Population pharmacokinetic/pharmacodynamic modeling and exposure-response analysis of ciprofol in the induction and maintenance of general anesthesia in patients undergoing elective surgery: A prospective dose optimization study

AIM

This study aimed to establish a population pharmacokinetic and pharmacodynamic (PK-PD) model to explore the optimal maintenance dose and appropriate starting time of maintenance dose after induction of ciprofol and investigate the efficacy and safety of ciprofol for general anesthesia induction and maintenance in patients undergoing elective surgery.

METHOD

A total of 334 subjects with 3092 concentration measurements from nine clinical trials and 115 subjects with 5640 bispectral index (BIS) measurements from two clinical trials were used in the population PK-PD analysis. Exposure-response relationships for both efficacy endpoints (duration of anesthesia successful induction, time to recovery from anesthesia, time to respiratory recovery, and time from discontinuation to the 1st/3rd consecutive Aldrete score ≥ 9) and safety variables (hypotension, bradycardia, and injection site pain) were evaluated based on the data gathered from 115 subjects in two clinical trials.

RESULT

Ciprofol pharmacokinetics (PK) were adequately described by a three-compartment model with first-order elimination from the central compartment and redistribution from the deep and shallow peripheral compartments. An inhibitory sigmoidal Emax model best described the relationship between ciprofol effect-site concentrations and BIS measurements. Body weight, age, sex, blood sampling site, and study type (short-term infusion vs long-term infusion) were identified as statistically significant covariates on the PK of ciprofol. No covariates were found to have a significant effect on the pharmacodynamic (PD) parameters. The PK-PD simulation results showed that the optimal maintenance dose was 0.8 mg/kg/h and the appropriate time to start the maintenance dose was 4-5 mins after the induction dose of ciprofol. Within the exposure range of this study, no meaningful correlations between ciprofol exposures and efficacy or safety endpoints were observed.

CONCLUSION

A population PK-PD model was successfully developed to describe the ciprofol PK and BIS changes. Efficacy was consistent across the exposure range with a well-tolerated safety profile indicating no maintenance dose adjustment is required for patients undergoing elective surgery.

Efficacy and safety of ciprofol (HSK3486) for procedural sedation and anesthesia induction in surgical patients: A systematic review and meta-analysis

Background

Ciprofol (HSK3486) is a novel gamma-aminobutyric acid type A (GABAA) receptor agonist that has attracted wide attention because of its lower injection pain and fewer adverse events. We summarized all available evidence and analyzed the efficacy and safety of ciprofol during procedural sedation and anesthesia induction.

Methods

An electronic search of PubMed, Embase, Cochrane Library, Web of Science, Google Scholar, Science Direct, the Chinese National Knowledge Infrastructure, Wan Fang Data, and the VIP Chinese Journal Service platform was conducted from inception of databases to March 1, 2023. Risk ratio (RR) and mean difference (MD) with 95 % confidence interval (CI) were used separately for binary categorical and continuous variables. We performed trial sequential analysis and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology to judge the certainty of evidence.

Results

Fifteen randomized controlled trials with 2441 patients were included in this study. Ciprofol showed similar advantages to propofol in terms of induction success rate (RR = 1, 95 % CI = 0.99, 1.01, moderate certainty) and induction time (MD = 3.31, 95 % CI = -0.34, 6.95, low certainty), but did not increase the incidence of adverse events (RR = 0.88, 95 % CI = 0.78, 1.00, very low certainty), such as bradycardia (RR = 0.96, 95 % CI = 0.77, 1.21, high certainty), hypoxia (RR = 0.79, 95 % CI = 0.46, 1.37, p = 0.40, moderate certainty) and other adverse events. Although it may be associated with a longer time to be fully alert (MD = 1.22, 95 % CI = 0.32, 2.12, very low certainty), ciprofol significantly reduced injection pain (RR = 0.15, 95 % CI 0.09, 0.24, low certainty) and may have reduced the incidence of hypotension (RR = 0.77, 95 % CI = 0.63, 0.94, low certainty) and respiratory depression (RR = 0.29, 95 % CI = 0.15, 0.56, moderate certainty).

Conclusion

Ciprofol and propofol had similar effects on most outcomes. While the time to full alertness may be prolonged, injection pain was significantly reduced, and hypotension and respiratory depression may be reduced compared with propofol. We believe that ciprofol is an effective alternative to intravenous anesthetic agents.

Model-informed drug development: The mechanistic HSK3486 physiologically based pharmacokinetic model informing dose decisions in clinical trials of specific populations

HSK3486, a central nervous system inhibitor, has demonstrated superior anesthetic properties in comparison with propofol. Owing to the high liver extraction ratio of HSK3486 and the limited susceptibility to the multi-enzyme inducer, rifampicin, the indicated population of HSK3486 is substantial. Nevertheless, in order to expand the population with indications, it is crucial to assess the systemic exposure of HSK3486 in specific populations. Moreover, the main metabolic enzyme of HSK3486 is UGT1A9, which shows a gene polymorphism in the population. Thus, to scientifically design the dose regimen for clinical trials in specific populations, a HSK3486 physiologically based pharmacokinetic model was developed in 2019 to support model-informed drug development (MIDD). Several untested scenarios of HSK3486 administration in specific populations, and the effect of the UGT1A9 gene polymorphism on HSK3486 exposure were estimated as well. The predicted systemic exposure was increased slightly in patients with hepatic impairment and in the elderly, consistent with later clinical trial data. Meanwhile, there was no change in the systemic exposure of patients with severe renal impairment and in neonates. However, under the same dose, the predicted exposure of pediatric patients aged 1 month to 17 years was decreased significantly (about 21%-39%). Although these predicted results in children have not been validated by clinical data, they are comparable to clinical findings for propofol in children. The dose of HSK3486 in pediatrics may need to be increased and can be adjusted according to the predicted results. Moreover, the predicted HSK3486 systemic exposure in the obese population was increased by 28%, and in poor metabolizers of UGT1A9 might increase by about 16%-31% compared with UGT1A9 extensive metabolizers. Combined with the relatively flat exposure-response relationship for efficacy and safety (unpublished), obesity and genetic polymorphisms are unlikely to result in clinically significant changes in the anesthetic effect at the 0.4 mg/kg dose in adults. Therefore, MIDD can indeed provide supportive information for dosing decisions and facilitate the efficient and effective development of HSK3486.

