Comparative clinical efficacy, onset and duration of action of levocetirizine and desloratadine for symptoms of seasonal allergic rhinitis in subjects evaluated in the Environmental Exposure Unit (EEU).

The Environmental Exposure Unit, an indoor pollen challenge system to test anti-allergic medications, was used to compare the onset and duration of action and the efficacy of levocetirizine and desloratadine, two recently developed H1-antagonists. In this double-blind, placebo-controlled, parallel-group study, qualified subjects were randomised to once-daily levocetirizine 5 mg (n = 141), desloratadine 5 mg (n = 140) or placebo (n = 92) and exposed to ragweed pollen on two consecutive days (7 h and 6 h). Symptoms were self-rated every 30 min. On both days, levocetirizine produced a greater improvement in the major symptom complex score (primary efficacy variable) than desloratadine (p = 0.015); both were better than placebo (p < 0.001). Levocetirizine acted earlier (1 h vs. 3 h) and produced greater symptom relief at 24 h than desloratadine (p = 0.003). Levocetirizine also alleviated nasal obstruction better than desloratadine (p = 0.007) on day 1; and better than placebo (p = 0.014) after the second dose on day 2, which was not observed with desloratadine. Levocetirizine and desloratadine were safe and well tolerated.

Onset of action of intranasal budesonide (Rhinocort aqua) in seasonal allergic rhinitis studied in a controlled exposure model.

BACKGROUND: Intranasal budesonide aqueous nasal spray (BANS) is recognized as an efficacious treatment for seasonal allergic rhinitis (SAR), but the time to onset of action is not known. OBJECTIVE: The primary objective was to evaluate the time at which the onset of action of BANS in the symptomatic relief of seasonal allergic rhinitis becomes evident within 12 hours after a single dose in a controlled ragweed pollen exposure setting. METHODS: The study was of a double-blind, randomized, parallel-group design, testing BANS (64 microgram and 256 microgram) and placebo on ragweed-sensitive subjects with symptoms for at least 1 year by using a controlled pollen challenge system (Environmental Exposure Unit). The efficacy variables were the combined nasal score (the sum of blocked nose, runny nose, and sneezing-itchy nose), individual nasal symptoms, overall evaluation of treatment efficacy reported by participants on diaries, and peak nasal inspiratory flow (PNIF). RESULTS: A total of 217 participants were treated with BANS or placebo. At 7 to 12 hours, BANS was better than placebo in reducing combined nasal and blocked nose symptoms. For PNIF, the time to onset of action was shortest for 256 microgram of BANS relative to placebo (3 hours, P =.003). BANS 64 microgram was better than placebo in reducing the individual scores of blocked nose, runny nose, and sneezing-itchy nose from 3 to 5 hours after administration. Treatment efficacy was higher for those receiving BANS compared with placebo starting at 5 hours. All treatments were well tolerated, and no specific adverse events occurred. CONCLUSIONS: The onset of action of intranasal BANS was 7 hours according to combined nasal and blocked nose symptom scores. Evidence of earlier response was observed at 3 hours for runny nose and PNIF.

Environmental exposure unit: a system to test anti-allergic treatment.

LEARNING OBJECTIVES: Reading this article will enable readers to recognize the Environmental Exposure Unit (EEU), its historic development and its current role as a system to test anti-allergic treatment; to recognize clinical relevance of this test system and its relationship with other pollen challenge methods of evaluation of anti-allergic medication; and, to recognize variables associated with standard clinical studies of anti-allergic medication. Readers will review four studies of antihistamines tested in the Environmental Exposure Unit, three studies on nasal corticosteroids, one on topical eye drops and one on immunotherapy conducted in the EEU. DATA SOURCES: The EEU has been in operation since 1985 preceded by a prototype challenge system to assess respiratory effects of urea formaldehyde foam insulation. A number of studies on the onset of action and efficacy of different antihistamines and nasal corticosteroids as well as other treatments have been completed producing accurate and consistent results influenced to some extent by study designs. STUDY SELECTION: Studies of commonly used antihistamines and nasal corticosteroids are discussed in detail and represent several of the studies undertaken to date in the EEU. RESULTS: Controlled ragweed pollen exposure using the EEU has shown that some antihistamines demonstrate an onset of action within 30 minutes while others have taken up to 3 hours to produce significant effect. Nasal corticosteroids evidenced the onset of clinical improvement at 5 to 6 hours with significance over placebo between 6 and 12 hours depending on dose. CONCLUSION: The EEU is an effective pollen delivery system that accurately and consistently determines the onset of action and efficacy of anti-allergic treatment in large groups of subjects. It eliminates variables associated with various other methods of evaluation of these medications but does not supplant the need for such evaluations.

