Conditions: Obstructive Sleep Apnea
Keywords: Obstructive Sleep Apnea Arousal threshold Venlafaxine
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 20
Healthy volunteers: no

Brief summary:
The investigators hypothesis is that obstructive sleep apnea (OSA) patients with a low arousal threshold may wake up too early during a respiratory event, before upper airway muscles can be activated to achieve stable ventilation. Thus, strategies to manipulate the respiratory arousal threshold could potentially improve the quality of sleep and sleep disordered breathing. Agents that raise arousal threshold are therefore likely to benefit some patients with OSA. The overall goal of this project is to determine the importance of the arousal threshold in OSA, determine which patients might benefit from a raised arousal threshold, and test this hypothesis by using pharmacological manipulation of the arousal threshold to achieve this goal.

Detailed description:
This study is a randomized double-blinded crossover pilot study. The investigators will test whether Venlafaxine has important effects on the apnea hypopnea index. Venlafaxine is a serotonin-norepinephrine reuptake inhibitor (SNRI) for the treatment of depression and anxiety. Venlafaxine increases serum serotonin level, which may affect arousal threshold. Furthermore, higher serotonin level theoretically may improve muscle tone, including upper airway muscle. Therefore, the investigators hypothesize that venlafaxine may decrease arousal threshold and improve muscle tone, leading to improvement of OSA.

Eligible participants will undergo overnight polysomonography as described below and will receive either Venlafaxine(50 mg 2 hour prior to sleep) or placebo (in random order) followed roughly 7 days later with placebo or donepezil. This aim will allow us to test the impact of Venlafaxine on the apnea hypopnea index.

The change in apnea hypopnea index will be compared in the Venlafaxine groups with the placebo group.

Arms:
arm 1: 50mg of Venlafaxine before sleep arm 2: One piece of placebo before sleep

Interventions: intervention 1: Venlafaxine intervention 2: Placebo
Intervention descriptions: intervention 1: Venlafaxine 50mg before sleep intervention 2: One piece of placebo before sleep

Protocol document: