Double-blind comparison of cetirizine and loratadine in children ages 2 to 6 years with perennial allergic rhinitis.

Antihistamines are the pharmacologic cornerstone of treatment for allergic rhinitis. The comparative effects of the newer, more specific H (1) -antagonists cetirizine and loratadine among younger patients are not well characterized. The efficacy and safety of cetirizine and loratadine were compared in a prospective, randomized, double-blind, longitudinal, parallel-group study of 80 children, 2 to 6 years of age, with perennial allergic rhinitis caused by house dust mites or plant pollens (verified by a radioallergosorbent or skin test). Patients received cetirizine or loratadine at 0.2 mg/kg once daily in the morning for 28 days. Histamine skin tests and eosinophil counts from nasal smears were performed at baseline and at the end of treatment. Individual rhinitis symptoms were assessed by the investigator at baseline and on day 28 and by parents at baseline and daily in symptom diaries. Global assessments were made by using a visual analog scale at baseline and at the end of treatment. Cetirizine produced significantly greater inhibition of the wheal response compared with loratadine (P <.0001). Eosinophil counts were improved to a comparable degree with both agents. Cetirizine and loratadine produced comparable improvements in symptoms and according to a global evaluation as assessed by the investigator at the end of treatment. Both agents produced substantial symptomatic relief according to patients' daily diary assessments; however, cetirizine was more effective than loratadine in relieving the symptoms of rhinorrhea, sneezing, nasal obstruction, and nasal pruritus (P <. 0001). Both treatments were well tolerated; two patients receiving cetirizine were dropped from the study because of adverse events. Cetirizine and loratadine provided effective, well-tolerated relief of the symptoms of perennial allergic rhinitis in small children. Cetirizine was more effective than loratadine in inhibiting the wheal response to histamine challenge and afforded greater reductions in most individual symptoms assessed daily by the parent.     

Cetirizine therapy for seasonal allergic rhinitis: alternative dosage schedules.

A double-blind, placebo-controlled clinical trial was undertaken for two weeks to evaluate three dosing schedules for administration of cetirizine in patients with seasonal allergic rhinitis. Average severity scores from the patients' ratings for sneezing and nasal itching were significantly reduced in all three cetirizine groups (10 mg QAM or QHS and 5 mg BID), compared with placebo. The effectiveness of cetirizine in once-daily dosing schedules indicates that significant antihistaminic activity is delivered over a full 24 hours. The possibility for flexibility in dosing combined with its relatively short half-life and low incidence of adverse effects make cetirizine an important second-generation H1-antihistamine for the management of seasonal allergic rhinitis.     

The pharmacokinetics, electrocardiographic effects, and tolerability of loratadine syrup in children aged 2 to 5 years

OBJECTIVE: We assessed the pharmacokinetics and tolerability of 5 mg loratadine syrup (1 mg/mL) in children aged 2 to 5 years. METHODS: Two studies were undertaken. A single-dose, open-label bioavailability study was performed to characterize the pharmacokinetic profiles of loratadine and its metabolite desloratadine. Plasma concentrations of loratadine and desloratadine were determined at 0, 1, 2, 4, 8, 12, 24, 48, and 72 hours after a single administration of 5 mg loratadine syrup to 18 healthy children (11 male, 7 female; 12 black, 5 white, 1 other; mean age +/- SD, 3.8 +/- 1.1 years; mean weight +/- SD, 17.4 +/- 4.4 kg). In addition, a randomized, double-blind, placebo-controlled, parallel-group study was performed to assess the tolerability of 5 mg loratadine syrup after multiple doses. Loratadine (n = 60) or placebo (n = 61) was given once daily for 15 days to children with a history of allergic rhinitis or chronic idiopathic urticaria. In the loratadine group, 27 boys and 33 girls (52 white, 8 black) were enrolled, with a mean age +/- SD of 3.67 +/- 1.13 years and a mean weight +/- SD of 17.2 +/- 3.8 kg. In the placebo group, 27 boys and 34 girls (53 white, 7 black, 1 Asian) were enrolled, with a mean age +/- SD of 3.52 +/- 1.12 years and a mean weight +/- SD of 17.3 +/- 2.9 kg. Tolerability was assessed based on electrocardiographic results, occurrence of adverse events, changes in vital signs, and results of laboratory tests and physical examinations. RESULTS: The peak plasma concentrations of loratadine and desloratadine were 7.78 and 5.09 ng/mL, respectively, observed 1.17 and 2.33 hours after administration of loratadine; the areas under the plasma concentration-time curve to the last quantifiable time point for loratadine and desloratadine were 16.7 and 87.2 ng x h/mL, respectively. Single and multiple doses were well tolerated, with no adverse events occurring with greater frequency after multiple doses of loratadine than after placebo. Electrocardiographic parameters were not altered by loratadine compared with placebo. There were no clinically meaningful changes in other tolerability assessments. CONCLUSION: Loratadine was well tolerated in this small, selected group of children aged 2 to 5 years at a dose providing exposure similar to that with the adult dose (ie, 10 mg once daily).     

