Conditions: Rhinitis
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 255
Healthy volunteers: no

Brief summary:
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 drug.

Detailed description:

Arms:
arm 1: Participants will receive one dose of loratadine following randomization at 120 minutes of exposure during visit 4. arm 2: Participants will receive one dose of fexofenadine following randomization at 120 minutes of exposure during visit 4. arm 3: Participants will receive one dose of placebo following randomization at 120 minutes of exposure during visit 4.

Interventions: intervention 1: loratadine intervention 2: fexofenadine intervention 3: placebo to loratadine intervention 4: placebo to fexofenadine
Intervention descriptions: intervention 1: loratadine, one 10 mg tablet, orally intervention 2: fexofenadine, one 180 mg tablet, orally intervention 3: one tablet, orally intervention 4: one tablet, orally

Protocol document: