Fospropofol: a new sedative-hypnotic agent for monitored anesthesia care

Effective doses of ciprofol combined with alfentanil in inhibiting responses to gastroscope insertion, a prospective, single-arm, single-center study

BACKGROUND

Ciprofol is a novel intravenous sedative and anesthetic. Studies have shown that it features a rapid onset of action, a fast recovery time, slight inhibition of respiratory and cardiovascular functions, and a low incidence of adverse reactions. This study aims to explore the median effective dose (ED50) and the 95% effective dose (ED95) of ciprofol in inhibiting responses to gastroscope insertion when combined with a low dose of alfentanil, and to evaluate its safety, to provide a reference for the rational use of ciprofol in clinical practices.

METHODS

We included 25 patients aged 18-64 years of either sex who underwent gastroscopy under intravenous general anesthesia, with a Body Mass Index (BMI) 18-28 kg/m2, and an American Society of Anesthesiologists (ASA) grade I or II. In this study, the dose-finding strategy of ciprofol followed a modified Dixon's up-and-down method with an initial dose of 0.30 mg/kg and an increment of 0.02 mg/kg. Ciprofol was administered after intravenous injection of 7 µg/kg of alfentanil, and 2 min later a gastroscope was inserted. When the insertion response of one participant was positive (including body movement, coughing, and eye opening), an escalation of 0.02 mg/kg would be given to the next participant; otherwise, a de-escalation of 0.02 mg/kg would be administered. The study was terminated when negative response and positive response alternated 8 times. A Probit model was used to calculate the ED50 and ED95 of ciprofol in inhibiting responses to gastroscope insertion when combined with alfentanil. Patients' recovery time, discharge time, vital signs and occurrence of adverse reactions were recorded.

RESULTS

The ED50 of single-dose intravenous ciprofol injection with 7 µg/kg of alfentanil in inhibiting gastroscope insertion responses was 0.217 mg/kg, and the ED95 was 0.247 mg/kg. Patients' recovery time and discharge time were 11.04 ± 1.49 min and 9.64 ± 2.38 min, respectively. The overall incidence of adverse reactions was 12%.

CONCLUSION

The ED50 of ciprofol combined with 7 µg/kg of alfentanil in inhibiting gastroscope insertion responses was 0.217 mg/kg, and the ED95 was 0.247 mg/kg. Ciprofol showed a low incidence of anesthesia-related adverse events.

TRIAL REGISTRATION

http://www.chictr.org.cn (ChiCTR2200061727).

Biological evaluation of a phosphate ester prodrug of 10-methyl-aplog-1, a simplified analog of aplysiatoxin, as a possible latency-reversing agent for HIV reactivation

10-Methyl-aplog-1 (10MA-1), a simplified analog of aplysiatoxin, exhibits a high binding affinity for protein kinase C (PKC) isozymes with minimal tumor-promoting and pro-inflammatory activities. A recent study suggests that 10MA-1 could reactivate latent human immunodeficiency virus (HIV) in vitro for HIV eradication strategy. However, further in vivo studies were abandoned by a dose limit caused by the minimal water solubility of 10MA-1. To overcome this problem, we synthesized a phosphate ester of 10MA-1, 18-O-phospho-10-methyl-aplog-1 (phos-10MA-1), to improve water solubility for in vivo studies. The solubility, PKC binding affinity, and biological activity of phos-10MA-1 were examined in vitro, and the biological activity was comparable with 10MA-1. The pharmacokinetic studies in vivo were also examined, which suggest that further optimization for improving metabolic stability is required in the future.

The efficacy and safety of ciprofol use for the induction of general anesthesia in patients undergoing gynecological surgery: a prospective randomized controlled study

Background

Ciprofol is a recently developed, short-acting γ-aminobutyric acid receptor agonist sedative that is more potent than propofol, but there have been few clinical studies of this agent to date. Here, we sought to examine the safety and efficacy of ciprofol use for the induction of general anesthesia in individuals undergoing gynecological surgery.

