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The present study was performed to study the participation of histamine H(3) receptors in nasal symptoms using Sch 50971, a potent and selective agonist of the H(3) receptor. Repeated topical application of antigen caused an increase in sneezing and nasal rubbing in sensitized mice. Oral administration of Sch 50971 and imetit, specific H(3)-receptor agonists, resulted in an inhibition of nasal symptoms induced by an antigen similar to an H(1)-receptor antagonist, cetirizine. Furthermore, simultaneous use of H(3)-receptor agonists, Sch 50971 or imetit, and an H(1)-receptor antagonist, cetirizine, caused a significant inhibitory effect on nasal symptoms at doses that showed no effect when used separately. The number of eosinophils in the nasal mucosa of mice sensitized with antigen was significantly decreased by cetirizine; however, Sch 50971 and imetit had no effect on eosinophil infiltration. These results clearly indicate that H(3) receptors are involved in the etiology of nasal allergy, and the stimulation of H(3) receptors may be useful as a novel therapeutic approach in nasal allergy.
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Cetirizine hydrochloride is an orally-active and selective histamine (H(1))-receptor antagonist. It is a second-generation antihistamine and a human metabolite of hydroxyzine. Therefore, its principal effects are mediated via selective inhibition of peripheral H(1) receptors. The antihistaminic activity of cetirizine has been documented in a variety of animal and human models. In vivo and ex vivo animal models have shown negligible anticholinergic and antiserotonergic activity. In clinical studies, however, dry mouth has been seen more commonly with cetirizine than with placebo. In vitro receptor binding studies have shown no measurable affinity for receptors other than H(1) receptors. Auto-radiographical studies with radiolabelled cetirizine in the rat have shown negligible penetration into the brain. Ex vivo experiments in the mouse have shown that systemically administered cetirizine does not significantly occupy cerebral H(1) receptors. Impairment of CNS function is comparable to other low-sedating antihistamines at the recommended dose of 10 mg/day for adults. It has anti-inflammatory properties that may play a role in asthma management. It does not interact with concomitantly administered medications, it has no cardiac adverse effects, and it does not appear to be associated with teratogenicity. Cetirizine is predominantly eliminated by the kidneys with a mean elimination half-life is 8.3 h. It is rapidly absorbed, and significant clinical inhibition of a wheal and flare response occurs in infants, children and adults within 20 min of a single oral dose and persists for 24 h. No tolerance to the wheal and flare response occurs even after 1 month of daily treatment. The clinical efficacy of cetirizine for allergic respiratory diseases has been established in numerous trials. There is evidence that cetirizine improves symptoms of urticaria. Concomitant use of cetirizine also decreases the duration and amount of topical anti-inflammatory preparations needed for the treatment of atopic dermatitis. Interestingly, several clinical studies suggest that cetirizine may be useful in the treatment and prevention of mild asthma.
We have documented the safety of cetirizine in this short-term investigation, the first randomized, double-blind, placebo-controlled study of any H(1)-antihistamine in infants. Additional prospective, randomized, double-blind, placebo-controlled, long-term studies of cetirizine and other H(1)-antihistamines are needed in this population.
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Histamine is responsible for the wheal and flare reaction in various allergic conditions. Classical antihistamines are the drugs which block the H 1 receptors and are widely used in various allergic conditions, whereas H 2 blockers are mainly used for acid peptic disease. Although H 1 receptor-mediated actions of histamine are primarily responsible for vasodilatation, vasopermeability, and itching, it has been observed that combined blocking of both H1 and H2 receptors may provide better relief.
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The antihistamine effects of olopatadine and levocetirizine, in standard-dose application described in their information (5 mg twice a day for olopatadine; 5 mg once daily for levocetirizine), were examined from 11.5 to 24 h after application. The test was designed in a double-blind, randomized, cross-over, placebo-controlled study of 12 healthy volunteers on histamine-induced flare and wheal response using an iontophoresis technique. The suppressive effect of olopatadine on the wheals induced by a 0.1-mA histamine iontophoresis lasted for 24 h after dosing. Both drugs inhibited flare induced by histamine iontophoresis almost completely until 24 h after the first administration. Suppression of the 0.2-mA-induced wheal response by levocetirizine, taken once daily, decreased with time, although 0.1-mA-induced flare was almost completely suppressed by the drug. Olopatadine completely suppressed even the wheal response induced by a 0.2-mA histamine iontophoresis. Compared with the placebo, the two drugs significantly suppressed the subjective itching assessed by visual analog scale at all intervals. There were no significant differences in subjective drowsiness and objective cognitive function between drug- and placebo-treated subjects. These results demonstrate that olopatadine seems to be more potent than levocetirizine when administrated in a standard dose. In conclusion, mild to moderate urticaria could be controlled by standard application as described in their information. On the other hand, severe urticaria could be managed by a standard application of olopatadine, but levocetirizine may need an additional dose to control severe urticaria.