Loratadine (SCH29851) 40 mg once daily versus terfenadine 60 mg twice daily in the treatment of seasonal allergic rhinitis

Seventy patients received loratadine 40 mg once daily, terfenadine 60 mg twice daily, or placebo in a 14-day, double-blind, randomized study. Four nasal and four non-nasal symptoms associated with allergic rhinitis were evaluated. At the endpoint (the last evaluable visit), the mean total scores of combined nasal and non-nasal symptoms decreased (improved) from the baseline by 51.8% and 55.7% with loratadine and terfenadine, respectively, but increased (worsened) by 6.1% with placebo. There was a significant difference between both the loratadine and terfenadine treatment groups and the placebo group (P = 0.001) but not between the active medication groups (P = 0.608). Overall therapeutic response was good or excellent in 14 of the 23 patients given loratadine, in 18 of the 24 given terfenadine and in none of the 23 given placebo. The difference between each active medication group and the placebo group was significant (P less than or equal to 0.01) but there was no significant difference between the two active treatment groups (P greater than 0.35). No loratadine patient had any adverse side-effects. Sedating effects occurred in one terfenadine patient, headache in one placebo patient and two terfenadine patients (one terfenadine patient with severe headache discontinued treatment), and dyspepsia in two placebo patients. No anti-cholinergic effects occurred in this study. Loratadine 40 mg once daily was effective and safe in the relief of symptoms of allergic rhinitis.     

Effect of nitric oxide inhibition on nasal airway resistance after nasal allergen challenge in allergic rhinitis

BACKGROUND: Nitric oxide has been detected by chemiluminescence in the lumen of nasal airway, which is increased in nasal breathing in patients with seasonal rhinitis during a chronic exposure. The purpose of this study was to determinate the effect of a NO-synthase inhibitor NGL-arginine methyl ester (L-NAME) on nasal airway resistance (NAR) in patients with seasonal allergic rhinitis after an acute challenge to the allergen. METHODS: Nitric oxide levels in the nose were measured by the chemiluminescence method in nine non-atopic volunteers and in seven patients with seasonal rhinitis at rest and after an acute challenge with the allergen. NAR were measured by active anterior rhinomanometry. RESULTS: Basal nasal NO concentration in allergic rhinitis was 496.5 +/- 151.4 parts per billion (ppb). (n = 7) and it was not significantly different from levels found in the control group: 458.4 +/- 105.9 ppb (n = 9). The topical administration of L-NAME in allergic rhinitis reduced the NO concentration (338.6 +/- 99.3 ppb, P < 0.001; n = 7). In the rhinitic patients the challenge with the allergen did not modify the nasal NO levels (504.5 +/- 138.5 ppb). The application of the allergen after the pretreatment with placebo caused a significant increase in NAR (from 0.32 +/- 0.11 Pa s cm-3 to 1.01 +/- 0.12 Pa s cm-3, P < 0.001; n = 7). Pre-treatment with L-NAME did not prevent the increase in NAR induced by allergen challenge (from 0.36 +/- 0.15 Pa s cm-3 to 1.06 +/- 0.26 Pa s cm-3). CONCLUSIONS: The results indicate that nasal administration of a NOS inhibitor L-NAME, at doses capable of decreasing nasal NO levels, has no effect on NAR and it does not prevent the NAR increase induced by an acute challenge with allergen in subjects with seasonal rhinitis.     