Methods

Women between the ages of 18 and 60 years (ASA physical status 1 or 2) who were scheduled to undergo elective gynecological surgery under general anesthesia were randomly assigned to two equally sized groups in which anesthesia induction was performed using either ciprofol or propofol. General anesthesia induction success rates were the primary outcome for this study, while secondary outcomes included changes in BIS during the 10 min following the first administration of the study drug, the duration of successful induction, and adverse event incidence.

Results

A total of 120 women were included in the study. A 100% rate of successful induction was achieved in both the ciprofol and propofol groups, with no significant differences between these groups with respect to the duration of successful induction (34.8 ± 15.5 s vs 35.4 ± 9.5 s, P = 0.832), the time to the disappearance of the eyelash reflex (33.7 ± 10.6 s vs 34.0 ± 6.5 s, P = 0.860), or tracheal intubation (58.2 ± 31.1 s vs 53.9 ± 25.4 s, P = 0.448). Adverse event rates, including intubation responses, were significantly lower in the ciprofol group as compared to the propofol group(20% vs 48.33%, P = 0.0019). Ciprofol was associated with reduced injection pain relative to propofol (16.7% vs 58.3%, P < 0.001).

Conclusions

Ciprofol exhibits comparable efficacy to that of propofol when used for the induction of general anesthesia in individuals undergoing gynecological surgery and is associated with fewer adverse events.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01782-7.

Sedation Effects Produced by a Ciprofol Initial Infusion or Bolus Dose Followed by Continuous Maintenance Infusion in Healthy Subjects: A Phase 1 Trial

Introduction

The effects of continuous infusions of ciprofol on its pharmacodynamic and pharmacokinetic properties and safety profiles in healthy Chinese subjects were evaluated.

Methods

In this open-label, randomized, two-way cross-over study, subjects received initial doses of continuous ciprofol/propofol as an infusion for 30 min in part 1 (n = 8) and a bolus dose in part 2 (n = 8) followed by maintenance infusions for a total of 4 h in part 1 and 12 h in part 2. Each subject participated in both parts with a washout time of at least 40 h.

Results

The safety and tolerability parameters of ciprofol were similar to those of propofol, and all treatment-emergent adverse events were mild. The incidences of injection pain and respiratory depression in subjects given ciprofol were lower than those receiving propofol. The pharmacokinetic parameters C_max, t_max, t_1/2, λz and MRT for ciprofol and propofol were similar, while CL, V_d and V_ss were statistically significantly different. Pharmacodynamic parameters including the Richmond Agitation Sedation Scale and bispectral index profiles of ciprofol were similar to those of propofol.

Conclusion

Ciprofol has potential for clinical application for continuous intravenous infusion to maintain sedation for 12 h with the same safety, tolerability and efficacy as propofol.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01914-4.

The preclinical pharmacological study on HX0969W, a novel water-soluble pro-drug of propofol, in rats

Background

Propofol is the most widely used intravenous sedative-hypnotic anesthetic in clinical practice. However, many serious side effects have been related to its lipid emulsion formulation. The pro-drug design approach was used to develop the water-soluble propofol, which could effectively resolve the limitations associated with the lipid emulsion formulation. Thus, the new water-soluble pro-drug of propofol, HX0969W, was designed and synthesized. The objective of this study was to conduct preclinical pharmacological studies on this novel water-soluble pro-drug of propofol.

Methods

The assessment of the loss of the righting reflex (LoRR) was used for the pharmacodynamic study, and liquid chromatography-tandem mass spectrometry and high-performance liquid chromatography- fluorescence were used for the pharmacokinetic study.

