Chemical encapsulation of rocuronium by synthetic cyclodextrin derivatives: reversal of neuromuscular block in anaesthetized Rhesus monkeys †

Efficacy and safety of adamgammadex for reversing rocuronium-induced deep neuromuscular blockade: A multicenter, randomized, phase IIb study

The rapid reversal of deep neuromuscular blockade (NMB) is important but remains challenging. This study aimed to evaluate the efficacy and safety of adamgammadex versus sugammadex in reversing deep rocuronium-induced NMB. This multicenter, randomized, phase IIb study included 80 patients aged 18-64 years, American Society of Anesthesiologists (ASA) grade 1-2, undergoing elective surgery under general anesthesia with rocuronium. Patients were randomized to the adamgammadex 7, 8, and 9 mg/kg group or the sugammadex 4 mg/kg group. The primary efficacy variable was the time to recovery of train-of-four ratio (TOFr) to 0.9. The secondary efficacy variables were the time to recovery of TOFr to 0.7, antagonistic success rate of the recovery of TOFr to 0.9 within 5 min, and incidence rate of recurarization within 30 min after drug administration. The explorative efficacy variable was the time to recovery of the corrected TOFr to 0.9 (actual/baseline TOF ratio). Adamgammadex 7, 8, and 9 mg/kg and sugammadex 4 mg/kg groups did not significantly differ in all efficacy variables. Importantly, adamgammadex 9 mg/kg permitted reversal within a geometric mean of 2.9 min. According to the safety profile, adamgammadex achieved good tolerance and low incidence of drug-related adverse events compared with the 4 mg/kg sugammadex. Adamgammadex 7, 8, and 9 mg/kg facilitated rapid reversal of deep rocuronium-induced NMB and had good tolerance and low incidence of drug-related adverse events. Therefore, adamgammadex is a potential and promising alternative to sugammadex.

Sugammadex for reversal of rocuronium-induced neuromuscular blockade during alfaxalone anesthesia in dogs

OBJECTIVE

To investigate the reversal effect of sugammadex on neuromuscular blockade induced by a single bolus of rocuronium in dogs under alfaxalone anesthesia.

STUDY DESIGN

Randomized, prospective, crossover experimental study.

ANIMALS

A group of six adult Beagle dogs (three females and three males), weighing 11.3-15.8 kg and aged 6-8 years, were used.

METHODS

Dogs were anesthetized twice with a 1.25 times minimum infusion rate of alfaxalone, with a washout period of at least 14 days between experiments. Neuromuscular function was monitored using acceleromyography with train-of-four (TOF) stimulation of the peroneal nerve. After recording the control TOF ratio (TOFRC), rocuronium (0.5 mg kg-1) was administered intravenously. Subsequently, sugammadex (4 mg kg-1) or an equal volume of saline (control treatment) was administered intravenously when the TOF count returned from 0 to 1 after neuromuscular blockade. Time from rocuronium injection to TOF count = 0 (onset time), time from TOF count = 0 to TOF count = 1 (maximum blockade period), time of first twitch amplitude recovery from 0.25 to 0.75 (recovery index), and time from sugammadex or saline administration to TOF ratio/TOFRC ≥ 0.9 (recovery time) were recorded.

RESULTS

The onset time and maximum blockade duration did not differ between sugammadex treatment [1.2 (0.7-1.5) minutes and 9.9 (6.3-10.5) minutes, respectively] and control treatment [median (range); 1.0 (0.7-1.1) minutes and 9.9 (8.8-11.5) minutes, respectively] (p = 0.219 and 0.844, respectively). Recovery index was 0.5 (0.3-0.7) minutes in sugammadex treatment, which was shorter than that in control treatment [4.5 (3.7-4.9) minutes] (p = 0.031). Recovery time was 0.8 (0.5-2.8) minutes in sugammadex treatment, which was shorter than that in control treatment [10.5 (6.8-14.3) minutes] (p = 0.031).

CONCLUSIONS AND CLINICAL RELEVANCE

Rocuronium-induced neuromuscular blockade was effectively reversed by sugammadex in dogs anesthetized with alfaxalone.

