Efficacy of Levocetirizine and Cetirizine in Reducing Symptoms of Seasonal Allergic Rhinitis in Ragweed Sensitive Subjects

Trial to Compare the Efficacy of Levocetirizine and Cetirizine in Reducing Symptoms of Seasonal Allergic Rhinitis in Ragweed Sensitive Subjects Exposed to Pollen Challenge in an Environmental Exposure Unit (EEU).

Status

Completed

Phases

Phase 3

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00544388

Enrollment

570

Registered

2007-10-16

Start date

2004-04-30

Completion date

2004-07-31

Last updated

2013-12-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Rhinitis, Allergic, Seasonal

Keywords

Levocetirizine dihydrochloride, Xyzal tablet

Brief summary

Controlled conditions of the EEU allow a reliable assessment of the efficacy and a determination of the action onset, action intensity and duration of effect of levocetirizine and cetirizine in order to establish the relative efficacy of these two drugs available for the treatment of SAR.

Interventions

DRUGlevocetirizine dihydrochloride

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

DOUBLE

Eligibility

Sex/Gender

ALL

Age

16 Years to No maximum

Healthy volunteers

Inclusion criteria

* Male/Female, aged \>= 16 years * seasonal allergic rhinitis that required pharmacologic therapy each year during the last 2 ragweed pollen seasons * documented seasonal allergy to ragweed pollen * total symptom score of at least 18 points.

Exclusion criteria

* nasal anatomic deformities ? 50% obstruction * acute sinusitis within 30 days of Period 2 * initiated or advanced an immunotherapy regimen * immunotherapy injections within 48 hours of pollen exposure * impaired hepatic function * history of malignancy * intolerance to histamines * asthma requiring medication more than occasionally

Design outcomes

Primary

Measure	Time frame
Mean change from baseline in major symptom complex score over Period 2 (21-29 hours after drug intake on Day 2).	—

Secondary

Measure	Time frame
Mean change from baseline in MSC score over each 2-hour interval.	—

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026