Twenty-four-hour activity and consistency of activity of levocetirizine and desloratadine in the skin

Lack of Clinical Relevance of Bilastine-Food Interaction in Healthy Volunteers: A Wheal and Flare Study

INTRODUCTION

The aim of this study was to compare the pharmacodynamic activity of bilastine administered under fasting and fed conditions in healthy volunteers.

METHODS

In this randomized, open-label, two-period, crossover study involving 24 healthy subjects, once-daily oral bilastine 20 mg was administered for 4 days under fasting and fed conditions, with a 7-day washout period. Bilastine plasma concentrations were measured for 24 h after the first and fourth doses in each period. Pharmacodynamic activity was assessed by wheal and flare surface inhibition and subjective assessment of itching, after intradermal injection of histamine 5 μg.

RESULTS

When administered under fed versus fasting conditions, exposure to bilastine 20 mg decreased (mean maximum plasma concentration and area under the curve from time 0 to 24 h decreased by 34.27% and 32.72% [day 1], respectively, and 33.08% and 28.87% [day 4]). Despite this, the antihistaminic effect of bilastine 20 mg was not altered by food. On day 1, as assessed by wheal and flare surface inhibition, the maximum effect and duration of action of bilastine did not differ to a significant extent between fasting and fed conditions, with only a short 30-min delay in the onset of wheal inhibition. At steady state (day 4), bilastine's pharmacodynamic effects were not significantly affected under fasting or fed conditions.

CONCLUSION

The pharmacokinetic interaction of bilastine with food does not imply a significant reduction of its peripheral antihistaminic efficacy. Despite a slight delay in onset of action on the first treatment day, the global clinical efficacy of bilastine is not affected by coadministration with food.

British Association of Dermatologists guidelines for the management of people with chronic urticaria 2021

The overall objective of the guideline is to provide up-to-date, evidence-based recommendations for the management of urticaria. The document aims to: offer an appraisal of all relevant literature up to March 2020, focusing on any key developments address important, practical clinical questions relating to the primary guideline objective provide guideline recommendations and if appropriate research recommendations The guideline is presented as a detailed review with highlighted recommendations for practical use in primary, secondary and tertiary care, in addition to an updated Patient Information Leaflet (PIL; available on the BAD Skin Health Information website, https://www.skinhealthinfo.org.uk/a-z-conditions-treatments/).

Efficacy of Desloratadine and Levocetirizine in Patients with Cedar Pollen-Induced Allergic Rhinitis: A Randomized, Double-Blind Study

BACKGROUND

No comparative study of antihistamines that differ in structural system has been conducted in allergic rhinitis.

OBJECTIVE

This was a randomized, double-blind, crossover comparative study to verify the efficacy of antihistamines that differ in structural system.

METHODS

A total of 50 patients with moderate or more severe Japanese cedar pollen-induced allergic rhinitis were randomized to receive either placebo, desloratadine 5 mg (a tricyclic), or levocetirizine 5 mg (a piperazine). One dose of the study drug was orally administered at 9 pm on the day before a pollen exposure test, which was performed for 3 h (9 a.m. to 12 p.m.) to assess symptoms in an environmental challenge chamber (ECC). Nasal and ocular symptoms were compared at an airborne pollen level of 8,000 grains/m3. The primary endpoint was mean total nasal symptom score (TNSS) from 120 to 180 min in the ECC. Subjects with a difference of ≥1 in TNSS between 2 drugs were extracted to the relevant drug-responsive group.

RESULTS

The difference in TNSS from placebo was -2.42 (p < 0.0001) with levocetirizine and -1.66 (p < 0.01) with desloratadine, showing that both drugs were significantly more effective than placebo in controlling symptoms, but with no statistically significant difference between the 2 drugs. There were 12 subjects in the desloratadine-responsive group and 24 subjects in the levocetirizine-responsive group, with no contributor to response was detected.

CONCLUSION

Levocetirizine tended to control nasal symptoms more effectively than desloratadine. However, the response to each antihistamine varied among individuals and the predictors to the response are unknown.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN ID: UMIN000029653.

Pharmacology of antihistamines

H1-antihistamines, the mainstay of treatment for urticaria, were developed from anticholinergic drugs more than 70 years ago. They act as inverse agonists rather than antagonists of histamine H1-receptors which are members of the G-protein family. The older first generation H1-antihistamines penetrate readily into the brain to cause sedation, drowsiness, fatigue and impaired concentration and memory causing detrimental effects on learning and examination performance in children and on impairment of the ability of adults to work and drive. Their use should be discouraged. The newer second-generation H1-antihistamines are safer, cause less sedation and are more efficacious. Three drugs widely used for symptomatic relief in urticaria, desloratadine, levocetirizine and fexofenadine are highlighted in this review. Of these levocetirizine and fexofenadine are the most potent in humans in vivo. However, levocetirizine may cause somnolence in susceptible individuals, whereas fexofenadine has a relatively short duration of action and may be required to be given twice daily for all round daily protection. Although desloratadine is less potent, it has the advantages of rarely causing somnolence and having a long duration of action.

Comparison of effects of 5 and 10 mg oral desloratadine and levocetirizine on histamine-induced wheal and flare response in healthy volunteers

BACKGROUND

Levocetirizine and desloratadine are mostly used as H1-antihistamines in the treatment of allergic disease in 5 and 10 mg doses.

OBJECTIVE

In this study, the efficacy of single oral dosages of 5 and 10 mg desloratadine and levocetirizine were compared by using histamine-induced wheal and flare reactions.

METHODS

Eighty healthy volunteers were randomized for four double-blinded treatment with desloratadine 5 and 10 mg and levocetirizine 5 and 10 mg. Wheal and flare responses were produced by histamine. Measurements were performed just before the ingestion of antihistamines (baseline) and afterward at 30, 60, 240 min and 24 h. The values obtained for each antihistamine were compared with baseline values.

