Inclusion Criteria:

• Must be 18 years of age and older, of either sex, and of any race.
• Must be clinically symptomatic at the Screening Visit (Day -7 to -4).
• Must be clinically symptomatic at the Baseline Visit (Day 1).
• At the Screening Visit, subject must have complaints of sleep disturbance while symptomatic with seasonal allergic rhinitis and must have a score of 30 or greater for the Sleep Disturbance Sleep Scale (items 1,3,7 and 8).
• At the Baseline Visit, subject must have complaints of sleep disturbance and daytime somnolence while symptomatic with seasonal allergic rhinitis and must have a score of 30 or greater for the Sleep Problems Index II (SLP9) and 30 or greater for the Daytime Somnolence Sleep Scale (items 6, 9, and 11).
• Must have a 2-year or longer history of seasonal allergic rhinitis occurring during the same season(s) as the current study.
• Must have skin tests (prick or intradermal) positive for outdoor allergens common in subjects with seasonal allergic rhinitis prevalent during the time of this study, such as, trees, grasses, weeds, ragweed, and molds. The skin tests should be performed at the Screening Visit if not done within 12 months prior to the Screening Visit.
• Must be free of clinically significant disease that would interfere with study evaluations.
• Female subjects of childbearing potential are required to use a medically accepted method of birth control prior to the Screening Visit and during the study, or provide documentation of surgical sterilization (eg, hysterectomy, tubal ligation). Females of childbearing potential should be counseled in the appropriate use of birth control while in this study. Females who are not sexually active at study enrollment must consent to the use a medically accepted method of birth control if/when they become sexually active during study participation.
• Female subjects of childbearing potential must have a negative urine pregnancy test at the time of enrollment at the Baseline Visit.

Exclusion Criteria:

• Subject is a female who is pregnant, intends to become pregnant during the study, or is nursing.
• Subject has evidence of nasal polyps, deviated septum, or other intranasal anatomical obstruction(s) that would interfere with nasal airflow.
• Subject has acute or chronic sinusitis currently being treated with antibiotics and/or topical or oral nasal decongestants.
• Subject has had an acute respiratory infection within 2 weeks of the Screening Visit.
• Subject has been diagnosed with clinically relevant sleep problems unassociated with allergies (eg, sleep apnea, narcolepsy, frequent nocturnal awakenings due to asthma).
• Subject is a female who is pregnant, intends to become pregnant during the study, or is nursing.
• Subject has evidence of nasal polyps, deviated septum, or other intranasal anatomical obstruction(s) that would interfere with nasal airflow.
• Subject has acute or chronic sinusitis currently being treated with antibiotics and/or topical or oral nasal decongestants.
• Subject has had an acute respiratory infection within 2 weeks of the Screening Visit.
• Subject has been diagnosed with clinically relevant sleep problems unassociated with allergies (eg, sleep apnea, narcolepsy, frequent nocturnal awakenings due to asthma).
• Subject has complained (within 12 months of the Screening Visit to their health-care provider) of difficulty sleeping or daytime sleepiness while not experiencing allergic rhinitis symptoms, and continue with these complaints.
• Subject has snoring associated with an enlarged uvula or other upper airway pathology.
• Subject has had episodes of snoring associated with gasping or choking.
• Subject has awakened suddenly, on more than 1 occasion during the month preceding the Screening Visit, with a gasping or choking feeling.
• Subject requires the use of oral appliances at night for the relief of bruxism (teeth gnashing) or temporomandibular joint problems.
• Subject has a diagnosis of asthma with daytime and nighttime asthma symptoms not controlled by short-acting β-2 adrenoceptor agonists.
• Subject has a dependence on nasal, oral or ocular decongestants, nasal topical antihistamines, or nasal steroids.
• Subject is currently undergoing a progressive course of immunotherapy (hyposensitization). Subjects on a regular maintenance schedule prior to the Screening Visit and wish to remain on this schedule during the study are eligible for study inclusion; however, subjects may not receive hyposensitization treatment within 24 hours prior to any study visit.
• Subject smokes, or is an ex-smoker who has smoked within the previous 6 months.
• Subject has a concomitant medical problem that may interfere with participation in the study, eg, repeated migraine episodes, uncontrolled convulsive disorders.
• Subject has any of the following clinical conditions: Active or quiescent tuberculosis infection of the respiratory tract, untreated fungal, bacterial, systemic viral infections or ocular herpes simplex.
• Subject is participating in any other clinical study(ies).
• Subject is allergic to or has a sensitivity to the study drug or its excipients.
• Subject is a night-shift worker or does not have a standard “asleep at night/awake during the day” cycle.