Absorption across the nasal airway mucosa in house dust mite perennial allergic rhinitis

House dust mite allergens express protease activity and it has been suggested that this property has pathogenic effects by increasing airway absorption. In accordance, house dust mite allergens may increase mucosal permeability in vitro. The objective of the present study was to examine nasal absorption of desmopressin (1-deamino-8-D-arginine vasopressin) in patients with perennial house dust mite allergic rhinitis and in healthy subjects in vivo. Patients with perennial allergic rhinitis were examined after a 4-week treatment withdrawal period, when symptoms of allergic rhinitis occurred, and healthy subjects were examined together with the patients. Desmopressin (20 microg ml(-1)) was moved into the nasal cavity using a nasal pool-device that contained 15 ml fluid. The fluid was kept in the nasal cavity for 15 min and then recovered. Urine was collected for 24 h after the nasal administration and the urinary excretion of desmopressin was determined as an index of nasal absorption. The urinary excretion of desmopressin was 1148+/-535 pmol 24 h(-1) in patients with perennial house dust mite allergic rhinitis and 1012+/-291 pmol 24 h(-1) in healthy subjects. We conclude that nasal airway absorption of the 1067 Da peptide desmopressin is unaffected in perennial house dust mite allergic rhinitis compared with healthy subjects.     

Comparative efficacy and safety of once-daily versus twice-daily loratadine-pseudoephedrine combinations versus placebo in seasonal allergic rhinitis

The objective of this study was to compare the efficacy and safety of Claritin-D 24 Hour (once daily) with that of Claritin-D 12 Hour (twice daily) and placebo in the treatment of patients with seasonal allergic rhinitis (SAR). In this double-blind, placebo-controlled, multicenter study, 469 patients with moderate-to-severe SAR symptoms were treated for 2 weeks with one of the following: Claritin-D 24 Hour (a combination tablet formulation of loratadine 10 mg in the coating and pseudoephedrine sulfate 240 mg in an extended-release core), Claritin-D 12 Hour (a combination tablet formulation of loratadine 5 mg in the tablet coating and 120 mg pseudoephedrine sulfate, 60 mg in the coating and 60 mg in the core), or placebo. Claritin-D 24 Hour and Claritin-D 12 Hour were consistently superior to placebo (P < 0.01) in reducing total, nasal, and nonnasal symptom scores. Patients in the Claritin-D 24 Hour and Claritin-D 12 Hour groups also had significantly greater (P 相似文献   

A leukotriene and thromboxane inhibitor (Sch 37224) blocks antigen-induced immediate and late responses and airway hyperresponsiveness in allergic sheep

Peptide leukotrienes and thromboxane A2 are putative mediators of allergen-induced late responses and allergen-induced airway hyperresponsiveness (AHR), respectively. Sch 37224 blocks antigen-induced leukotriene D4 and thromboxane B2 release in guinea pig lung fragments. It also inhibits leukotriene-mediated allergic guinea pig bronchospasm. Sch 37224 was, therefore, tested in allergic sheep (n = 6) with documented immediate and late airway responses and AHR to inhaled Ascaris suum antigen. For these studies, base-line airway dose-response curves to histamine and carbachol were determined on the same day. The sheep were challenged 1 to 2 days later with Ascaris suum antigen, once after placebo treatment and once after 10 mg/kg of Sch 37224, administered orally 18 and 2 hr before challenge (total dose, 20 mg/kg). Airway dose-response curves were subsequently performed 24 hr after antigen challenge. In the placebo trial, antigen challenge caused significant peak immediate and peak late increases over base line in specific lung resistance (SRL) of 286 +/- 51 and 196 +/- 29%, respectively. SRL returned to baseline values 24 hr later, but the sheep had AHR to both histamine and carbachol as indicated by 2.6- and 3.1-fold increases in the slopes of the dose-response curves (P less than .05). Sch 37224 treatment reduced the peak immediate and peak late increases in SRL to 128 +/- 32 and 43 +/- 17%, respectively (both P less than .05 vs. placebo). Furthermore, 24 hr later, the antigen-induced AHR to both histamine and carbachol was blocked (P less than .05 vs. placebo).(ABSTRACT TRUNCATED AT 250 WORDS)     