RESULTS

It was found that except the flare reactions at 30th min, levocetirizine 5 and 10 mg suppressed histamine-induced wheal and flare reactions more than desloratadine 5 and 10 mg did. There were not any significant differences between desloratadine 5 and 10 mg in all periods. Levocetirizine 10 mg suppressed wheal and flare reactions significantly more than levocetirizine 5 mg only at 24th h.

CONCLUSION

In this study, it was observed that levocetirizine 5 and 10 mg had a higher activity than desloratadine 5 and 10 mg.

H(1)-antihistamines and urticaria: how can we predict the best drug for our patient?

Urticaria, and especially chronic spontaneous urticaria (CSU), is a difficult condition to treat. Consequently, clinicians need to use the best H(1)-antihistamines currently available and the pharmaceutical industries need to keep developing H(1)-antihistamines that are more effective than the ones we have today. To do this we need to be able to compare the clinical efficacy of both established and new drugs. Obviously, the ideal way to do this is to use head-to-head studies in CSU. However, such studies are extremely expensive and, in the case of novel molecules, have ethical and logistical problems. Consequently, we need to have predictive models. Although determination of Ki, an indicator of the in vitro potency of an H(1)-antihistamine, may help in the initial selection of candidate molecules, the large differences in volume of distribution and tissue accumulation in humans, precludes this from being a good predictor of clinical efficacy in CSU. From the data reviewed in this article, especially the direct comparative data of desloratadine and levocetirizine in weal and flare studies and CSU, weal and flare response would appear to be the best indicator we have of effectiveness of H(1)-antihistamines in clinical practice. However, it must be pointed out that the conclusion is, essentially, based on detailed comparisons of two drugs in studies sponsored by pharmaceutical companies. Consequently, to confirm the conclusions of this review, a multicentre study independent from the influence of pharmaceutical companies should be commissioned to compare the speed of onset and effectiveness of desloratadine, fexofenadine and levocetirizine in chronic spontaneous urticaria and against histamine-induced weal and flare responses in the same patients so that we have a clear understanding of the predictive value of our models.

Pharmacology of antihistamines

This article reviews the molecular biology of the interaction of histamine with its H1-receptor and describes the concept that H1-antihistamines are not receptor antagonists but are inverse agonists i.e. they produce the opposite effect on the receptor to histamine. It then discourages the use of first-generation H1-antihistamines in clinical practice today for two main reasons. First, they are less effective than second generation H1-antihistamines. Second, they have unwanted side effects, particularly central nervous system and anti-cholinergic effects, and have the potential for causing severe toxic reactions which are not shared by second-generation H1-antihistamines. There are many efficacious and safe second-generation H1-antihistamines on the market for the treatment of allergic disease. Of the three drugs highlighted in this review, levocetirizine and fexofenadine are the most efficacious in humans in vivo. However, levocetirizine may cause somnolence in susceptible individuals while fexofenadine has a relatively short duration of action requiring twice daily administration for full all round daily protection. While desloratadine is less efficacious, it has the advantages of rarely causing somnolence and having a long duration of action. Lastly, all H1-antihistamines have anti-inflammatory effects but it requires regular daily dosing rather than dosing 'on-demand' for this effect to be clinically demonstrable.

Pharmacology of antihistamines

This article reviews the molecular biology of the interaction of histamine with its H₁-receptor and describes the concept that H₁-antihistamines are not receptor antagonists but are inverse agonists i.e. they produce the opposite effect on the receptor to histamine. It then discourages the use of first-generation H₁-antihistamines in clinical practice today for two main reasons. First, they are less effective than second generation H₁-antihistamines. Second, they have unwanted side effects, particularly central nervous system and anti-cholinergic effects, and have the potential for causing severe toxic reactions which are not shared by second-generation H₁-antihistamines. There are many efficacious and safe second-generation H₁-antihistamines on the market for the treatment of allergic disease. Of the three drugs highlighted in this review, levocetirizine and fexofenadine are the most efficacious in humans in vivo. However, levocetirizine may cause somnolence in susceptible individuals while fexofenadine has a relatively short duration of action requiring twice daily administration for full all round daily protection. While desloratadine is less efficacious, it has the advantages of rarely causing somnolence and having a long duration of action. Lastly, all H₁-antihistamines have anti-inflammatory effects but it requires regular daily dosing rather than dosing 'on-demand' for this effect to be clinically demonstrable.

Levocetirizine: a modern H1-antihistamine for the treatment of allergic rhinitis

Levocetirizine is the latest of the H(1)-antihistamines indicated for adults and children (as young as 2 years old) suffering from allergic rhinitis and chronic idiopathic urticaria. Currently, it is the only therapy registered for treatment of persistent allergic rhinitis, as defined by the Allergic Rhinitis & its Impact on Asthma guidelines. Pharmacologic studies have shown levocetirizine to have a more favorable pharmacokinetic/pharmacodynamic profile than other commonly employed H(1)-antihistamines. This reflects its superiority in controlling the symptoms of seasonal, perennial and persistent allergic rhinitis in well-controlled trials. Clinical trials and postmarketing surveillance have indicated that levocetirizine is safe and well tolerated, and leads to clinically significant improvements in the quality of life of patients. It is also reported to reduce comorbidities as well as overall treatment costs when administered continuously over the longterm.

Suppression of histamine- and allergen-induced skin reactions: comparison of first- and second-generation antihistamines

BACKGROUND

Nonsedating antihistamines (nsAHs) are recommended as first-line therapeutics for the treatment of mast cell-driven disorders, including allergic rhinitis and urticaria. However, their superiority over first-generation AHs (fgAHs) has recently been called into question, mainly because of the lack of supporting head-to-head therapeutic studies.

