This pilot study will establish the feasibility of a larger trial to investigate whether reboxetine, a medication used to treat depression, can reduce the severity of obstructive sleep apnea (OSA) including increased blood oxygenation in post-surgical OSA patients where positive airway pressure (CPAP) therapy is either frequently poorly tolerated or not an option immediately post surgery. In this randomized, placebo-controlled, double-blind study, participants will use at-home sleep monitoring equipment before and after surgery plus measures of oxygenation. They will be prescribed either reboxetine or a placebo for seven days after surgery and complete questionnaires at the beginning and end of the study.

Inclusion Criteria:

• Age >18 years
• Undergoing elective upper airway surgery
• History of obstructive sleep apnoea (OSA)

Exclusion Criteria:

• Clinically significant cardiac disease (e.g., arrhythmia, coronary artery disease, or cardiac failure)
• History of clinically significant urinary retention, bladder outlet obstruction, or benign prostatic hyperplasia
• Poorly controlled hypertension
• Epilepsy
• History of schizophrenia, schizoaffective disorder or bipolar disorder according to Diagnostic and Statistical Manual of Mental Disorders-V or International Classification of Disease 10th edition criteria
• History of attempted suicide or suicidal ideation within 1 year prior to screening, or current suicidal ideation
• Narrow angle glaucoma

Participants will be informed in plain language through the consent form that their deidentified data may be made available to other researchers. Deidentified participant data will only be shared with other researchers upon request to the chief investigator after study publication and subject to ethical approval

At conclusion of the study and any related publications

IPD may be shared for research purposes on application to the chief investigator and subject to applicable ethical review.

Identical capsule for placebo and study drug prepared by study pharmacist