Results

The potency of HX0969W (ED₅₀ [95% CI], 46.49 [43.89–49.29] mg/kg) was similar to that of fospropofol disodium (43.66 [43.57–43.75] mg/kg), but was lower than that of propofol (4.82 [4.8–14.82] mg/kg). Administered with a dose of 2-fold ED₅₀, propofol required a shorter time to cause LoRR than that of HX0969W and fospropofol. However, the LoRR duration was significantly longer in response to the administration of HX0969W and fospropofol disodium than that caused by propofol. In the pharmacokinetic study, the C_max of fospropofol was higher than that of HX0969W. HX0969W had a shorter mean residual time and a rapid clearance rate than that of fospropofol disodium. There was no significant difference between the T_max of the propofol whether it was released by HX0969W or fospropofol disodium; the C_max of propofol released by HX0969W was similar to that of propofol, which was higher than the propofol released by fospropofol disodium.

Recent progress in prodrug design strategies based on generally applicable modifications

The development of prodrugs has progressed with the aim of improving drug bioavailability by overcoming various barriers that reduce drug benefits in clinical use, such as stability, duration, water solubility, side effect profile, and taste. Many conventional drugs act as the precursors of an active agent in vivo; for example, the anti-HIV agent azidothymidine (AZT) is converted into its corresponding active triphosphate ester in the body, meaning that AZT is a prodrug in the broadest sense. However prodrug design is generally difficult owing to the lack of general versatility. Thus, these prodrugs, broadly defined, are often discovered by chance or trial-and-error. Recently, many prodrugs that could release the corresponding parent drugs with or without enzymatic action under physiological conditions have been reported. These prodrugs can be easily designed and synthesized because of their generally applicable modifications. This digest paper provides an overview of recent development in prodrug strategies for drugs with a carboxylic acid or hydroxyl/amino group on the basis of a generally applicable modification strategy, such as esterification, amidation, or benzylation.

A randomized open-label phase I pilot study of the safety and efficacy of total intravenous anesthesia with fospropofol for coronary artery bypass graft surgery

OBJECTIVE

To determine safety and efficacy of the water-soluble prodrug fospropofol for anesthesia in cardiac surgery and to compare the pharmacodynamic profiles of fospropofol and propofol.

DESIGN

Pilot study and a prospective, phase I, open-label, single-center, randomized clinical trial.

SETTING

University hospital; single institution.

PARTICIPANTS

Sixteen patients undergoing elective first-time coronary artery bypass surgery.

INTERVENTIONS

Patients were randomized to receive total intravenous anesthesia with fospropofol (n = 8) or propofol (n = 8) combined with alfentanil as total intravenous anesthesia. Bispectral index, arterial blood pressure, and heart rate were recorded continuously, and pulmonary artery catheter measurements were obtained. Plasma concentrations of formate, phosphate, and Ca(2+) were monitored closely. Safety and tolerability were assessed by adverse events, neurologic examinations, clinical laboratory tests, and vital signs.

MEASUREMENTS AND MAIN RESULTS

The total doses of fospropofol and propofol during anesthesia were 11.3±2.5 and 4.4±1.0 mg/kg/h, respectively. According to the achieved bispectral index (BIS) values, fospropofol was as effective as propofol in providing general anesthesia and sedation. There were no clinical signs of formate toxicity in the fospropofol group. The only treatment-related adverse event after administration of fospropofol was a transient burning sensation in the perineal and perianal region during induction of sedation or anesthesia.

CONCLUSIONS

Fospropofol could be used to provide general anesthesia in patients undergoing coronary artery bypass graft surgery. Further larger studies are needed to prove the safety of fospropofol when given to provide general anesthesia for major cardiac surgical procedures.

An improved design of water-soluble propofol prodrugs characterized by rapid onset of action

BACKGROUND

Phosphate ester prodrugs of propofol (fospropofol, HX0969W) were designed to avoid the unsatisfactory water solubility of the parent drug. However, in previous clinical trials, there were reported prodrug side effects such as paresthesia and pruritus. The accumulation of a phosphate ester component was found to be the main culprit. To exclude this potential risk, we designed 2 amino acid propofol prodrugs (HX0969-Gly-F3, HX0969-Ala-HCl) based on the lead compound (HX0969) by introducing the amino acid group into the structures of the propofol prodrugs. We hypothesized that the improved propofol prodrugs could not only eliminate those adverse effects but also retain their rapid action and good water solubility.