OBJECTIVE

To compare the effects of 3 modem nsAHs with those of the fgAH hydroxyzine on histamine- and allergen-induced skin reactions in a controlled, double-blind, clinical trial.

METHODS

Skin prick tests with histamine and Dermatophagoides pteronyssinus extract were performed before and 4 hours after treatment with hydroxyzine, 25 mg; desloratadine, 5 mg; epinastine, 20 mg; fexofenadine, 120 mg; or placebo. Wheal and erythema development was evaluated by digital photography and planimetric analyses.

RESULTS

The nsAHs prevented the development of positive reactions to histamine in only 10% to 20% of all individuals tested (n = 75). In contrast, more than 50% of all hydroxyzine-treated individuals showed negative test reactions to histamine (ie, wheals <7 mm2 in area or <3 mm in diameter). Similar differences, although less pronounced, were detected when comparing the effects of nsAHs with hydroxyzine on D pteronyssinus prick testing in a limited number of D pteronyssinus-sensitized individuals.

CONCLUSIONS

These results indicate that hydroxyzine is more effective than nsAHs when given as recommended in suppressing histamine-induced or allergic skin reactions. Our results suggest that higher doses of nsAHs than those currently recommended are required for the treatment of skin responses to obtain antihistaminic and antiallergic effects that are equivalent to those of fgAHs.

From pharmacokinetics to therapeutics

Whilst pharmacokinetics describe the relationship between dose levels and concentration-time profiles of a drug in the body and pharmacodynamics describe the concentration-response relationships, pharmacokinectics-pharmacodynamics(PK-PD) models link these two items providing a framework for modelling the time course of drug response. In this chapter, PK-PD models, describing the therapeutic effects of drugs used for the therapy of allergic diseases have been reviewed. Emphasis was given also to the description of the receptor occupancy, which is tightly related to the downstream clinical response. PK - PD models describing unwanted effects were also commented. An integrated use of these models allows choosing appropriate dosing regimens and providing an objective evaluation of the benefit/risk balance.

Pruritus: an updated look at an old problem

Pruritus is among the most common dermatological complaints. The authors examine the pathophysiology of itch according to the most common mediators uncovered by researchers. They also discuss the encompassing etiologies, which include dermatological, psychological, and systemic causes. Finally, they discuss the diagnostic approach and the latest, most appropriate treatment options. (J Clin Aesthetic Dermatol. 2009;2(7):30-36.).

Comparison of the efficacy of levocetirizine 5 mg and desloratadine 5 mg in chronic idiopathic urticaria patients

BACKGROUND

Nonsedating H(1)-antihistamines are recommended for the treatment of urticaria by the recent EAACI/GA(2)LEN/EDF guidelines. The aim of this study was to compare the efficacy, after 4 weeks of treatment, with levocetirizine 5 mg and desloratadine 5 mg, both once daily in the morning, in symptomatic chronic idiopathic urticaria (CIU) patients.

METHODS

This multi-center, randomized, double-blind study involved 886 patients (438 on levocetirizine and 448 on desloratadine). The primary objective was to compare their efficacy on the mean pruritus severity score after 1 week of treatment. Mean pruritus severity score over 4 weeks and pruritus duration score, number and size of wheals, mean CIU composite score (sum of the scores for pruritus severity and numbers of wheals), quality of life, and the patient's and investigator's global satisfaction with treatment, were secondary efficacy measures.

RESULTS

Levocetirizine led to a significantly greater decrease in pruritus severity than desloratadine over the first treatment week; mean pruritus severity scores of 1.02 and 1.18 for levocetirizine and desloratadine, respectively (P < 0.001). The result was similar for the entire 4-week treatment period (P = 0.004). In addition, levocetirizine decreased pruritus duration and the mean CIU composite scores to a significantly greater extent than desloratadine during the first week (P = 0.002 and 0.005, respectively) and over the entire study (P = 0.009 and P < 0.05, respectively). Similarly, levocetirizine increased the patients' global satisfaction after one and 4 weeks (P = 0.012 and 0.021, respectively), compared with desloratadine. Safety and tolerability were similar in both groups.

CONCLUSIONS

Levocetirizine 5 mg was significantly more efficacious than desloratadine 5 mg in the treatment of CIU symptoms.

Once daily levocetirizine for the treatment of allergic rhinitis and chronic idiopathic urticaria

Levocetirizine is the pharmacologically active enantiomer of cetirizine. It is a potent histamine H-1 receptor antagonist with anti-inflammatory and antiallergic properties. The review analyses the levocetirizine's properties in terms of safety and efficacy both in allergic rhinitis and urticarioid syndromes.

Non-interventional study comparing treatment satisfaction in patients treated with antihistamines

BACKGROUND AND OBJECTIVE

Allergic rhinitis and urticaria are common allergic disorders that may affect approximately 15% of people at some time in their lives. Antihistamines are the most widely used therapeutic interventions for these disorders but the newer generation agents have differing pharmacokinetic characteristics that may result in different patient satisfaction and preferences. The objective of this study was to investigate patients' and physicians' satisfaction with their current antihistamine treatment for allergic disease.

METHODS

In an observational study, physicians in nine European countries completed questionnaires evaluating 7,274 patients treated with an oral antihistamine. The satisfaction of patients and physicians with the efficacy and tolerability of treatment was rated on a visual analogue scale. In addition, the proportion of patients satisfied with treatment (overall satisfaction) and willing to continue treatment with the same antihistamine were assessed. Safety and tolerability data were also gathered.

RESULTS

The results of this study indicate that modern antihistamines are generally considered effective and well tolerated by patients. In general, levocetirizine scored significantly higher in terms of perception of efficacy, tolerability and overall satisfaction. In terms of tolerability, three-quarters of patients were 'very satisfied' and a further fifth were moderately satisfied with levocetirizine and almost all (95%) were happy to continue treatment. Overall, the most commonly reported adverse event in this study was somnolence, a well known effect of antihistamines. The rate of somnolence in the levocetirizine group (3.8%) was similar to that for fexofenadine (both doses) and desloratadine, two products which are considered to be nonsedating antihistamines, and significantly less than half the rate for cetirizine.