Onset of action and efficacy of terfenadine, astemizole, cetirizine, and loratadine for the relief of symptoms of allergic rhinitis.

BACKGROUND: Terfenadine, astemizole, cetirizine, and loratadine are compared in their abilities to produce relief of symptoms of allergic rhinitis. OBJECTIVE: The aim of this study was to compare the onset of action and efficacy of the study medications. METHODS: 111 ragweed-sensitive subjects were primed with pollen in the Environmental Exposure Unit. Study entry required adequate symptoms over a 3 hour exposure to 5000 +/- 300 grains/m3 of ragweed pollen. On the test day, subjects were given a single dose of either terfenadine 60 mg (22), astemizole 10 mg (22), cetirizine 10 mg (23), loratadine 10 mg (22), or placebo (22) when sufficiently symptomatic after a 60-minute exposure. Allergen levels were maintained and symptoms recorded every 30 minutes. RESULTS: Proportions of subjects with clinically important relief were cetirizine, 69.6%; terfenadine, 54.5%; loratadine, 50.0%; astemizole, 40.9%; and placebo, 31.8% but differences weren't significant between treatment groups (P = .119). Survival curves for times to onset of clinically important relief for the four treatment groups were not different (P = .119). Subjects realizing definitive relief were cetirizine, 65.2%; terfenadine, 45.5%; loratadine, 31.8%; placebo, 27.3%; and astemizole, 22.7% (P = .023). Survival analysis of onset time for definitive relief found significant differences (P = .010). The ranking was cetirizine --> terfenadine --> loratadine --> astemizole (quickest to slowest). Global evaluation based on subject willingness to take the medication again yielded percentages: cetirizine, 82.6%; terfenadine, 66.7%; astemizole, 63.6%; loratadine, 40.9%; and placebo, 36.4% (P = .036). CONCLUSION: Cetirizine and terfenadine continuously ranked higher in terms of onset of action and efficacy, while loratadine and astemizole ranked lower. Significance was detected in definitive relief and relative efficacy.

Onset of action, efficacy, and safety of a single dose of fexofenadine hydrochloride for ragweed allergy using an environmental exposure unit.

BACKGROUND: Fexofenadine hydrochloride is the active acid metabolite of terfenadine. Fexofenadine's anti-allergic properties require confirmation in a clinical setting. OBJECTIVE: The purpose of this study was to characterize the time to onset of clinically important relief of symptoms of allergic rhinitis in subjects taking single doses of either 60 mg or 120 mg fexofenadine HCl, or placebo, after exposure to ragweed pollen in a controlled environment. Other objectives were to assess the efficacy and safety of single doses of fexofenadine HCl. METHODS: One hundred forty-six ragweed-sensitive subjects were primed in the off-season with ragweed pollen in the environmental exposure unit. One hundred thirty-six subjects who adequately responded to priming entered a single-dose placebo phase. Placebo-responders were disqualified from the study, leaving 99 subjects with adequate symptoms to be randomized and given a single dose of either fexofenadine HCl 120 mg (33), 60 mg (33) or placebo (33), after 60 minutes of allergen exposure. Exposure continued over five hours and subjects recorded symptoms every 20 minutes. This study was of a randomized, placebo-controlled, double-blind, parallel design. RESULTS: Median time to onset for relaxed criteria clinically important relief was 60 minutes for both fexofenadine treatment groups, and 100 minutes for placebo (P = .018). The proportion with relief was 82% at 60 mg, 85% at 120 mg, and 64% for placebo. Treated groups had reductions in symptom scores double that of placebo. CONCLUSIONS: Fexofenadine is safe and efficacious at single doses of 60 mg and 120 mg. Average time to onset was 60 minutes using controlled pollen exposure in an environmental exposure unit.

Efficacy of immunotherapy to ragweed antigen tested by controlled antigen exposure.

BACKGROUND: Immunotherapy is a recognized component in the management of allergic rhinitis. Its efficacy has been evaluated in a number of clinical field trials. These methods of evaluation are limited by control of antigen exposure. OBJECTIVE: A study was designed to evaluate the efficacy of immunotherapy in ragweed-induced rhinoconjunctivitis using an environmental exposure unit. METHODS: Forty-three subjects were grouped into (1) immunotherapy group: ragweed-allergic subjects on maintenance ragweed immunotherapy for at least 2 years (N = 16), (2) positive control group: ragweed-allergic subjects who had never received immunotherapy (n = 16), and (3) negative control group: ragweed-nonallergic subjects (N = 11). Ragweed specific skin tests and ragweed IgE levels were obtained prior to exposure. The study was done in a room where levels of 2,500 to 3,000 grains m3 of ragweed were maintained over three hours. Symptoms were recorded every 15 minutes. RESULTS: Nasal symptoms in the immunotherapy group were significantly less than in the positive control group after 45 minutes (P = .025). Significant differences were not observed for ocular symptoms. Combined nasal and ocular scores were 50% less in the immunotherapy group than in the positive control group by 75 minutes (P = .039). Ragweed-specific skin tests and IgE were significantly less in the immunotherapy group than in the positive control group. Rhinoconjunctivitis symptoms in the negative control group were absent throughout. CONCLUSIONS: Controlled ragweed pollen exposure in this setting demonstrated that ragweed immunotherapy significantly reduced symptoms of ragweed-allergic rhinitis but had no significant effect on ocular symptoms. This system presents opportunities for additional studies on immunotherapy for allergic respiratory conditions.