METHODS

The lead compound HX0969 was synthesized by the sodium borohydride-iodine system. HX0969W, HX0969-Gly-F3, and HX0969-Ala-HCl were synthesized from HX0969. The solubility of fospropofol, HX0969W, HX0969-Gly-F3, and HX0969-Ala-HCl in normal saline was tested. The bioconversions from those prodrugs to propofol in different physiological media (rat plasma, rhesus monkey plasma, and rat hepatic microsomes) were determined in vitro. An in vivo test in the rats was performed to measure the 50% effective dose (ED50) of the 4 propofol prodrugs. Their action onset time and duration time were also measured after their equipotent doses were given.

RESULTS

(1) The water solubility of fospropofol, HX0969W, HX0969-Gly-F3, and HX0969-Ala-HCl was 461.46 ± 26.40 mg/mL, 189.45 ± 5.02 mg/mL, 49.88 ± 0.58 mg/mL, and 245.99 ± 4.83 mg/mL, respectively; (2) The hydrolysis tests in both the rat plasma and the rhesus monkey plasma revealed that the 2 amino acid prodrugs released propofol to a greater extent at a more rapid rate than the 2 phosphate prodrugs during the testing period of 5 hours. All 4 prodrugs released propofol rapidly in the presence of rat hepatic enzymes; (3) Compared with the previous prodrugs (fospropofol, HX0969W), the 2 novel compounds (HX0969-Gly-F3, HX0969-Ala-HCl) had a much shorter onset time when a much lower dose was given.

CONCLUSIONS

Application of the amino acid group to the propofol prodrug can make the prodrug have good water solubility and a more rapid onset of action. In rat plasma, the 2 improved amino acid prodrugs (HX0969-Ala-HCl, HX0969-Gly-F3) had a more rapid rate of propofol release than the 2 phosphate ester prodrugs (fospropofol, HX0969W). The in vivo tests showed that HX0969-Ala-HCl and HX0969-Gly-F3 given IV could have a more rapid onset of action in a smaller dose than fospropofol and HX0969W. This novel design can enhance the efficiency of prodrugs converting to propofol.

A comparison of fospropofol to midazolam for moderate sedation during outpatient dental procedures

Moderate intravenous (IV) sedation combined with local anesthesia is common for outpatient oral surgery procedures. An ideal sedative agent must be safe and well tolerated by patients and practitioners. This study evaluated fospropofol, a relatively new sedative/hypnotic, in comparison to midazolam, a commonly used benzodiazepine, for IV moderate sedation during oral and maxillofacial surgery. Sixty patients were randomly assigned to either the fospropofol or the midazolam group. Each participant received 1 μg/kg of fentanyl prior to administration of the selected sedative. Those in the fospropofol group received an initial dose of 6.5 mg/kg, with 1.6 mg/kg supplemental doses as needed. Those in the midazolam group received initial doses of 0.05 mg/kg, followed by 0.02 mg/kg supplemental doses. The quality of sedation in each patient was evaluated with regard to (a) onset of sedation, maintenance, and recovery profile; (b) patient and surgeon satisfaction; and (c) hemodynamic stability and adverse effects. The fospropofol group demonstrated shorter physical recovery times than midazolam patients, taking a mean of 11.6 minutes versus 18.4 minutes for physical recovery (P = .007). Cognitive recovery comparison did not find any difference with a mean of 7.5 minutes versus 8.8 minutes between the 2 drug groups (P = .123). The fospropofol group had a higher rate of local anesthetic injection recall (90.5 vs 44.4%, P = .004). Other parameters of recall were comparable. Two adverse effects demonstrated significance, with more patients in the midazolam group experiencing tachycardia (48.2 vs 9.4%, P = .001), and more patients in the fospropofol group experiencing perineal discomfort (40.6 vs 0, P < .001). No significant difference was found in any other measures of sedation safety, maintenance, or satisfaction. Fospropofol, when administered intravenously by a dentist anesthesiologist at the indicated dose in this study, appears to be a safe, well-tolerated alternative to midazolam for intravenous moderate sedation during minor oral surgery procedures.