CONCLUSION

Levocetirizine is considered an effective and well tolerated option for treating allergic disease by patients and physicians alike, particularly when the best available effectiveness and tolerability are required.

Inhibition of allergen-induced wheal and flare reactions by levocetirizine and desloratadine

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

The reproducible and standardized histamine-induced wheal and flare model helps identify the objective effectiveness of antihistamines in humans, as well as their differences in onset and duration of action. Some of the newest antihistamines have already been compared in a head-to-head setting using this model. However, their objective action at inhibiting the allergen-induced wheal and flare response has not been reported yet.

WHAT THIS STUDY ADDS

The time-response study presented here shows the objective activity of two of the newest generation of antihistamines, levocetirizine and desloratadine, at inhibiting the allergen-induced wheal and flare response in a randomized, cross over, placebo-controlled trial. This model is interesting to the clinical setting since allergic subjects are recruited, and the response to allergen involves mast cell degranulation and release of numerous vasoactive and pro-inflammatory mediators additionally to histamine. In addition, this study reports receptor occupancy for both antihistamines at therapeutic dosage, leading to analysis of potential differences in activity. This study clearly shows the potential anti-inflammatory properties of desloratadine and levocetirizine in their skin activity when allergen is the challenging agent as occurs in the clinical situation.

AIMS

To evaluate the inhibitory activity of the new-generation antihistamines levocetirizine and desloratadine at their therapeutic doses on the allergen-induced wheal and flare reaction at 1.5 h, 4 h, 7 h, 12 h and 24 h postdose, and to measure their plasma and skin concentrations.

METHODS

A double-blind, randomized, cross-over, placebo-controlled study in 18 allergic subjects was carried out. The time-response of the wheal and flare reaction areas under the curve (AUC) were compared by anova.

RESULTS

Both antihistamines significantly (P < 0.001) inhibited the allergen-induced wheal and flare reactions compared with placebo. Levocetirizine was significantly more potent than desloratadine. Mean +/- SEM wheal AUC(0-24 h) was 506.4 +/- 81.0 with levocetirizine and 995.5 +/- 81.0 mm(2) h with desloratadine as compared with placebo (1318.5 +/- 361.0 mm(2) h). Flare AUC(0-24 h) was 5927.3 +/- 1686.5 and 15838.2 +/- 1686.5 mm(2) h, respectively [P < 0.001 for both compared with placebo (22508.2 +/- 7437.1 mm(2) h)]. Levocetirizine showed significant inhibition of wheal and flare already at 1.5 h postdose compared with placebo (P <or= 0.001); desloratadine achieved a significant effect only after 4 h. The mean total plasma concentration at 12 h and 24 h after intake was higher for levocetirizine (58.1 +/- 13.4 and 20.0 +/- 8.1 ng ml(-1), respectively) as compared with desloratadine (0.82 +/- 0.24 and 0.45 +/- 0.16 ng ml(-1)). Similarly, higher mean unbound skin concentrations were observed for levocetirizine 24 h after intake (1.80 ng g(-1)) than for desloratadine (0.07 ng g(-1)). This was associated with greater receptor occupancy for levocetirizine (54%) than desloratadine (34%) at 24 h.

CONCLUSIONS

Levocetirizine suppressed the cutaneous allergic reactions with a higher potency than desloratadine, which correlated with its high receptor occupancy. Receptor occupancy rather than drug affinity or plasma half-life is more representative of antihistamine potency.

Inhibition of the histamine-induced weal and flare response: a valid surrogate measure for antihistamine clinical efficacy?

Histamine plays a central role in allergic responses. Inhibition of the weal and flare response to histamine is a traditional pharmacodynamic tool to measure the activity of H(1)-receptor antagonists. The time course and duration of cutaneous weal and flare inhibition are often used as surrogate measures of clinical efficacy. Pharmacodynamic differences among antihistamines are often interpreted to indicate differences in clinical efficacy. A systematic review of literature from 1980 to 2006 regarding the histamine induced weal and flare was undertaken. Search terms included 'histamine', 'skin test', 'weal', 'flare', and 'antihistamine'; retrieved articles were searched for relevant studies not identified initially. Data from human studies on the inhibition of the weal and flare by second-generation antihistamines were extracted and assessed. A literature search from 1980 to 2006 was undertaken for comparative studies of second-generation antihistamines in the clinical settings of allergic rhinitis (AR) and chronic idiopathic urticaria; data extracted from these studies underwent systematic review. Differences were noted among second-generation antihistamines in terms of their ability to inhibit the histamine-induced weal and flare. Corresponding differences in terms of clinical efficacy in AR and chronic urticaria were not identified following a systematic review. The reasons for the disconnect between pharmacodynamic effects and clinical efficacy may include differences between the route and concentration of histamine, the involvement of mediators other than histamine in the allergic response, and the short time course of pharmacodynamic studies. The histamine-induced weal and flare response is a pharmacodynamic test that should not be used to compare the clinical efficacy of different antihistamines, and is not an adequate alternative to clinical end-point assessments in AR or chronic idiopathic urticaria.

Comparative efficacy of cetirizine and levocetirizine in chronic idiopathic urticaria

H1 receptor antagonists are the mainstay of treatment for chronic idiopathic urticaria. Newer hydroxyzine derivatives such as cetirizine and levocetirizine have been found to be equally efficacious in preclinical studies in patients with chronic idiopathic urticaria. In this study, the clinical efficacy of cetirizine and levocetirizine has been studied sequentially in individual patients. Fifty chronic idiopathic urticaria patients received 10 mg of levocetirizine daily for 6 weeks. Some 45 patients out of these showed reasonably good clinical efficacy on a visual analog scale to qualify for comparison with levocetirizine. A total of 30 patients completed the study period of 6 weeks each of cetirizine and levocetirizine sequentially. Thus, the clinical efficacy of cetirizine and levocetirizine was comparable with a marginal advantage of better antipruritic effect with levocetirizine, probably at the cost of increased sedation.