丙酸氟替卡松鼻喷雾剂联合氯雷他定治疗变应性鼻炎

【目的】观察丙酸氟替卡松鼻喷雾剂、氯雷他定单独及联合应用治疗常年性变应性鼻炎的临床疗效。【方法】选择163例临床确诊为持续性变应性鼻炎患者,按照2004年兰州标准分为轻度和中、重度。轻度、中重度组内又随机分为3组,分别予以丙酸氟替卡松鼻喷雾剂（200μg,1次／d）、氯雷他定片（10mg,1次／d）及两药联合治疗。比较各组治疗前后总的鼻部症状和体征积分,进行疗效评价。【结果】轻度组单用丙酸氟替卡松、氯雷他定、联合用药其有效率分别为93．56％、88．00％和96．43％,各组有效率差异无显著性（x2=1．45,P〉0．05）。而中重度组有效率则分别为70．37％、59．09％和93．33％,前两组之间有效率差异无显著性,;而前两组与联合用药组之间有效率差异均有显著性（x2=5．180、x2=8．923,均P〈0．05）。【结论】丙酸氟替卡松鼻喷雾剂、氯雷他定单一疗法与联合用药治疗轻度常年性变应性鼻炎疗效无明显差别,两者联合应用治疗中重度常年性变应性鼻炎比单独应用疗效显著。     

Loratadine versus cetirizine: assessment of somnolence and motivation during the workday

OBJECTIVE: This parallel-group, double-blind study compared the somnolence and motivation profiles of 2 second-generation antihistamines, loratadine and cetirizine, in patients with allergic rhinitis. BACKGROUND: Second-generation antihistamines were developed to provide symptomatic relief from allergic disorders without the unwanted side effects of first-generation antihistamines, including somnolence. Recent research has indicated that not all second-generation antihistamines are comparable with respect to somnolence and other cognitive processes. METHODS: Patients aged > or = 12 years and actively exhibiting symptoms of allergic rhinitis were randomized to 2 treatment groups to receive 10 mg loratadine or 10 mg cetirizine daily at 8:00 AM for 1 week. After patients took the medication, their somnolence and degree of motivation to perform activities were recorded in an electronic diary using a visual analog scale 4 times during the workday (8:00 AM, 10:00 AM, noon, and 3:00 PM). RESULTS: Sixty patients (31 men, 29 women) were randomized to treatment. Somnolence scores were similar for both groups at baseline and at the time of dosing (8:00 AM). However, there was a statistically significant difference in somnolence scores between the loratadine and cetirizine groups at 10:00 AM (P = 0.008), noon (P = 0.001), and 3:00 PM (P < 0.001), with the cetirizine group showing a greater degree of somnolence. The scores on motivation to perform activities were similar for both groups at the baseline and 8:00-AM measurements. In parallel with the somnolence scores, there were statistically significant differences in motivation scores between the loratadine and cetirizine groups at 10:00 AM (P = 0.014), noon (P = 0.001), and 3:00 PM (P < 0.001), indicating that patients taking loratadine were relatively more motivated during the workday. CONCLUSION: The results of this study demonstrate that in patients aged > or = 12 years who had allergic rhinitis, cetirizine use promoted somnolence and decreased motivation to perform activities during the workday compared with loratadine.     

Delayed genomic and acute nongenomic action of glucocorticosteroids in seasonal allergic rhinitis

BACKGROUND: Glucocorticosteroids are effective in the treatment of allergic rhinitis, a disease characterized by a variety of symptoms, e.g. rhinorrhea and itching. The time course of symptomatic relief for allergic rhinitis by steroids has not been examined in detail to date, although the onset of steroid action is one of the main discriminations between genomic and nongenomic actions of steroids. We therefore investigated the time course of subjective and objective measures of nasal affection after steroid administration in patients with allergic rhinitis following specific allergen challenge. METHODS: Six female and 18 male volunteers (median age 26 years) with a history of allergic rhinitis but currently free of symptoms were included in this randomized, placebo-controlled, double-blind, three-period crossover study. A single dose of either betamethasone (60 mg), methylprednisolone (400 mg) or placebo was given intravenously, 5 min after intranasal allergen provocation. After 10, 20, 60, 150 and 240 min, nasal itching and nasal obstruction were assessed using a standardized visual analogue scale. In addition, nasal airflow was measured by anterior rhinomanometry. RESULTS: Nasal itching was markedly reduced following either of the two steroids within 10 min after administration of study drug. Itching was depressed by 38% following betamethasone (P<0.05) and by 18% following methylprednisolone (P=0.07) compared with placebo. Nasal airflow and nasal obstruction were not significantly altered by steroids during the first 2 h of the study. However, after 150 min, nasal airflow was 21% rsp. 19% higher after methylprednisolone and betamethasone (P<0.05) compared with placebo. After 240 min, nasal airflow was increased by 20% following betamethasone (P<0.05) and by 19% following methylprednisolone. Nasal obstruction was also beneficially affected by both steroids 150 and 240 min after administration compared with placebo (P<0.05 for both time points following betamethasone). CONCLUSION: This study for the first time shows rapid in vivo effects of external glucocorticosteroids in humans. Itching, a pathophysiologically complex sensation, is favourably influenced by steroids within 10 min, therefore presumably via nongenomic mechanisms. Though no detailed mechanisms can be derived from this study, steroid interaction with receptors in the central nervous system may play an important role in mediating this effect.     