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This international multicentre, open-label, parallel-group trial was undertaken to compare the therapeutic efficacy and tolerability of topical levocabastine and oral cetirizine in patients with perennial allergic rhinoconjunctivitis, with particular reference to the comparative onset of action of the two drugs. A total of 207 patients were randomized to receive either levocabastine nasal spray (0.5 mg/ml, two sprays in each nostril twice daily) plus levocabastine eye drops as required (0.5 mg/ml, one drop in each eye twice daily p.r.n.) or cetirizine orally (10 mg once daily) with a treatment duration of 2 weeks. Onset of action was found to be significantly more rapid with levocabastine than with cetirizine for both nasal and ocular symptoms (p < 0.001). Within 15 min of study drug administration, 36% of levocabastine-treated patients reported relief from nasal symptoms and 32% relief from ocular symptoms compared with 10% and 17% of patients on cetirizine, respectively. At 1 h, the percentages of patients reporting relief were 76% and 38% for nasal symptoms, and 81% and 48% for ocular symptoms in the levocabastine and cetirizine treatment groups, respectively. At 8 h there were no differences between the two treatments. Overall therapeutic efficacy was found to be comparable in the two treatment groups over the 2-week study period with no significant intergroup differences in symptom severity or global therapeutic efficacy. Both drugs were well tolerated with no significant differences in the incidence or type of adverse reactions between the two groups. In conclusion, levocabastine eye drops and nasal spray are as effective and well tolerated as oral cetirizine for the treatment of perennial allergic rhinoconjunctivitis with the advantage of a significantly faster onset of action for both nasal and ocular symptoms.
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The three included studies varied in age of subjects, sample size, inclusion criteria, type of anti-histamine and length of intervention. These 3 studies included 182 randomised subjects with 162 completing the trials although in one study, children with recurrent wheeze were also included. Clinical heterogeneity was evident and limited data prevented combining data for meta-analysis. The two larger studies described significant improvement in both the intervention and the placebo/placebo-like arms with no significant difference between the two groups. In the study with the smallest sample size, cetirizine (a second generation anti-histamine) was significantly more efficacious than placebo in reducing chronic cough in children associated with seasonal allergic rhinitis, and the effect was seen within 2 weeks of therapy.
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We compared the efficacy and safety of 5 mg cetirizine (CTZ), 120 mg pseudoephedrine retard (PER) and their combination (COM), given twice daily for three weeks, for the treatment of perennial allergic rhinitis. Two hundred and ten evaluable patients (97 males and 113 females) were included in the study and randomly allocated to one of three treatment groups, each of 70 patients. Nasal obstruction, sneezing, rhinorrhoea, nasal and ocular pruritus were scored each day throughout the study by patients using a symptom scale ranging from 0 (no symptom) to 3 (severe). The mean proportion of days without symptoms was higher in the COM group (11.8%) than in the CTZ (6.8%) and PER (5.1%) groups, but the differences were not statistically significant. The mean percentage of days when symptoms were absent or at most mild was significantly higher in the COM group (64.8%) than in either CTZ (45.5%; p = 0.003) or PER groups (40.6%; p = 0.0001). In addition, evaluation of symptoms by investigators and their global evaluation at the end of treatment showed statistically significant differences in favour of COM compared, to both CTZ and PER. The most frequent adverse events were somnolence in the CTZ and COM groups (8.6% and 12.9%, respectively) while insomnia was most frequent in the PER group. No clinically significant abnormalities were found in haematological or biochemical tests. These results indicate that the combined treatment was more effective than and as well tolerated as treatment with each individual agent.
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The use of solid oral dosage forms is typically favored with regard to stability and ease of administration. The aim of this study was to investigate whether cyclodextrins (CD) or ion exchange resins (IER) could be used to taste-mask cetirizine HCl when formulated in a freeze-dried oral formulation. The oral lyophilisates were produced using the Zydis(®) technology that offer the opportunity to produce the dosage form directly in the aluminum laminate blister packs. This study confirmed that a pre-formed resinate of cetirizine HCl and various cyclodextrins can be successfully incorporated into the Zydis(®) oral lyophilisate. A chemically stable product with acceptable release profile was obtained in the case of cyclodextrin. This study has also demonstrated that the Insent(®) taste sensing system is a useful technique for predicting the taste-masking potential of Zydis(®) formulations. The electronic taste sensing system (e-tongue) data can be used to provide guidance on the selection of taste-masked formulations. Principal component analysis (PCA) of sensor data by plotting the PCA scores revealed the effects of used taste-masking techniques on the e-tongue sensors, indicating the successful taste improvement. The PCA plot of the taste sensor data revealed larger distances between the non-taste-masked sample and the CD- and IER-loaded samples, and the shift toward the drug-free formulations and excipient signals indicates a modification of the product taste. The human taste trial confirms the acceptability of the selected promising formulations. The taste evaluation results showed that an effectively taste-masked formulation has been achieved using β-cyclodextrin and cherry/sucralose flavor system with over 80% of volunteers finding the tablet to be acceptable.
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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.
These results suggest that domiciliary measurements of nasal peak flow correlate significantly with symptoms of seasonal allergic rhinitis and may therefore be a potentially useful objective short-term marker of treatment response.
Adverse cardiac effects have been related to the use of H1-receptor antagonists terfenadine and astemizole.