Efficiency and Safety of the Selective Relaxant Binding Agent Adamgammadex Sodium for Reversing Rocuronium-Induced Deep Neuromuscular Block: A Single-Center, Open-Label, Dose-Finding, and Phase IIa Study

Background: Rapid reversal of neuromuscular block after surgery and anesthesia is often necessary. Here, we reported the primary efficacy and safety data from a phase IIa study on adamgammadex sodium, a newly developed modified γ-cyclodextrin derivative.

Methods: This was a phase IIa, single-center, randomized, open-label, and dose-finding study that enrolled 35 patients under general anesthesia who received the neuromuscular blocking agent rocuronium for induction and maintenance of neuromuscular blockade. The subjects were randomized to one of the five adamgammadex dose groups (2, 4, 6, 8, and 10 mg kg⁻¹) and to the 4 mg kg⁻¹ sugammadex group. Pharmacological efficacy was the recovery time from the start of adamgammadex or sugammadex administration to train-of-four (TOF) ratio ≥0.9, 0.8, and 0.7 among the different dose groups. Adverse events were recorded throughout the study.

Results: The efficacy in reversing deep neuromuscular block was the same between 4 mg kg⁻¹ sugammadex and adamgammadex. However, in the lowest dose groups of 2 and 4 mg kg⁻¹ adamgammadex, adequate reversal could not be achieved in all subjects. The recovery time of TOF ratio to 0.9, 0.8, and 0.7 was shorter in the adamgammadex 10 mg kg⁻¹ group than in the sugammadex 4 mg kg⁻¹ group. The average values of the TOF ratio after 3 min of administration of adamgammadex 8 and 10 mg kg⁻¹ and sugammadex 4 mg kg⁻¹ were >90%. There were no serious adverse events after the use of adamgammadex, and no subjects had to be withdrawn from the trial.

Conclusions: Adamgammadex enabled quick, predictable, and tolerable reversion of rocuronium-induced deep neuromuscular block in a dose-dependent manner. Adamgammadex doses of 6–10 mg kg⁻¹ might be the recommended dose range for further exploration of efficacy. Clinical Trial Registration: This study was registered at chictr.org.cn, identifier: ChiCTR2000038391.

Comparison of the effects of sugammadex and neostigmine on postoperative nausea and vomiting

BACKGROUND AND OBJECTIVES

The aim of our study is to compare the effects of sugammadex and neostigmine, used for neuromuscular blockage antagonism, on postoperative nausea and vomiting (PONV).

METHODS

Our study was completed with 98 ASA I-II risk patients undergoing endotracheal intubation under general anesthesia. At the end of the surgery patients were randomly divided into two groups given 2mgkg^-1 sugammadex (Group S) or 50μgkg^-1 neostigmine plus 0.2mgkg^-1 atropine (Group N). Monitoring and recording times were set as 1 hour postoperative and from 1-6, 6-12, and 12-24hours. The anti-emetic amounts administered were recorded.

RESULTS

In the first hour postoperative 13 patients in Group N (27%) and 4 in Group S (8%) were observed to have nausea and/or vomiting and the difference was statistically significant (p=0.0016). During the 24 hours of monitoring there was no significant difference in the incidence and severity of PONV (p>0.05), however the number of patients given ondansetron for PONV treatment in Group N was statistically significantly higher than the number in Group S (16 in Group N, 6 in Group S, p<0.011).

CONCLUSIONS

At the end of our study comparing neostigmine with sugammadex for neuromuscular blockage antagonism, we found use of sugammadex had lower incidence of PONV in the postoperative 1st hour and less anti-emetic use in 24 hours of monitoring.

Comparative study between sugammadex and neostigmine in neurosurgical anesthesia in pediatric patients

BACKGROUND

Postoperative recurarization remains a risk following the use of the conventional neuromuscular blocking agents. In addition, none of the commonly used reversal agents, such as neostigmine or edrophonium are capable of reliably reversing profound blockade. The present comparative and randomized study investigated the use of sugammadex for reversing profound neuromuscular blockade (NMB) in pediatric neurosurgical patients undergone posterior fossa tumor excision.

