Neurokinin-1 and novel serotonin antagonists for postoperative and postdischarge nausea and vomiting

The Application and Pharmaceutical Development of Etomidate: Challenges and Strategies

Etomidate is a synthetic imidazole anesthetic that exerts hypnotic effects by potentiating the action of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) or directly activating the anionic GABA (GABAA) receptor. It stands out among many anesthetics because of its multiple advantages, such as good hemodynamic stability and minimal inhibition of spontaneous respiration. However, its low water solubility and side effects, such as adrenal cortex inhibition and myoclonus, have limited the clinical application of this drug. To address these issues, extensive research has been conducted on the drug delivery of etomidate in recent decades, which has led to the emergence of different etomidate preparations. Despite so many etomidate preparations, so far some of the toxic side effects have not yet been effectively addressed. Herein we discuss the pharmaceutical design of etomidate that may resolve the above problem. We also propose targeted strategies for future research on etomidate preparations and discuss the feasibility of different administration routes and dosage forms to expand the application of this drug. Through this review, we hope to draw more attention to the potential of etomidate and its application challenges and provide valuable insights into the development of new etomidate preparations.

Olanzapine for the Prevention of Postdischarge Nausea and Vomiting after Ambulatory Surgery: A Randomized Controlled Trial

BACKGROUND

Postdischarge nausea and vomiting after ambulatory surgery is a common problem that is not adequately addressed in current practice. This prospective, randomized, double-blind, parallel-group, placebo-controlled study was designed to test the hypothesis that oral olanzapine is superior to placebo at preventing postdischarge nausea and vomiting.

METHODS

In a single-center, double-blind, randomized, placebo-controlled trial, the authors compared a single preoperative dose of olanzapine 10 mg to placebo, in adult female patients 50 years old or less, undergoing ambulatory gynecologic or plastic surgery with general anesthesia. All patients received standard antiemetic prophylaxis with dexamethasone and ondansetron. The primary composite outcome was nausea and/or vomiting in the 24 h after discharge. Secondary outcomes included severe nausea, vomiting, and side effects.

RESULTS

A total of 140 patients were randomized and evaluable. The primary outcome occurred in 26 of 69 patients (38%) in the placebo group and in 10 of 71 patients (14%) in the olanzapine group (relative risk, 0.37; 95% CI, 0.20 to 0.72; P = 0.003). Severe nausea occurred in 14 patients (20%) in the placebo group and 4 patients (6%) in the olanzapine group (relative risk, 0.28; 95% CI, 0.10 to 0.80). Vomiting occurred in eight patients (12%) in the placebo group and two patients (3%) in the olanzapine group (relative risk, 0.24; 95% CI, 0.05 to 1.10). The median score for sedation (scale 0 to 10, with 10 being highest) in the 24 h after discharge was 4 (interquartile range, 2 to 7) in the placebo group and 6 (interquartile range, 3 to 8) in the olanzapine group (P = 0.023).

CONCLUSIONS

When combined with ondansetron and dexamethasone, the addition of olanzapine relative to placebo decreased the risk of nausea and/or vomiting in the 24 hafter discharge from ambulatory surgery by about 60% with a slight increase in reported sedation.

Neurokinin-1 inhibitors in the prevention of nausea and vomiting from highly emetogenic chemotherapy: a network meta-analysis

A network meta-analysis of the comparative effectiveness of neurokinin 1 (NK-1) inhibitors in the prophylaxis of highly emetogenic chemotherapy induced nausea and vomiting has been conducted. Eligible studies included randomized trials evaluating aprepitant, fosaprepitant, netupitant (NEPA), casopitant and rolapitant containing regimens in the setting of highly emetogenic chemotherapy. Primary outcomes of interest include complete response (CR) and rate of no significant nausea. After preclusion of ineligible studies, 19 studies were included in the final analysis. The majority of the regimens containing NK-1 inhibitors (including NEPA, aprepitant/palonosetron (palono)/dexamethasone (dexa), casopitant/granisetron (grani) or ondansetron (ondan)/dexa, aprepitant/ondan/dexa) are better than regimens not containing them (palono/dexa, ondan/dexa, grani/dexa) in terms of achieving a CR in the overall phase. Moreover, casopitant/grani or ondan/dexa and aprepitant/grani or ondan/dexa are better than rolapitant/ondan or grani/dexa in terms of CR achievement [odds ratio (OR) 1.62, 95% credible interval (CrI) 1.14-2.23, and OR 1.28, 95% CrI 1.01-1.59, respectively]. Taking into consideration the limitations of cross-trial comparisons, regimens containing neurokinin inhibitors are associated with higher CR rates than regimens not containing them. Moreover, casopitant and aprepitant regimens seem to be more effective than rolapitant regimens.

