Comparison of the potency-ratio of ciprofol and propofol on sedative effects in painless hysteroscopy: a randomized double-blind dose-response study.

PURPOSE: Ciprofol has been investigated as a potential alternative to propofol for anesthesia because of its tendency to depress the respiratory and circulatory systems to a lesser extent and its association with less pain during injection. However, the relative potency of these two intravenous anesthetics has not been fully determined.

METHODS

In this randomized double-blind trial, 232 patients undergoing elective hysteroscopy were allocated to 8 groups (n = 29 each) receiving ciprofol (0.2, 0.3, 0.4, 0.5 mg/kg) or propofol (1.0, 1.5, 2.0, 2.5 mg/kg) as a single intravenous bolus. Dose-response relationships were analyzed using probit regression to estimate ED50(dose giving a 50% response) and ED95(dose giving a 95% response) and nonlinear regression (sigmoidal Emax model) to validate curve fitting. The primary endpoint was the success rates of anesthesia induction (MOAA/S ≤1 within 2 min).

RESULTS

Data from 230 patients were available for analysis. The ED95 of ciprofol [0.53 mg/kg, 95% confidence interval (95% CI) 0.48–0.60] was non-overlapping with propofol (2.16 mg/kg, 95% CI 1.96–2.45), confirming the relative potency ratio for the two drugs 4.1 (95% CI 2.4–9.0). Ciprofol showed significantly lower incidences of injection pain (0% vs. 34.5%, P<0.01) and respiratory depression (27.6% vs. 55.2%, P<0.05) at doses around the ED50.

CONCLUSION

Ciprofol demonstrated a 4.1:1.0 potency ratio over propofol with superior safety in patients undergoing painless hysteroscopy, supporting its use as an alternative for brief procedures requiring rapid anesthesia induction and recovery. TRIAL REGISTRATION: Clinicaltrials.gov identifier ChiCTR2200059853, May 13, 2022.