Pharmacodynamic Modeling of Blood Pressure Reduction During Remimazolam Induction in Elderly Patients: A Modified Logistic Model with Body Weight as a Covariate

Remimazolam is a newer hypnotic that generally preserves cardiovascular stability better than propofol during general anesthesia, a benefit that appears pronounced in older adults. Despite this, the extent to which remimazolam lowers blood pressure in a dose-related manner has not been formally quantified in this age group. We re-examined information from 432 individuals aged ≥ 65 years enrolled in a randomized trial comparing remimazolam with propofol for elective gastrectomy. Remimazolam was infused at a constant 6 mg/kg/h, whereas propofol was administered with a TCI system employing the Schnider model. Mean arterial pressure (MBP) values were expressed as fractional reductions relative to baseline. To relate cumulative remimazolam dose to MBP decline, we constructed a modified logistic regression model and assessed body weight as a potential influencing factor. Data from 209 participants per arm were suitable for evaluation. The customized logistic model reliably captured the dose–response pattern for MBP reduction produced by remimazolam, and model accuracy improved when body weight was included as a covariate. The remimazolam group showed a statistically larger MBP drop before intubation (28.0 ± 9.9% vs 25.8 ± 10.1%, P = 0.024), although the magnitude of this difference lacked practical clinical importance. In older patients receiving remimazolam for induction, the association between administered dose and MBP decrease was well represented by the modified logistic approach, with body weight exerting a meaningful influence. These findings imply that TCI-style dosing could help maintain more stable hemodynamics during induction. Clinical Research Information Service, KCT0006877, registered December 27, 2021.