Pharmacokinetics and Safety of Ebastine in Patients with Impaired Hepatic Function Compared with Healthy Volunteers

Ebastine impairs metastatic spread in triple-negative breast cancer by targeting focal adhesion kinase

We sought to investigate the utility of ebastine (EBA), a second-generation antihistamine with potent anti-metastatic properties, in the context of breast cancer stem cell (BCSC)-suppression in triple-negative breast cancer (TNBC). EBA binds to the tyrosine kinase domain of focal adhesion kinase (FAK), blocking phosphorylation at the Y397 and Y576/577 residues. FAK-mediated JAK2/STAT3 and MEK/ERK signaling was attenuated after EBA challenge in vitro and in vivo. EBA treatment induced apoptosis and a sharp decline in the expression of the BCSC markers ALDH1, CD44 and CD49f, suggesting that EBA targets BCSC-like cell populations while reducing tumor bulk. EBA administration significantly impeded BCSC-enriched tumor burden, angiogenesis and distant metastasis while reducing MMP-2/-9 levels in circulating blood in vivo. Our findings suggest that EBA may represent an effective therapeutic for the simultaneous targeting of JAK2/STAT3 and MEK/ERK for the treatment of molecularly heterogeneous TNBC with divergent profiles. Further investigation of EBA as an anti-metastatic agent for the treatment of TNBC is warranted.

A Critical Review of Physicochemical Properties and Analytical Methods Applied to Quantitative Determination of Ebastine

Allergic diseases are the most common conditions in children and the second most frequent in adults. Currently, there are two well-defined generations of antihistamines, those belonging to first generation, with inherent side effects such as drowsiness and anticholinergic effects. These side effects are often attributed to their high lipophilicity and high affinity for brain H1 receptors. The ebastine is a modern antihistaminic drug belongs to the second generation and has lower lipophilicity, which diminish the undesirable side effects. To ensure the quality, efficacy, safety, and effectiveness of ebastine drug products, efficient and reliable analytical methods are mandatory. Besides official compendial methods, alternative methods are often developed and used in quality control of pharmaceuticals as well as in pharmacokinetic studies. In this work, we present a critical review on characteristics, physicochemical properties, and analytical methods applied in the analysis of ebastine.

Pharmacokinetics in special populations

Pharmacokinetics are typically dependent on a variety of physiological variables (e.g., age, ethnicity, or pregnancy) or pathological conditions (e.g., renal and hepatic insufficiency, cardiac dysfunction, obesity, etc.). The influence of some of these conditions has not always been thoroughly assessed in the clinical studies of antiallergic drugs. However, the knowledge of the physiological grounds of the pharmacokinetics can provide some insight for predicting the potential alterations and guiding the initial prescription strategies. It is important to recognize that both pharmacokinetic and pharmacodynamic differences between populations should be considered. The available information on drugs used for the therapy of allergic diseases is reviewed in this chapter.

Ebastine in allergic rhinitis and chronic idiopathic urticaria

Histamine is a key mediator in the development of allergy symptoms, and oral H(1)-antihistamines are among the most widely used treatments for symptomatic relief in conditions such as allergic rhinitis and chronic urticaria. Ebastine is a second-generation antihistamine which has been shown to be an effective treatment for both seasonal and perennial allergic rhinitis. In controlled clinical trials in adult and adolescent patients with allergic rhinitis, ebastine 10 mg once-daily improved symptoms to a significantly greater extent than placebo and to a similar extent as loratadine 10 mg and cetirizine 10 mg (both once-daily), while ebastine 20 mg proved to be more effective than these two comparator antihistamines. In addition, ebastine was significantly more effective than placebo at relieving the symptoms of chronic idiopathic urticaria. Ebastine provides efficacy throughout the 24-h dosing interval with once-daily administration and clinical benefit is seen from the first day of treatment. Small studies have found beneficial effects for ebastine in patients with other disorders, including cold urticaria, dermographic urticaria, atopic asthma, mosquito bites and (in combination with pseudoephedrine) the common cold. In addition to the regular ebastine tablet, a fast-dissolving tablet (FDT) formulation, which disintegrates in the mouth without the aid of a drink, is also available. It has been shown to be bioequivalent to the regular tablet, and to be significantly more effective than desloratadine at reducing histamine-induced cutaneous wheals. A number of patient surveys demonstrated that the majority of individuals who tried the fast-dissolving formulation reported it to be convenient for use, fast-acting and preferred it to their previous antihistamine medication. Perhaps most importantly, a large proportion of patients indicated that they would prefer to use this new formulation in the future. Ebastine has a rapid onset of action and it can be administered once-daily, with or without food. Dose modifications are not needed in elderly patients, or in those with renal or mild to moderate hepatic impairment. Ebastine is generally well-tolerated, and clinical studies showed that at usual therapeutic doses of 10 and 20 mg once-daily, it had no clinically relevant adverse effects on cognitive function and psychomotor performance or on cardiovascular function. In conclusion, ebastine is an effective and generally well-tolerated treatment for allergic rhinitis and chronic idiopathic urticaria. In addition to the regular tablet formulation, ebastine is available as a FDT, providing a treatment option that is particularly convenient for patients.

