The purpose of this study is to determine the onset of action of two commercially available
over-the-counter antihistamines (Loratadine and Fexofenadine) in a model of seasonal
allergic rhinitis (SAR). Participants undergo sensitization exposures to Mountain Cedar
(juniperus ashei) pollen in a Biogenics Research Chamber; those who demonstrate an adequate
allergic response determined by the Major Symptom Complex (MSC) score will then receive
||Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Treatment
|Ages Eligible for Study:||18 Years|
|Genders Eligible for Study:||Both|
|Accepts Healthy Volunteers:||No|
- Female participants of child bearing potential must demonstrate a negative urine
pregnancy test at Screening (Visit 1) and Visit 4 (prior to randomization) and agree
to use (and/or have their partner use) 2 acceptable methods of birth control
beginning at the Screening visit and throughout the study.
- Willing to stop use of current decongestant and allergy medications at the start of
the washout period (Visit 1) and during the trial.
- Documented history or participant-reported history of seasonal allergic rhinitis
caused by mountain cedar pollen within the last 2 years and documented or
participant-reported symptoms over at least the last 2 mountain cedar allergy
- Documented skin testing (prick with wheal ? 4 mm larger than the diluent) within the
last 1 year to mountain cedar pollen present.
- Capable of reading English.
- Body mass index (BMI) <35.
- Any significant medical condition which, in the judgment of the investigator, is a
contraindication to the use of loratadine, fexofenadine or might interfere with the
trial. These may include thyroid disease (e.g., hyperthyroidism, hypothyroidism),
uncontrolled diabetes mellitus, coronary heart disease, ischemic heart disease,
elevated intraocular pressure, prostatic hypertrophy.
- Have started allergen immunotherapy within 1 month preceding enrollment or
participants starting allergen immunotherapy or anticipating immunotherapy dose
change during the trial. Xolair (omalizumab) may not be used within 4 years prior to
- Known allergy or intolerance to loratadine, desloratadine, or fexofenadine.
- History of rhinitis medicamentosa.
- Use of systemic (oral, rectal, injectable), topical (up to 1% topical hydrocortisone
is permitted), or nasal corticosteroids in the last 30 days or current or expected
use of disallowed medications as listed in the protocol.
- Asthma, with the exception of mild intermittent asthma