A randomized, double-blind, placebo-controlled, controlled antigen delivery study of the onset of action of aerosolized triamcinolone acetonide nasal spray in subjects with ragweed-induced allergic rhinitis.

BACKGROUND: Clinically apparent relief of nasal symptoms of allergic rhinitis is generally recognized to occur within 3 days to 1 week when intranasal corticosteroids are used. OBJECTIVE: A study was designed to evaluate the onset of action of triamcinolone acetonide (TA) in patients with ragweed-induced allergic rhinitis with an environmental exposure unit (EEU). METHODS: Eighty-five adults with ragweed-induced allergic rhinitis were primed with ragweed allergen in the EEU. Symptoms were recorded during a baseline exposure in the EEU, and subjects were randomized with a 5:1 ratio to receive either TA 400 micrograms (n = 71) or its propellant (n = 14). Subjects received study medication for 7 days under supervision in the morning and returned to the EEU in the evening for ragweed allergen challenge and symptom assessment. Clinically apparent onset of action was defined as a 25% decrease in symptom scores from baseline. RESULTS: A mean reduction in nasal congestion from baseline of greater than 25% (onset of action) was observed in the TA group, but not in the placebo group, by 10 hours. This was also observed for itching of the nose or palate and a combined measure of symptoms. In addition, the proportion of subjects with less nasal congestion after 1 day of treatment was greater in the TA group (41%) than in the placebo group (7%) (p less than 0.05). CONCLUSION: The unexpected early relief of symptoms observed in the TA group and, to a lesser extent in the placebo group, has important clinical implications in the treatment of allergic rhinitis.

Intranasal fluticasone propionate versus loratadine in the treatment of adolescent patients with seasonal allergic rhinitis.

Fluticasone propionate (FP) is a topical corticosteroid with minimal systemic activity. We examined safety and compared the efficacy of FP aqueous nasal spray, 200 micrograms every day with loratadine tablets, 10 mg by mouth every day in 240 adolescents with ragweed pollen-induced seasonal allergic rhinitis for 4 weeks in a randomized, double-blind, parallel-group study. Nasal and eye symptoms were recorded daily on a 4-point (0 to 3) scale. A higher percentage of symptom-free days was observed for nasal blockage on waking during treatment with FP (p < 0.0001). Significant results were also obtained for all other nasal symptoms when analyzed for both symptom-free days and symptom scores. No differences were found for eye irritation symptoms (p = 0.14). Morning and evening nasal peak inspiratory flow (PIF) was recorded daily by 57 subjects. FP treatment was associated wit significantly higher PIF values than loratadine both morning (p = 0.0051) and evening (p = 0.0036). A greater improvement over 4 weeks was observed for PIF morning values in the FP group (p = 0.008) but not for evening values (p = 0.358). Statistically significant correlations were found for nasal blockage and PIF in the morning (r = -0.54, p = 0.0001) and in the evening (r = -0.46, p = 0.008).

Efficacy and safety of intranasal budesonide in the treatment of perennial rhinitis in adults and children.

The efficacy and safety of intranasal budesonide were evaluated in a placebo-controlled double-blind study of 51 children (6 to 18 years) and 48 adults with perennial (allergic or nonallergic) rhinitis. The trial commenced with a 2-week baseline period without treatment for perennial rhinitis. This was followed by a treatment period of 4 weeks. Treatment was either intranasal budesonide 200 micrograms bid or matching placebo bid. Nasal symptoms were rated daily on a scale from 0 (absent) to 3 (severe). Safety was monitored by laboratory assessments (hematology, blood chemistry, urinalysis) as well as by rhinoscopy and recording of adverse events. Budesonide reduced the nasal symptoms as compared with baseline. The reduction was greater than in the placebo group and symptoms were improved significantly on budesonide treatment compared with placebo. Laboratory assessments demonstrated no differences between budesonide and placebo. Adverse responses to intranasal budesonide were few and minor, and compliance was high. Intranasal budesonide, 200 micrograms bid, thus appears to be efficacious, highly acceptable, and safe for the treatment of perennial rhinitis.