The safety and efficacy of desloratadine for the management of allergic disease

Allergic disease is an increasing problem worldwide. Allergic rhinitis, an inflammatory response to an allergen, affects an estimated 20-40 million people in the US, while chronic idiopathic urticaria is a dermatoallergic condition that affects 0.1-3% of people in the US and Europe. The primary goals of treatment for allergic rhinitis are to reduce symptoms, which include sneezing, rhinorrhoea and nasal congestion, improve quality of life and prevent the sequelae associated with this disease, while the goal for chronic idiopathic urticaria is the rapid and prolonged control of symptoms. Quantitatively, histamine is the most abundant mediator present during an allergic episode - thus, antihistamines (historically called histamine H(1) receptor antagonists, now called H(1) receptor inverse agonists) are a first-line defense against allergic rhinitis and chronic idiopathic urticaria. Although first-generation antihistamines can cause sedation and cognitive impairment, second-generation antihistamines are relatively non-sedating and free of such adverse events owing to their comparative inability to penetrate the blood-brain barrier. Desloratadine is one such second-generation antihistamine and is indicated for the treatment of allergic diseases, including allergic rhinitis and chronic idiopathic urticaria. It has proven efficacy against the symptoms associated with seasonal and perennial allergic rhinitis, including nasal congestion, and chronic idiopathic urticaria. As a result, it has been shown to improve patients' quality of life. The safety and efficacy profiles of desloratadine are well established, and published postmarketing analyses have assessed >54 000 patients. Although earlier second-generation antihistamines have been associated with cardiovascular adverse effects, desloratadine has been shown to be safe and well tolerated at nine times the recommended dose. In addition, it has been shown to not interact with concomitantly administered drugs and food. Overall, current data indicate that desloratadine is a safe and effective treatment for allergic diseases.

Facial thermography is a sensitive tool to determine antihistaminic activity: comparison of levocetirizine and fexofenadine

AIMS

To assess the antihistaminic activity of levocetirizine and fexofenadine 2 h and 24 h after drug administration using facial thermography and to compare the results with those using well-established parameters of antihistaminic activity in the nose and skin.

METHODS

This was a randomized, double-blind, three-treatment, three-period, single-dose, cross-over study in healthy males taking levocetirizine 5 mg, fexofenadine 120 mg or placebo. The primary endpoint was nasal skin temperature after nasal histamine challenge recorded for 20 min at 2 and 24 h after drug intake. The secondary endpoints were nasal symptoms and a histamine skin prick test.

RESULTS

Thirty subjects were randomized. At 2 h after drug intake the inhibition of the nasal temperature increase from baseline was not significantly different between levocetirizine and fexofenadine. At 24 h it was significantly more pronounced after levocetirizine than fexofenadine (difference: least-squares mean: -0.13 degrees C; P < or = 0.024, 95% CI -0.24, -0.02). Both drugs significantly reduced (P < or = 0.001) the mean temperature increase from baseline compared with placebo at 2 and 24 h (least-squares mean increase and (95% CI): levocetirizine, -0.28 degrees C (-0.42, -0.14) and -0.32 degrees C (-0.43, -0.21); fexofenadine -0.35 degrees C (-0.49, -0.21) and -0.19 degrees C (-0.30, -0.08), respectively). Results of nasal symptom score and wheal and flare were consistent with the thermography results.

CONCLUSIONS

Facial thermography is an objective, non-invasive and sensitive method to study antihistaminic activity at the nose level. Levocetirizine and fexofenadine demonstrate the same activity at 2 h after drug intake, but levocetirizine has a more sustained activity at 24 h.

Desloratadine for chronic idiopathic urticaria: a review of clinical efficacy

Chronic idiopathic urticaria (CIU) is a disabling affliction that considerably limits patients' daily activities and interferes with sleep. Clinical studies have shown that histamine H1-receptor antagonists (antihistamines) are highly effective for inhibiting the hives/wheals and pruritus associated with CIU, as well as improving patients' quality of life. Desloratadine is a rapid-acting, once-daily, nonsedating selective H1-receptor antagonist/inverse receptor agonist with proven clinical efficacy in patients with CIU. It has 10-20 times the in vivo H1 receptor-binding affinity of loratadine, its parent compound, and 52-194 times the H1 receptor-binding affinity of cetirizine, ebastine, loratadine, and fexofenadine. Desloratadine displays linear pharmacokinetics after oral administration. Age and sex have no apparent effect on the drug's metabolism and elimination, and food does not affect its bioavailability or absorption. Desloratadine also exerts anti-inflammatory effects via mechanisms that are independent of H1-receptor antagonism. Results from randomized, double-blind, placebo-controlled studies of 6 weeks' duration in adults and adolescents with moderate-to-severe CIU indicate that desloratadine significantly minimizes the severity of pruritus, reduces the number and size of hives, and improves disease-impaired sleep and daily activities. Improvements were noted after a single dose of desloratadine and were maintained over 6 weeks of treatment. Desloratadine was safe and well tolerated in clinical trials of patients with CIU. The adverse effect profile of desloratadine in adults, as well as in children aged from 6 months to 11 years, is comparable to that of placebo. Evaluations of cognitive and psychomotor performance in adults indicate no impairment of function with dosages of desloratadine 5 mg/day. In conclusion, desloratadine is an important therapeutic option for prompt and enduring symptom relief in patients with moderate-to-severe CIU. In addition to efficacy and safety, desloratadine affords a convenient administration regimen, rapid onset of action, and an absence of drug-drug or drug-food interactions. Other important prescribing considerations are that, unlike all first-generation and some second-generation antihistamines, desloratadine is nonsedating at its clinically approved dosage and does not impair psychomotor function.