Cetirizine and loratadine: a comparison using the ED50 in skin reactions

To quantify objectively the comparative potencies of the antihistamines, loratadine and cetirizine, we determined the dose that inhibits histamine-induced skin reactions by 50% of the maximum response (ED50) for each drug. Cetirizine at 2.5, 5 or 10 mg, loratadine at 10, 20 or 40 mg or placebo were given to 14 healthy female subjects in a randomized double-blind crossover design. Inhibition of the wheal and flare response to the histamine prick test (10, 100 and 500 mg/ml) was evaluated. Depending on the histamine concentrations, the ED50s for wheals were in the ranges 4.3 - 4.7, 2.1 - 2.2 and 1.7 - 1.9 mg cetirizine, 2, 4 and 6 h after dosing, respectively. For loratadine, the ED50 for wheals were in the ranges 35.6 - > 40, 9.1 - 24.1 and 9.1 - 13.9 mg, 2, 4 and 6 h after dosing, respectively. Calculation of the ED50 demonstrated that, on average, cetirizine is seven to nine times more potent than loratadine at inhibiting wheal and flare reactions.     

Onset of action of loratadine and placebo and other efficacy variables in patients with seasonal allergic rhinitis.

In a double-blind study, 185 patients with seasonal allergic rhinitis were randomly assigned to receive 10 mg of loratadine or placebo once daily for three days. On day 1 of treatment, the onset of relief of symptoms within 30 minutes of drug administration was reported by 13% of the loratadine-treated patients and by 4% of the placebo patients (P less than 0.05). At two hours after drug administration, 65% of the loratadine-treated patients and 48% of the placebo patients reported symptom relief. On day 3, the loratadine-treated patients reported a significantly greater relief of symptoms, and according to both physician and patient evaluations, the treatment response was significantly superior in the loratadine-treated than in the placebo patients. The incidence of sedation was 2% in the loratadine group and 1% in the placebo group.     

Inhibitory effect of cetirizine 2HCl on eosinophil migration in vivo

The effect of a potent antihistamine, cetirizine, was studied on allergic patients and normal subjects by means of an in-vivo 'skin window' technique. All subjects showed significant inhibition of skin-test responses to grass pollen, compound 48/80, histamine and methacholine, after administration of a single dose (10 mg) of cetirizine. Compared to placebo, cetirizine significantly decreased the eosinophils attraction at skin sites challenged with grass pollen and compound 48/80. In allergic patients no change in eosinophil migration pattern was noted with histamine and methacholine skin-tested sites. In normal subjects, compound 48/80 and histamine did not induce eosinophil accumulation and cetirizine did not modify cellular patterns as compared to placebo. These results suggest that cetirizine acts on eosinophil migration by inhibiting the release of mast cell mediators or inhibiting the eosinophilotactic mediators themselves.     