Protective effects of combined treatment with ciprofol and mild therapeutic hypothermia during cerebral ischemia-reperfusion injury

Despite improvement in cardiopulmonary resuscitation (CPR) performance, cardiac arrest (CA) is still associated with poor prognosis. The high mortality rate is due to multi-organ dysfunction caused by cerebral ischemia and reperfusion injury (I/R). The guidelines for CPR suggest the use of therapeutic hypothermia (TH) as an effective treatment to decrease mortality and the only approach confirmed to reduce I/R injury. During TH, sedative agents (propofol) and analgesia agents (fentanyl) are commonly used to prevent shiver and pain. However, propofol has been associated with a number of serious adverse effects such as metabolic acidosis, cardiac asystole, myocardial failure, and death. In addition, mild TH alters the pharmacokinetics of agents (propofol and fentanyl) and reduces their systemic clearance. For CA patients undergoing TH, propofol can be overdosed, leading to delayed awakening, prolonged mechanical ventilation, and other subsequent complications. Ciprofol (HSK3486) is a novel anesthetic agent that is convenient and easy to administer intravenously outside the operating room. Ciprofol is rapidly metabolized and accumulates at low concentrations after continuous infusion in a stable circulatory system compared to propofol. Therefore, we hypothesized that treatment with HSK3486 and mild TH after CA could protect the brain and other organs.

Safety, pharmacokinetics and pharmacodynamics of a novel γ-aminobutyric acid (GABA) receptor potentiator, HSK3486, in Chinese patients with hepatic impairment

BACKGROUND

The primary objective of this study was to investigate if hepatic impairment alters the safety, pharmacokinetics, and pharmacodynamics of HSK3486.

RESEARCH DESIGN AND METHODS

This was a clinical trial of HSK3486 in subjects with normal hepatic function (n = 8), and mild (Child-Pugh A; n = 8), or moderate (Child-Pugh B; n = 8) hepatic impairment. Each subject received an IV bolus dose of 0.4 mg/kg HSK3486 for 1 min, immediately followed by a maintenance infusion of 0.4 mg/kg/h HSK3486 for 30 min.

RESULTS

In total, 24 subjects were enrolled and completed the study. HSK3486 was generally well tolerated by all subjects. There were no serious AEs and no deaths reported during the study. The incidence of AEs was numerically highest in subjects with moderate hepatic impairment. The exposure (AUC) of HSK3486 increased gradually with the decrease in hepatic function; however, degree of hepatic impairment had little effect on HSK3486 PD (MOAA/S and BIS).

CONCLUSIONS

Overall, there were no clinically relevant differences in HSK3486 exposure or PD in subjects with mild or moderate hepatic impairment compared to normal control. These data imply that HSK3486 dose adjustment is not warranted in subjects with mild or moderate hepatic impairment.

TRIAL REGISTRATION

The trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT04145596).Key MessageHSK3486 at an IV bolus dose of 0.4 mg/kg and a maintenance infusion of 0.4 mg/kg/h was safe and well tolerated by all mild or moderate hepatic impairment subjects and normal hepatic function subjects.There were no clinically relevant differences in HSK3486 exposure or PD in subjects with mild or moderate hepatic impairment compared to subjects with normal hepatic function.HSK3486 dose adjustment is not required in subjects with mild or moderate hepatic impairment.

Safety, Pharmacokinetics, and Pharmacodynamics of a Single Bolus of the γ-aminobutyric Acid (GABA) Receptor Potentiator HSK3486 in Healthy Chinese Elderly and Non-elderly

Background: The present clinical trial investigated the potential influences of dosage and age on the pharmacokinetic properties and safety profile of HSK3486, and whether any adjustment in dosing regimen is necessary in elderly patients.

Methods: Twenty-four elderly participants (65–73 years) were apportioned to three equal cohorts to receive a single IV bolus of 0.2, 0.3, and 0.4 mg/kg HSK3486, respectively. An additional control group comprised eight non-elderly participants (21–44 years), who each received a single IV bolus dose of 0.4 mg/kg. Safety was assessed throughout the study, and the clinical effects were assessed based on modified observer’s assessment of alertness/sedation and bispectral index (BIS) monitor. Pharmacokinetic parameters were calculated.

Results: The rates of drug-related adverse reactions among the elderly groups were a little higher than that of the non-elderly, and were slightly higher in the elderly receiving 0.4 mg/kg compared with the elderly given lower doses. The pharmacokinetic characteristics of 0.4 mg/kg HSK3486 in the elderly and non-elderly were comparable. The time to recovery was similar in elderly 0.3 mg/kg, elderly 0.4 mg/kg and non-elderly 0.4 mg/kg groups. In the elderly 0.2 mg/kg group, the time to loss of consciousness was a little longer, and the time to recovery was shorter, relative to the other three groups.

Conclusions: Administration of 0.3 mg/kg to the elderly and 0.4 mg/kg to the non-elderly were similarly efficacious. A dose of HSK3486 of 0.3 mg/kg may be chosen for clinical use in elderly patients.