Levocetirizine is an effective treatment in patients suffering from chronic idiopathic urticaria: a randomized, double-blind, placebo-controlled, parallel, multicenter study

BACKGROUND

Chronic idiopathic urticaria (CIU) is defined by the almost daily presence of urticaria for at least 6 weeks without an identifiable cause. Symptoms include short-lived wheals, itching, and erythema. CIU impedes significantly a patient's quality of life (QoL). Levocetirizine is an antihistamine from the latest generation approved for CIU.

AIM

To investigate the efficacy of levocetirizine, 5 mg, and placebo for the symptoms and signs of CIU, as well as for the QoL and productivity.

METHODS

The primary criteria of evaluation were the pruritus severity scores over 1 week of treatment and over 4 weeks. The QoL was assessed via the Dermatology Life Quality Index (DLQI).

RESULTS

Baseline pruritus severity scores were comparable in the two treatment groups (2.06+/-0.58). After 1 week, levocetirizine was superior to placebo and demonstrated a considerable efficacy (difference=0.78, P<0.001). This efficacy was maintained over the entire study period (4 weeks, P<0.001). The number and size of wheals were considerably reduced compared with placebo over 1 week and over the total treatment period (P <or= 0.001). This was paralleled by an improvement in the QoL (DLQI: 7.3 units in the levocetirizine group and 2.4 units in the placebo group) and a higher productivity at work in the levocetirizine group (3.0 workdays lost per patient per month in the placebo group, 0.3 in the levocetirizine group). No unexpected adverse events occurred.

CONCLUSIONS

Levocetirizine, 5 mg once daily, is an effective treatment for CIU, characterized not only by a rapid and sustained response, but also by an important improvement in QoL.

Levocetirizine: a review of its use in the management of allergic rhinitis and skin allergies

Levocetirizine (Xyzal) is a selective, potent, oral histamine H(1) receptor antagonist of the latest generation that is licensed for the symptomatic treatment of allergic rhinitis (including persistent allergic rhinitis [PER]) and chronic idiopathic urticaria (CIU). Large, well designed trials indicate that levocetirizine is effective and generally well tolerated in the treatment of allergic rhinitis and CIU. Its pharmacological profile offers many positive aspects: a rapid onset and long duration of antihistaminic effect; rapid absorption and high bioavailability; a low potential for drug interactions; a low volume of distribution; and a lack of effect on cognition, psychomotor function and the cardiovascular system. Allergen challenge chamber studies suggest that levocetirizine has better efficacy than desloratadine, loratadine or fexofenadine. Well controlled, long-term studies with other later-generation H(1) receptor antagonists are required to fully define its clinical profile relative to other agents in this class. Overall, levocetirizine is a valuable addition to the oral H(1) receptor antagonists available for the treatment of allergic rhinitis and as first-line therapy in patients with CIU.

Experimental models for the evaluation of treatment of allergic rhinitis

OBJECTIVE

To review the experimental models used for the clinical evaluation of treatments for allergic rhinitis.

DATA SOURCES

Peer-reviewed clinical studies and review articles were selected from the PubMed database using the following relevant keywords: allergic rhinitis in combination with efficacy, wheal and flare, nasal challenge, park, cat room, or exposure unit. Regulatory guidance documents on allergic rhinitis were also included.

STUDY SELECTION

The authors' knowledge of the field was used to limit references with emphasis on recent randomized and controlled studies. References of historical significance were also included.

RESULTS

Traditional outpatient studies are universally accepted in the evaluation of treatment for allergic rhinitis. Experimental models provide ancillary information on efficacy at different stages of treatment development. Skin histamine and allergen challenge, as well as direct nasal challenge with histamine and allergen, are often used as early steps in assessing drug efficacy. Exposure units, park settings, and cat rooms better approximate real life by drawing on the natural mode of allergen exposure and delivering the sensitizing allergen to allergic individuals in the ambient air. Park studies make use of allergens in the outdoors, whereas cat rooms and exposure units present the sensitizing allergens indoors, with the latter providing consistent predetermined allergen levels. Exposure unit and park studies are acknowledged for the determination of onset of action and are also suited to the measurement of duration of effect and other measures of efficacy. Onset and duration of effect are 2 important pharmacodynamic properties of antihistamines and nasal corticosteroids as determined by the Allergic Rhinitis and Its Impact on Asthma and the European Academy of Allergology and Clinical Immunology workshop group.

CONCLUSIONS

All challenge models serve as important instruments in the evaluation of antiallergic medications and provide additional information to complement traditional studies.

Cost Effectiveness of Levocetirizine in??Chronic Idiopathic Urticaria

BACKGROUND

Chronic idiopathic urticaria is a distressing condition that severely affects patients' quality of life. The overall costs associated with this disease, both for the healthcare payer and society, are unknown. The objective of this study was to evaluate the cost effectiveness of levocetirizine, a first-line treatment for urticaria.

METHODS

Data were collected from two placebo-controlled trials and from official French databases. The effectiveness of the treatment was assessed by the mean number of pruritus-free days experienced by the patient within a 30-day period (PFD30). Direct cost parameters were medications used, medical procedures and hospitalisations for urticaria or treatment of adverse events. Productivity cost parameters were the workdays lost, defined as absenteeism and/or presenteeism, resulting from urticaria. The costing was performed using a French societal perspective. Costs were reported in euro (2002 values) and were standardised to a 30-day month. Whenever possible, incremental cost-effectiveness ratios (ICERs) were derived from these data.

