Approximately ¹⁄₃ of all obstructive sleep apnoea (OSA) patients have poor upper airway muscle activity during sleep which contributes to the repetitive narrowing or closure of the airway during sleep. This leads to abrupt arousals and disruption of sleep throughout the night which can lead to various health problems including diabetes, cardiovascular diseases, obesity, high blood pressure, impaired cognitive function, decreased quality of life and patients are more likely to be involved in motor vehicular accidents.

Recent studies have found that combination of these noradrenergic and antimuscarinic agents help to improve upper airway muscle activity during sleep. Therefore, this clinical study will focus on determining the effects of these agents on the severity of sleep apnoea in OSA patients in hopes to improve treatment outcomes for OSA patients in the future. The study also aims to determine the effects of these combination of agents on cognitive alertness and other sleep parameters which are impaired in patients with OSA.