Single-patient drug trial methodology for allergic rhinitis

BACKGROUND: Historically, single-patient trials (SPTs) have been specifically designed for each patient, requiring significant time and effort for execution. There has been no previous attempt to standardize an SPT for routine commercial availability. OBJECTIVE: To validate the use of an SPT method to discriminate effectiveness and adverse events while comparing drugs/doses in patients with allergic rhinitis. DESIGN: Double-blind, randomized, 4 paired-period, multiple-crossover SPT. SETTING: Academic and commercial investigative sites. PATIENTS: Thirty-six patients with allergic rhinitis were evaluated for the most appropriate treatment; 6 of these participated in 2 different SPTs. INTERVENTIONS: Treatment of symptoms of allergic rhinitis by comparing either loratadine with chlorpheniramine maleate or loratadine with placebo in a series of SPTs. MEASUREMENTS: Effectiveness endpoints were selected from a modern, Food and Drug Administration (FDA)-approved new drug application. Expected adverse events were directly solicited; unsolicited events were also recorded. Total signs and symptoms cumulatively included sneezing, runny nose, itchy nose, teary eyes, and itchy eyes. Quality of life was measured by the most bothersome symptom and the patient's global evaluation. RESULTS: Of 42 initiated SPTs, 40 (95%) provided complete data and 1 (2%) provided partial data, resulting in 41 (98%) evaluable tests. Thirty-one evaluable SPTs compared loratadine 10 mg/d with chlorpheniramine maleate 12 mg twice daily, and 10 SPTs compared loratadine 10 mg/d with placebo. Four of 31 SPTs (13%) showed significant superiority for loratadine over chlorpheniramine maleate and 5 of 31 (16%) for chlorpheniramine maleate over loratadine. Twenty-two of 31 (71%) showed parity performance between loratadine and chlorpheniramine maleate. Loratadine was significantly superior to placebo in 3 of 10 trials (30%), consistent with rates found in 3 pivotal group trials used for FDA approval (24%, 17%, and 0%). Sleepiness could be discriminated for loratadine versus placebo and for chlorpheniramine maleate versus loratadine. CONCLUSIONS: The allergic rhinitis SPT proved to be acceptable to patients, feasible to administer, and reproducible. It can statistically discriminate effectiveness and adverse events, serving as a useful, prognostic tool in community practice.     

A review of the efficacy of desloratadine,fexofenadine, and levocetirizine in the treatment of nasal congestion in patients with allergic rhinitis

Background: Nasal congestion is the most troublesome symptom of allergic rhinitis (AR). First-generation and older second-generation antihistamines, while effective against nasal itching, sneezing, and rhinorrhea, have limited efficacy in relieving nasal congestion.Objective: This review included nasal challenge studies and clinical trials that reported the effects on nasal congestion of the newer second-generation antihista-mines desloratadine, fexofenadine, and levocetirizine.Methods: MEDLINE and EMBASE were searched for nasal challenge studies and clinical trials published in English between January 1, 1991, and January 31, 2009, using the following terms, alone or in combination: antihistamines, second-generation antihistamines, allergic rhinitis, intermittent allergic rhinitis, perennial allergic rhinitis, persistent allergic rhinitis, seasonal allergic rhinitis, nasal challenge, nasal blockage, and nasal congestion. Studies that were not active or placebo controlled, that did not evaluate change in nasal congestion scores, or that focused on treatments other than desloratadine, fexofenadine, and levoce-tirizine for nasal congestion associated with AR were excluded.Results: Twenty-six clinical trials met the criteria for inclusion in the review. In 11 placebo-controlled trials that included objective assessment of nasal congestion, desloratadine, fexofenadine, and levocetiri-zine were associated with reductions in the severity of nasal congestion through maintenance of nasal airflow. The mean AUC for nasal airflow over 6 hours was significantly greater with desloratadine compared with placebo in 3 studies (P < 0.05); placebo-controlled trials of fexofenadine and levocetirizine had similar results. In 25 placebo- and active-controlled trials that reported subject-rated symptom scores, the 3 newer antihistamines were efficacious in the treatment of nasal congestion associated with AR. In 10 trials that reported objective and/or subjective measures, desloratadine was associated with significant improvements in nasal congestion compared with placebo (P ≤ 0.05), beginning as early as the first 2 hours after allergen challenge. Fexofenadine was associated with significantly lower nasal congestion scores compared with placebo in 4 studies (P <- 0.05); nasal congestion scores were significantly reduced with levocetirizine in 3 placebo-controlled trials (P ≤ 0.005).Conclusions: In the studies reviewed, desloratadine, fexofenadine, and levocetirizine were effective in relieving the nasal congestion associated with AR compared with placebo. This effect began as early as day 2 and was consistent and progressive throughout treatment. Desloratadine, fexofenadine, and levocetirizine are appropriate options for the treatment of nasal congestion in patients with AR.     