Comparison of inhibition of cutaneous histamine reaction of ebastine fast-dissolving tablet (20 mg) versus desloratadine capsule (5 mg): a randomized, double-blind, double-dummy, placebo-controlled, three-period crossover study in healthy, nonatopic adults

BACKGROUND

Ebastine is a long-acting, second-generation, selective histamine H1-receptor antagonist. A fast-dissolving tablet formulation of ebastine has been developed at 10- and 20-mg doses, with the intention of facilitating administration to patients experiencing problems with swallowing, including those confined to bed and elderly people, as well as those who may need to use ebastine when they do not have easy access to water to aid swallowing a tablet.

OBJECTIVES

This study was conducted to assess the pharmacodynamic effects (ie, inhibition of wheal response to cutaneous histamine challenge, and subjective assessments of itching, flare, and pain) and tolerability of the fast-dissolving 20-mg ebastine tablet formulation compared with desloratadine 5-mg capsule and placebo. Acceptability and convenience of the fast-dissolving tablet were also evaluated.

METHODS

This double-blind, double-dummy, randomized, placebo-controlled, 3-period crossover study was conducted at the Drug Research Centre, Department of Clinical Pharmacology, the Hospital de la Santa Creu i Sant Pau, Barcelona, Spain. Healthy, nonatopic, white adults aged 18 to 40 years were randomly assigned to 1 of 6 study sequences: ABC, ACB, BAC, BCA, CBA, or CAB, where A was the ebastine fast-dissolving 20-mg tablet, B was the desloratadine 5-mg capsule, and C was placebo. All study drugs were given orally once daily (8-9 AM) on days 1 to 5 of each study period. Study periods were separated by a washout period of 7 to 10 days. Histamine skin-prick test (SPT) challenge was performed before study drug administration on day 1 of each period (baseline), and then every 20 minutes for 2 hours after administration and again after 24 hours. The final SPT was 24 hours after the day-5 dose was administered. The primary end point was inhibition o f the histamine response, defined as the percentage reduction from baseline wheal area 24 hours after 5 days of administration. Subjective symptoms (itching, flare, and pain) were assessed by subjects using visual analog scales every 20 minutes for 2 hours after administration on day 1. At study end, acceptability (taste, convenience, and overall preference) of the fast-dissolving tablet and capsule formulations were assessed using a questionnaire completed by subjects. Tolerability was assessed using physical examination, laboratory analysis, physician questioning, and spontaneous reporting.

RESULTS

Thirty-six people were randomized (22 women, 14 men; mean [SD] age, 24.7 [4.1] years; mean [SD] weight, 63.2 [9.9] kg); 35 completed the study (1 subject was lost to follow-up after the second study period). Unadjusted mean (SD) wheal areas 24 hours after dose administration on day 5 were 72.9 (29.5), 115.0 (32.1), and 146.7 (32.2) mm(2), for ebastine, desloratadine, and placebo, respectively. Mean differences in reduction from baseline in wheal area were 29.0% for ebastine versus desloratadine and 43.7% for ebastine versus placebo (both, P < 0.001). Corresponding unadjusted mean (SD) wheal areas 24 hours after administration of the first dose on day 1 were 76.5 (22.5), 128.9 (24.0), and 140.5 (33.1) mm(2). Mean itching, flare, and pain ratings were not significantly different between study drugs. Results from the preference questionnaire indicated that the majority (80%) preferred the ebastine fast-dissolving tablet to the desloratadine capsule (and hypothetically also to tablets and oral solution, which were not tested in this study). Ninety-seven percent of subjects were of the opinion that compliance in the home setting would be facilitated by the fas-tdissolving tablet formulation. Fourteen adverse events (AEs) were reported in 9 (25%) volunteers; all AEs were of mild or moderate intensity. Five occurred with ebastine 20 mg (intermittent somnolence, back pain, pharyngolaryngeal pain, pyrexia, and oral pain [1 patient each]), 5 occurred with desloratadine 5 mg (asthenia [2 patients] and dry mouth, somnolence, and back pain [1 patient each]), and 4 occurred with placebo (diarrhea [2 patients] and somnolence and headache [1 patient each]). The relationship with the study drugs was considered unlikely in 6 cases and possible in the remaining 8 cases. An additional AE (back pain) occurred during a washout period.

