Drug interactions with aprepitant or fosaprepitant: Review of literature and implications for clinical practice

Postoperative nausea and vomiting: is the big little problem becoming a smaller little problem?

Postoperative nausea and vomiting (PONV) has been identified as a big (very frequently encountered) little (not linked to life-threatening outcomes) problem. Traditional drugs (dexamethasone, droperidol or similar drugs, serotonin receptor antagonists) each have significant but limited effect, leading to an increasing use of combination therapies. High-risk patients, often identified through use of risk scoring systems, remain with a significant residual risk despite combining up to three traditional drugs. A recent correspondence in this Journal proposes the use of up to five anti-emetic drugs to further minimise the risk. This disruptive strategy was supported by favourable initial results, absence of side-effects and lower acquisition costs of the added new drugs (aprepitant and palonosetron) because of their recent loss of patent protection. These results are provocative and hypothesis generating, but need confirmation and do not warrant immediate changes in clinical practice. The next steps will also necessitate wider implementation of protocols protecting patients from PONV and a search for additional drugs and techniques aimed at treating established PONV.

Chronic pruritus: from pathophysiology to drug design

Pruritus, the most common symptom in dermatology, is an innate response capable of protecting skin against irritants. Nonetheless, when it lasts more than six weeks it is assumed to be a chronic pathology having a negative impact on people's lives. Chronic pruritus (CP) can occur in common and rare skin diseases, having a high prevalence in global population. The existing therapies are unable to counteract CP or are associated with adverse effects, so the development of effective treatments is a pressing issue. The pathophysiological mechanisms underlying CP are not yet completely dissected but, based on current knowledge, involve a wide range of receptors, namely neurokinin 1 receptor (NK1R), Janus kinase (JAK), and transient receptor potential (TRP) ion channels, especially transient receptor potential vanilloid 1 (TRPV1) and transient receptor potential ankyrin 1 (TRPA1). This review will address the relevance of these molecular targets for the treatment of CP and molecules capable of modulating these receptors that have already been studied clinically or have the potential to possibly alleviate this pathology. According to scientific and clinical literature, there is an increase in the expression of these molecular targets in the lesioned skin of patients experiencing CP when compared with non-lesioned skin, highlighting their importance for the development of potential efficacious drugs through the design of antagonists/inhibitors.

Long-Term Daily Administration of Aprepitant for the Management of Intractable Nausea and Vomiting in Children With Life-Limiting Conditions: A Case Series

BACKGROUND

Nausea and vomiting is a common symptom in children through their end of life journey. Aprepitant, a NK-1 antagonist, has become a potent weapon in the fight against chemo-induced nausea and vomiting. However, its use in palliative care for refractory nausea and vomiting has been limited due to limited experience or evidence of continuous use. Emerging evidence suggests that continuous use is not only safe, but also effective in patients with nausea and vomiting refractory to multiple lines of antiemetic therapy.

METHODS

We conducted a single centre retrospective chart review of children receiving care from a specialist palliative care team who were given continuous daily aprepitant for nausea and vomiting and were unresponsive to at least two prior lines of antiemetic therapy. Parental reports of the impact of nausea on mobility and feeding were used as proxy efficacy markers. Duration of effect and toxicity was also evaluated.

RESULTS

Ten children (eight with cancer as a primary diagnosis and two with noncancer diagnoses) received continuous aprepitant and all showed resolution of nausea and vomiting and an increased ability to mobilize and tolerate feeds. No adverse events noted.

CONCLUSION

Our review suggests a role for aprepitant in management of refractory nausea and vomiting, demonstrating safety and efficacy. This case series is the first report of aprepitant use in this manner in the paediatric palliative care setting.

Liquid formulation of ifosfamide increased risk of encephalopathy: A case-control study in a pediatric population

BACKGROUND

Several clusters of encephalopathy occurred after the market change from Holoxan® (ifosfamide lyophilized powder) to Ifosfamide EG® (liquid formulation) and justified a formal survey in 2015. In June 2016, the regulatory authority decided to apply a precautionary measure in reducing the shelf life of Ifosfamide EG® at 7 months. One-year study from spontaneous reports lead to suspect a potential residual risk. Due to the many limitations associated with spontaneous notifications, we performed a multicentric observational study, aiming to better explore this pharmacovigilance signal.