NIPTE: a multi-university partnership supporting academic drug development

The strategic goal of academic translational research is to accelerate translational science through the improvement and development of resources for moving discoveries across translational barriers through 'first in humans' studies. To achieve this goal, access to drug discovery resources and preclinical IND-enabling infrastructure is crucial. One potential approach of research institutions for coordinating preclinical development, based on a model from the National Institute for Pharmaceutical Technology and Education (NIPTE), can provide academic translational and medical centers with access to a wide variety of enabling infrastructure for developing small molecule clinical candidates in an efficient, cost-effective manner.

Sedation and monitoring for gastrointestinal endoscopy

The safe sedation of patients for diagnostic or therapeutic procedures requires a combination of properly trained physicians and suitable facilities. Additionally, appropriate selection and preparation of patients, suitable sedative technique, application of drugs, adequate monitoring, and proper recovery of patients is essential. The goal of procedural sedation is the safe and effective control of pain and anxiety as well as to provide an appropriate degree of memory loss or decreased awareness. Sedation practices for gastrointestinal endoscopy (GIE) vary widely. The majority of GIE patients are ambulatory cases. Most of this procedure requires a short time. So, short acting, rapid onset drugs with little adverse effects and improved safety profiles are commonly used. The present review focuses on commonly used regimens and monitoring practices in GIE sedation. This article is to discuss the decision making process used to determine appropriate pre-sedation assessment, monitoring, drug selection, dose of sedative agents, sedation endpoint and post-sedation care. It also reviews the current status of sedation and monitoring for GIE procedures in Thailand.

[Fospropofol: A new prodrug of propofol]

The development of new propofol formulations has advanced rapidly in the last ten years with the achievement of the marketing a new prodrug of propofol: fospropofol, pharmacologically different from the original compound. It is a water soluble compound that requires metabolism of the prodrug to propofol, which leads to a time delay between its administration and the appearance of its pharmacological effect. Its pharmacokinetic and pharmacodynamic characteristics are different to the original formula. Due to its formulation it does not cause pain on intravenous injection, does not lead to hyperlipidaemia or excess bacterial growth. Although it is currently unavailable in Spain, it has been approved by the FDA (American Food and Drug Administration) for sedation in controlled care in diagnostic and therapeutic procedures in adults. It must only be administered by personnel qualified to administer anaesthesia, and the patients must be monitored throughout the whole procedure.

Receptor specificity defines algogenic properties of propofol and fospropofol

BACKGROUND

Propofol-evoked injection site pain is not observed with fospropofol. We hypothesized that unlike propofol, fospropofol does not activate the irritant receptor, transient receptor potential 1 (TRPA1).

METHODS

We tested the hypothesis using electrophysiology and behavioral studies.

RESULTS

Our data demonstrate that propofol (100 μM) evokes an inward current only in TRPA1-expressing neurons. However, fospropofol (100 μM and 1 mM) is unable to evoke depolarizing currents in either TRPA1-positive or TRPA1-negative neurons. Both propofol and fospropofol produced general anesthesia.

CONCLUSIONS

The lack of algogenic activity in fospropofol is most likely the result of its inability to activate TRPA1 on nociceptors.

General anesthetic actions on GABA(A) receptors

General anesthetic drugs interact with many receptors in the nervous system, but only a handful of these interactions are critical for producing anesthesia. Over the last 20 years, neuropharmacologists have revealed that one of the most important target sites for general anesthetics is the GABA_A receptor. In this review we will discuss what is known about anesthetic – GABA_A receptor interactions.