Postoperative nausea and vomiting: A simple yet complex problem

Postoperative nausea and vomiting (PONV) is one of the complex and significant problems in anesthesia practice, with growing trend toward ambulatory and day care surgeries. This review focuses on pathophysiology, pharmacological prophylaxis, and rescue therapy for PONV. We searched the Medline and PubMed database for articles published in English from 1991 to 2014 while writing this review using “postoperative nausea and vomiting, PONV, nausea-vomiting, PONV prophylaxis, and rescue” as keywords. PONV is influenced by multiple factors which are related to the patient, surgery, and pre-, intra-, and post-operative anesthesia factors. The risk of PONV can be assessed using a scoring system such as Apfel simplified scoring system which is based on four independent risk predictors. PONV prophylaxis is administered to patients with medium and high risks based on this scoring system. Newer drugs such as neurokinin-1 receptor antagonist (aprepitant) are used along with serotonin (5-hydroxytryptamine subtype 3) receptor antagonist, corticosteroids, anticholinergics, antihistaminics, and butyrophenones for PONV prophylaxis. Combination of drugs from different classes with different mechanism of action are administered for optimized efficacy in adults with moderate risk for PONV. Multimodal approach with combination of pharmacological and nonpharmacological prophylaxis along with interventions that reduce baseline risk is employed in patients with high PONV risk.

Postdischarge Nausea and Vomiting Remains Frequent After Le Fort I Osteotomy Despite Implementation of a Multimodal Antiemetic Protocol Effective in Reducing Postoperative Nausea and Vomiting

PURPOSE

To assess the prevalence of postdischarge nausea and vomiting (PDNV) after Le Fort I osteotomy with and without the use of a multimodal antiemetic protocol shown to decrease postoperative nausea and vomiting (PONV).

MATERIALS AND METHODS

Consecutive patients undergoing Le Fort I osteotomy with or without additional procedures at a single academic institution formed the intervention cohort for an institutional review board-approved prospective clinical trial with a retrospective comparison group. The intervention cohort was managed with a multimodal antiemetic protocol. The comparison group consisted of consecutive patients who underwent similar surgical procedures at the same institution before protocol implementation. All patients were asked to complete a postdischarge diary documenting the occurrence of nausea and vomiting. Those who completed the diaries were included in this analysis. Data were analyzed with the Fisher exact test and the Wilcoxon rank sum test. A P value less than .05 was considered significant.

RESULTS

Diaries were completed by 85% of patients in the intervention group (79 of 93) and 75% of patients in the comparison group (103 of 137). Patients in the intervention (n = 79) and comparison (n = 103) groups were similar in the proportion of patients with validated risk factors for PDNV, including female gender, history of PONV, age younger than 50 years, opioid use in the postanesthesia care unit (PACU), and nausea in the PACU (P = .37). The prevalence of PDNV was unaffected by the antiemetic protocol. After discharge, nausea was reported by 72% of patients in the intervention group and 60% of patients in the comparison group (P = .13) and vomiting was reported by 22% of patients in the intervention group and 29% of patients in the comparison group (P = .40).

CONCLUSION

Modalities that successfully address PONV after Le Fort I osteotomy might fail to affect PDNV, which is prevalent in this population. Future investigation will focus on methods to minimize PDNV.

Comparison of vestipitant with ondansetron for the treatment of breakthrough postoperative nausea and vomiting after failed prophylaxis with ondansetron

BACKGROUND

Postoperative nausea and vomiting (PONV) is common; ondansetron is often used as prophylaxis or for breakthrough episodes. Vestipitant is a neurokinin 1 (NK-1) receptor antagonist that is effective for prophylaxis, but its efficacy for treating established PONV is unknown. This study was performed to evaluate the efficacy and safety of vestipitant, compared with ondansetron for the treatment of breakthrough PONV in patients who had already received prophylactic ondansetron before surgery.

METHODS

A multicentre, randomized, single-blind (sponsor-open), parallel group study. Of 527 surgical patients, 130 (25%) had breakthrough PONV and were equally randomized to one of six i.v. doses of vestipitant (4-36 mg) or ondansetron 4 mg. The primary endpoint was the rate of patients exhibiting complete response, defined as no emesis and no further rescue medication from 10 min after infusion up to 24 h after surgery or hospital discharge.

RESULTS

All doses of vestipitant were non-inferior to ondansetron in treating PONV after failed prophylaxis with ondansetron. However, vestipitant was superior to ondansetron in decreasing episodes of postoperative emesis and retching. The complete response rate analysis using Bayesian model averaging indicated that no vestipitant dose was superior to ondansetron. Nausea numerical rating scale scores and the times-to-PONV or discharge were similar between the vestipitant and ondansetron treatment groups.