PATIENTS AND METHODS

Forty pediatric patients undergoing elective craniotomy for posterior fossa tumor excision were randomly divided into either of neostigmine or sugammadex group in which muscle relaxant was reversed at the end of anesthesia either with neostigmine 0.04 mg/kg added to atropine 0.02 mg/kg or sugammadex 4 mg/kg alone, respectively. The primary endpoint was the time from the administration of sugammadex or neostigmine to recovery of the train of four (TOF) ratio to 90% after rocuronium-induced neuromuscular block. Unpaired t-test was used to compare continuous variables between groups. Meanwhile, repeated ANOVA was used to detect intragroup differences.

RESULTS

Patients in sugammadex group attained a TOF ratio 90% in statistically shorter time (1.4 ± 1.2 min) than those in neostigmine group (25.16 ± 6.49 min) for reversal of the rocuronium. Mean arterial pressure and heart rate were significantly higher in neostigmine group at 2, 5 and 10 min after administration of the reversal agents and returned nonsignificantly different after that. With no recurarization in any patient throughout the study period.

CONCLUSION

Sugammadex rapidly and effectively reverses rocuronium-induced NMB in pediatric patients undergoing neurosurgery when administered at reappearance of T2 of TOF at dose 4 mg/kg.

Effects of sugammadex and rocuronium mast cell number and degranulation in rat liver

We investigated the effect of rocuronium- and sugammadex-induced mast cell increase and degranulation in rat portal triads. Forty-two rats, in six groups, received either rocuronium 1 mg.kg(-1); sugammadex 15 mg.kg(-1); sugammadex 100 mg.kg(-1); rocuronium 1 mg.kg(-1) and 5 min later, sugammadex 15 mg.kg(-1); rocuronium 1 mg.kg(-1) and 5 min later, sugammadex 100 mg.kg(-1); or isotonic saline. Total mast cell numbers were significantly higher with rocuronium only, than in all other groups (p<0.003), although in all active groups, the number was greater than the control. Total mast cell number was significantly higher with rocuronium and low-dose sugammadex compared with low-dose sugammadex only. The number of tryptase-positive mast cells with rocuronium only was significantly higher than in all other groups (p<0.003). Tryptase-positive mast cell numbers in both groups receiving both rocuronium and sugammadex were significantly higher compared with both groups receiving sugammadex only. Rocuronium increased mast cell numbers, and degranulation was mitigated by sugammadex. These results suggest that sugammadex may be beneficial in treatment of rocuronium-induced anaphylaxis.

Sugammadex: cyclodextrins, development of selective binding agents, pharmacology, clinical development, and future directions

Neuromuscular blocking agents are widely used in perioperative medicine to aid in endotracheal intubation, facilitate surgery, and in critical care/emergency medicine settings. Muscle relaxants have profound clinical uses in current surgical and intensive care and emergency medical therapy. This article reviews cyclodextrins, development of selective binding agents, clinical development, and future directions of sugammadex.

[Sugammadex, a novel drug for neuromuscular blockade reversal]

Significant progress in the management of aminosteroid nondepolarizing neuromuscular blockers will follow the introduction of sugammadex (Org 25969). Safety and rapid recovery of muscle force will improve and the adverse effects of acetylcholinesterase inhibitors will be avoided. Sugammadex is a modified gamma-cyclodextrin agent developed for the specific reversal of rocuronium and, to a lesser extent, vecuronium. This novel drug functions by means of encapsulation (chelation). Sugammadex was recently approved by the European Medicines Evaluation Agency and became available in Spain in 2009, leading to a series of changes related to patient safety and surgical conditions. We review the literature on sugammadex published to date.

