This study will investigate if an intra-nasal nose spray of the drug oxytocin can decrease the amount of pressure needed from the automatic Continuous Positive Airway Pressure (CPAP) device while sleeping decreasing some of the harmful effects of low oxygen in people with sleep apnea.

This study will last 35 nights and involves spending three nights in the sleep lab at George Washington University. There are no additional costs to participants and no compensation for being involved in the study.

This is a rigorous randomized, double-blinded, cross-over study. Patients will self-administer either oxytocin nasal spray (40IU/ml), or sterile water spray, for 2 weeks, followed by 2 weeks of the spray not used initially (with a one week washout period in between). Subjects will have been using (for a minimum of 1 month) an auto-adjusting/titrating positive airway pressure (auto-CPAP device) as this is the mainstay of treatment for OSA and considered standard-of-care. All auto-CPAP devices are capable of recording frequency and duration of patient use (thus helping with compliance monitoring) and also recording the pressure needed to keep the airway open.

After obtaining consent, forty subjects will undergo the following (at Day 1): (a) venipuncture to obtain 50 ml of blood (to be stored for use to analyze inflammatory markers and biomarkers of oxidative stress, (b) an overnight sleep study in the sleep-lab (with their auto-CPAP) to assess sleep architecture, (c) download of their compliance report from the auto-CPAP to assess mean PAP pressure. They will then be randomized to receive either 40 i.u (1 ml/10 nasal sprays) intranasally of oxytocin per night for 2 weeks (14 days), or matching placebo (1 ml/10 sprays) intranasally per night for 2 weeks (14 days). The researchers and subjects will be blinded to the order of oxytocin versus placebo and to the randomization process (will be done by the MFA-investigational drug pharmacy). The end of the 2 week (14 day) period will mark day 14. Subjects will continue using their auto-CPAP during these 2 weeks as per standard-of-care. At day 14: (a) subjects will undergo another overnight in-lab sleep study (with their auto-CPAP) to assess sleep architecture, and (b) have another venipuncture to collect 50 ml of blood, (c) download of compliance report from their auto-CPAP, and continue to take either the placebo or oxytocin. Each subject will then have a wash-out period of 1 week (Days 14-21, they will continue using their auto-CPAP during this week as per standard-of-care). Beginning at Day 21 each subject will then receive either oxytocin or placebo (the opposite of what they did not receive the first time at point A) for 14 days (2 weeks) Days 21-35: nightly dose of either 40 i.u of oxytocin (1 ml/10 sprays) or matching placebo intranasally after a wash out period of 1 week (days 14-21). Again, the researchers and subjects will be blinded to the compound given to the subjects. Subjects will continue using their auto-CPAP during these 2 weeks as per standard-of-care. At the end of this 2 week period will be day 35, when subjects will undergo another overnight in-lab sleep study and continue to take either the placebo or oxytocin (with their auto-CPAP) to assess sleep architecture, have another venipuncture to collect 50 ml of blood, and we will download the compliance report and pressure data from their auto-CPAP. The subject and all investigators will be blinded to the sequence of oxytocin or placebo until the study is unblinded at the end of the 35 day protocol.

Inclusion Criteria:

• Men or women 18 years of age or older.

Exclusion Criteria:

• subjects not willing to or otherwise unable to use CPAP for treatment of OSA.
• Presence of other sleep disorders
• Pregnant or breastfeeding women
• Women of child-bearing age (WOCBA) not willing or unable to use an accepted method to avoid pregnancy for the entire duration of the study
• Prisoners or subjects who are involuntarily incarcerated
• Subjects who are compulsorily detain or treatment of either a psychiatric or physical (i.e. infectious disease) illness
• Patients unable to give consent because of a language barrier, or other reason.

All study staff are masked except the pharmacist.