Rocuronium-specific antibodies drive perioperative anaphylaxis but can also function as reversal agents in preclinical models

Neuromuscular blocking agents (NMBAs) relax skeletal muscles to facilitate surgeries and ease intubation but can lead to adverse reactions, including complications because of postoperative residual neuromuscular blockade (rNMB) and, in rare cases, anaphylaxis. Both adverse reactions vary between types of NMBAs, with rocuronium, a widely used nondepolarizing NMBA, inducing one of the longest rNMB durations and highest anaphylaxis incidences. rNMB induced by rocuronium can be reversed by the synthetic γ-cyclodextrin sugammadex. However, in rare cases, sugammadex can provoke anaphylaxis. Thus, additional therapeutic options are needed. Rocuronium-induced anaphylaxis is proposed to rely on preexisting rocuronium-binding antibodies. To understand the pathogenesis of rocuronium-induced anaphylaxis and to identify potential therapeutics, we investigated the memory B cell antibody repertoire of patients with suspected hypersensitivity to rocuronium. We identified polyclonal antibody repertoires with a high diversity among V(D)J genes without evidence of clonal groups. When recombinantly expressed, these antibodies demonstrated specificity and low affinity for rocuronium without cross-reactivity for other NMBAs. Moreover, when these antibodies were expressed as human immunoglobulin E (IgE), they triggered human mast cell activation and passive systemic anaphylaxis in transgenic mice, although their affinities were insufficient to serve as reversal agents. Rocuronium-specific, high-affinity antibodies were thus isolated from rocuronium-immunized mice. The highest-affinity antibody was able to reverse rocuronium-induced neuromuscular blockade in nonhuman primates with kinetics comparable to that of sugammadex. Together, these data support the hypothesis that antibodies cause anaphylactic reactions to rocuronium and pave the way for improved diagnostics and neuromuscular blockade reversal agents.

Mechanisms of human drug-induced anaphylaxis

Drug-induced anaphylaxis is a hyperacute reaction affecting multiple organs that can be of fatal consequence. Its incidence is increasing, consistent with a global increased sensitization to various allergens and drugs in the population. Few risk factors and mechanisms have been identified from human studies due to the rarity of anaphylactic events and their unpredictability. This systemic reaction is caused by the rapid release of a large range of functionally diverse mediators, including histamine and platelet-activating factor as the main drivers identified. Mechanisms defined from models of experimental anaphylaxis identify drug-specific antibodies of the IgE and IgG class that link the drug to antibody receptors on multiple cell types, causing their activation and mediator release. In the case of drugs with peculiar chemical structures, antibodies may not be necessary because drug-binding receptors, such as Mas-related G protein-coupled receptor member X2, have been identified. This review describes the complex reaction leading to drug-induced anaphylaxis that can involve various antibody classes, various cell types-including mast cells, neutrophils, platelets, basophils, macrophages, and monocytes-and their mediators and receptors that, importantly, can be activated alone or in association to participate in the severity of the reaction.

Advantages and pitfalls of clinical application of sugammadex

Sugammadex, a modified γ-cyclodextrin, is one of the drugs focused on in the anesthetic field because it provides rapid and complete reversal from neuromuscular blockade (NMB) by encapsulating rocuronium. Its introduction has revolutionized anesthesia practice because it is a safe, predictable, and reliable neuromuscular antagonist. Hence, its use has increased worldwide. Further, it has been in the spotlight for recovering from deep NMB in laparoscopic surgery and improving the surgical condition. Recently, studies have been conducted on the postoperative outcome after deep NMB and use of sugammadex in various clinical conditions. However, with increase in sugammadex use, reports regarding its complications are increasing. Appropriate dosing of sugammadex with quantitative neuromuscular monitoring is emphasized because under-dosing or over-dosing of sugammadex might be associated with unexperienced complications. Sugammadex is now leaping into an ideal reversal agent, changing the anesthesia practice.

Unrestricted and Restricted Access to Sugammadex and Side Effect Profile in a Teaching Hospital Centre for Year 2014- Database Audit Study

Background

Sugammadex is used for the rapid reversal of neuro muscular block. It was used on an unrestricted basis in our facility prior to July 2014 but has subsequently been restricted due to the removal of cost subsidies. Our aim is to determine the impact of restricting the use of Sugammadex on clinical outcomes.

Methods

A retrospective audit was conducted for the period January 1st to December 31st 2014. Sugammadex use was unrestricted during the first 6 months of this period and restricted over the following period. Patients who had endotracheal intubation for any surgery were included in the audit. Non- intubated patients, patients with incomplete data and patients who were intubated and transferred to the intensive care unit were excluded. The Operating Room Information System and medical records were used to obtain information on the operating theatre time, post-anesthesia care unit time and side effects such as postoperative nausea and vomiting, oxygen-de-saturation during recovery and anaphylaxis; Sugammadex usage and cost data obtained from the hospital pharmacy.

Results

1347 and 1302 patients were included for the unrestricted and restricted periods, respectively. There were no significant differences between the time periods with respect to patient characteristics (Age, ASA) or side effects (oxygen de-saturation, nausea). While mean time in theatre was similar across the time periods, mean recovery time was significantly longer during the restricted period (P < 0.0001). One case of anaphylaxis was reported during the restricted period while no cases occurred during the unrestricted period. Median Sugammadex dose was 200 mg and its usage dropped by 54% in the restricted time. The cost of sugammadex was $180 AUD and Neostigmine $1.80 AUD.

Conclusions

Though unrestricting Sugammadex reduced recovery time but has had minimal impact on other clinical outcomes. Neostigmine represents a cheaper alternative and its use remains standard practice in our facility.

Sugammadex: What do we Know and What do we Still Need to Know? A Review of the Recent (2013 to 2014) Literature

Since its launch in 2008, sugammadex has been considered one of the most significant developments in anaesthesia-related pharmacology. With almost 500 sugammadex-related publications and over nine million patient exposures worldwide, user experience and scientific data have grown exponentially. However, several important questions are yet to be answered. This article reviews the sugammadex-related literature in 2013 and 2014 to determine which of these questions have been answered more fully over the last 18 months and which questions require more information and research.

Hypersensitivity associated with sugammadex administration: a systematic review

Sugammadex is a drug used to reverse neuromuscular blockade induced by rocuronium or vecuronium. It has not yet been approved by the Food and Drug Administration in the USA due to concerns regarding hypersensitivity. The objective of this review was to identify similarities in the presentation of hypersensitivity reactions to sugammadex. A comprehensive search was performed in PubMed, Scopus and Web of Science for cases reporting hypersensitivity reactions to sugammadex. In addition, we contacted regulatory agencies and the company marketing the drug for unpublished reports. Reports were included if they were in English, primary investigations, lacked an alternative probable explanation for the reaction and included a comprehensive description of the hypersensitivity. We identified 15 cases of hypersensitivity following sugammadex administration. All cases that reported exact timing (14/15) occurred in 4 min or less. Most of the patients (11/15; 73%) met World Anaphylaxis Organization criteria for anaphylaxis. Awareness must be raised for the possibility of drug-induced hypersensitivity during the critical 5-min period immediately following sugammadex administration.