METHODS

We performed a case-control study in pediatric oncology Departments of 25 university hospitals between July 1st, 2016 and July 1st, 2018. All children (<18 y.o.) receiving liquid formulation or lyophilized powder formulation during the study period were included. Patients with at least one occurrence of encephalopathy were considered as cases. Logistic regression model was used to estimate the odds ratio of encephalopathy between exposure groups.

RESULTS

During the study period, 52 cases and 495 controls were included. A residual over-risk of encephalopathy was associated with ifosfamide 7-month shelf-life liquid formulation compared to lyophilized powder (adjusted OR 1.91, 95% CI: 1.03-3.53).

CONCLUSIONS

Observed difference does not seem to be related to the pathology treated, the doses used, the co-medications, a meningeal localization and/or an irradiation of the central nervous system. This study confirms data from spontaneous reports that led to the precautionary measure for the liquid formulation. Even if the risk of encephalopathy seems reduced, our study suggests the persistence of a residual risk of encephalopathy associated with liquid formulation compared to the lyophilized powder.

Efficacy, Safety And Feasibility Of Antiemetic Prophylaxis With Fosaprepitant, Granisetron And Dexamethasone In Pediatric Patients With Hemato-Oncological Malignancies

Background

Chemotherapy-induced nausea and vomiting (CINV) are a major burden for patients undergoing emetogenic chemotherapy. International guidelines recommend an antiemetic prophylaxis with corticosteroids, 5-HT₃R-antagonists and NK₁R-antagonists. The NK₁R-antagonist fosaprepitant has shown favorable results in pediatric and adult patients. There is little pediatric experience with fosaprepitant.

Methods

This non-interventional observation study analyzed 303 chemotherapy courses administered to 83 pediatric patients with a median age of 9 years (2-17 years), who received antiemetic prophylaxis either with fosaprepitant and granisetron with or without dexamethasone (fosaprepitant group/FG; n=41), or granisetron with or without dexamethasone (control group/CG; n=42), during moderately (CINV risk 30-90%) or highly (CINV risk>90%) emetogenic chemotherapy. The two groups' results were compared with respect to the safety and efficacy of the antiemetic prophylaxis during the acute (0-24hrs after chemotherapy), delayed (>24-120hrs after chemotherapy) and both CINV phases. Laboratory and clinical adverse events were compared between the two cohorts.

Results

Adverse events were not significantly different in the two groups (p>0.05). Significantly fewer vomiting events occurred during antiemetic prophylaxis with fosaprepitant in the acute (23 vs 142 events; p<0.0001) and the delayed (71 vs 255 events; p<0.0001) CINV phase. In the control group, the percentage of chemotherapy courses with vomiting was significantly higher during the acute (24%/FG vs 45%/CG; p<0.0001) and delayed CINV phase (28%/FG vs 47%/CG; p=0.0004). Dimenhydrinate (rescue medication) was administered significantly more often in the CG, compared to the FG (114/FG vs 320/CG doses; p<0.0001). Likewise, in the control group, dimenhydrinate was administered in significantly more (p<0.0001) chemotherapy courses during the acute and delayed CINV phases (79 of 150; 52.7%), compared to the fosaprepitant group (45 of 153; 29.4%).

Conclusion

Antiemetic prophylaxis with fosaprepitant and granisetron with or without dexamethasone was well tolerated, safe and effective in pediatric patients. However, larger prospective trials are needed to evaluate these findings.

Nightmares and hallucinations with aprepitant and opium powder: a suspected drug-drug interaction

Polypharmacy of elderly oncology patients and fragmented medication management are well-known risk factors for drug-drug interactions (DDIs). These interactions can occur among antineoplastic, ongoing chronic treatment(s) and chemotherapy-associated treatments, like antiemetics. Clinically relevant interactions based on enzyme- or transporter-inhibition phenomena of active drugs can increase the frequency of their DDIs. We describe a strongly suspected elderly cancer patient's DDI between aprepitant and opium powder in the context of an irinotecan-based regimen manifested by nightmares and visual hallucinations. We discuss this DDI's hypothetical pharmacological mechanisms and management.

