Impact of reboxetine plus oxybutynin treatment for obstructive sleep apnea on cardiovascular autonomic modulation

Area of Science:

• Cardiovascular Physiology
• Sleep Medicine
• Pharmacology

Background:

• Obstructive sleep apnea (OSA) is linked to autonomic dysfunction.
• The combination of reboxetine (noradrenergic) and oxybutynin (antimuscarinic) has shown potential in reducing OSA severity.
• Data on the cardiac autonomic effects of this drug combination in OSA patients are lacking.

Purpose of the Study:

• To investigate the impact of a 1-week treatment with reboxetine plus oxybutynin (reb-oxy) on cardiovascular autonomic control in patients with OSA.
• To assess changes in heart rate variability (HRV), ambulatory blood pressure (BP), and baroreflex sensitivity following reb-oxy treatment.

Main Methods:

• A double-blind, crossover trial was conducted with 16 OSA patients.
• Participants received either 4 mg reboxetine plus 5 mg oxybutynin (reb-oxy) or a placebo for OSA treatment.
• 24-hour ambulatory blood pressure monitoring, heart rate variability analysis, and baroreflex sensitivity testing were performed.

Main Results:

• Reb-oxy treatment did not significantly alter 24-hour heart rate or blood pressure compared to placebo.
• No modifications in heart rate variability (HRV) were observed with reb-oxy.
• Reb-oxy significantly increased baroreflex sensitivity and did not induce orthostatic hypotension.

Conclusions:

• Short-term (1-week) administration of reb-oxy in OSA patients did not result in clinically relevant sympathetic overactivity.
• The combination therapy demonstrated an improvement in baroreflex function alongside a reduction in OSA severity.