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Effects of Remimazolam on Intracellular Calcium Dynamics in Myotubes Derived from Patients with Malignant Hyperthermia and Functional Analysis of Type 1 Ryanodine Receptor Gene Variants

Abstract

Remimazolam is a novel general anesthetic and its safety in patients with malignant hyperthermia (MH) is unknown. We used myotubes derived from the skeletal muscle of patients with MH to examine the response to ryanodine receptor 1 (RYR1) agonist and remimazolam in MH-susceptible patients. Patients underwent muscle biopsy for the Ca-induced Ca release (CICR) rate test, a diagnostic tool for MH in Japan. Ten patients had myotubes obtained from skeletal muscle cultures, and the genes associated with malignant hyperthermia in these patients were analyzed. The EC of caffeine, cresol, and remimazolam to induce intracellular calcium concentration change were compared between myotubes from CICR-negative genetic test patients and myotubes from other patients. Eight of the ten were CICR-positive, five of whom had RYR1 causative gene mutations or variants. Two patients had CICR-negative genetic tests, and as expected had the highest EC (the concentration of a drug that gives a half-maximal response) in response to caffeine, 4CmC and remimazolam. Three patients had a positive CICR but no known variants in RYR1 or CACNA1S (voltage-gated calcium channel subunit alpha1S). Myotubes in these patients had significantly lower EC50s for all agents than myotubes in CICR-negative patients. When myotubes from a patient who was CICR-negative and had no gene variant were used as a control, myotubes from CICR-positive patients were more hyper-responsive than controls to all stimulants used. The EC for remimazolam was lowest for myotubes from CICR-positive, RYR1-mutant patients, at 206 µM (corresponding to 123 µg/mL). The concentration was more than 80-times higher than the clinical concentration. gene variants in R4645Q and W5020G were shown to be causative gene mutations for MH. Intracellular calcium in myotubes from MH patients are elevated at high concentrations of remimazolam but not at clinically used concentrations of remimazolam. Remimazolam appears to be safe to use in patients with MH.

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References
1.
Migita T, Mukaida K, Hamada H, Kobayashi M, Nishino I, Yuge O . Effects of propofol on calcium homeostasis in human skeletal muscle. Anaesth Intensive Care. 2009; 37(3):415-25. DOI: 10.1177/0310057X0903700313. View

2.
Urabe T, Miyoshi H, Narasaki S, Yanase Y, Uchida K, Noguchi S . Characterization of intracellular calcium mobilization induced by remimazolam, a newly approved intravenous anesthetic. PLoS One. 2022; 17(2):e0263395. PMC: 8806057. DOI: 10.1371/journal.pone.0263395. View

3.
Miyoshi H, Watanabe T, Kido K, Kamiya S, Otsuki S, Narasaki S . Remimazolam Requires Less Vasopressor Support during Induction and Maintenance of General Anesthesia in Patients with Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement: A Retrospective Analysis from a Single Center. Biomed Res Int. 2022; 2022:6386606. PMC: 9617702. DOI: 10.1155/2022/6386606. View

4.
Hopkins P, Ruffert H, Snoeck M, Girard T, Glahn K, Ellis F . European Malignant Hyperthermia Group guidelines for investigation of malignant hyperthermia susceptibility. Br J Anaesth. 2015; 115(4):531-9. DOI: 10.1093/bja/aev225. View

5.
Weigl L, Ludwig-Papst C, Kress H . 4-chloro-m-cresol cannot detect malignant hyperthermia equivocal cells in an alternative minimally invasive diagnostic test of malignant hyperthermia susceptibility. Anesth Analg. 2004; 99(1):103-107. DOI: 10.1213/01.ANE.0000118110.90277.D2. View