Pharmacokinetics, Safety, and Tolerability of Rolapitant Administered Intravenously Following Single Ascending and Multiple Ascending Doses in Healthy Subjects

Rolapitant is a selective and long-acting neurokinin-1 receptor antagonist approved in an oral formulation in combination with dexamethasone and a 5-hydroxytryptamine type 3 receptor antagonist for the prevention of delayed chemotherapy-induced nausea and vomiting in adults. The pharmacokinetic and safety profiles of intravenous (IV) rolapitant were evaluated in two open-label, phase 1 trials in healthy subjects. Single ascending dose (SAD) and multiple ascending dose studies were conducted in one trial (PR-11-5012-C), and a supratherapeutic SAD study was conducted in a separate trial (PR-11-5022-C). In the SAD and supratherapeutic studies, rolapitant maximum plasma concentration, area under the plasma drug concentration-time curve (AUC) from time zero to time of last measured concentration, and AUC from time zero to infinity increased dose-proportionally following single IV infusions of 18 to 270 mg. In the multiple ascending dose study, following 10 daily IV infusions of rolapitant 18, 36, or 54 mg, the mean day 10:day 1 maximum concentration ratio was 1.97, 1.52, and 2.07, respectively, and the mean day 10:day 1 ratio of AUC from 0 to 24 hours was 4.30, 4.59, and 5.38, respectively, indicating drug accumulation over time. Across all studies, rolapitant was gradually eliminated from plasma, with a half-life of 135-231 hours. Rolapitant was safe and well tolerated across all studies, with no serious or severe rolapitant-related treatment-emergent adverse events. The most common rolapitant-related treatment-emergent adverse events were headache, dry mouth, and dizziness, which were predominantly mild in severity. Overall, the pharmacokinetic and safety profiles of IV rolapitant were consistent with those of the oral formulation.

Antiemetic Guidelines: Using Education to Improve Adherence and Reduce Incidence of CINV in Patients Receiving Highly Emetogenic Chemotherapy

BACKGROUND

With the development of increasingly effective antiemetic regimens, guideline adherence can prevent 70%-80% of chemotherapy-induced nausea and vomiting (CINV) in patients with cancer.

OBJECTIVES

This quality improvement project aims to increase rates of adherence to national guidelines and, ultimately, decrease rates of CINV experienced by patients receiving highly emetogenic chemotherapy.

METHODS

A retrospective chart analysis was performed. In-person education was provided to staff nurses and advanced practice providers on guidelines, followed by a survey immediately postintervention and again at three months.

FINDINGS

Prior to the intervention, 49% of patients were found to experience CINV, with only 7% receiving guideline-appropriate prophylaxis. At three months, 37% of patients experienced CINV, with 22% receiving appropriate prophylaxis.

Influence of aprepitant on the pharmacodynamics and pharmacokinetics of gliclazide in rats and rabbits

Background

Concomitant drug administration is a general phenomenon in patients with chronic diseases such as diabetes mellitus. Among the currently available oral antidiabetic drugs, gliclazide is a commonly prescribed drug considering its multiple benefits in diabetic patients. Aprepitant is a commonly prescribed antiemetic drug which is mainly metabolized by CYP3A4, reported to have modest inductive and inhibitory effects on CYP2C9 and CYP3A4, respectively. Since gliclazide is metabolized by CYP2C9 (major) and CYP3A4 (minor), it is very difficult to predict the influence of aprepitant and its metabolic interaction with gliclazide. Considering the complexity associated with the combination of aprepitant and gliclazide, this study was designed to evaluate the influence of aprepitant on the pharmacodynamics (PD) and pharmacokinetics (PK) of gliclazide in animal models.

Methods

The PD interaction studies were conducted in both rodent (normal and alloxan-induced diabetic rats) and non-rodent (rabbits) animal models (n = 6) while the PK interaction study was conducted in normal rabbits (n = 6). An extrapolated human therapeutic oral dose of gliclazide, aprepitant and their combination were administered to rats and rabbits with 7 days washout between each treatment. For the multiple-dose interaction study, the same groups were administered with an interacting drug (aprepitant) for 7 days and then the combination of aprepitant and gliclazide on the 8th day. From the collected animal blood samples, blood glucose (by Glucose-Oxidase/Peroxidase method), insulin (by ELISA method) and gliclazide concentration levels (by HPLC method) were determined. Non-compartmental PK analysis was conducted by Phoenix WinNonlin software to determine the PK parameters of gliclazide. Statistical analysis was performed by student’s paired t-test.

