Pharmacokinetic-pharmacodynamic Modelling of NH600001 in Healthy Subjects and Patients Undergoing Gastroscopy

NH600001 is a new general anaesthetic drug with a structure similar to etomidate. The objective of this study was to investigate the relationship between concentrations of NH600001 and sedation efficacy based on data from phase I-II studies and factors influencing the pharmacokinetics and pharmacodynamics of NH600001. The dataset consisted of 2 phase I studies in healthy subjects and 1 phase II study in patients undergoing gastroscopy. Nonlinear mixed effects modeling was used in developing the population pharmacokinetics and pharmacodynamics (PopPK/PD) model of NH600001. Three-compartment model was used to describe the PK profile of NH600001. Parameters were used for allometric scaling on body weight, where the exponents were set to 0.75 for clearance and 1 for volumes. Co-administration of alfentanil hydrochloride influenced the distribution volume of the central compartment and clearance. Effect of patients undergoing gastroscopy (compared with healthy subjects) on clearance, the distribution volume of the superficial peripheral compartment and inter-compartmental clearance for deep peripheral compartment and central compartment was included the final PopPK model. The effect compartment model well characterized the PK/PD relationship of NH600001. Simulation results showed that an initial dose of 0.25 mg/kg of NH600001 resulted in rapid sedation, and three additional doses at 5-min intervals could maintain sedation for more than 20 min. A PopPK/PD model was successfully constructed for NH600001 in healthy subjects and in patients undergoing gastroscopy that could inform the dosing regimens of the forthcoming phase III study. Graphical Abstract