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This multicenter, double-blind trial randomized adults with SAR, sensitized to at least 1 grass allergen, to receive levocetirizine, 5 mg, or placebo once daily in the evening for 2 weeks. The primary end point was the 24-hour reflective Total 5-Symptom Score (T5SS; sum of rhinorrhea, sneezing, nasal congestion, and nasal and ocular pruritus) during the entire treatment period. Secondary assessments included the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), Work Productivity and Activity Impairment-Allergy Specific (WPAI-AS) questionnaire, and Epworth Sleepiness Scale (ESS), each assessed at week 1, week 2, and the end of treatment.
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Cetirizine affects information processing speed, but these effects were not sufficient to serve as a model for cognitive deficits in clinical disorders.
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Allergic rhinitis (AR) is a very common disease, occurring in approximately 10% of children and up to 20% of adolescents. It is often underdiagnosed and its importance as a cause of morbidity is also underestimated, especially in asthmatic children. It has been estimated that 75% of asthmatic children suffer from AR, and its prevalence has increased during the last years, due to changes in environmental factors. AR may be a cause of serious discomfort for the child as well as for the family. AR may cause several complication, including serous otitis media, abnormal facial development with orthodontic problems, eustachian tube dysfunction and sinusitis. The frequent association of paranasal sinusitis in children with asthma has been observed and sinusitis has been considered a contributing factor in bronchial asthma Second-generation antihistamines are the golden therapy for AR. However, reports of potentially life-threatening dysrhythmias, specifically torsades de pointes, were described. In conclusion, we comment the in vitro inhibition of several ion channels, in particular predisposing the heart to dysrhythmias by terfenadine and astemizole. In this paper we examine recent reports on safety of both cetirizine and loratadine.
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Cetirizine did not significantly inhibit either the EAR or LAR documented by maximum percentage fall in FEV1 (0-3 and 6-9 h) or as area under the curve (AUC between 0 and 3 and 6-9 h). Beclomethasone inhibited the LAR compared with placebo (P = 0.02) when expressed as AUC (6-9 h). This did not quite reach statistical significance (P = 0.06) when expressed as maximal percentage late fall in FEV1 between 6 and 9 h. A greater than twofold increase in airways responsiveness to methacholine was observed 3 h after challenge which was significantly reduced by beclomethasone compared with placebo (P < 0.02) and cetirizine (P < 0.05). The data suggest that oral cetirizine does not significantly inhibit either the EAR or LAR. Beclomethasone inhibited both the early increase in airways responsiveness and the subsequent LAR. Our study also confirms the view that early increases in airway responsiveness precede the late response and suggests that these associated events are not dissociable by the pharmacological treatments employed in this study.
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Serotonin type 3 (5-HT3) receptor antagonists have been reported to be a novel therapeutic principle for the treatment of cholestatic and uremic pruritus.
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In all, 736 patients were selected. Of them, 543 (73.8%) were randomized in three different groups: placebo (n = 185), cetirizine (n = 175) and rupatadine (n = 183). Rupatadine (P = 0.008) but not cetirizine (P = 0.07) statistically reduced the baseline i6TSS vs placebo (47.8%, 44.7% and 38.8%, respectively), after 12 weeks. Onset of action was observed at the first 24 h for both treatments (rupatadine vs placebo, P = 0.013; cetirizine vs placebo, P = 0.015). Furthermore, instantaneous total nasal symptoms score (iTNSS) (including nasal blockage) mean change from baseline showed a significant reduction with rupatadine 10 mg in comparison with placebo, along all treatment duration of 12 weeks. Study treatments were well tolerated.
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To investigate the potential rules and knowledge of Traditional Chinese Medicine (TCM) and Western Medicine (WM) treatment on chronic urticaria (CU) based on data-mining methods.
Acute and chronic symptoms of allergic rhinitis (AR) can disrupt school and leisure activities, significantly reducing quality of life. Symptoms often impair sleep, resulting in tiredness and poor concentration. Children with seasonal AR perform significantly worse in summer exams, relative to their mock exam results, when compared with their peers. Those individuals showing most symptoms are also likely to be affected by other allergic diseases, magnifying the detrimental impact on quality of life. Nasal blockage is the most common complaint associated with chronic AR, with acute exacerbations causing sneezing, clear nasal discharge and itchy eyes following exposure to the relevant airborne triggers. Allergen avoidance measures should be instituted according to seasonal or perennial symptomatology guided by allergy testing, alongside nonsedating antihistamines such as cetirizine or loratadine. Continued symptoms should be treated with regular intranasal steroid spray. Anti-leukotrienes should be considered early in children presenting with multi-trigger wheeze. Temporal patterns of exacerbation give clues as to the most important aeroallergens implicated. In the UK, tree pollen allergy predominates throughout the spring, whereas those affected by grass pollen allergy may find their symptoms increasing over the summer months. Perennial AR symptoms are the result of exposure to house dust mites, animals and moulds. Children who are allergic to these often find the winter more troublesome as they spend more time indoors and the central heating disperses these household allergens. Where continuing deterioration presents a challenge and allergic symptoms remain uncontrolled, patients should be referred to a specialist allergy service to be considered for immunotherapy.
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.