Preclinical pharmacology of sugammadex

Since the introduction of nondepolarizing neuromuscular blocking agents, acetylcholinesterase inhibitors have been used to increase the speed of recovery from neuromuscular blockade. The major disadvantages of acetylcholinesterase inhibitors are their lack of activity against profound neuromuscular blockade and their activity outside the neuromuscular junction resulting in unwanted side effects, requiring cotreatment with a muscarinic antagonist. An alternative to acetylcholinesterase inhibitors is the encapsulating agent sugammadex. This agent has been specifically designed to encapsulate the steroidal neuromuscular blocking agents rocuronium and vecuronium. This review describes the effects of sugammadex in in vitro tissue and in vivo animal experiments. The encapsulation approach allows reversal of any degree of neuromuscular blockade because the dose of sugammadex can be adjusted to encapsulate sufficient neuromuscular blocking molecules to cause effective reversal. Because this interaction is a drug-drug interaction, reversal can be achieved very fast but is limited by the circulation time. Sugammadex is also effective against neuromuscular blockade under conditions with reduced acetylcholine release, which potentiate the action of neuromuscular blocking agents. Sugammadex does not cause cholinergic side effects, preventing the need of coadministration of muscarinic antagonists. Because of these properties, sugammadex has the potential to become a very useful drug for the management of neuromuscular blockade.

Reversal of rocuronium-induced (1.2 mg kg −1 ) profound neuromuscular block by accidental high dose of sugammadex (40 mg kg −1 ) †

Sugammadex is the first selective relaxant binding agent and reverses rocuronium-induced neuromuscular block. A case is reported in which a patient accidentally received a high dose of sugammadex (40 mg kg-1) to reverse a rocuronium-induced (1.2 mg kg-1) profound neuromuscular block. A fast and efficient recovery from profound neuromuscular block was achieved and no adverse events or other safety concerns were reported.

Sugammadex: Another Milestone in Clinical Neuromuscular Pharmacology

Sugammadex is a revolutionary investigational reversal drug currently undergoing Phase III testing whose introduction into clinical practice may change the face of clinical neuromuscular pharmacology. A modified gamma-cyclodextrin, sugammadex exerts its effect by forming very tight water-soluble complexes at a 1:1 ratio with steroidal neuromuscular blocking drugs (rocuronium > vecuronium >> pancuronium). During rocuronium-induced neuromuscular blockade, the IV administration of sugammadex creates a concentration gradient favoring the movement of rocuronium molecules from the neuromuscular junction back into the plasma, which results in a fast recovery of neuromuscular function. Sugammadex is biologically inactive, does not bind to plasma proteins, and appears to be safe and well tolerated. Additionally, it has no effect on acetylcholinesterase or any receptor system in the body. The compound's efficacy as an antagonist does not appear to rely on renal excretion of the cyclodextrin-relaxant complex. Human and animal studies have demonstrated that sugammadex can reverse very deep neuromuscular blockade induced by rocuronium without muscle weakness. Its future clinical use should decrease the incidence of postoperative muscle weakness, and thus contribute to increased patient safety. Sugammadex will also facilitate the use of rocuronium for rapid sequence induction of anesthesia by providing a faster onset-offset profile than that seen with 1.0 mg/kg succinylcholine. Furthermore, no additional anticholinesterase or anticholinergic drugs would be needed for antagonism of residual neuromuscular blockade, which would mean the end of the cardiovascular and other side effects of these compounds. The clinical use of sugammadex promises to eliminate many of the shortcomings in our current practice with regard to the antagonism of rocuronium and possibly other steroidal neuromuscular blockers.

A Randomized, Dose-Finding, Phase II Study of the Selective Relaxant Binding Drug, Sugammadex, Capable of Safely Reversing Profound Rocuronium-Induced Neuromuscular Block

BACKGROUND

The reversal of a deep neuromuscular blockade remains a significant clinical problem. Sugammadex, a modified gamma-cyclodextrin, encapsulates steroidal neuromuscular blocking drugs, promoting their rapid dissociation from nicotinic receptors. Sugammadex is the first drug that acts as a selective relaxant binding agent.