CONCLUSIONS

In this small study in healthy, nonatopic white subjects, inhibition of the response to histamine injection was significantly greater with the ebastine 20-mg fast-dissolving tablet compared with desloratadine 5-mg capsule and placebo after 1 and 5 days of administration. Most participants expressed an overall preference for the fast-dissolving tablet formulation over capsules. All study drugs were well tolerated.

A comparison of ebastine 10 mg fast-dissolving tablet with oral desloratadine and placebo in inhibiting the cutaneous reaction to histamine in healthy adults

BACKGROUND AND OBJECTIVE

Ebastine is a long-acting, second-generation selective histamine H(1) receptor antagonist. The pharmacodynamics of a new 10mg fast-dissolving tablet (FDT) oral lyophilisate tablet formulation of ebastine were compared with those of desloratadine and placebo following histamine skin intradermal test challenge. The acceptability of the FDT was also assessed.

METHODS

This was a double-blind, double-dummy, placebo-controlled, randomised, crossover, three-period study in 36 healthy adults. The histamine skin intradermal test (0.05 mL of 100 microg/mL solution) was administered into volunteers' forearms, and wheal area was measured 15 minutes later. Ebastine 10 mg FDT, desloratadine 5mg capsule or placebo were given on days 1-5. On day 1, a skin intradermal test was performed at baseline, then every 20 minutes for 2 hours after administration and at 24 hours. The final skin intradermal test was on day 6, 24 hours after the last drug dose. Subjective symptoms (itching, heat and pain) were assessed on day 1 for 2 hours following the first drug dose. There was a washout period of 7-10 days between treatments. At study end, the acceptability of the new ebastine formulation was evaluated using a questionnaire.

RESULTS

Ebastine 10mg inhibited the wheal response to histamine significantly more than desloratadine 5 mg or placebo 24 hours after 5 days' treatment (mean difference between treatments in wheal area reduction from baseline: 26.7%, p < 0.0001; 46.9%, p < 0.0001, respectively), and after 24 hours on day 1 (mean difference: 16.2%, p = 0.0082; 34.2%, p < 0.0001, respectively). The results with desloratadine were also significantly different from placebo on day 1 and after 5 days, but less than with ebastine after 5 days (difference, desloratadine vs placebo: 20.2%, p = 0.0001). No differences in itching, heat and pain were observed between the treatments. Most participants (70%) preferred the FDT, and all reported that it made adherence easier.

CONCLUSION

Ebastine 10 mg FDT demonstrated significantly superior antihistamine activity compared with desloratadine and placebo.

MR arthrography of the shoulder, hip, and wrist: evaluation of contrast dynamics and image quality with increasing injection-to-imaging time

OBJECTIVE

The purpose of our study was to investigate the contrast dynamics and the relationship between visualization of intraarticular structures and time elapsed between intraarticular injection of contrast agent and MRI in symptomatic patients referred for MR arthrography of the shoulder, hip, and wrist.

SUBJECTS AND METHODS

Our local ethics committees and the national drug administration approved this multicentric study. We prospectively studied 11 shoulders, 11 hips, and 10 wrists. After the intraarticular gadolinium injection, patients underwent a baseline MR arthrography protocol (time point [TP] 1) and subsequent MRI at another four time points (TP 2-TP 5) up to 240 minutes. The course of contrast-to-noise ratio (CNR) over time was calculated. Three observers assessed the degree of visualization of different intraarticular structures and the overall image quality at each time point using a 3-point scale and a 5-point scale, respectively.

RESULTS

For all joints, CNR measurements showed peak CNR at TP 1 (21 minutes) and TP 2 (45 minutes) with a subsequent, near-logarithmic decline of CNR values over time. Visualization of different anatomic structures decreased over time. Overall image quality was insufficient for diagnostic purposes at TP 3 (96 minutes) in three (27%) of 11 shoulders and in three (27%) of 11 hips. In two (20%) of 10 wrists, image quality was insufficient at TP 2 (45 minutes).

CONCLUSION

For MR arthrography, the degree of visualization of intraarticular structures depends on the time elapsed between contrast injection and MRI. MR arthrography of the shoulder and hip should be performed within 90 minutes, and MR arthrography of the wrist should be performed within 45 minutes, after intraarticular injection.

The effect of CYP2J2, CYP3A4, CYP3A5 and the MDR1 polymorphisms and gender on the urinary excretion of the metabolites of the H-receptor antihistamine ebastine: a pilot study

AIMS

To determine the effect of gender and the genetic polymorphisms of CYP2J2, CYP3A4, CYP3A5 and MDR1 on the urinary excretion of the H(1) antihistamine ebastine in healthy subjects.

METHODS

Eighty-nine Caucasians were studied. The presence of polymorphisms in genes known to be involved in ebastine metabolism and transport (CYP2J2*2,*3,*4,*6,*7, CYP3A4*1B, CYP3A5*3, *6 and MDR1(ABCB1)(C3435T)) was assessed by means of PCR-restriction fragment length polymorphism and sequencing methods. Genotype was correlated with the urinary excretion of the main ebastine metabolites (desalkylebastine and carebastine) under basal conditions and after administration of grapefruit juice.

