentanyl, etomidate, propofol, and remimazolam, intraoperative body movement, patient and endoscopist satisfaction scores, supplemental dose of sedative and fentanyl, and incidence and severity of adverse events.

Results

The procedure success rate was 96.52% in the RT group and 100% in the EP group. The difference in procedure success rate between the RT and EP groups was −3.48% (95% confidence interval: −6.81%, −0.15%). Four patients in the RT group required rescue midazolam. Compared with patients in the RT group, the onset time of the EP group was significantly lower (p < 0.05), whereas time to fully alert (p = 0.001), ready for discharge (p = 0.001), and hospital discharge (p = 0.002) were all significantly higher in the EP group. However, there were no significant differences in procedure time (p = 0.846) or cecal intubation time (p = 0.320) between the two groups. Although the frequency of intraoperative body movement was higher in the RT group, the difference was not significant (p = 0.508). There were no significant differences in patients’ demographic and baseline characteristics, supplemental doses of sedative and fentanyl, or patient and endoscopist satisfaction scores (p > 0.05). Muscular tremor and pain on injection were recorded more frequently in the EP group (p < 0.05). However, there were no significant differences in hypoxia, respiratory depression, or incidence of postoperative nausea and vomiting. The severity of adverse events was all mild (grade 1) across both groups.

Conclusion

RT may have non-inferior efficacy and a higher safety profile than EP in elderly outpatients undergoing colonoscopy, which suggests that RT may be more suitable for elderly outpatients undergoing colonoscopy.

Difference between remimazolam toluenesulfonic acid and propofol in waking quality and conscious state after general anesthesia

Objective

To explore the difference of anesthesia recovery and postoperative conscious state between remimazolam toluenesulfonic acid and propofol after induction and maintenance of general anesthesia.

Methods

104 patients undergoing elective tracheal intubation general anesthesia in our hospital were randomly divided into 2 groups: Remimazolam Toluenesulfonic acid group (Group R) and Propofol group (Group P). MOAA/S score, the modified Aldrete score, recovery index, time point, a state of consciousness, interpretative vital signs and adverse events were monitored at different time.

Results

Compared with the Group P, the extubation time and orientation recovery time of the Group R were significantly shorter. When the operation time was less than 1 hour, the MOAA/S score of the Group R was shorter than that of Group P at 5 min and 15 min after the operation. To compare with the Group P, the score of MOAA/S in the Group R increased at 5 min, 20 min and 30 min after the operation. When the operation time was less than or equal to 1 h, the modified Aldrete score in the Group R was slightly higher than that in the Group P at 30 min after extubation. There was no injection pain in the the Group R, and the incidence of hypotension was lower than that of propofol.

Conclusion

Compared with Propofol, when the operation time of general anesthesia is more than 1 hour, recovery time of Remimazolam Toluenesulfonic acid is shorter, with more complete and higher-quality recovery.

Remimazolam: A Review in Procedural Sedation

Remimazolam (Byfavo™) is a benzodiazepine sedative that is indicated for the induction and maintenance of procedural sedation in adults. Remimazolam was efficacious in three phase III trials in patients requiring endoscopies. Significantly higher procedure success rates (composite of the completion of the procedure, top-up doses of study drug within predefined limits and no requirement for rescue therapy) were observed with remimazolam than with placebo, with the majority of placebo recipients requiring rescue midazolam. Furthermore, remimazolam significantly reduced times to onset of sedation and recovery in comparison with placebo (plus rescue). Remimazolam is generally well tolerated, with hypotension and hypertension the most common adverse drug reactions. Higher doses of concomitant fentanyl with remimazolam may increase the incidence of adverse drug reactions and deep sedation events. However, no correlation was observed between depth of sedation and vital signs. In summary, remimazolam is a useful option for the induction and maintenance of procedural sedation. Although pharmacoeconomic analyses for remimazolam are not yet available, the rapid induction of sedation and short recovery times with remimazolam may be beneficial in improving patient throughput in clinics.