METHODS

We enrolled 50 patients into a Phase II dose-finding study of the efficacy and safety of sugammadex. Subjects, anesthetized with nitrous oxide and propofol, were randomized to one of two doses of rocuronium (0.6 or 1.2 mg/kg) and to one of five doses of sugammadex (0.5, 1.0, 2.0, 4.0, or 8.0 mg/kg). Neuromuscular monitoring was performed using the TOF Watch SX acceleromyograph. Recovery was defined as a train-of-four ratio > or =0.9. Sugammadex was administered during profound block when neuromuscular monitoring demonstrated a posttetanic count of one or two.

RESULTS

Reversal of neuromuscular block was obtained after administration of sugammadex in all but the lowest dose groups (0.5-1.0 mg/kg) where several subjects could not be adequately reversed. At the 2 mg/kg dose all patients were reversed with sugammadex, but there was significant variability (1.8-15.2 min). Patient variability decreased and speed of recovery increased in a dose-dependent manner. At the highest dose (8 mg/kg), mean recovery time was 1.2 min (range 0.8-2.1 min). No serious adverse events were reported during this trial.

CONCLUSIONS

Sugammadex was well tolerated and effective in rapidly reversing profound rocuronium-induced neuromuscular block. The mean time to recovery decreased with increasing doses. Profound rocuronium-induced neuromuscular block can be reversed successfully with sugammadex at doses >/=2 mg/kg.

Drug development in anaesthesia: industrial perspective

PURPOSE OF REVIEW

In this review, we summarize the new drugs in development in the anaesthesia field.

RECENT FINDINGS

There are some interesting approaches, including pro-drugs of propofol such as Aquavan (MGI Pharma, Bloomington, Minnesota, USA) and novel 'soft-drug' sedatives and hypnotics (e.g. CNS-7259X and TD-4756) as well as a novel approach to terminate the action of steroidal neuromuscular blockers (sugammadex). There is also significant activity in the field of novel analgesics. Particularly addressing the fields of sedatives, hypnotics and neuromuscular blockers, however, there is relatively little drug discovery activity currently. Part of the reason for this may be that the mechanisms of action of anaesthetics are not fully understood. This cannot be the whole story, however, since attractive new targets have recently been identified. For example, an agent with selective actions at the beta3-containing subunit of the gamma-amino butyric acid-A receptor is likely to have the hypnotic effects of propofol without the cardiac depressant side-effects.

SUMMARY

We consider the main reason for low activity is the perception in industry that there is little need for new drugs in anaesthesia because the needs are well addressed by existing agents. If this is not the case then anaesthesiologists need to be more effective in communicating their requirements.

Time course of action of sugammadex (Org 25969) on rocuronium-induced block in the Rhesus monkey, using a simple model of equilibration of complex formation

BACKGROUND

Reversal of neuromuscular block can be accomplished by chemical encapsulation of rocuronium by sugammadex (Org 25969), a synthetic gamma-cyclodextrin derivative. The present study determined the time course of the reversal action of sugammadex on rocuronium-induced block in the anaesthetized Rhesus monkey using train-of-four stimulation.

METHODS

A bolus injection of rocuronium 100 microg kg(-1) (about 1xED(90)) was given to determine the degree of neuromuscular block reached by this dose. After complete spontaneous recovery, a rapid bolus injection of sugammadex, 1 mg kg(-1), was given and at different time intervals (15, 30 or 60 min, in three different experiments) the effect of another rocuronium bolus injection of 100 microg kg(-1) was determined.

RESULTS

Injection of the first dose of rocuronium resulted in a mean neuromuscular block (depression of first twitch) of 93 (SEM=1.6)%. Fifteen minutes after injection of sugammadex the same rocuronium dose resulted in 17% (SEM=5.6) block. After 30 and 60 min these maximum blocks amounted to 49% (SEM=7.6) and 79% (SEM=4.2), respectively. The estimated half-life of sugammadex in Rhesus monkey is 30 (SEM=4.9) min.

CONCLUSIONS

The half-life of sugammadex (Org 25969), a new fast and efficient reversal agent for rocuronium-induced block, is relatively short in the Rhesus monkey, implying the possibility to perform neuromuscular block by rocuronium shortly after reversal of a prior block. In translation to the human situation differences in rocuronium sensitivity and kinetics should be taken into account.