Results

The pharmacodynamic activity (blood glucose reduction and insulin levels) of gliclazide was significantly (p < 0.05) influenced by aprepitant in normal and diabetic condition without any convulsions in animals. There was a significant (p < 0.05) increase in concentration levels and Area Under the Curve of gliclazide while significant (p < 0.05) decrease in clearance levels of gliclazide in rabbits. The PK interaction with gliclazide is relatively more with the multiple dose treatment of aprepitant over single dose treatment.

Conclusion

In combination, aprepitant significantly influenced the pharmacodynamic activity of gliclazide in animal models. Considering this, care should be taken when this combination is prescribed for the clinical benefit in diabetic patients.

Influence of aprepitant and localization of the patch on fentanyl exposure in patients with cancer using transdermal fentanyl

Background and Objectives

The cutaneous fentanyl patch is widely used to treat continuous pain in patients with cancer. Its use is hampered by a high inter- and intrapatient pharmacokinetic variability. Factors that influence this pharmacokinetic variability are largely unclear. The aim of these studies was to test if common patient variables, i) the use of the moderate CYP3A4 inhibitor aprepitant and ii) the localization of the fentanyl patch (upper arm versus thorax) influence systemic exposure to fentanyl in patients with cancer using a transdermal fentanyl patch.

Results

The AUC_{0-6 h} of fentanyl was 7.1% (95% CI: -28% to +19%) lower if patients concurrently used aprepitant, compared to the period when patients used fentanyl only. The AUC_{0-4 h} of fentanyl was 7.4% (95% CI: -22% to +49%) higher when the cutaneous fentanyl patch was applied to the upper arm compared to application at the thorax.

Conclusions

Neither the concurrent use of aprepitant, nor the localization of the fentanyl patch showed a statistically significant influence on fentanyl pharmacokinetics.

Methods

We performed two prospective cross-over pharmacokinetic intervention studies. Both studies had two eight-day study periods. At day 8 of each study period blood samples were collected for pharmacokinetic analysis. In each study 14 evaluable patients were included.

Fosaprepitant Dimeglumine: A Review in the Prevention of Nausea and Vomiting Associated with Chemotherapy

Intravenous fosaprepitant dimeglumine (Emend(®) for injection, IVEmend(®); henceforth referred to as fosaprepitant) is a prodrug of and is rapidly converted to the antiemetic aprepitant, and is approved in several countries worldwide (as part of an antiemetic regimen) for the prevention of nausea and vomiting associated with highly and moderately emetogenic chemotherapy (HEC and MEC). This narrative review discusses the pharmacological properties of intravenous fosaprepitant and its clinical efficacy and tolerability in the prevention of nausea and vomiting associated with HEC and MEC. In large, randomized phase III clinical trials, a single intravenous dose of fosaprepitant 150 mg was an effective and generally well tolerated addition to an antiemetic regimen that included dexamethasone and a serotonin 5-HT3 receptor antagonist in adult cancer patients undergoing treatment with HEC or MEC. It was also noninferior to an oral aprepitant-based regimen in adult cancer patients undergoing HEC treatment. The tolerability profile of a fosaprepitant-based regimen was typical of that in patients receiving emetogenic chemotherapy, and adverse events were generally consistent with those observed with an aprepitant-based regimen. Fosaprepitant provides a useful addition to antiemetic therapy regimens.

Fosaprepitant dimeglumine for the management of chemotherapy-induced nausea and vomiting: patient selection and perspectives

Chemotherapy-induced nausea and vomiting (CINV) is a debilitating side effect of antineoplastic agents. Several treatment regimens are used to address this problem. Fosaprepitant is a neurokinin-1 receptor blocker used in the prevention and treatment of CINV, especially for moderately and severely emetogenic chemotherapy. It is highly effective in the treatment of delayed CINV. Data from previous studies show that fosaprepitant is noninferior to aprepitant in the management of CINV. Fosaprepitant is given as a single-dose intravenous infusion, thus offering better patient compliance. The dose-limiting side effect of fosaprepitant is an infusion-related reaction, ranging from pain at the infusion site to thrombophlebitis. This side effect has been reported with coadministration of anthracycline agents.