Perspectives on the role of fospropofol in the monitored anesthesia care setting

Monitored anesthesia care (MAC) is a safe, effective, and appropriate form of anesthesia for many minor surgical procedures. The proliferation of outpatient procedures has heightened interest in MAC sedation agents. Among the most commonly used MAC sedation agents today are benzodiazepines, including midazolam, and propofol. Recently approved in the United States is fospropofol, a prodrug of propofol which hydrolyzes in the body by alkaline phosphatase to liberate propofol. Propofol liberated from fospropofol has unique pharmacological properties, but recently retracted pharmacokinetic (PK) and pharmacodynamic (PD) evaluations make it difficult to formulate clear conclusions with respect to fospropofol's PK/PD properties. In safety and efficacy clinical studies, fospropofol demonstrated dose-dependent sedation with good rates of success at doses of 6.5 mg/kg along with good levels of patient and physician acceptance. Fospropofol has been associated with less pain at injection site than propofol. The most commonly reported side effects with fospropofol are paresthesia and pruritus. Fospropofol is a promising new sedation agent that appears to be well suited for MAC sedation, but further studies are needed to better understand its PK/PD properties as well its appropriate clinical role in outpatient procedures.

Sedation: not quite that simple

The number of diagnostic and therapeutic interventions performed under sedation is growing rapidly. While providing patients with an improved experience secondary to anxiolysis, analgesia, and amnesia, sedation also puts them at risk for associated cardiorespiratory and other complications. Several medications are available for sedation, all of which have unique advantages and disadvantages. The combination of patient characteristics, procedural factors, and side effects associated with each medication places each patient at risk and therefore, vigilance during sedation cannot be overemphasized. Due vigilance includes proper monitoring, training, staffing, and equipment, all of which are essential to the safe delivery of sedation.

Sedation and Analgesia in Critically Ill Neurologic Patients

Critically ill neurologic patients can pose a challenge when it comes to providing sedation and analgesia, primarily with the balance of maintaining sedation to provide patient comfort while still allowing a neurological examination. Determination of the optimal agent requires assessment and understanding of the underlying requirement for sedation: provision of analgesia, anxiolysis, or treatment of delirium. Pharmacological options exist that can affect individual or multiple underlying sedation requirements. Numerous evaluation tools exist to monitor the efficacy of sedation as well as help clinicians titrate agents to predefined goals; these tools allow the safe administration of drugs that can otherwise have serious adverse effects. Sedation regimens must ultimately be individualized to each patient to account for differences in pharmacokinetics and dynamics of the various agents, and this is particularly true in sedating neurologically injured patients. The agents frequently used to provide sedation and analgesia in the critically ill neurologic patient will be reviewed.

Adverse drug events associated with the use of analgesics, sedatives, and antipsychotics in the intensive care unit

As critically ill patients frequently receive analgesics, sedatives, and antipsychotics to optimize patient comfort and facilitate mechanical ventilation, adverse events associated with the use of these agents can affect all organ systems and result in substantial morbidity and mortality. Although many of these adverse effects are common pharmacologic manifestations of the agent, and therefore frequently reversible, others are idiosyncratic and thus unexpected. The critically ill are more susceptible to adverse drug events than nonintensive care unit patients due to the high doses and long periods for which each of these agents are often administered, the frequent use of intravenous formulations that contain adjuvants that may lead to toxicity in some instances, and the high prevalence of end-organ dysfunction that affects the pharmacokinetic and pharmacodynamic response to therapy. This paper will review the most common and serious adverse drug events reported to occur with the use of sedatives, analgesics, and antipsychotics in the intensive care unit; highlight the pharmacokinetic, pharmacodynamic, and pharmacogenetic factors that can influence analgesic, sedative, and antipsychotic response and safety in the critically ill; and identify strategies that can be used to minimize toxicity with these agents.