RESULTS

The pooled sample contained 294 patients. Compared with placebo, patients in the levocetirizine group experienced an additional mean 6.5 (95% CI 3.8, 9.3) pruritus-free days per month (p < 0.001). Considering only direct medical costs, the incremental cost of treatment with levocetirizine was totally offset by the reduction in other medical costs (i.e. reduced cost of additional medications, medical procedures and hospitalisations). From the perspective of society, treatment with levocetirizine was cost saving, with a net gain of Euro 91.93 per patient per month.

CONCLUSION

Treating chronic idiopathic urticaria with levocetirizine is a dominant strategy for society since it is more effective (in terms of pruritus-free days gained) and less costly than placebo.

Levocetirizine in the treatment of chronic idiopathic urticaria: a randomized, double-blind, placebo-controlled study

BACKGROUND

Chronic urticaria is a common skin condition. It is frequently a disabling disease because of the persistence of clinical symptoms, the unpredictable course and its negative influence on the quality of life.

OBJECTIVES

To determine whether levocetirizine is efficacious in the treatment of chronic idiopathic urticaria.

METHODS

A randomized, double-blind, placebo-controlled study was conducted in 106 patients with a diagnosis of chronic idiopathic urticaria. A 1-week single blind placebo run-in period (baseline) was followed by a 6-week double blind active treatment period. The patients were randomized to receive one of the following treatments once daily: (a) oral levocetirizine 5 mg, or (b) oral placebo. The study ended after another 1-week single blind placebo washout period.

RESULTS

The evaluable population consisted of 100 patients. Levocetirizine administered once daily is effective and well tolerated in the treatment of the symptoms of chronic idiopathic urticaria and in improving the patient's quality of life. Levocetirizine was superior to placebo in reducing the mean total symptoms score as well as individual symptoms, the number of daily episodes and the number of weals, the overall severity of symptoms and the quality of life. The significant beneficial effects of levocetirizine lasted only during the active trial, while at follow-up there was a significant worsening of all the variables evaluated in this study, after the end of the active trial (week 7).

CONCLUSIONS

A global assessment indicates that levocetirizine 5 mg once daily is an effective agent in patients with chronic idiopathic urticaria, as its action provides a rapid and satisfactory control of the symptoms and measures of subjective disease, although this is limited to the duration of treatment.

A Review of the Evidence from Comparative Studies of Levocetirizine and Desloratadine for the Symptoms of Allergic Rhinitis

BACKGROUND

Levocetirizine and desloratadine are newer antihistamines indicated for the treatment of allergic rhinitis and chronic idiopathic urticaria.

OBJECTIVE

This article discusses the pharmacokinetics and pharmacodynamics of levocetirizine and desloratadine and reviews studies that have directly compared the effects of these 2 drugs in allergic rhinitis and urticaria.

METHODS

Relevant articles were identified through a search of MEDLINE from 1999 through 2004 using the main search terms levocetirizine and desloratadine.

RESULTS

Levocetirizine is absorbed rapidly and reaches a steady-state plasma concentration more quickly than does desloratadine. It is also metabolized to a lesser extent than desloratadine, has a lower V(d), and has higher specificity for histamine(1) receptors. Eight well-controlled trials were identified that directly compared the effects of levocetirizine and desloratadine in the skin and nose of healthy individuals and patients with allergic rhinitis. Drug activity was measured in terms of wheal, flare, and itch reactions; nasal symptoms or symptom scores; increases in concentrations of inflammatory markers; or facial thermography. In most of these trials, levocetirizine had a faster onset and greater consistency of effect than desloratadine. The differences in the pharmacokinetic and pharmacodynamic profiles of the 2 drugs may partially explain these clinical findings.

CONCLUSIONS

Levocetirizine may be preferred to desloratadine as a treatment option for allergic rhinitis because of its faster onset of action and greater consistency of effect. Although comparative studies in chronic idiopathic urticaria are not available, data from histamine-induced wheal and flare studies in healthy volunteers suggest that levocetirizine may be more effective in preventing itching than desloratadine.

Potential of levocetirizine in the relief of nasal congestion

Nasal congestion is a common and troublesome symptom of allergic rhinitis. Because it impairs the natural human drive for nasal breathing, it -- in addition -- leads to lower self-esteem and to impaired quality of life. It is a symptom that is difficult to treat. Traditionally, intranasal steroids, because of their potent anti-inflammatory properties, and vasoconstrictors have been utilized for relieving the nasal passages from the inflamed and congested mucosal tissues. Recent studies with the last-generation antihistamines have demonstrated the decongestant properties of these antihistamines in both the more acute seasonal allergic rhinitis and the more chronic and lasting perennial allergic rhinitis. This study aims to review the efficacy of the potent antihistamine, levocetirizine, in relieving nasal congestion as reported in various studies and settings. Comparisons with placebo and with other antihistamines have been presented in order to help general medical practitioners differentiate between the properties of the various available antihistamines.

Levocetirizine: the allergist’s arsenal grows larger

Antihistamines are the cornerstone of treatment for many allergic diseases, such as allergic rhinitis and chronic urticaria. Since the discovery of their beneficial effects in the 1940s, scientists have found molecules with greater selectivity to block specific histamine receptors without some of the detrimental side effects that are seen if antihistamines cross the blood-brain barrier. Levocetirizine is the active enantiomer of cetirizine and a selective H(1)-histamine blocker. It exhibits many favourable characteristics of an ideal antihistamine, both pharmacodynamically and pharmacokinetically, including high bioavailability, rapid onset of action, limited distribution and low degree of metabolism. Furthermore, clinical trials indicate that it is safe and effective for the treatment of allergic rhinitis and chronic urticaria with a minimal amount of untoward effects.