CONCLUSIONS

Although overall efficacy was non-inferior between vestipitant and ondansetron, the rate of emesis was lower with vestipitant. These data suggest that vestipitant may be a useful agent for the management of PONV, similar to other NK-1 antagonists.

CLINICAL TRIAL REGISTRATION

NCT01507194.

Multimodal protocol reduces postoperative nausea and vomiting in patients undergoing Le Fort I osteotomy

PURPOSE

To assess the impact of a multimodal antiemetic protocol on postoperative nausea and vomiting (PONV) after Le Fort I osteotomy.

MATERIALS AND METHODS

Consecutive patients undergoing Le Fort I osteotomy with or without additional procedures at a single academic institution were recruited as the intervention cohort for an institutional review board-approved prospective clinical trial with a retrospective comparison group. The intervention cohort was managed with a multimodal antiemetic protocol, including total intravenous anesthesia; prophylactic ondansetron, steroids, scopolamine, and droperidol; gastric decompression at surgery end; opioid-sparing analgesia; avoidance of morphine and codeine; prokinetic erythromycin; and fluids at a minimum of 25 mL/kg. The comparison group consisted of consecutive patients from a larger study who underwent similar surgical procedures before protocol implementation. Data, including occurrence of PONV, were extracted from medical records. Data were analyzed in bivariate fashion with the Fisher exact and Wilcoxon rank-sum tests. Logistic regression was used to compare the likelihood of nausea and vomiting in the 2 cohorts after controlling for demographic and surgical characteristics. A P value less than .05 was considered significant.

RESULTS

The intervention (n = 93) and comparison (n = 137) groups were similar in gender (58% and 65% female patients; P = .29), race (72% and 71% Caucasian; P = .85), age (median, 19 and 20 years old; P = .75), proportion of patients with known risk factors for PONV (P = .34), percentage undergoing bimaxillary surgery (60% for the 2 groups), and percentage for whom surgery time was longer than 180 minutes (63% and 59%; P = .51). Prevalence of postoperative nausea was significantly lower in the intervention group than in the comparison group (24% vs 70%; P < .0001). Prevalence of postoperative vomiting was likewise significantly lower in the intervention group (11% vs 28%; P = .0013). The likelihood that patients in the comparison group would develop nausea was 8.9 and that for vomiting was 3.7 times higher than in the intervention group.

CONCLUSION

This multimodal protocol was associated with substantially decreased prevalence of PONV in patients undergoing Le Fort I osteotomy.

Intravenous Pharmacokinetics, Local Tolerability, and Hemolysis of an SBE7-β-Cyclodextrin Formulation of the Neurokinin-1 Receptor Antagonist Vestipitant

Vestipitant is a potent and selective neurokinin 1 (NK-1) receptor antagonist that was investigated as a potential treatment for post-operative nausea and vomiting (PONV). A previous mannitol-based formulation of vestipitant was associated with hemolytic activity in preclinical studies. In an effort to reduce the hemolytic potential and develop an IV formulation of vestipitant that could be administered more rapidly, an IV formulation containing sulfobutylether-7-beta-cyclodextrin (SBE7-β-CD, Captisol™) was developed and tested in a phase 1 clinical study. This was a randomized, single-blind (subjects and investigator—blinded, sponsor-unblinded), placebo controlled, dose escalation study in healthy subjects in which 7 cohorts of 8 subjects per cohort received SBE7-β-CD -based vestipitant (2 mg/mL) or placebo (saline) in a 3:1 ratio (active:placebo) at different doses and infusion rates. The results demonstrated the ability to infuse up to 48 mg vestipitant in a 2 mg/mL formulation over 30 seconds with no evidence of hemolytic effects. Cohorts of subjects at lower doses and longer infusion duration (>1 minute) reported more AEs related to the infusion site than those at the higher doses and faster infusion rates.

Consensus guidelines for the management of postoperative nausea and vomiting

The present guidelines are the most recent data on postoperative nausea and vomiting (PONV) and an update on the 2 previous sets of guidelines published in 2003 and 2007. These guidelines were compiled by a multidisciplinary international panel of individuals with interest and expertise in PONV under the auspices of the Society for Ambulatory Anesthesia. The panel members critically and systematically evaluated the current medical literature on PONV to provide an evidence-based reference tool for the management of adults and children who are undergoing surgery and are at increased risk for PONV. These guidelines identify patients at risk for PONV in adults and children; recommend approaches for reducing baseline risks for PONV; identify the most effective antiemetic single therapy and combination therapy regimens for PONV prophylaxis, including nonpharmacologic approaches; recommend strategies for treatment of PONV when it occurs; provide an algorithm for the management of individuals at increased risk for PONV as well as steps to ensure PONV prevention and treatment are implemented in the clinical setting.