Pharmacological and clinical evalutation of nasal obstruction: application to xylometazoline

Nasal obstruction, a prominent feature of rhinitis, may be quantified in humans by haemodynamic techniques (measuring local blood flux), static methods (measuring the geometry of nasal cavities) and dynamic methods (assessing the patency of nasal airways through the measure of resistance to air flow). These methods demonstrated the nasal decongestant activity of xylometazoline in healthy volunteers and rhinitis patients. Controlled double-blind studies established the clinical efficacy of xylometazoline in infectious and allergic (seasonal and perennial) rhinitis versus placebo and in comparison with various reference substances. The effects on nasal epithelium ciliary activity which are observed in vitro are modest and even less pronounced in vivo owing to dilution in situ and protective physiological processes.     

Nitric oxide attenuates platelet-activating factor induced nasal airway plasma extravasation in healthy subjects

BACKGROUND: Paranasal sinuses and the nose are important sources of nitric oxide (NO) in humans but the relevance of NO production to the control of nasal airway plasma exudation and its response to inflammatory mediators such as platelet-activating factor (PAF) in healthy subjects is not well known. DESIGN: In this study we aimed to evaluate the effect of the nitric oxide synthase (NOS) inhibitor NG L-arginine methyl ester (L-NAME) on nasal airway plasma extravasation at baseline and after an acute challenge with PAF that induces most symptoms of rhinitis. Eleven healthy subjects were enrolled in the study. Plasma extravasation in the nasal airway was assessed by measuring the albumin content of nasal lavage. RESULTS: PAF challenge caused a significant increase in concentrations of albumin in the nasal lavage fluid (from 0.59 +/- 0.13 mg dL(-1) to 2.46 +/- 0.45 mg dL(-1)) after placebo. Pretreatment with L-NAME significantly prevented the increase of albumin in the nasal lavage fluid induced by PAF as compared to placebo (from 0.53 +/- 0.11 mg dL(-1) to 1.70 +/- 0.28 mg dL(-1); P < 0.005). CONCLUSION: Topical administration of a NO inhibitor is able to attenuate the nasal airway plasma extravasation induced by PAF, suggesting that NO release in vivo is involved in the nasal response to PAF.     

药物和聚焦超声治疗变应性鼻炎的随机对照研究

目的探讨药物和聚焦超声治疗中-重度持续性变应性鼻炎(allergic rhinitis,AR)的临床疗效及安全性。方法100例中-重度持续性AR根据随机分配方案(完全随机设计),按1∶1比例随机分配到药物组和聚焦超声组,每组各50例。药物组予鼻用皮质类固醇布地奈德鼻喷剂,以及抗组胺药氯雷他定,治疗4周;聚焦超声组使用CZB型超声波鼻炎治疗仪进行治疗。治疗结束后随访6个月进行疗效和安全性评估。结果药物组显效率24%,有效率36%,无效率40%,总有效率为60%;聚焦超声组显效率38%,有效率50%,无效率12%,总有效率为88%。两组总有效率差异有统计学意义(P<0.05)。术后患者均未出现并发症。结论鼻内镜下采用聚焦超声治疗中-重度持续性AR具有操作简单、创伤小等优点,安全性高,近期效果优于药物组。     

Loss of size-selectivity at histamine-induced exudation of plasma proteins in atopic nasal airways

Plasma proteins occur in the airway lumen in inflammatory airway diseases. This study tests the hypothesis that airway microvascular-epithelial exudation of plasma proteins, as induced by a non-injurious inflammatory mediator, is characterized by loss of size-selectivity. Using a nasal pool-device, the nasal mucosa of 10 allergic individuals, without current disease, was sequentially exposed to saline and histamine (40 and 400 microg ml(-1)). Nasal lavage fluid and blood-levels of albumin (69 kD) and alpha2-macroglobulin (720 kD) were determined. Histamine produced concentration-dependent exudation of albumin and alpha2-macroglobulin. The albumin/alpha2-macroglobulin concentration ratio of the saline lavage fluid (baseline) was 40+/-19. However, at the histamine challenges the ratios were 25+/-3 and 22+/-2, respectively, which did not differ from that of circulating plasma (22+/-2). We conclude that there is minor and size-selective luminal entry of plasma proteins at baseline. However, at concentration-dependent exudative responses to histamine, plasma proteins enter the airway lumen without being sieved. These data indicate that inflammatory stimulus-induced extravasation, lamina propria distribution and paracellular epithelial passage of plasma occur with minimal size-selectivity. Inferentially, the full immunological capacity of plasma proteins may readily be made available at the surface of human intact airway mucosa.