Second-Generation Antihistamines

Antihistamines are useful medications for the treatment of a variety of allergic disorders. Second-generation antihistamines avidly and selectively bind to peripheral histamine H1 receptors and, consequently, provide gratifying relief of histamine-mediated symptoms in a majority of atopic patients. This tight receptor specificity additionally leads to few effects on other neuronal or hormonal systems, with the result that adverse effects associated with these medications, with the exception of noticeable sedation in about 10% of cetirizine-treated patients, resemble those of placebo overall. Similarly, serious adverse drug reactions and interactions are uncommon with these medicines. Therapeutic interchange to one of the available second-generation antihistamines is a reasonable approach to limiting an institutional formulary, and adoption of such a policy has proven capable of creating substantial cost savings. Differences in overall efficacy and safety between available second-generation antihistamines, when administered in equivalent dosages, are not large. However, among the antihistamines presently available, fexofenadine may offer the best overall balance of effectiveness and safety, and this agent is an appropriate selection for initial or switch therapy for most patients with mild or moderate allergic symptoms. Cetirizine is the most potent antihistamine available and has been subjected to more clinical study than any other. This agent is appropriate for patients proven unresponsive to other antihistamines and for those with the most severe symptoms who might benefit from antihistamine treatment of the highest potency that can be dose-titrated up to maximal intensity.

Comparison of pharmacokinetics and metabolism of desloratadine, fexofenadine, levocetirizine and mizolastine in humans

Abstract Absorption, distribution, metabolism and excretion of desloratadine, fexofenadine, levocetirizine, and mizolastine in humans have been compared. The time required to reach peak plasma levels (tmax) is shortest for levocetirizine (0.9 h) and longest for desloratadine (> or =3 h). Steady-state plasma levels are attained after about 6 days for desloratadine, 3 days for fexofenadine, 2-3 days for mizolastine and by the second day for levocetirizine. The apparent volume of distribution is limited for levocetirizine (0.4 L/kg) and mizolastine (1-1.2 L/kg), larger for fexofenadine (5.4-5.8 L/kg) and particularly large for desloratadine (approximately 49 l/kg). Fexofenadine and levocetirizine appear to be very poorly metabolized (approximately 5 and 14% of the total oral dose, respectively). Desloratadine and mizolastine are extensively metabolized. After administration of 14C-levocetirizine to healthy volunteers, 85 and 13% of the radioactivity are recovered in urine and faeces, respectively. In contrast, faeces are the preferential route of excretion for 14C-fexofenadine (80% vs. 11% of the radioactive dose in urine). The corresponding values are 41% (urine) and 47% (faeces) for 14C-desloratadine, 84-95% (faeces) and 8-15% (urine) for 14C-mizolastine. The absolute bioavailability is 50-65% for mizolastine; it is high for levocetirizine as the percentage of the drug eliminated unchanged in the 48 h urine is 77% of the oral dose; the estimation for fexofenadine is at least 33%; no estimation was found for desloratadine. Fexofenadine is a P-glycoprotein (P-gp) substrate and P-gp is certainly involved both in the poor brain penetration by the compound and, at least partially, in a number of observed drug interactions. An interaction of desloratadine with P-gp has been suggested in mice, whereas the information on mizolastine is very poor. The fact that levocetirizine is a substrate of P-gp, although weak in an in vitro model, could contribute to prevent drug penetration into the brain, whereas it is unlikely to be of any clinical relevance for P-gp-mediated drug interactions.

Comparison of the Effects in the Nose and Skin of a Single Dose of Desloratadine and Levocetirizine over 24 Hours

BACKGROUND

Desloratadine (DL) and levocetirizine (LCZ) are the newest commercialized antihistamines. Pharmacokinetics, pharmacodynamics and clinical data are available for both drugs, but there is to date no direct comparison involving the nose and skin at the same time. We compared the effects of a single dose of the two drugs in the nose and skin over 24 h.

METHODS

Twenty-three patients with symptomatic allergic rhinitis were enrolled in a randomized double-blind crossover administration of DL and LCZ. The histamine-induced wheal and flare was measured at baseline and 2 and 24 h after dosing. A reflective total symptom score (rTSS) for the previous 24 h was assessed before and after each dose. An instant symptom score was also measured at various time points after each drug.

RESULTS

LCZ provided greater inhibition of the flare at 2 h (p = 0.05) and at 24 h (p = 0.007) and greater inhibition of the wheal only at 2 h (p = 0.02). The decrease in wheal and flare was significant versus baseline (p = 0.007) with both drugs. The rTSS of the previous 24 h decreased significantly with both LCZ (11.53 vs. 8.0; p < 0.05) and DL (11.3 vs. 7.9; p < 0.05). The instant TSS progressively decreased in parallel with both drugs, but a difference in favor of LCZ was seen 2 h after dosing.

CONCLUSIONS

Single doses of DL and LCZ had a comparable effect on nasal symptoms, but LCZ was faster and displayed a greater effect on histamine wheal.

Levocetirizine better protects than desloratadine in a nasal provocation with allergen

BACKGROUND

Direct comparisons of antihistamines are rare but very much needed. Newly available antihistamine preparations, levocetirizine, the R-enantiomer of racemate cetirizine, and desloratadine, an active metabolite of loratadine, have been recently released for allergic rhinitis.

OBJECTIVE

We sought to compare levocetirizine and desloratadine in a nasal provocation test (NPT) with grass pollen.

METHODS

Twenty-four volunteers with grass pollen allergy and a history of rhinitis were enrolled in a double-blind, placebo-controlled, crossover study. Three NPTs were performed in a dose-escalating manner during the out-of-season period 4 hours after a single dose of levocetirizine (5 mg), desloratadine (5 mg), or placebo.

RESULTS

CONCLUSIONS

This study demonstrates a better overall protection of a single dose of levocetirizine compared with desloratadine in an NPT with grass pollen allergen. In contrast to late-phase inflammatory markers, which were unaffected, extravascular leakage of the early-phase marker albumin was significantly limited by levocetirizine.