Neurochemical mechanisms and pharmacologic strategies in managing nausea and vomiting related to cyclic vomiting syndrome and other gastrointestinal disorders

Nausea and vomiting are common gastrointestinal complaints which could be triggered by stimuli in both the peripheral and central nervous systems. They may be considered as defense mechanisms when threatening toxins/agents enter the gastrointestinal tract or there is excessive retention of gastrointestinal contents due to obstruction. The pathophysiology of nausea and vomiting is complex and much still remains unknown. Therefore, treatments are restricted or ineffective in many cases. Nausea and vomiting with functional etiologies including cyclic vomiting syndrome are challenging in gastroenterology. In this article, we review potential pathways, neurochemical transmitters, and their receptors which are possibly involved in the pathophysiology of nausea and vomiting including the entity cyclic vomiting syndrome.

Opioid induced nausea and vomiting

Opioids are broad spectrum analgesics that are an integral part of the therapeutic armamentarium to combat pain in the palliative care population. Unfortunately, among the adverse effects of opioids that may be experienced along with analgesia is nausea, vomiting, and/or retching. Although it is conceivable that in the future, using combination agents (opioids combined with agents which may nullify emetic effects), currently nausea/vomiting remains a significant issue for certain patients. However, there exists potential current strategies that may be useful in efforts to diminish the frequency and/or intensity of opioid-induced nausea/vomiting (OINV).

Cisplatin causes over-expression of tachykinin NK(1) receptors and increases ERK1/2- and PKA- phosphorylation during peak immediate- and delayed-phase emesis in the least shrew (Cryptotis parva) brainstem

Scant information is available regarding the effects of cisplatin on the expression profile of tachykinin NK(1) receptors and downstream signaling during cisplatin-induced emesis. Cisplatin causes peak early- and delayed-phase emesis in the least shrew at 1-2 and 33 h post-injection. To investigate the expression profile of NK(1) receptor during both emetic phases, we cloned the cDNA corresponding to a ~700 base pairs of mRNA flanked by two stretches of nucleotides conserved among different species and demonstrated that the shrew NK(1) receptor nucleotide sequence shares ~90% sequence identity with the human NK(1) receptor. Of the 12 time-points tested, significant increases in expression levels of NK(1) receptor mRNA in the shrew brainstem occurred at 2 and 28 h post-cisplatin injection, whereas intestinal NK(1) receptor mRNA was increased at 28 h. Shrew brainstem and intestinal substance P mRNA levels also tended to increase during the two phases. Furthermore, expression levels of NK(1) receptor protein were significantly increased in the brainstem at 2, 8, and 33 h post-cisplatin. No change in brainstem 5-HT(3) receptor protein expression was observed. The temporal enhancements in NK(1) receptor protein expression were mirrored by significant increases in the phosphorylation status of the brainstem ERK1/2 at 2, 8, and 33 h post-cisplatin. Phosphorylation of PKA significantly increased at 33rd and 40th hour. Our results indicate associations between cisplatin's peak immediate- and delayed-phase vomiting frequency with increased: (1) expression levels of NK(1) receptor mRNA and its protein level, and (2) downstream NK(1) receptor-mediated phosphorylation of ERK1/2 and PKA signaling.

Management of postoperative nausea and vomiting: how to deal with refractory PONV

Postoperative nausea and vomiting (PONV) constitutes a significant factor in delaying recovery after anesthesia and impairing patient satisfaction. To date the prevention of PONV using single or multimodal interventions, usually based on risk assessment, has gained some popularity. However, comprehensive implementation and knowledge transfer of the latest accomplishments in the prevention of PONV is only slowly being adopted into clinical practice. Preventing PONV is the first step in avoiding refractory PONV. This review comments mainly on the management of refractory PONV. As the data on coping with established PONV are rare, further studies focusing on treatment of established PONV are needed.

Development of aprepitant, the first neurokinin-1 receptor antagonist for the prevention of chemotherapy-induced nausea and vomiting

Chemotherapy can be a life-prolonging treatment for many cancer patients, but it is often associated with profound nausea and vomiting that is so distressing that patients may delay or decline treatment to avoid these side effects. EMEND (aprepitant) is the first and only neurokinin-1 (NK-1) receptor antagonist available on the market for the prevention of acute and delayed chemotherapy-induced nausea and vomiting (CINV). Aprepitant acts centrally at NK-1 receptors in vomiting centers within the central nervous system to block their activation by substance P released as an unwanted consequence of chemotherapy. By controlling nausea and vomiting, EMEND helps improve patients' daily living and their ability to complete multiple cycles of chemotherapy. The development of aprepitant included a novel nanoparticle formulation to optimize oral absorption and innovative chemistry to discover a prodrug form suitable for intravenous administration to improve compliance and convenience for healthcare professionals and cancer patients.