This study is to evaluate the effectiveness of a new drug on congestion in subjects with seasonal allergic rhinitis. This effect will be compared to placebo and to the decongestant, pseudoephedrine.

Inclusion Criteria:

• Subjects must be 18 to 65 years of age, of either sex, and of any race.
• Subjects must have a history of SAR due to ragweed for the last two consecutive ragweed seasons.
• Subjects must be skin-test positive for the ragweed pollen allergen used in the Environmental Exposure Unit (pollen chamber at the Screening Visit or within 12 months prior to the Screening Visit.
• Subjects must develop a pre-defined severity of allergy symptoms within 90-minute after entering the pollen chamber during the pollen challenge at the Priming visit (Visit 2), and prior to dosing (Visit 3), in order to qualify for the study.
• Female subjects of childbearing potential must have a negative serum pregnancy test at Screening and a negative urine pregnancy test prior to randomization at the Treatment Visit. Female subjects and female partners of male subjects must be using an acceptable form of birth control during the study.
• Blood pressure and pulse rate must be within normal ranges.

Exclusion Criteria:

• Subjects who have had an upper or lower respiratory tract infection within approximately 28 days (4 weeks) before Priming (Visit 2) and thereafter.
• Subjects who have a dependence upon nasal, oral, or ocular decongestants, nasal topical antihistamines, or nasal steroids, in the opinion of the investigator.
• Subjects with any clinically significant condition or situation, other than the condition being studied that, in the opinion of the investigator, would interfere with the study evaluations or optimal participation in the study.
• Subjects who have used any investigational drugs, including placebo, within 30 days of Screening or for the duration of this stud, or who are participating in any other clinical study.
• Subjects with a history of rhinitis medicamentosa.
• Subjects with a history of anaphylaxis or severe or serious reaction to skin testing.
• Subjects who are being medically treated for any of the following conditions: narrow-angle glaucoma, increased intraocular pressure, urinary retention, hypertension, severe coronary artery disease, ischemic heart disease, diabetes mellitus, hyperthyroidism, renal impairment, or prostatic hypertrophy; current treatment with monoamine oxidase (MAO) inhibitors.
• Subjects with a history of a positive test, or are symptomatic, for HIV, TB (not due to vaccination), and hepatitis B (not due to vaccination) or hepatitis C.
• Subjects with asthma that requires medication other than occasional (<=3 uses per week) use of an inhaled short-acting b-2 agonist.