RESULTS

Women excreted statistically greater amounts of desalkylebastine in urine (mean +/- SD (95% confidence intervals, 95% CI), 23.0 +/- 19.5 (18.1, 27.9) micromol) than men (12.4 +/- 11.0 (7.9, 16.9)), (mean difference: 10.6 (2.4, 18.7), P < 0.005). The CYP2J2, CYP3A4 and CYP3A5 analysed polymorphisms did not greatly affect ebastine metabolite excretion. The MDR1(C3435T) polymorphism was found to affect both the urinary excretion of the active metabolite carebastine (32.3 +/- 18.3 (23.1, 41.4), 22.8 +/- 14.7 (18.6, 27.0) and 21.5 +/- 15.3 (14.7, 28.3) for CC, CT and TT carriers, respectively; P < 0.05) and the grapefruit juice-induced inhibition of its transport/formation (mean fold-decrease +/- SD (95% CI), 1.5 +/- 0.8 (1.0, 2.0), 1.1 +/- 0.9 (0.7, 1.4) and 0.9 +/- 0.4 (0.6, 1.2) for CC, CT and TT carriers, respectively; P = 0.01).

CONCLUSIONS

Gender and the presence of the MDR1(C3435T) polymorphism both influence the excretion of ebastine metabolites in urine.

Characterization of Ebastine, Hydroxyebastine, and Carebastine Metabolism by Human Liver Microsomes and Expressed Cytochrome P450 Enzymes: Major Roles for CYP2J2 and CYP3A

Ebastine undergoes extensive metabolism to form desalkylebastine and hydroxyebastine. Hydroxyebastine is subsequently metabolized to carebastine. Although CYP3A4 and CYP2J2 have been implicated in ebastine N-dealkylation and hydroxylation, the enzyme catalyzing the subsequent metabolic steps (conversion of hydroxyebastine to desalkylebastine and carebastine) have not been identified. Therefore, we used human liver microsomes (HLMs) and expressed cytochromes P450 (P450s) to characterize the metabolism of ebastine and that of its metabolites, hydroxyebastine and carebastine. In HLMs, ebastine was metabolized to desalkyl-, hydroxy-, and carebastine; hydroxyebastine to desalkyl- and carebastine; and carebastine to desalkylebastine. Of the 11 cDNA-expressed P450s, CYP3A4 was the main enzyme catalyzing the N-dealkylation of ebastine, hydroxyebastine, and carebastine to desalkylebastine [intrinsic clearance (CL(int)) = 0.44, 1.05, and 0.16 microl/min/pmol P450, respectively]. Ebastine and hydroxyebastine were also dealkylated to desalkylebastine to some extent by CYP3A5. Ebastine hydroxylation to hydroxyebastine is mainly mediated by CYP2J2 (0.45 microl/min/pmol P450; 22.5- and 7.5-fold higher than that for CYP3A4 and CYP3A5, respectively), whereas CYP2J2 and CYP3A4 contributed to the formation of carebastine from hydroxyebastine. These findings were supported by chemical inhibition and kinetic analysis studies in human liver microsomes. The CL(int) of hydroxyebastine was much higher than that of ebastine and carebastine, and carebastine was metabolically more stable than ebastine and hydroxyebastine. In conclusion, our data for the first time, to our knowledge, suggest that both CYP2J2 and CYP3A play important roles in ebastine sequential metabolism: dealkylation of ebastine and its metabolites is mainly catalyzed by CYP3A4, whereas the hydroxylation reactions are preferentially catalyzed by CYP2J2. The present data will be very useful to understand the pharmacokinetics and drug interaction of ebastine in vivo.

A review of the second-generation antihistamine ebastine for the treatment of allergic disorders

Ebastine is a once-daily, non-sedating, selective, long-acting, second-generation antihistamine. The use of ebastine is indicated in patients suffering from intermittent and persistent allergic rhinitis and chronic idiopathic urticaria. Ebastine 10 mg/day, appears as effective as other second-generation antihistamines, such as cetirizine and loratadine. Ebastine 20 mg/day is indicated in patients with moderate and severe allergic symptoms. No cardiovascular effects of ebastine are described, although there is a pharmacokinetic interaction when ketoconazole or macrolides are co-administered. Ebastine has no relevant effects on the psychomotor performance. Even with ebastine 20 mg/day skilled performance does not appear to be impaired. Furthermore, ebastine 5-10 and 2.5 mg, appears to be efficient and can be used safely in children 6-11 and 2-5 years of age, respectively. Ebastine appears to be a safe, effective and well-tolerated second-generation antihistamine in the treatment of allergic rhinitis and chronic idiopathic urticaria.