Effectiveness and safety of sedation in gastrointestinal endoscopy: An opinion review Ryoji Ichijima, Mitsuru Esaki, Sho Suzuki, Chika Kusano, Hisatomo Ikehara, Takuji Gotoda https://www.wjgnet.com/2308-3840/full/v8/i2/48.htm CURRENT STATUS IN THE USAGE OF SEDATIVES
MIDAZOLAM’S CHARACTERISTICS AND CLINICAL TRIALS
PROPOFOL CHARACTERISTICS AND CLINICAL TRIALS
WHICH DRUG IS MORE EFFECTIVE FOR SADATION MIDAZOLAM OR PROPOFOL?
REMIMAZOLAM: A NEW SEDATIVE Remimazolam is an ultra-short-acting intravenous novel benzodiazepine sedative, with a shorter half-life (approximately 40 min) compared with other conventional benzodiazepines. It can rapidly pass through the blood-brain barrier and provide a rapid effect because it is a fat-soluble drug. Remimazolam is rapidly metabolized by carboxylic acid elastase, which does not involve the liver enzyme CYP3A4, and shows organ-independent metabolism. Its organ-independent metabolism makes it less likely to impair liver and kidney function. Remimazolam’s metabolites are pharmacologically inactive. Therefore, the adjustability of remimazolam seems to be superior to Midazolam. Remimazolam is safer than propofol because it can be reversed with flumazenil to rapidly terminate sedation, similar to other benzodiazepines if necessary. Furthermore, remimazolam’s half-life is as short as flumazenil’s and therefore, there is low risk of re-sedation unlike other benzodiazepines. In a phase IIa study conducted in the United States, the induction times from drug administration to sedation was 1.5-2.5 min in remimazolam (0.10-0.20 mg/kg) and 5 min in midazolam (0.075 mg/kg) in upper gastrointestinal endoscopies[36] .The time to recover from sedation (3 consecutive Modified Observer’s Assessment of Alertness and Sedation scores of 5) was significantly shorter in remimazolam than that in midazolam (6.8-9.9 min vs 11.5 min, respectively). These results suggest that remimazolam had a faster onset of action and a faster recovery time after endoscopic examination/treatment compared with midazolam. In a phase IIb study conducted in the United States, remimazolam (5.0 mg, 7.0 mg, and 8.0 mg) achieved a lower rate of additional administrations compared with Midazolam (2.5 mg) during colonoscopies[37] . Similarly in a phase III study conducted in the United States, remimazolam (5 mg) achieved a higher procedural completion rate without the requirement for additional fixed doses (5 doses in any 15-min interval), compared with placebo (5 doses in any 15-min interval) and midazolam (3 doses in any 12-min interval; aged < 60 years, 1.75 mg; aged ≥ 60 years, 1.0 mg) in outpatient colonoscopies[38] . All studies have suggested that remimazolam was as safe as Midazolam as a sedative for gastrointestinal endoscopy. Remimazolam, has the combined advantage of a short half-life, similar to propofol and an antagonist like midazolam. Furthermore, it can be managed by non-anesthesiologists. Therefore, remimazolam may increasingly be used as a sedative for gastrointestinal endoscopies. The use of Remimazolam in clinical practice remains insufficient. New issues might arise after clinical administration. To the best of our knowledge, there are no studies comparing the clinical outcomes of remimazolam with propofol. There is a lack of clinical data on Remimazolam. Various additional clinical studies to improve the efficacy and safety of remimazolam as a sedative for endoscopic procedures is desired in the future. Preparation for clinical trial for insurance coverage are currently in progress in Japan
CONCLUSION Conscious sedation, without tracheal intubation, during endoscopy differs greatly depending on the country and region. Endoscopic examination using sedation should be safely completed without pain. Currently, benzodiazepine sedatives and propofol are the predominant drugs administered during endoscopic examinations. Propofol might be useful for patients in countries or regions with sufficient anesthesiologists. While a novel benzodiazepine sedative, remimazolam, could be a desired option in countries or regions without adequate numbers of anesthesiologists to attend endoscopic procedures. |